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Record 1 of 10
AUTHOR
TITLE
Africa /
PUBLISHER
SHELF NO
Hewitson, Bruce C.
Atmospheric moisture transport and sources for southern
by B. C. Hewitson, W. Tennant, R. Walawege.
Gezina, South Africa : Water Research Commission, 2004.
551.5770968 HEW.
Record 2 of 10
TITLE
first
World water resources at the beginning of the twentycentury / edited by I.A. Shiklomanov and John C.
Rodda.
PUBLISHER
2003.
Cambridge, UK ; New York : Cambridge University Press,
Record 3 of 10
AUTHOR
TITLE
ocean
Rautenbach, C. J. de W.
Seasonal climate predictions with a coupled atmospheregeneral circulation model : (clipwater) / by C.J. de
W.
PUBLISHER
SHELF NO
Rautenbach.
Gezina, Pretoria : Water Research Commission, 2002.
551.52460968 RAU.
Record 4 of 10
AUTHOR
TITLE
Southern
PUBLISHER
SHELF NO
Hewitson, Bruce C.
Global and regional climate modeling : application to
Africa / by B.C. Hewitson.
[Pretoria] : WRC, 2001.
551.6968HEW.
Record 5 of 10
AUTHOR
TITLE
PUBLISHER
SHELF NO
Hewitson, Bruce C.
Deriving regional precipitation scenarios from general
circulation models / by B.C. Hewitson.
[Pretoria] : WRC, 1999.
551.5170968HEW.
Record 6 of 10
TITLE
Earth, air, fire, water : humanistic studies of the
environment /
edited by Jill Ker Conway, Kenneth Keniston, and Leo
Marx.
PUBLISHER
Amherst : University of Massachusetts Press, c1999.
SHELF NO
304.28EAR.
Record 7 of 10
TITLE
change /
PUBLISHER
SHELF NO
The role of water and the hydrological cycle in global
edited by Howard R. Oliver, Sylvia A. Oliver.
Berlin : Springer, 1995.
551.6ROL.
Record 8 of 10
TITLE
by Ehrhard
PUBLISHER
SHELF NO
Energy and water cycles in the climate system / edited
Raschke, Daniela Jacob.
Berlin : Springer, c1993.
551.5ENE.
Record 9 of 10
AUTHOR
Dobrovolski, Serguei G.
TITLE
Global climatic changes in water and heat transfer :
accumulation
PUBLISHER
SHELF NO
processes / by Serguei G. Dobrovolski.
Amsterdam : Elsevier, 1992.
551.52DOB.
Record 10 of 10
TITLE
on the
The influence of climate change and climatic variability
hydrologic regime and water resources / edited by S.I.
Solomon,
PUBLISHER
SHELF NO
M. Beran, W. Hogg.
Wallingford, Oxfordshire : International Association of
Hydrological Sciences, 1987.
551.48INF.
1 to 26 of 26 Marked Records (Citations+Abstracts) (show 146 Total Results)
Holtzhausen, L.
1.
Climate change - the last straw for communities at risk?: climate
change.
The water wheel Vol. 5, Iss 1, 17-21, Jan/Feb, 2006 ISSN: 0258-2244
Abstract: Considers the potential effects human induced climate change
could have on southern Africa, its biodiversity, water resources, the
economy of the region and the health of the people.
OpenURL Links
2.
Alexander, W.J.R.
Development of a multi-year climate prediction model.
Water S A Vol. 31, Iss 2, p. 209-217, Apr, 2005 ISSN: 0378-4738
Abstract: Reports on the development of a multi-year climate prediction
model based on the statistically significant 21-year periodicity in the
hydrometeorological processes, and its direct association with
corresponding periodicity in solar activity in southern Africa.
OpenURL Links
3.
4.
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Climate change and water resources in Southern Africa: Studies on
Scenarios, Impacts, Vulnerabilities and Adaptation WRC Report No.
1430/1/05. Gezina: Water Research Commission, 2005.
ISBN: 1770053654 view Database Record
Schulze, R E
Climate change and water resources in Southern Africa.
Water Research Commission [WRC] Report 2005(1430/1/05): pp.
Exec. summary,i-vi; 2005 ISBN: 1-77005-365-4
NATCHA Abstract: This Executive Summary is presented under the
following headings: .Background .Project Objectives .Project Outcomes
.Summaries of Chapter Contents .Take-Home Messages from the Project, in
a Nutshell .Acknowledgements .Capacity Building .Recommendations for
Future Research BACKGROUND A focus on potential impacts of climate
change on the water sector of southern Africa (in the context of this
report, made up of the Republic of South Africa together with Lesotho and
Swaziland) was triggered by a series of activities and events in the first
three years of the new millennium which included the World Summit on
Sustainable Development, the Intergovernmental Panel on Climate
Change reports in 2001, the third World Water Forum, as well as active
South African participation in the International Geosphere Biosphere
Programme and Dialogue on Water and Climate, among others.
Additionally, there was the realisation that perturbations in climate
parameters, particularly of rainfall, were largely amplified by the
hydrological system and that if climate changes were to manifest
themselves in the manner which international science was predicting, it
would add a further layer of concern to the management of southern
Africa's already high risk and stressed water sector, with potential
implications to the entire region's socio-economic well being, but
particularly that of the poor. These concerns culminated in the Water
Research Commission's soliciting a two-year research project in mid 2002
titled "Climate Change and Water Resources in South Africa: Potential
Impacts of Climate Change and Mitigation Strategies" The project was
awarded to a consortium of four South African universities, viz. KwaZulu
Natal (lead organisation), Cape Town, Witwatersrand and Pretoria, within
each of which specialist expertise and international experience existed in
one or more of climate scenario development, impacts modelling and/or the
human dimension and climate change.
AFRICAN DEVELOPMENT Abstract: This Executive Summary is
presented under the following headings: .Background .Project Objectives
.Project Outcomes .Summaries of Chapter Contents .Take-Home Messages
from the Project, in a Nutshell .Acknowledgements .Capacity Building
.Recommendations for Future Research BACKGROUND A focus on potential
impacts of climate change on the water sector of southern Africa (in the
context of this report, made up of the Republic of South Africa together
with Lesotho and Swaziland) was triggered by a series of activities and
events in the first three years of the new millennium which included the
World Summit on Sustainable Development, the Intergovernmental Panel
on Climate Change reports in 2001, the third World Water Forum, as well
as active South African participation in the International Geosphere
Biosphere Programme and Dialogue on Water and Climate, among others.
Additionally, there was the realisation that perturbations in climate
parameters, particularly of rainfall, were largely amplified by the
hydrological system and that if climate changes were to manifest
themselves in the manner which international science was predicting, it
would add a further layer of concern to the management of southern
Africa's already high risk and stressed water sector, with potential
implications to the entire region's socio-economic well being, but
particularly that of the poor. These concerns culminated in the Water
Research Commission's soliciting a two-year research project in mid 2002
titled "Climate Change and Water Resources in South Africa: Potential
Impacts of Climate Change and Mitigation Strategies" The project was
awarded to a consortium of four South African universities, viz. KwaZulu
Natal (lead organisation), Cape Town, Witwatersrand and Pretoria, within
each of which specialist expertise and international experience existed in
one or more of climate scenario development, impacts modelling and/or the
human dimension and climate change.
view Database Record
5.
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Archibong, E O
Climate change, community water supply and sanitation in Nigeria.
Pan Africa Pages workshop on African Palaeoenvironments: Linking
the past to the present and the future 2004(N/A): pp. 16-17; 2004
NATCHA Abstract: This paper discussed planning for successful water
supply and sanitation programs that requires' a wide range of different
skills from those responsible for their implementation especially in Nigeria.
Field works need to understand technical, managerial and social subjects
and should know how to apply this knowledge if they are to make the best
use of their resources. The paper concludes by the need for a basic
understanding of how water and sanitation related diseases are
transmitted and to recognized the importance of hygiene and health
education.
AFRICAN DEVELOPMENT Abstract: This paper discussed planning for
successful water supply and sanitation programs that requires' a wide
range of different skills from those responsible for their implementation
especially in Nigeria. Field works need to understand technical, managerial
and social subjects and should know how to apply this knowledge if they
are to make the best use of their resources. The paper concludes by the
need for a basic understanding of how water and sanitation related
diseases are transmitted and to recognized the importance of hygiene and
health education.
6.
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Savage, M J; Everson, C.S.; Odhiambo, G O; Mengistu, M G; Jarmain,
CJ
Theory and practice of evaporation measurement, with special focus on SLS
as an operational tool for the estimation of spatially avreaged evaporation.
WRC REPORT November(1335/1/04): pp. i-xvi, a-r, 1-191; 2004
ISBN: 1-77005-247-X
NATCHA Abstract: The need for increased food and timber production has
led to increases in irrigated and forestry lands in South Africa. Agriculture
and forestry face increased competition for water by industries,
municipalities and other groups. This ever growing demand for water
makes it imperative that water resource management procedures and
policies are wisely implemented and improved. The accurate assessment of
evaporation is essential if this is to be done. Furthermore, the real and/or
potential impact of global warming and climate change on all forms of
water resources increases the imperative for a knowledge base on water
use (and productivity) of commercially managed lands and natural
vegetation. In particular, what is the potential impact of these large scale
changes on evaporation? Implied in this question is the definition of a
standard or a benchmark for evaporation measurement or estimation. The
1998 Republic of South Africa National Water Act refers to the possible
prescription, by the Minister, of methods for making a volumetric
determination of water for purposes of water allocation and charges in the
case of activities resulting in stream flow reduction. Given this scenario and
the above-mentioned demand on water resources it is important to
consider how evaporation, one of the main components of the water
balance, is to be measured or estimated routinely with reliable accuracy
and precision. So, what is the standard or benchmark for evaporation
measurement or its estimation? This important and fundamental question
needs to be addressed to achieve the ideal of accurate and reliable
evaporation data. This investigation focuses on one method, using a
surface layer scintillometer (SLS) and other measurements, to estimate
evaporation. The SLS method involves the more fundamental aspects of
micrometeorological research. Advances in this field will have direct
benefits to water resources assessments and management processes.
Examples of areas not easily addressed using the more traditional
evaporation measurement and modelling methods include amongst others:
measurement of evaporation in riparian zones; determination of open
water evaporation from rivers and dams (both large and small); effluent
water management from saline dams in the mining environment;
measurement of evaporation from slimes tailings; water use of trees and
crops in agro-forestry trials; remote sensing applications; determination of
baseline evaporation from natural communities (e.g., indigenous forests);
irrigation research.
7.
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Hewitson, B Water Research Commission
Climate change - a cause for concern.
Water Wheel 3(3): pp. 22-28; 2004 ISSN: 0258-2244
OpenURL Links
8.
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Schulze, R.E.
Conceptual issues and case study applications. [Modelling as a tool in
integrated water resources management.]
Water Research Commission [WRC] Report Water Research
Commission (WRC) Report; 2004(WRC 749/1/04): pp. 1-258; 2004
ISBN: 1-77005-143-0
AFRICAN DEVELOPMENT Abstract: This project, a component of the
Hydrological Modelling Systems Programme funded by the WRC at the
School of Bioresources Engineering and Environmental Hydrology (formerly
the Department ofAgricultural Engineering) at the University of Natal in
Pietermaritzburg, commenced in 1996 and was completed in 2002. a)
Objectives The project objectives were o the development and applications
of a linked agrohydrological modelling infrastructure (i.e. model plus
databases and decision support systems) o to assess benefits of integrated
catchment management (ICM) o in order to address and quantify real and
contentious issues which characterise South African catchments, often
under stress, and which make their management difficult with respect to,
inter alia, - the vagaries of climatic variability - hydrological risk
management - multi-sectoral water demands - land use intensification,
e.g. by afforestation and sugarcane plantations - land use extensification,
e.g.by veld degradation - best management practices in irrigation or future climates o and where the benefits could imply, inter alia, - taking
cogniscance of the interactions of the natural with the social, political, legal
and economic environments - addressing impacts of land use and its
change - pro-actively planning catchment operations with respect to
optimising land and water resources - identifying environmentally
sensitive areas within a catchment and - identifying areas where conflict
management could be undertaken with the aid of modelling. b) Motivation
and Method The motivation for this project was that water related issues,
which often result in conflicts over allocation and use, be managed
holistically, through working partnerships between researchers and
stakeholders. These stakeholders may be water users, land holders,
environmental interest groupa, communities and government agencies, as
well as NGOs. Such holistic management would require, inter alia, versatile
agrohydrological modelling tools with process representations and
configurations appropriate for southern African conditions. The ACRU
modelling system was to be the `carrier' for this project because it was
deemed suitable to be applied simultaneously as a o scenario planning
model - assessing alternative land and water uses and - assessing
impacts, sensitivities and thresholds on catchments o a multi-specialist
model - providing a versatile modelling framework for further development
and interlinkages to other models/modules and o an operational model - to
be used in management decisions.Apart from further model development,
specialist fieldwork, decision support and database development, a major
methodological focus of this project was to be the application of the model
in appropriate case studies. c) Directions given ... directions taken It was in
the course of this project that major conceptual rethinking took place in
regard to ICM, which is a very far-reaching overarching concept of water
management and which, in hindsight, was found to be beyond the scope of
a project such as this. The focus of this report is, therefore, rather on
Integrated Water Resources Management, IWRM, which is a (still wideranging) subset of ICM (cf. Chapter 1). Simultaneously, the late 1990s saw
major paradigm shifts in the management of water resources as well as,
of course, the promulgation of the National Water Act of 1998. The
ushering in of this Act had major repercussions on directions taken in, and
research undertaken through, this project, and many of the chapters bear
testimony to that. In light of the project's objectives, motivations, methods
and new directions which evolved during the project's duration, this report
of 14 chapters is presented in three broad sections: o Section A :
Conceptual and Modelling Issues This consists of six chapters covering perspectives on integrated water resources management (IWRM) thoughts on, and concepts, basic premises and requirements of models for
IWRM - concepts, structure and typical applications of the ACRU
agrohydrological modelling system - background to impacts of land cover
and land use on hydrological responses - the use of detailed information in
modelling and - a framework for hydrological risk management, with
examples from southern Africa. o Section B : On Modelling Impacts of Land
Use on Hydrological Responses This section contains a further six chapters
which cover - a forest hydrology decision support system - a regional study
on streamflow reduction activities by different land uses - water use by,
and water use efficiencies of, sugarcane - a sensitivity study on competing
land uses, viz. afforestation and irrigation - compensatory forestry from
riparian zone alien vegetation clearance and - impacts of veld degradation
and rehabilitation on catchment sediment yields. o Section C : Looking
Towards the Future This section has two chapters which address - the
application of seasonal rainfall forecasts to sugarcane yield forecasts and a threshold analysis on when, and where, climate change is likely to
impact on water resources in South Africa. A number of the chapters
titles and most of the chapter subheadings have been posed as questions
to which the respective contents provide some answers. Each chapter,
while linked conceptually and contextually to the others, can in essence be
read as an entity.
9.
Steyn, M
Water allocations amidst drought.
S A Irrigation 26(6): pp. 8-9; 2004
OpenURL Links
10.
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ISSN: 0258-5081
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Department of Water Affairs and Forestry
Chapter 2 South Africa's water situation and strategies to balance supply
and demand. [IN: National Water Resource Strategy]: pp. 17-54;
2004
AFRICAN DEVELOPMENT Abstract: This chapter provides aggregated
estimates of the present availability and requirements for water in each
of the water management areas, indicates how water availability and
water requirements may be expected to change in the future, and
describes possible strategies and interventions for achieving a balance
between water availability and requirements. Some basic concepts
relating to water resources management are explained. See also
Appendix D - Additional Information and Strategic Perspectives with
respect to Water Management Areas, which presents a more detailed
analysis of South Africa's water situation by providing present and future
water balance information and possible reconciliation interventions for
subdivisions of the 19 water management areas. view Database Record
11.
Oreilly, C M; Alin, S R; Plisnier, P D; Cohen, A S; Mckee, B A
Climate change decreases aquatic ecosystem productivity of Lake
Tanganyika, Africa.
Nature 424(6950): pp. 766-768; 2003 ISSN: 0028-0836
NATCHA Abstract: Although the effects of climate warming on the
chemical and physical properties of lakes have been documented, biotic
and ecosystem-scale responses to climate change have been only
estimated or predicted by manipulations and models. Here we present
evidence that climate warming is diminishing productivity in Lake
Tanganyika, East Africa. This lake has historically supported a highly
productive pelagic fishery that currently provides 25-40% of the animal
protein supply for the populations of the surrounding countries. In parallel
with regional warming patterns since the beginning of the twentieth
century, a rise in surface-water temperature has increased the stability of
the water column. A regional decrease in wind velocity has contributed to
reduced mixing, decreasing deep-water nutrient upwelling and
entrainment into surface waters. Carbon isotope records in sediment
cores suggest that primary productivity may have decreased by about
20%, implying a roughly 30% decrease in fish yields. Our study provides
evidence that the impact of regional effects of global climate change on
aquatic ecosystem functions and services can be larger than that of local
anthropogenic activity or overfishing.
view Database Record
12.
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Van der Merwe, L.H.
Climate change: engineering challenge of the 21st century: climate:
investigation.
Water Sewage and Effluent Vol. 23, Iss 1, p. 20-22, Jan, 2003
ISSN: 0257-8700
Abstract: Investigates the phenomenon of climate change and how it
affects water professionals. Highlights climate change in Africa and its
effect on water engineering.
view Database Record
13.
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Jury, Mark R
The coherent variability of African river flows: composite climate structure
and the Atlantic circulation.
Water S A 29(1): pp. 1-10; 2003 ISSN: 0378-4738
NATCHA Abstract: The composite structure of the ocean and
atmosphere around Africa is studied in the context of river flow variability.
Annual are analysed for the Blue and White Nile, Congo. Niger, Senegal,
Zambezi, and Orange Rivers, and inflow to Lake Malawi. Spectral energy
is concentrated in 6.6- and 2.4-year bands. The interannual variability of
many river flows is significantly cross-correlated (p <.05) over the period
1950-1995, following removal of the mean trend. A combined river flow
index indicates that flows were highest in 1961, 1962, 1968, 1977, 1978
and lowest in 1971, 1972, 1982, 1983, 1991. Forming a composite of
differences between high- and low-flow years, SST anomalies and other
atmospheric fields are investigated to better understand climatic factors
driving hydrological extremes. During high flows, NCEP reanalysis data
reveal a composite La Nina event off Peru-Ecuador. SST patterns reveal
an inter-hemispheric dipole in the Atlantic (e.g. warm - north) and below
normal SST in the west Indian Ocean during years with high flow. The
equatorial east Atlantic undergoes warming through the `composite year'
in a manner consistent with its opposing response to the Indo-Pacific
LaNina. Tropical upper winds are easterly and symmetrical about the
equator, and may explain why inter-annual variability of river flows south
of the equator are correlated with those of the north at 6-month lag. Low
level westerly winds are greater during high flow years, particularly along
the Guinea coast. Differences of OLR and upper velocity potential
demonstrate two distinct centers of action either side of the tropical
Atlantic. It is concluded that hydrological events over Africa and South
America are sensitive to tropical Atlantic coupling with the global El Nino Southern Oscillation signal.
AJOL Abstract: The composite structure of the ocean and atmosphere
around Africa is studied in the context of river flow variability. Annual
streamflows are analysed for the Blue and White Nile, Congo, Niger,
Senegal, Zambezi, and Orange Rivers, and inflow to Lake Malawi. Spectral
energy is concentrated in 6.6- and 2.4-year bands. The interannual
variability of many river flows is significantly cross-correlated (p <.05)
over the period 1950-1995, following removal of the mean trend. A
combined river flow index indicates that flows were highest in 1961, 1962,
1968, 1977, 1978 and lowest in 1971, 1972, 1982, 1983, 1991. Forming a
composite of differences between high- and low-flow years, SST
anomalies and other atmospheric fields are investigated to better
understand climatic factors driving hydrological extremes. During high
flows, NCEP reanalysis data reveal a composite La Nina event off PeruEcuador. SST patterns reveal an inter-hemispheric dipole in the Atlantic
(eg. warm - north) and below normal SST in the west Indian Ocean during
years with high flow. The equatorial east Atlantic undergoes warming
through the 'composite year' in a manner consistent with its opposing
response to the Indo-Pacific La Nina. Tropical upper winds are easterly
and symmetrical about the equator, and may explain why inter-annual
variability of river flows south of the equator are correlated with those of
the north at 6-month lag. Low level westerly winds are greater during high
flow years, particularly along the Guinea coast. Differences of OLR and
upper velocity potential demonstrate two distinct centers of action either
side of the tropical Atlantic. It is concluded that hydrological events over
Africa and South America are sensitive to tropical Atlantic coupling with
the global El Nino - Southern Oscillation signal.
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14.
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Paturel, J.E.; Ouedraogo, M; Servat, E.; Mahe, G.
The concept of rainfall and streamflow normals in West and Central Africa
in a context of climatic variability.
Hydrological Sciences Journal 48(1): pp. 125-; 2003 ISSN: 02626667
NATCHA Abstract: This contribution to the debate on the revision of
rainfall and streamflow normals concerns three countries of West Africa:
Burkina Faso, Ivory Coast and Mali. The rainfall deficit (15-20 percent on
average in the study area) and the river flow deficit (about 30-50 percent
and sometimes more) observed over the past 30 years in West and
Central Africa raise the problem of the reference period that must be
considered in estimates of hydrological characteristics. The hypothesis of
the concept of "normal" supporting these estimates is a stability of the
climate. However, the effect of taking or not taking into account the data
of recent years on the estimates of these characteristics can lead to very
different results. This would have serious consequences for the
development and management of water resources systems, as seen in
two examples of dams.
15.
OpenURL Links
Odada, E O; Olago, D O; Kulindwa, K; Karimumuryango, J; West,
K; Ntiba, M; Wandiga, S; Aloo-Obudho, P; Achola, P
Environmental assessment of the East African Rift Valley lakes.
Aquatic Sciences 65(3): pp. 254-271; 2003 ISSN: 1015-1621
NATCHA Abstract: An assessment of the East African Rift Valley lakes
was initiated by the United Nations Environment Programme (UNEP) with
funding from Global Environment Facility as part of the Global
International Waters Assessment (GIWA). The purpose of GIWA was to
produce globally comparable assessments and examine stresses on
international waters: marine, coastal and fresh; surface and
groundwaters. The assessment of the East African Rift Valley lakes was
undertaken from the perspective of water quality and quantity,
associated biodiversity and habitats, their use by society and societal
causes of the regionally identified issues and problems. Assuming intrinsic
values of aquatic ecosystems, the assessment of social perspective
focused on human use of water and considered the incremental costs of
measures to encourage sustainable development. The assessment
identified the major concerns facing the East African Rift Valley lakes. By
and large, pollution and unsustainable exploitation of fisheries and other
living resources emerged as critical concerns attributable to human
activities. East Africa has a very high concentration of humans and
economic activities. Pollution is from uncontrolled discharge of wastes
directly into the lakes. Unsustainable exploitation of fisheries and other
living resources is caused by over-fishing, destructive fishing practices,
and introduction of non-native species that affect the composition of the
native communities, resulting sometimes in the collapse of certain species
and dominance by resilient ones. Loss of biodiversity also was identified as
a major concern; and the issues of excessive by-catch and discards are
also relevant. Trawling using undersized mesh-nets for target species and
indiscriminate fishing gear or poison is serious, in most cases resulting in
indiscriminate catches, including juvenile fish. Given the transboundary
nature of the issues identified in this assessment, appropriate multilateral
policy and institutional arrangements need to be established in East Africa
to address the main concerns of these large lakes. Riparian countries must
pay attention to the regional management of these transboundary water
bodies, and appropriate planning of human population sizes and their
settlement, land-use and waste disposal to control pollution. Although
East African lakes contribute relatively little emission of greenhouse gases,
there is a need to reduce the rate of deforestation and even restore
cleared areas since forests serve as sinks of greenhouse gases towards
mitigating adverse climatic changes.
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16.
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Chifamba, P C
The relationship between fish catches in Lake Kariba and climatic factors.
African Fish and Fisheries pp. 225-226; 2003
NATCHA Abstract: Catch data from the small-scale commercial gill-net
fishery and the experimental fishing of Lake Kariba was used to determine
the relationship between climatic factors and fish catches. The small-scale
commercial gill-net fishery data was not separated by species and
represented catches from different areas of Lake Kariba. Eight species
from the experimental data was used. The climatic factors used were
temperature, rainfall, river flow and the lake levels. Data was analysed
using Pearson Correlation Analysis. There were no clear patterns in the
relationship between the small scale fisheries pooled data and the climatic
variables. Hydrocynus vittatus showed a high degree of negative
significant correlation with temperature (R = 0.72, p < 0.05) and a
positive significant correlation with rainfall (R = 0.549, p < 0.05).
Oreochromis mortimeri had positive significant correlations with the lake
level (R = 0.50, p < 0.05) and riverflow (R = 0.67, p < 0.05) and rainfall
(R = 0.68, p < 0.05). The other species Tilapia rendalli, Clarias spp.,
Synodontis spp. and Labeo spp. showed no clear relationship with these
climatic factors. A probable reason for the observed results is the
utilization of flowing water by H. vitattus for breeding upstream migration
triggered by changes in temperature and onsets of rains. O. mortimeri is a
plankton feeder and the abundance of plankton is known to be related to
river inflows. Knowledge of these relationships is important in
understanding of the likely impact of climate change on the fish
resource of lake Kariba.
17.
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Gyau-Boakye, P*; BINEY, C A
Management of freshwater bodies in Ghana.
Water International 27(4): pp. 476-484; 2002 ISSN: 0250-8060
NATCHA Abstract: Until recent times, there was an incorrect perception
in many developing countries, including Ghana, that considerable water
resources were available. Faced with increasing population,
intensification of agricultural, mining, and industrial activities together
with natural events, the demand on both the quantity and quality of
Ghana's water resources is now becoming a major concern. The
population of Ghana increased from 6.7 million in 1960 to 8.6 million in
1970 to 12.3 million in 1984 to 18.9 million in 2000. The increasing
population in Ghana contradicts sharply with the observed decline in
rainfall amounts in many parts of the country, the rising temperatures
nation-wide, and the pollution of water bodies from both natural and
human activities. The freshwater bodies of Ghana are thus vulnerable and
must have to be efficiently managed and utilized to sustain the socioeconomic growth of the nation. Towards this objective, recommendations
and suggestions have been made in terms of a joint participatory
approach between local communities and state agencies in addition to
suggestions for enactment of policies, education, and enforcement of
laws.
19.
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New, M.
Climate change and water resources in the southwestern Cape, South
Africa.
South African Journal of Science Vol. 98, Iss 7/8, p. 369-376, Jul-aug,
2002 ISSN: 0038-2353
Abstract: Describes the sensitivity of discharge from four mountainous
catchments in the southwestern Cape to climate change, using a
catchment hydrological simulation model. Interprets these simulations in
the context of recent general circulation model projections of climate
change for the region. Discusses some implications for water resources
planning.
18.
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Holtzhausen, L.
The war for water - fighting the battle for the last drop: leading news -
exclusive.
Water Sewage and Effluent Vol. 22, Iss 2, p.26-29, May, 2002
ISSN: 0257-8700
Abstract: Reports on a study which found that the world's fresh water
resource is being threatened as never before by increasing water
pollution, growing populations and global climate change. Investigates
the serious consequences for South Africa, with particular reference to
water-borne diseases, the low ratio of run-off water, low rainfall,
demand for water, water quality, legislation, and human development
versus the conservation of the environment
view Database Record
20.
OpenURL Links
|
Department of Water Affairs and Forestry
Chapter 2 South Africa's water situation, and strategies to balance supply
and demand. [IN: Proposed First Edition National Water Resource
Strategy]: pp. 12-45; 2002
AFRICAN DEVELOPMENT Abstract: South Africa is located in a
predominantly semi-arid part of the world. The climate varies from desert
and semi-desert in the west to sub-humid along the eastern coastal area,
with an average rainfall for the country of about 450 mm per year, well
below the world average of about 860 mm per year, while evaporation is
comparatively high. As a result, South Africa's water resources are, in
global terms, scarce and extremely limited in extent. There are no truly
large or navigable rivers in South Africa and the total flow of all the rivers
in the country combined amounts to approximately 49 200 million cubic
metres per year; less than half of that of the Zambezi River, the closest
large river to South Africa. Groundwater plays a pivotal role in especially
rural water supplies in the country. However, due to the predominantly
hard rock nature of the South African geology, few major groundwater
aquifers exist that could be utilised on a large scale. Due to the poor
spatial distribution of rainfall as shown in Figure 2.1 (map) the natural
availability of water across the country is also highly uneven. This is
compounded by the strong seasonality of rainfall over virtually the entire
country as well as the high within-season variability of rainfall and
consequently of runoff. As a result, streamflow in South African rivers is at
relatively low levels for most of the time, with sporadic high flows
occurring; characteristics which limit the proportion of streamflow that can
be relied upon to be available for use, and also have implications for
water related disasters such as floods and droughts (see Part 7 of
Chapter 3). To aggravate the situation, most urban and industrial
development, as well as some dense rural settlements, have been
established in locations remote from large watercourses; dictated by the
occurrence of mineral riches and influenced by the political dispensation of
the past, rather than by the plentiful availability of water. As a result, the
requirements for water already far exceed the natural availability of
water in several river basins. Widely spread and often large-scale
transfers of water across catchments have, therefore, been implemented
in South Africa in the past. Four of the main rivers in South Africa are
shared with other countries. These are the Limpopo, Inkomati, Pongola
(Maputo) and Orange (Senqu) Rivers, which together drain about 60% of
the land area and contribute over 30% of the country's total surface
runoff (river flow). Approximately 70% of the gross domestic product
(GDP) of South Africa and a similar percentage of the population of the
country are supported by water supplied from these rivers, making the
judicious joint management thereof of paramount importance to South
Africa. In order to facilitate the management of water resources, the
country has been divided into 19 catchment-based water management
areas, as described in more detail in Part 5 of Chapter 3. The imbalances
between the occurrence of and requirements for water are profoundly
evident when comparing some basic parameters with respect to the
different water management areas, as presented by the statistics to
follow. Of the 19 water management areas in the country, only the
Mzimvubu to Keiskamma water management area is currently not linked
to another water management area through inter-catchment transfers,
giving effect to one of the main principles of the National Water Act,
which designates water as a national resource. Eleven water
management areas share international rivers. The location and boundaries
of the water management areas, schematically showing interwater
management area transfers, is given in Figure 2.2.(map) Key statistics
with respect to each water management area as well as a concise
description of strategic action plans are given in the parts to follow, in
compliance with Section 6(1) of the National Water Act. More detail in
this regard can be found in Appendix D. A graphical comparison of the
natural occurrence of water, the population and the economic activity per
water management area is given in Figure 2.3, clearly demonstrating the
exceedingly varied conditions among the water management areas. The
Crocodile West and Marico water management area for example, where
the largest proportional contribution to the gross domestic product is
produced, is one of the water management areas with the smallest mean
annual runoff. In contrast, economic activity in the Mzimvubu to
Keiskamma water management area is relatively low, despite it being the
water management area with the highest mean annual runoff in the
country. view Database Record
21.
Schulze, R.; Horan, M.
Present and past future vulnerability of eastern and southern Africa's
hydrology and water resources.
South African Journal of Science Vol. 97, Iss 3/4, p.150-160, Mar-apr,
2001 ISSN: 0038-2353
Abstract: Presents a synthesis of water as a vulnerable and variable
natural resource in space and time under present climatic conditions by
assessing various rainfall, evaporation and runoff indices in the eastern
and southern African region
view Database Record
22.
23.
OpenURL Links
|
Better techniques to understand the impact of global climate changes in
South Africa: WRC news.
S A Irrigation Vol. 22, Iss 1, p.33, Dec-jan, 2000 ISSN: 0258-5081
Abstract: Reports that South Africa needs to know the future impact on
its climate of global and regional changes. The variable nature of the
climate system in the country and the high degree of vulnerability to
changes make it essential to understand what the influences of these
changes will be in future decades. The possible impact on South Africa's
water resources was the main reason why the Water Research
Commission commissioned and sponsored a study to derive regional
climate change scenarios from Global Climate Models (GCMs)
view Database Record
Matondo, Jonathan I.; Msibi, Kenneth M.
Evaluation of the Impact of Climate Change on Water Resources in
Usutu River Basin, Swaziland.
UNISWA Research Journal of Agriculture, Science and Technology
Vol. 4, No. 2 (2000), page 135-146
AJOL Abstract: The greenhouse effect is expected to cause high
temperature increase globally and this will lead to an increase in
precipitation in some regions while other regions will experience reduced
precipitation. Therefore, countries are engaged in the exercise of
evaluating the impact of expected climate change on water resources
using General Circulation Models (GCM) and hydrologic models. The Wat
Ball model has been found appropriate for the evaluation of the impact of
climate on water resources. The Usutu catchment was selected for the
evaluation of the impact of climate change on water resources
because it covers two thirds of the country and traverses the four
physiographic regions. The results of GCM models (precipitation,
temperature and thus potential evapotranspiration) have been used as
input to the calibrated Wat Ball model to forecast stream flow for Usutu
catchment for the wet, dry and average year for year 2075. A comparison
between observed and simulated stream flow without taking into
consideration of population increase and expanded agricultural activities
reveals that all the GCM models are simulating low flows from June to
September for the wet years and from May to September for the dry and
normal years. What can be concluded here is that, stream flows will be
low during the winter months. Therefore, optimal water resources
management will be crucial. Adaptation options have been suggested and
range from modification of the existing infrastructure to water demand
OpenURL Links
management.
|
view Database Record with link to More Info.
24.
Matarira, Caxton H. Unganai, Leonard
Global climate change and implications for water resources
management in Zimbabwe. (Edited by Unganai, Leonard.)
Geographical journal of Zimbabwe 31, 2000, 37-54
OpenURL Links
25.
ARNELL, Nigel W.
Climate change and global water resources.
Global Environmental Change VOL. 9. 1999.- P. S31-S49; 1999
ISSN: 0959-3780
26.
| view Database Record
OpenURL Links
| view Database Record
Magbagbeola, N. Olalekan
Economic growth and environmental development in Nigeria : impact on
climate change.
Nigerian Journal of Economic & Social Studies vol. 41, no. 2, p. 275294 : graf., tab, 1999 ISSN: 0029-0092
ASC LEIDEN Abstract: This paper examines climatic change, as it
relates to economic growth and environmental development in Nigeria.
Burning of fossil fuels and changes in land use and land cover increase the
atmospheric concentration of greenhouse gases and other radioactive
waste that have a warming effect on the atmosphere. Greenhouse
emissions play a signficant part in global warming (or climate change)
with serious socioeconomic implications. Global warming affects
agriculture, water resources, fishing, energy supply, transportation,
manufacturing, and construction. Climate change, resulting in a rise in
the sea level, could lead to damage and losses due to erosion, inundation,
devegetation, and an increase in salinization of surface and ground
water. To address these adverse economic effects, some strategies are
suggested to reduce the production of greenhouse gases. In the energy
sector, it is suggested that the government should continue to impose a
tax on companies for gas flaring. Other strategies include awareness
programmes, the establishment of carbon reservoirs, and the
encouragement of efficient use of energy in household and industrial
equipment. Bibliogr., sum. [Journal abstract, edited]
OpenURL Links
| view Database Record
Record 1 of 23
Author(s): Islam, MS (Islam, Md. Sirajul); Oki, T (Oki, Taikan); Kanae, S (Kanae,
Shinjiro); Hanasaki, N (Hanasaki, Naota); Agata, Y (Agata, Yasushi); Yoshimura, K
(Yoshimura, Kei)
Title: A grid-based assessment of global water scarcity including virtual water trading
Source: WATER RESOURCES MANAGEMENT, 21 (1): 19-33 JAN 2007
Author Keywords: global water scarcity; virtual water trading; grid-based analysis;
water stress index; spatial distribution of stress
Keywords Plus: RUNOFF INTEGRATING PATHWAYS; CLIMATE-CHANGE; LANDSURFACE; MODEL; RESOURCES; FOOD; VULNERABILITY; AVAILABILITY
Abstract: A 0.5-degree grid-based assessment of the scarcity of global water
resources including virtual water trading has been made. The three components of
water availability considered for each grid were local runoff, routed flow from
upstream and virtual water trading. Several assumptions were postulated to convert
country-base estimations of virtual water trading to grid values. The results show that
unequal spatial distribution of global water resources had been considerably
neutralized by virtual water trading. A large proportion of people in the Middle-East,
North-Africa and Sub-Sahara region are able to relieve their water stress through
virtual water import. The paper also reports two hypothetical scenarios with extremes
of natural flow availability based on the presence and absence of routed upstream
flow.
ISSN: 0920-4741
Record 2 of 23
Author(s): Schulze, RE (Schulze, Roland E.)
Title: Some Foci of Integrated Water Resources Management in the"South" which are
oft-forgotten by the "North": A perspective from southern Africa
Source: WATER RESOURCES MANAGEMENT, 21 (1): 269-294 JAN 2007
Author Keywords: integrated water resources management; lesser developed
countries; water poverty; climate change; biological river health; downstream water
obligations; hydrological modelling
Abstract: Following some definitions of IWRM within a context of integrated
catchment management, and a summary of the major goals and strategies as well as
scale considerations in IWRM, this paper highlights some differences between IWRM in
Lesser Developed Countries (LDCs), i.e. the so-called "South", and Developed
Countries (DCs), i.e. the so-called "North", by outlining characteristics of DCs and
LDCs which shape their respective needs in IWRM. Thereafter inherent problems in
regard to IWRM in LDCs are identified. This is followed by examples from four case
studies in southern African catchments which focus on some of the uniquenesses of
IWRM issues in LDCs which, in the author's experiences, are often forgotten by
theorists and practitioners from the "North",viz.that
while catchment studies tend to emphasise mainstem river discharge
characteristics,these are not the sources of rural water supply problems in LDCs (a
case study from the Thukela HELP catchment in South Africa);
water poverty is acute in many meso-scale catchments and is likely to be exacerbated
by global warming (again, a case study from the Thukela catchment);
water quality problems for the rural poor, who are still without potable water supplies,
frequently revolve around the biological health of rivers, rather than those related to
chemical or physical water quality (a case study from the Mgeni catchment in South
Africa); and
climate change may have severe impacts on both within-country reservoir
management and out-of-country outflow obligations to downstream countries on
already stressed catchments dominated by high water demanding irrigated crops (a
case study from theMbuluzi catchment in Swaziland).
In each case study simulation modelling has been used as a tool in IWRM. A
concluding section therefore focuses on some selected problems which have been
identified by the author in regard to hydrological modelling in LDCs. These revolve
around issues of governance, human resources and practicalities.
ISSN: 0920-4741
Record 3 of 23
Author(s): Brown, C (Brown, Casey); Lall, U (Lall, Upmanu)
Title: Water and economic development: The role of variability and a framework for
resilience
Source: NATURAL RESOURCES FORUM, 30 (4): 306-317 NOV 2006
Author Keywords: economic development; water scarcity; climate variability;
infrastructure; water policy
Keywords Plus: CLIMATE; POPULATION; GROWTH
Abstract: The article advances the hypothesis that the seasonal and inter-annual
variability of rainfall is a significant and measurable factor in the economic
development of nations. An analysis of global datasets reveals a statistically
significant relationship between greater rainfall variability and lower per capita GDP.
Having established this correlation, we construct a water resources development
index that highlights areas that have the greatest need for storage infrastructure to
mitigate the impacts of rainfall variability on water availability for food and basic
livelihood. The countries with the most critical infrastructure needs according to this
metric are among the poorest in the world, and the majority of them are located in
Africa. The importance of securing water availability in these nations increases every
day in light of current population growth, economic development, and climate change
projections.
ISSN: 0165-0203
Record 4 of 23
Author(s): Legesse, D; Ayenew, T
Title: Effect of improper water and land resource utilization on the central Main
Ethiopian Rift lakes
Source: QUATERNARY INTERNATIONAL, 148: 8-18 MAY 2006
Keywords Plus: HYDROLOGICAL RESPONSE; TROPICAL AFRICA; VALLEY; ABIYATA;
CLIMATE; SERIES
Abstract: The Ethiopian Rift is characterized by a chain of lakes varying in size,
hydrological and hydrogeological setting. Some of the lakes and tributary rivers are
used for irrigation, soda abstraction, commercial fish farming and recreation; and they
support a wide variety of endemic birds and wild animals. Few lakes shrunk due to
excessive abstraction of water; others expanded due to increase in surface runoff and
groundwater flux from percolated irrigation water. Excessive land degradation,
deforestation and over-irrigation resulted in sedimentation in lakes and increase in
soil salinity. The chemistry of some of the lakes has also been changed dramatically.
This paper addresses the major environmental changes in the last few decades in the
central Main Ethiopian Rift takes that resulted mainly from anthropogenic factors. The
methods employed include field hydrogeological mapping Supported by aerial
photograph and satellite imagery interpretations, hydro-meteorological data analysis,
water balance estimation, catchment hydrological and groundwater flow modelling
and hydrochemical analysis. A converging evidence or integrated approach has been
adapted to reconstruct the temporal and spatial variations of lake levels and
hydrochemistry. The result revealed that the major changes in the rift valley are
related mainly to recent improper utilization of water and land resources in the lakes
catchment and direct lake water abstraction aggravated intermittently by climatic
changes. The terminal lakes show dramatic reduction in level and increase in salinity.
These changes appear to have grave environmental consequences on the fragile rift
ecosystem, which demands extremely Urgent integrated basin-wide water
management practice. (c) 2005 Elsevier Ltd and INQUA. All rights reserved.
ISSN: 1040-6182
Record 5 of 23
Author(s): Kebede, S; Travi, Y; Alemayehu, T; Marc, V
Title: Water balance of Lake Tana and its sensitivity to fluctuations in rainfall, Blue
Nile basin, Ethiopia
Source: JOURNAL OF HYDROLOGY, 316 (1-4): 233-247 JAN 10 2006
Author Keywords: Lake Tana; water budget; lake level simulation; sensitivity; Blue
Nile; Ethiopia
Keywords Plus: CLIMATIC-CHANGE; RIFT-VALLEY; WHITE NILE; VICTORIA;
IMPACT; EVAPORATION; RESOURCES; AFRICA; RUNOFF; EGYPT
Abstract: The annual water budget of Lake Tana is determined from estimates of
runoff, rainfall on the lake, measured outflow and empirically determined evaporation.
Simulation of lake level variation (1960-1992) has been conducted through modeling
at a monthly time step. Despite the +/- 20% rainfall variations in the Blue Nile basin
in the last 50 years, the lake level remained regular. A preliminary analysis of the
sensitivity of level and outflow of the lake suggests that they are controlled more by
variation in rainfall than by basin-scale forcing induced by human activities. The
analysis shows that a drastic (40-45%) and sustained (7-8 years) rainfall reduction is
required to change the lake from out flowing to terminal (cessation of outflow).
However, the outflow from the lake shows significant variation responding to the
rainfall variations. Unlike the terminal lakes in the Ethiopian rift valley or the other
large lakes of Tropical Africa, at its present hydrologic condition, the Lake Tana level
is less sensitive to rainfall variation and changes in catchment characteristics. (c)
2005 Elsevier B.V. All rights reserved.
ISSN: 0022-1694
Record 6 of 23
Author(s): Matondo, JI; Peter, G; Msibi, KM
Title: Managing water under climate change for peace and prosperity in Swaziland
Source: PHYSICS AND CHEMISTRY OF THE EARTH, 30 (11-16): 943-949 2005
Author Keywords: greenhouse gases; climate change; general circulation models;
Watball model; simulation results; efficient water utilization
Abstract: The enhanced greenhouse gas effect is expected to cause high temperature
increase globally (1.0-3.5 degrees C) and this will lead to an increase in precipitation
in some regions while other regions will experience reduced precipitation (+/- 20%).
The impact of expected climate change will affect almost all aspects of human
endeavour. The major focus of this paper is management of water resources under
climate change for peace and prosperity in Swaziland. The impact of climate change
on hydrology and water resources has been evaluated using general circulation model
(GCM) results (rainfall, potential evapotranspiration, air temperature, etc.) as inputs
to a rainfall runoff model. The evaluation of the effect of climate change on hydrology
and water resources in Swaziland has been carried out in three catchments namely:
Mbuluzi, Komati and Ngwavuma.
MAGICC model was used to simulate the climate parameters for Swaziland given the
baseline conditions. Eleven GCMs were evaluated and three of them were found to
simulate very well the observed precipitation for Swaziland. These GCMs are: the
Geophysical Fluid Dynamics Laboratory (GFDL), the United Kingdom Transient
Resalient (UKTR) and the Canadian Climate Change Equilibrium (CCC-EQ). The three
GCMs were used to project the temperature and precipitation changes for Swaziland
for year 2075. This information was used to generate the temperature, precipitation
and potential evapotranspiration values for the three catchments for year 2075. This
information was used as input data to a calibrated WatBall rainfall runoff model.
Simulation results (after taking into consideration water use projections) show a
water deficit from June to September in both the Komati and Ngwavuma catchments
and a water deficit from May to September in the Mbuluzi catchment. Efficient water
utilization in the agricultural sector (i.e., using drip irrigation) gives a water savings of
33.6 x 10(6) m(3) per year (1.065 m(3)/s), 47.6 x 10(6) m(3) per year (1.509
m(3)/s) and 16.8 x 10(6) m(3) per year (0.533 m(3)/s) in the Komati, Mbuluzi and
Ngwavurna catchments, respectively. The saved water could be used for other
economic activities and meeting Swaziland's water release obligations to downstream
riparian states of South Africa and Mozambique. (c) 2005 Elsevier Ltd. All rights
reserved.
ISSN: 1474-7065
Record 7 of 23
Author(s): Macdonald, IAW
Title: Recent research on alien plant invasions and their management in South Africa:
A review of the inaugural research symposium of the Working for Water programme
Source: SOUTH AFRICAN JOURNAL OF SCIENCE, 100 (1): 21-26 JAN-FEB 2004
Abstract: This paper reviews the 40 verbal presentations and 14 poster papers from
the inaugural research symposium of the Working for Water programme, held at
Kirstenbosch, Cape Town, in August 2003. Papers and posters were presented under
six themes hydrology [8 papers and posters], ecology (including the ecology of
wetlands) [19], biological control [5], operations management [110], social
development [6], and natural resource and development economics [6]. The research
reported on is generally of a high standard and is highly relevant to the practical
issues that managers of invasive alien plants face in South Africa. The biological
control, hydrology, and ecology fields are particularly strong. Although already
showing much promise, resource economics in this field is still in its infancy and
requires further investment to realize its undoubted potential to help improve the
management of invasive alien plants. Improved research is required on the
operational management and social development aspects of research in this area. It is
recommended that particular attention be paid to the following in future research: (i)
biodiversity consequences of invasive alien plants and of alternative management
options (with a particular view to optimizing unaided ecosystem recovery following
clearing), (ii) interactions between global climate change and all aspects of alien plant
invasions and their control, (iii) improving the empirical base of the hydrological
models of impacts arising from invasions by alien plants, and their control, and (iv)
prevention of invasions. A much greater investment should be made in biological
control research in order to (i) maximize the contribution of this, the most costeffective and sustainable control technology, (ii) build on and maintain South Africa's
track record of being a world-leader in this internationally transferable field, and (iii)
ensure that we create a new cohort of biocontrol researchers nationally. In all fields,
researchers should work closely with managers to take full advantage of the
unparalleled opportunities that the massive landscape-scale clearing interventions
present for elucidating all aspects of the interaction of invasive alien plants and their
control with the country's natural and socio-economic systems. In turn, this should
lead the Working for Water programme into a truly strategic 'adaptive management'
mode of operation, with research becoming an integral part of this management.
Resource economics should become a key tool for translating the invasive alien plant
issue into language that decision-makers understand (and for informing management
decisions). However, these economic analyses will only be correct if the underlying
scientific understanding of alien invasions and their impacts is sound. Investment in
research on invasive alien plants will continue to give excellent returns for South
Africa.
ISSN: 0038-2353
Record 8 of 23
Author(s): Arnell, NW
Title: Climate change and global water resources: SRES emissions and socioeconomic scenarios
Source: GLOBAL ENVIRONMENTAL CHANGE-HUMAN AND POLICY DIMENSIONS, 14
(1): 31-52 APR 2004
Author Keywords: climate change impacts; global water resources; water resources
stresses; SRES emissions scenarios; macro-scale hydrological model; multi-decadal
variability
Keywords Plus: MODEL; VULNERABILITY; SIMULATION
Abstract: In 1995, nearly 1400 million people lived in water-stressed watersheds
(runoff less than 1000m(3)/capita/year), mostly in south west Asia, the Middle East
and around the Mediterranean. This paper describes an assessment of the relative
effect of climate change and population growth on future global and regional water
resources stresses, using SRES socio-economic scenarios and climate projections
made using six climate models driven by SRES emissions scenarios. River runoff was
simulated at a spatial resolution of 0.5 x 0.5degrees under current and future climates
using a macro-scale hydrological model, and aggregated to the watershed scale to
estimate current and future water resource availability for 1300 watersheds and small
islands under the SRES population projections. The A2 storyline has the largest
population, followed by B2, then A 1 and B I (which have the same population). In the
absence of climate change, the future population in water-stressed watersheds
depends on population scenario and by 2025 ranges from 2.9 to 3.3 billion people;
(36-40% of the world's population). By 2055 5.6 billion people would live in waterstressed watersheds under the A2 population future, and "only" 3.4 billion under
A1/B1.
Climate change increases water resources stresses in some parts of the world where
runoff decreases, including around the Mediterranean, in parts of Europe, central and
southern America, and southern Africa. In other water-stressed parts of the worldparticularly in southern and,eastern Asia-climate change increases runoff, but this
may not be very beneficial in practice because the increases tend to come during the
wet season and the extra water may not be available during the dry season. The
broad geographic pattern of change is consistent between the six climate models,
although there are differences of magnitude and direction of change in southern Asia.
i By the 2020s there is little clear difference in the magnitude of impact between
population or emissions scenarios, but a large difference between different climate
models: between 374 and 1661 million people are projected to experience an increase
in water stress.
By the 2050s there is kill little difference between the emissions scenarios, but the
different population assumptions have a clear effect. Under the A2 population
between 1092 and 2761 million people have an increase in stress; under the B2
population the range is 670-1538 million, respectively. The range in estimates is due
to the slightly different patterns of change projected by the different climate models.
Sensitivity analysis showed that a 10% variation in the population totals under a
storyline could lead to variations in the numbers of people with an increase or
decrease in stress of between 15% and 20%. The impact of these changes on actual
water stresses will depend on how water resources are managed in the future. (C)
2003 Elsevier Ltd. All rights reserved.
ISSN: 0959-3780
Record 9 of 23
Author(s): Wichelns, D
Title: Policy recommendations to enhance farm-level use of fertilizer and irrigation
water in sub-Saharan Africa
Source: JOURNAL OF SUSTAINABLE AGRICULTURE, 23 (2): 53-77 2003
Author Keywords: agriculture; productivity; sub-Saharan Africa; fertilizer; irrigation
Keywords Plus: SOIL NUTRIENT DEPLETION; PEARL-MILLET PRODUCTION; FOOD
SECURITY; WEST-AFRICA; AGRICULTURAL PRODUCTIVITY; SOUTHERN AFRICA;
GREEN-REVOLUTION; MAIZE PRODUCTION; CLIMATE-CHANGE; MANAGEMENT
Abstract: Food production per capita has declined in sub-Saharan Africa in recent
years, as population has increased faster than agricultural production. The causes of
slow growth in agricultural productivity include poor soil fertility, insufficient use of
chemical and organic supplemental fertilizer, and inadequate investments in irrigation
systems and other infrastructure. In addition, government policies that have taxed
agriculture heavily have limited the farm-level accumulation of capital and
discouraged farmers from making the investments needed to enhance productivity.
This paper describes public policies and investments that will enhance the farm-level
availability and use of fertilizer and water resources, with the ultimate goals of
improving food production and rural incomes, and enhancing food security. Examples
include enabling farmers to obtain market prices for their output, requiring them to
pay per-unit prices for irrigation water and fertilizer, and supporting investments in
infrastructure and institutions that will enhance the delivery of water and fertilizer to
remote, rural areas. Public investments and policies that lead to higher rates of
growth in agricultural productivity may generate substantial public benefits in many
countries. (C) 2003 by The Haworth Press, Inc. All rights reserved.
ISSN: 1044-0046
Record 10 of 23
Author(s): Tao, FL; Yokozawa, M; Hayashi, Y; Lin, E
Title: Terrestrial water cycle and the impact of climate change
Source: AMBIO, 32 (4): 295-301 JUN 2003
Keywords Plus: GLOBAL DISTRIBUTION; SOIL; VARIABILITY; RESOURCES
Abstract: The terrestrial water cycle and the impact of climate change are critical for
agricultural and natural ecosystems. In this paper, we assess both by running a
macro-scale water balance model under a baseline condition and 2 General Circulation
Model (GCM)-based climate change scenarios. The results show that in 2021-2030,
water demand will increase worldwide due to climate change. Water shortage is
expected to worsen in western Asia, the Arabian Peninsula, northern and southern
Africa, northeastern Australia, southwestern North America, and central South
America. A significant increase in surface runoff is expected in southern Asia and a
significant decrease is expected in northern South America. These changes will have
implications for regional environment and socioeconomics.
ISSN: 0044-7447
Record 11 of 23
Author(s): Yang, H; Reichert, P; Abbaspour, KC; Zehnder, AJB
Title: A water resources threshold and its implications for food security
Source: ENVIRONMENTAL SCIENCE & TECHNOLOGY, 37 (14): 3048-3054 JUL 15
2003
Keywords Plus: CLIMATE-CHANGE; SCARCITY; 21ST-CENTURY; IRRIGATION;
MANAGEMENT; COUNTRIES; EGYPT
Abstract: Cereal import has played a crucial role in compensating local water deficit.
A quantitative account of water deficit and cereal import relations therefore is of
significance for predicting future food import demand and formulating corresponding
national and international policies. On the basis of data for countries in Asia and
Africa, we estimated a water resources threshold with respect to cereal import. Below
the threshold, the demand for cereal import increases exponentially with decreasing
water resources. There appeared to be a declining trend in the threshold, from 2000
m(3)/(capita year) in the early 1980s to 1500 m(3)/(capita year) by the end of the
1990s. Until recently, most countries below the threshold were oil-rich and thus were
able to afford cereal import. However, the next 30 yr may see many poor and
populous countries dropping below the threshold in association with their rapid
population growth and the depletion of fossil groundwater. Water deficit-induced food
insecurity and starvation could intensify because cereal import may not be affordable
for these countries.
ISSN: 0013-936X
Record 12 of 23
Author(s): New, M
Title: Climate change and water resources in the southwestern Cape, South Africa
Source: SOUTH AFRICAN JOURNAL OF SCIENCE, 98 (7-8): 369-376 JUL-AUG 2002
Keywords Plus: MODEL; SIMULATION; IRRIGATION; IMPACTS; SOIL; CO2
Abstract: Increases in atmospheric CO2 are predicted to raise global and regional
temperatures, and produce changes in other climate variables that drive the
terrestrial hydrological cycle, most notably precipitation and potential evaporation. At
the same time, a warmer world is predicted to result in increased water use in
domestic, agricultural and industrial sectors. This article describes the simulated
sensitivity of runoff in four mountainous catchments in the southwestern Cape to a
range of possible future changes in climate over the next fifty years, and assesses this
sensitivity in the light of recent general circulation model predictions of future climate
over the region. The 'most likely' streamflow response is then considered in terms of
current and projected water resource supply capacity and demand in the Cape
Metropolitan Region (CMR). Supply capacity is shown to decrease non-linearly as
either precipitation decreases or potential evapotranspiration increases, both of which
are the most likely predicted changes in regional climate. More and catchments show
a higher sensitivity to these changes. The most likely variation in water supply
capacity in the CMR is a reduction of 0.32% per annum to 2020. Using information
from other studies, climate change is predicted to raise water demand by 0.6% per
annum, which will be superimposed on other demand increases. Under current water
resource development plans, the predicted reduced supply and increased demand
result in a permanent inability to meet the 1:50 year supply yield in the CMR, with the
consequence that the frequency of supply failure will be greater than expected.
ISSN: 0038-2353
Record 13 of 23
Author(s): Sullivan, C
Title: Calculating a water poverty index
Source: WORLD DEVELOPMENT, 30 (7): 1195-1210 JUL 2002
Author Keywords: water; poverty; management tools; global; local; index
Keywords Plus: CLIMATE-CHANGE IMPACTS; SOUTHERN AFRICA; RESOURCES;
ECONOMY; EGYPT
Abstract: This paper provides discussion of ways in which an interdisciplinary
approach can be taken to produce an integrated assessment of skater stress and
scarcity, linking physical estimates of water availability with socioeconomic variables
that reflect poverty, i,e., a Water Poverty Index. It is known that poor households
often suffer from poor water provision, and this results in a significant loss of time
and effort. especially for, omen, By linking the physical and social sciences to address
this issue. a more equitable solution for water allocation may be found. For the
purpose of initiating discussion. a summary of different approaches to establishing a
Water Poverty Index is discussed. (C) 2002 Elsevier Science Ltd. All rights reserved.
ISSN: 0305-750X
Record 14 of 23
Author(s): Varis, O; Fraboulet-Jussila, S
Title: Water resources development in the lower Senegal River basin: Conflicting
interests, environmental concerns and policy options
Source: INTERNATIONAL JOURNAL OF WATER RESOURCES DEVELOPMENT, 18 (2):
245-260 JUN 2002
Keywords Plus: QUALITY; GUIERS; LAC
Abstract: The Senegal River is the lifeline of the westernmost part of the sahelian
zone in Africa. This zone has extreme problems with high population growth, rapid
and uncontrolled urbanization, climate changes, widespread poverty, growing
inequity, ethnic confrontations and stagnant economic development. This paper
analyses the management system of Lac de Guiers-one of the largest lakes in West
Africa-which is among the Senegal River's key management entities. A Bayesian
network model is used to study the conflicting interests among the various
stakeholders, the environmental and social concerns in the region and the viability of
a series of policy options for water resources development.
ISSN: 0790-0627
Record 15 of 23
Author(s): Ragab, R; Prudhomme, C
Title: Climate change and water resources management in arid and semi-arid
regions: Prospective and challenges for the 21st century
Source: BIOSYSTEMS ENGINEERING, 81 (1): 3-34 JAN 2002
Abstract: The overgrowing population and the recent droughts are putting water
resources under pressure and calling for new approaches for water planning and
management if escalating conflicts are to be avoided and environmental degradation
is to be reversed. As countries are using their water resources with growing intensity,
poor rainfall increasingly leads to national water crises as water tables fall and
reservoirs, wetlands and rivers empty. Global warming could cause further changes,
further variability and further uncertainty: The UK Hadley Centre's global climate
model was run at a spatial scale of 2.5 by 3.75degrees (latitude and longitude) grid
squares to simulate the global climate according to scenarios of greenhouse gas
concentration emission. Runs of the model assuming the emission scenario proposed
by the Intergovernmental Panel on Climate Change in 1995 are analysed here for the
2050s time horizon. Outputs provide estimations of climate variables, such
as,precipitation and temperature, at a monthly time step. Those results, assumed
representative of future climatic conditions, are compared to mean monthly values
representative of the current climate and expressed in terms of percentage change.
The results show that, for the dry season (April-September), by the 2050s, North
Africa and some parts of Egypt, Saudi Arabia, Iran, Syria, Jordan and Israel, are
expected to have reduced rainfall amounts of 20-25% less than the present mean
values. This decrease in rainfall is accompanied by a temperature rise in those areas
of between 2 and 2.75 degreesC. For the same period, the temperature in the coastal
areas of the Mediterranean countries will rise by about 1.5degreesC. In wintertime,
the rainfall will decrease by about 10-15% but would increase over the Sahara by
about 25%. Given the low rainfall rate over the Sahara, the increase by 25% will not
bring any significant amount of rain to the region. In wintertime, the temperature in
the coastal areas will also increase but by only 1.5degreesC on average, while inside
the region it will increase by 1.75-25degreesC.
In southern Africa (Angola, Namibia, Mozambique, Zimbabwe; Zambia, Botswana and
South Africa), results suggest an increase of the annual average temperature ranging
between 1.5 and 2.5degreesC in the south to between 2.5 and 3degreesC in the
north. The summer range is between 1.75 and 2.25degreesC in the south, and
increases towards the north to between 2.75 and 3.0degreesC while the winter range
is between 1.25 and 2degreesC in the south, and increases towards the north to
between 2.5 and 2.75degreesC. On the other hand, the annual average will decrease
by 10-15% in the south and by 5-10% in the north. The annual average decrease is
10%. However, some places will have an increase i.e. by 5-20% in South Africa in
wintertime. In the Taklimakan region (Tarim Basin) west of China, the annual average
temperature is shown to increase by 1.75-2.5degreesC. Annual average rainfall
should increase by 5- > 25% in most of the region but decrease by 5-10% in some
small parts. In summer, an increase by 5-15% is indicated in most of the region, and
an increase by up to 25% or more during the wintertime.
In the Thar Desert (India-Pakistan-Afghanistan), estimations suggest that the annual
average increase in temperature ranges from 1.75 to 2.5degreesC, ranging from 1.5
to 2.25degreesC in winter and from 2 to 2.5degreesC in summer. Annual average
precipitation is shown to decrease by 5-25% in the region. The winter will have values
closer to the annual average but the summer will have more decrease and most of the
region will see a decrease closer to 25%.
In the Aral Sea basin (Kazakhstan, Turkmenistan and Uzbekistan), estimates suggest
an annual average increase in temperature ranging from 1.75 to 2.25degreesC,
higher in summer (between 2 and 2.75degreesC) than in winter (between 1.5 and
2degreesC). Rainfall should increase by 5-20% annually, in summer increasing by 510% in the north but decreasing by up to 5% in the south, while in wintertime, both
south and north should undergo increases of 5-10% and 20-25%, respectively.
In Australia, results indicate an increase in the annual average temperature ranges of
1-1.5degreesC in the south to 2.5-2.75degreesC in the north, slightly higher during
the summer than in the winter. The summer range is between 1 and 2degreesC in the
south and increases towards the north to 2.5-3.0degreesC while the winter range is
between 1 and 1.5degreesC in the south, and increases towards the north to between
2 and 2.25degreesC. Rainfall annual average is shown to decrease by 20-25% in the
south and by 5-10% in the north.
Given the above-mentioned facts, in order to meet the water demands in the next
century, same dams and water infrastructure will be built in some countries and a
new paradigm by rethinking the water use with the aim of increasing the productive
use of water will have to be adopted. Two approaches are needed: increasing the
efficiency with which current needs are met and increasing the efficiency with which
water is allocated among different uses. In addition, non-conventional sources of
water supply such as reclaimed, recycled water and desalinated brackish water or
seawater is expected to play an important role. (C) 2001 Silsoe Research Institute.
ISSN: 1537-5110
Record 16 of 23
Author(s): Schulze, R; Meigh, J; Horan, M
Title: Present and potential future vulnerability of eastern and southern Africa's
hydrology and water resources
Source: SOUTH AFRICAN JOURNAL OF SCIENCE, 97 (3-4): 150-160 MAR-APR 2001
Keywords Plus: GENERAL-CIRCULATION MODELS; CLIMATE-CHANGE;
SIMULATIONS; IMPACTS
Abstract: Eastern and southern Africa is a region beset with often unique climatic
and developmental problems as well as with a high agricultural water usage. This
paper presents a synthesis of water as a vulnerable and variable natural resource in
space and time under present climatic conditions by assessing various rainfall,
evaporation and runoff indices in the region. Further uncertainties regarding this
already high-risk natural environment are compounded by superimposing elements of
potential climate change for a year 2050 scenario over the region. To the hazards of
present and potential future climates the human dimension is added by assessing
water demand as well as water availability for present and assumed future conditions.
The paper concludes by highlighting the need for more detailed secondary and higherorder impact studies of climate change on water resources.
ISSN: 0038-2353
Record 17 of 23
Author(s): Meigh, JR; McKenzie, AA; Sene, KJ
Title: A grid-based approach to water scarcity estimates for eastern and southern
Africa
Source: WATER RESOURCES MANAGEMENT, 13 (2): 85-115 APR 1999
Author Keywords: Africa; grid-based models; climate change; water demands;
water resources modelling; water scarcity
Keywords Plus: SCALE; HYDROLOGY
Abstract: A novel approach is taken to the problem of estimating global water
scarcity, using a realistic and consistent procedure applied across many countries.
Water demands, surface flows and groundwater availability are estimated on a
gridded basis, and various water availability indices are derived comparing the
resource with the projected demand. Surface flows are estimated using a conceptual
rainfall-runoff model linking climate to runoff and, in the major river basins, the runoff
estimates for individual grid cells are accumulated to give estimates for the total flows
at all points of interest. Groundwater availability is derived from hydrogeological maps
based on estimates of the potential yield that can be expected from a borehole and
the likely maximum borehole density. Estimates of potential groundwater recharge
derived from the surface water model are also taken into account. Water demands are
based on current and projected population and livestock numbers, and information on
irrigation schemes and industrial water use. Results are presented for the application
of the model to a region covering the whole of eastern and southern Africa. The main
scenario considered includes the combined impact of climate change, population
growth and improved living standards to the year 2050. The results for this scenario
show that water scarcity is likely to increase in many countries in the region, with
particular problems in the countries around Lake Victoria and in the southernmost
parts of the pilot region.
ISSN: 0920-4741
Record 18 of 23
Author(s): Arnell, NW
Title: Climate change and global water resources
Source: GLOBAL ENVIRONMENTAL CHANGE-HUMAN AND POLICY DIMENSIONS, 9:
S31-S49 Suppl. S 1999
Author Keywords: climate change; global water resources; global runoff;
hydrological impacts of climate change
Abstract: By 2025, it is estimated that around 5 billion people, out of a total
population of around 8 billion, will be living in countries experiencing water stress
(using more than 20% of their available resources). Climate change has the potential
to impose additional pressures in some regions. This paper describes an assessment
of the implications of climate change for global hydrological regimes and water
resources. It uses climate change scenarios developed from Hadley Centre climate
simulations (HadCM2 and HadCM3), and simulates global river flows at a spatial
resolution of 0.5 x 0.5 degrees using a macro-scale hydrological model. Changes in
national water resources are calculated, including both internally generated runoff and
upstream imports, and compared with national water use estimates developed for the
United Nations Comprehensive Assessment of the Freshwater Resources of the World.
Although there is variation between scenarios, the results suggest that average
annual runoff will increase in high latitudes, in equatorial Africa and Asia, and
southeast Asia, and will decrease in mid-latitudes and most subtropical regions. The
HadCM3 scenario produces changes in runoff which are often similar to those from the
HadCM2 scenarios - but there are important regional differences. The rise in
temperature associated with climate change leads to a general reduction in the
proportion of precipitation falling as snow, and a consequent reduction in many areas
in the duration of snow cover. This has implications for the timing of streamflow in
such regions, with a shift from spring snow melt to winter runoff. Under the HadCM2
ensemble mean scenario, the number of people living in countries with water stress
would increase by 53 million by 2025 (relative to those who would be affected in the
absence of climate change). Under the HadCM3 scenario, the number of people living
in countries with water stress would rise by 113 million. However, by 2050 there
would be a net reduction in populations in stressed countries under HadCM2 (of
around 69 million), but an increase of 56 million under HadCM3. The study also
showed that different indications of the impact of climate change on water resource
stresses could be obtained using different projections of future water use. The paper
emphasises the large range between estimates of "impact", and also discusses the
problems associated with the scale of analysis and the definition of indices of water
resource impact. (C) 1999 Elsevier Science Ltd. All rights reserved.
ISSN: 0959-3780
Record 19 of 23
Author(s): Valentin, C; d'Herbes, JM; Poesen, J
Title: Soil and water components of banded vegetation patterns
Source: CATENA, 37 (1-2): 1-24 SEP 1999
Author Keywords: landscape patchiness; banded vegetation pattern; soil crusting;
water-harvesting; semi-arid zone
Keywords Plus: WEST-AFRICA; EASTERN AUSTRALIA; ARID ECOSYSTEM; BURKINAFASO; NIGER; RUNOFF; EROSION; FORESTS; AREAS; CLASSIFICATION
Abstract: Banded landscapes are comprised of alternating bands of vegetation and
bare ground aligned along the contours in arid and semi-arid regions (50-750 mm
rainfall), on very gentle and uniform slopes (0.2-2%), Vegetated bands can be
perpendicular to the direction of the dominant wind, or more frequently of the slope.
Under given climatic conditions, slope gradient is the controlling factor of the type of
pattern ('spotted', 'broadly' or 'typically' banded). For a given slope gradient, mean
annual rainfall determines the contrast between the vegetated and bare phase, as
well as the band length and the interband width:band width ratio. A typical transect
through such two-phase mosaic includes a dynamic succession of surface crusts which
generates a run-off-run-on system. This favours the capture of limited water
resources and thus a biomass production greater for banded patterns than spotted
patterns or uniformly scattered vegetation. Moreover, vegetated bands act as natural
bench structures that greatly limit soil erosion. As suggested by modelling, banded
vegetation patterns can equally be derived from nearly bare areas or from dense
vegetation patterns. Because banded vegetation patterns have often been considered
as a form of degradation of previous continuous vegetation cover, many attempts
have been made by foresters to restore this initial cover by reforestation of the bare
interbands. However the numerous failures of reforestation of the bare interbands
illustrate the key role of these mosaic components in the maintenance of the tiger
bush ecosystem. Banded vegetation patterns are more resilient to climate change
than to human disturbances. The loss of landscape patchiness due to the clearing of
the bands either for fuelwood or for ephemeral cropping induces a rapid decline in soil
fertility and water infiltration potential. Long-term monitoring shows that the
interband width:band width ratio adapts to rainfall variations that are intrinsic of
semi-arid zones. Moreover, climatic changes might also induce a change in the type of
patterning, suggesting that banded vegetation pattens are highly self-sustainable. The
ecological differences between the pioneer and the decaying edges of the vegetated
bands, the temporal/spatial succession of soil crusts, as well as other indices such as
the spatial distribution of soil organic matter and termite nests suggest the upslope
migration of the bands. Nevertheless field evidence of such a shift remains scarce.
Profound lessons can be learnt from the study of banded landscapes in terms of
ecosystems functions. When designing water-harvesting systems, or restoring
degraded arid and semi-arid land, banded vegetation patterns should be imitated to
optimize biomass production and limit land degradation. (C) 1999 Elsevier Science
B.V. All rights reserved.
ISSN: 0341-8162
Record 20 of 23
Author(s): Feddema, JJ
Title: Future African water resources: Interactions between soil degradation and
global warming
Source: CLIMATIC CHANGE, 42 (3): 561-596 JUL 1999
Keywords Plus: SURFACE AIR-TEMPERATURE; CLIMATE-CHANGE; POTENTIAL
EVAPOTRANSPIRATION; SPATIAL VARIABILITY; CARBON-DIOXIDE;
DESERTIFICATION; MOISTURE; DROUGHT; BALANCE; SAHEL
Abstract: This study uses a well-established water balance methodology to evaluate
the relative impact of global warming and soil degradation due to desertification on
future African water resources. Using a baseline climatology, a GCM global warming
scenario, a newly derived soil water-holding capacity data set, and a worldwide
survey of soil degradation between 1950 and 1980, four climate and soil degradation
scenarios are created to simulate the potential impact of global warming and soil
degradation on African water resources for the 2010-2039 time period.
Results indicate that, on a continental scale, the impact of global warming will be
significantly greater than the impact of soil degradation. However, when only
considering the locations where desertification is an issue (wet and dry climate
regions), the potential effects of these two different human impacts on local water
resources can be expected to be on the same order of magnitude. Drying associated
with global warming is primarily the result of increased water demand (potential
evapotranspiration) across the entire continent. While there are small increases in
precipitation under global warming conditions, they are inadequate to meet the
increased water demand. Soil degradation is most severe in highly populated, wet and
dry climate regions and results in decreased water-holding capacities in these
locations. This results in increased water surplus conditions during wet seasons when
the soil's ability to absorb precipitation is reduced. At the same time, water deficits in
these locations increase because of reduced soil water availability in the dry seasons.
The net result of the combined scenarios is an intensification and extension of drought
conditions during dry seasons.
ISSN: 0165-0009
Record 21 of 23
Author(s): Feddema, JJ
Title: Estimated impacts of soil degradation on the African water balance and climate
Source: CLIMATE RESEARCH, 10 (2): 127-141 AUG 14 1998
Author Keywords: climate change; soil degradation; Africa; water balance
Keywords Plus: SURFACE AIR-TEMPERATURE; CLIMATONOMIC DESCRIPTION;
SPATIAL VARIABILITY; ENERGY BALANCE; CARBON-DIOXIDE; CENTRAL SAHEL;
DESERTIFICATION; MOISTURE; RAINFALL; PRECIPITATION
Abstract: This study uses a well-established water balance methodology, the
Thornthwaite-Mather approach, to evaluate the effects of soil water holding capacity
assumptions on estimates of African evapotranspiration rates, moisture deficit, and
moisture surplus conditions. Under constant climate conditions, the model tests the
impact of using a constant 150 mm soil water holding capacity compared to using a
newly derived soil water holding capacity data set (the Dunne-Willmott data set). The
study also uses a worldwide survey of soil degradation between 1950 and 1980
(GLASOD: Global Assessment of Soil Degradation) to evaluate the impacts of humaninduced soil degradation on local water balances. The GLASOD data are used to alter
local soil water holding capacities based on the Dunne-Willmott data to simulate
human soil degradation patterns in Africa. Results indicate that the use of simplified
soil water holding capacities can lead to significant errors in estimated
evapotranspiration rates and water surplus and deficit conditions in Africa. Regions
most affected are those with seasonal wet and dry climates, which are also those
locations with the greatest climate variability. Because these are often the climates
most studied to detect and model environmental change, it is important that accurate
soil moisture estimates be used to simulate climate conditions in these regions.
Results also indicate that soil degradation occurring over a 30 yr period (1950 to
1980) has had a significant impact on local water resources. The greatest impacts of
these changes are in some of the more productive agricultural areas in the wetter
sub-humid climates. Changes include increased runoff during wet seasons and an
extended drought period during the dry seasons. Given that these agricultural
systems have less flexibility to respond to long-term desiccation as compared to
pastoral systems, this could lead to significant changes in local growing seasons and
perhaps overall productivity in the future.
ISSN: 0936-577X
Record 22 of 23
Author(s): Thomas, T
Title: Domestic water supply using rainwater harvesting
Source: BUILDING RESEARCH AND INFORMATION, 26 (2): 94-101 MAR-APR 1998
Author Keywords: domestic water; rainwater harvesting; roofs; alternative
technologies; building services; sustainability
Abstract: World-wide pressure on water resources is mounting as populations grow,
consumption per capita increases, 'fossil' water resources are mined and the climate
changes. Domestic water usage is a significant component of water demand. Under
favourable circumstances, it can be met in part or in whole by rainwater collected
close to an individual dwelling. Interest in such systems is growing especially in rural
areas where either rainfall is well distributed through the year, or where surface water
is absent, groundwater mineralized and centralized piped supplies unaffordable.
Roofwater collection is also being practised on low-rise and high-rise buildings in some
cities having wet climates, The principles and components of rainwater harvesting are
reviewed. Factors leading to the growing use of domestic rainwater harvesting in
three different developing countries (North China, East Africa cmd Singapore) as case
studies are discussed along with current practices, design options for system
components and considerations for water quality and treatment. The lessons from
developing countries can be applied to a European context as some European towns
are beginning to require rainwater collection for toilet/laundry facilities in some new
buildings.
ISSN: 0961-3218
Record 23 of 23
Author(s): Venema, HD; Schiller, EJ; Adamowski, K; Thizy, JM
Title: A water resources planning response to climate change in the Senegal River
Basin
Source: JOURNAL OF ENVIRONMENTAL MANAGEMENT, 49 (1): 125-155 JAN 1997
Author Keywords: Senegal River; hydrology; climate change; simulation; irrigation
policy
Keywords Plus: TIME-SERIES ANALYSIS
Abstract: The Senegal River Basin (SRB), located in the Sahel region of West Africa,
is simultaneously undergoing fundamental environmental, hydrologic and
socioeconomic transitions. The tri-nation (Senegal, Mauritania and Mali) river basin
development authority, the Organisation pour la Mise en Valeur du Fleuve Senegal
(OMVS), is attempting to execute a shift to irrigated rice production for domestic
consumption in the river basin in order to ease the severe foreign exchange shortfalls
these riparian nations face. With the recent completion of the Manantali and Diama
dams, year-round irrigated agriculture is now possible in the SRB. The full agricultural
development potential of the SRB is constrained, however, by the basin's limited
water resources. Significantly, a time series analysis of Senegal River hydrology has
provided powerful evidence that the prolonged Sahelian drought may be permanent.
The basic hydrologic constraint on development is revealed in a time series
decomposition of Senegal River annual flow volumes, which strongly suggests that
water resources availability has been substantially curtailed since 1960. Two
alternative time series mechanisms are hypothesized to account for the decreased
flow volumes in recent decades. The first time series model suggests the presence of
a long-term periodicity, while the second model hypothesizes an ARMA(1,1) process.
The second hypothesis provides a superior model fit. The stationary ARMA(1,1) model
can be fit successfully, however, only after explicitly removing a non-stationary
component by linearly detrending after 1960. The implication of non-stationarity in
Senegal River hydrology provides analytic evidence that the landscape degradation
and desertification processes observed in Sahelian Africa can be in part attributed to
climate change effects.
The negative impact of the state-imposed rice production policy compounds the
severe effects of the drought on the river basin ecology. Rice production in the arid
river valley has been a financial and social failure. Irrigated rice projects suffer a high
rate of abandonment and have intensified the desertification process in the river
valley. As an alternative use of the basin's scarce water resources, an agricultural
development policy based on village-scale irrigation projects and intensive, irrigated
agro-forestry projects has been proposed. Village-scale irrigation is dedicated to lowwater-consumption cereal grain crops and is managed by traditional socio-political
structures. The agroforestry production system analysed has the dual objectives of
using irrigation to re-establish a protective bio-mass cover in the desertifying river
valley and of reversing the drought-induced migration from rural to urban areas.
A comparative river system simulation study was conducted to analyse the effects of
both the rice production development policy (policy RP) and the natural resources
management policy (policy NRM) on the SRB's full agricultural development potential.
The simulation study compared three alternative hydrologic scenarios using, (1) the
pre-drought era, (2) the 1970s level drought and (3) the 1980s level drought.
Principles of dynamic programming were applied to Manantali reservoir management
to optimize water allocation in each scenario. All the hydrologic scenarios generated
showed that the lower overall water-demand pattern exerted by policy NRM allows a
higher full agricultural development potential than does policy RP. (C) 1997 Academic
Press Limited
ISSN: 0301-4797