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An Assessment On Deforestation For Strengthening The Implementation Of Climate Change Policies
Badra S. Hearath,University of Sri Jayewardhenepura,Sri Lanka
Prabath N. Edirisinghe, Forest Department, Sri Lanka
An assessment on deforestation for strengthening the implementation of climate change policies: Case of dry
Zone forests in Galgamuwa/North Central Province, Sri Lanka.
Abstract
Carbon emissions from deforestation and forest degradation in developing countries account for approximately 2025% of Global Green House Gas (GHG) emissions. Deforestation Implies the conversion of forest to another land
use or long term reduction of tree canopy below the minimum 10% threshold. Forest degradation refers to changes
within the forest which negatively affect the structure or function of the stand or site. Forest management policies
based on reducing emissions from deforestation and forest degradation (REDD+) in developing countries plays a
crucial role in pursuing the ultimate objective of the United Nations Framework Convention on Climate Change
(UNFCC) and in holding the increase in global temperature rise below 2 degrees celsious above pre-industrial level.
Trading of carbon credits generated by way of avoiding deforestation and forest degradation brings substantial
multiple benefits for developing countries including Sri Lanka. Such policy measures for climate change mitigation
and adaptation also can ensure the continued delivery of other forest related benefits or ancillary benefits such as
poverty alleviation reduce food insecurity, improve rural livelihoods etc Sri Lanka also has been included into
REDD+ initiative country list by the UNFCC in year 2010. However, the challenge faced by Sri Lanka when
initiating REDD+ policy is lack of scientific data for establishing baseline information such as magnitude , spatial
distribution and factors of deforestation. According to previous studies deforestation and forest degradation is taken
place in North Central Province in Sri Lanka at alarming rate. Therefore this study on assessing deforestation
generates useful information to implement climate change policies in forestry sector in Sri Lanka effectively.
1.Introduction
Deforestation implies the conversion of forest to another land use or long term reduction tree canopy cover below
the minimum 10 percent threshold (FAO, 2001). It decreases the areacovered by forests. It cannot be defined
without adding a reference to its use or allocation. Some forests are allocating for clear cutting for timber or fuel
wood production ( Lanly 2003). Since such forests are regenerated naturally or artificially they are not considered in
the trerm of deforestation.
Forest degradation refers to change within the forest which negatively affect the structure or function of of the stand
or site, and thereby lower the capacity to supply products and services ( FAO,2001). Thereby, a degraded forest
delivers a reduced supply of goods and services from the given siteand maintains only a limited biological diversity.
Biological diversity of the degraded forest includes many non-tree components, which may dominate in the under
canopy vegetation (UNEP, 2008). Forest degradation does not involove a reduction of the forest area. It is
quantitatively (biomass) and or qualitatively (species) loss of vegetation cover a long time within the forest
(FAO,1993).
In northern dry zone area in Sri Lanka both deforestation and forest degradation have take place over the past years.
The change of closed forest to open forest is a result of forest degradation. The change closed forest or open forest to
shrub land which canopy density less than 10% is considered as deforestation. The reduction of the closed forest
cover in these area from 1983 – 1999 was 23% and is the third highest level in the country. The annual reduction of
closed forest in Kurunegala district in North-western province in Sri Lanka is around 2.5% which is higher than the
annual change of (1.11%) of Sri Lanka ( Legg and Jewel, !995).
There are number of causes for deforestation and forest degradation in Northern dry Zone in Sri Lanka such as
shifting cultivation, conversion of forest lands into permanent agriculture, encroachment of forest lands for residing,
conversion of forest lands for development activities, illegal felling, grazing and forest fires.
The severity and nature of deforestation and forest degradation are not similar in everywhere in the district. In the
areas where the above mentioned factors exist the problem may high. Factors of deforestation and forest degradation
can be influenced by secondary aspects such as soil condition, slope, proximity to roads, proximity to villages,
proximity to water sources and socio economic factors. Understanding of the spatial distribution and the factors of
deforestation and forest degradation with the other influencing aspects is important to take actions to protect the
forest resources in the Northern dry Zone area in Sri Lanka. Forest cover data and other land use data for Northern
Sri Lanka are not updated after 1992 since no study has been done in the area.
In the context of global climate change, deforestation and forest degradation in developing countries contributes
significantly to global CO2 emission. Significant emission reduction could be made, however, if appropriate
compensation mechanisms can be created. Climate change mitigation and adaptation policies such as Reducing
carbon emissions from deforestation and forest degradation in developing countries (REDD) is of central
importance in effort to combat climate change. Bali Action Plan (COP 13) of the UNFCC has extended the scope of
the REDD to REDD+ to add 3 additional important elements: a)conservation of forests, b). Sustainable management
of forests and c) Enhancement of forest carbon stocks.
Properly designed and implemented climate change mitigation and adaptation policy like REDD+ will ensure the
continued delivery of forest related benefits as well as ancillary benefits/co benefits such as poverty alleviation
reduce food insecurity, improve rural livelihoods etc. in forest depended people in developing countries by way of
active participation during implementation. Therefore implementation of such policies under Sri Lankan context
brings immense local socio-economic and environmental benefits locally and so called environment benefits
globally. However, the major challenge face in policy intervention is lack of scientific data and information on
various aspects of deforestation and forest degradation.
Sri Lanka also has been included in to REDD+ list by UNFCC in 2009. Sri Lanka is facing the challenge of
initiating REDD+ policies due to lack of relevant historical (past) scientific data and information on quantitative
determinants of deforestation , forest degradation and its dynamic. To generate such data application of Satellite
based remote sensing plays an important role , for assessing the spatial distribution and magnitude of deforestation
and forest degradation, as well as monitoring of carbon dynamics of forests. However application of such technique
to assess the severity of deforestation and forest degradation in Sri Lanka is analytically vacuumed.
2. Objectives
Main objective:
•
to assess the severity of deforestation in dry zone forests in North Central Forest Areas of Sri Lanka.
Specific objectives:
• Develop land cover maps for an interval of ten years for North Central forest area.
• Develop forest change maps over the same ten years considering major cover classes.
• Estimate the rate of deforestation.
3. Methodology
Selection of the Study area.
The Galgamuwa forest area is located Northern dry zone area in Kurunegala District ,Sri Lanka between 7 0 55’ – 80
10’ Nlatitude and 800 05’ – 800 25’ E longitude. Forests in the area are catogorise as moist monsoon forests and
degraded sparse and open forests. These forest areas are highly vulnerable to deforestation and forest degradation
due to number of reasons.
Data collection and information
Data:
Satellite images
Topographical maps
Auxiliary data
Information
Information on deforestation and forest degradation
Method
The following steps were adopted
1. Selection of images which cover the study area with minimum clouds
2. Dereferencing and geo-coding of images and geo-referencing the maps
3.
4.
5.
6.
7.
8.
9.
10.
Obtain subsets of the images for the study area.
Supervised classification of images using EDRAS
Create land cover maps in ArcGIS using the output of the step 4
Create the land cover change maps in ERDAS and
Analyze land cover changes
Application of the 3x3 majority filter
Identify the effect of filter
Analyze factors of deforestation and forest degradation .
4. Results
4.1 Land cover classes in Galgamuwa Area in 1992
The following land cover classes were detected in Galgamuwa area in 1992.
Figure 4.1 Land Cover map of 1992
The classified map was compared with the 1988 topographical map and the 1992 TM image in false colour
composite. This comparison was done to assess the accuracy of the classification. since it is impossible to take
sample points relevant to the 1992 image. This comparison revealed that most of the pixels are correctly classified
but that some pixels apparently are misclassified. The subsequent section describes the occurrence and possible
reasons for such misclassification.
Table 4.1 Land cover changes between 1988 to 1992
Land cover in
Reasons for changes
Topographical
map 1988
Classified image
1992
Forests
Closed forests
No change
Scrub jungle
Open forest
No change
Forests
Open forests
Human interventions such as illegal felling may be the reason.
Forests
Shrub/Grass lands
Human interventions such as chena (shifting) cultivation can be the
cause for the change.
Forests
Paddy
Misclassification of pixels
Forest
Bare land
Reason to be found with ground verification since this is a major
land cover change. But according to the comparison of colour of the
TM1992 image and classified image this cannot be a
misclassification.
Scrub Jungle
Shrub/Grass lands
Human intervention
Scrub Jungle
Bare land
Reason to be found with ground verification since this is a major
land cover change. But according to the comparison of colour of the
TM1992 image and classified image this cannot be a
misclassification.
4.2 Land cover change from 1992 to 2001
The two classified images were compared to detect the land cover change in the area from 1992 to 2001. A first
approach is to simply compare the total area under the different cover types in 1992 and 2001 and express the
difference in area change as a percentage of the 1992 land area for that land cover type. However in 1992 classified
image area of 3076 ha is unidentified due to clouds and cloud shadows but 2001 classified image there are no
unidentified areas. Therefore, unidentified areas were removed from the 2001 classified image for comparison.
Table 4.1 shows the results of this.
Figure 4.2 Land cover map of 2001
Table 4.2 Land cover difference from 1992 to 2001
Land cover class
Area (ha)
in 2001
Area(ha) in
2001
without
undefined
area
3,206
3,788
3,689
15
Open Forests
20,699
10,902
10,477
-49
Grass/Shrub/Homesteads
12,146
24,532
23,490
93
Bare lands
15,918
11,023
10,490
-34
Paddy
2,321
2,435
2,311
0
Moist Paddy
8,631
0
0
-100
0
12,076
11,476
100
10,952
14,511
13,787
26
Closed Forests
Fallow Paddy
Paddy sub total
Area (ha) in
1992
% Change
compared
to 1992
without
undefined
area
Water
Shallow / Sediments water
Unidentified due to clouds and
shadows
Total
1,070
1,247
1,206
13
492
1,556
1,344
173
3076
67,559
3076
67,559
67,559
It shows that closed forest cover has increased by 15% during the study period but the open forest cover has
decreased by 49%. The Grass/Shrub/Homestead cover has increased by 93% at the expense of mainly open forests.
4.5 Changes in Important cover classes
Figure 4,3 Changes of important cover classes from 1992 to 2001
4.6 Factors of forest degradation and deforestation and its spatial distribution
The following factors were identified as the causes for deforestation and forest degradation in Galgamuwa Area .
1.
2.
Expansion of shifting cultivation into undisturbed forests
Intensification of shifting cultivation with short fallow period
3.
4.
5.
6.
7.
Direct conversion of land cover to small scale-permanent agriculture
Direct conversion of the land covet to large-scale agriculture
Grazing
Illegal Felling
Encroachment of lands for residing
5.Conclusions and recommendations
Conclusions
•
Major changes were appeared in open forest areas which were heavily subjected to deforestation at an
alarming rate in Galgamuwa area.
•
The main reason for change is unsustainable agriculture practices.
•
Chena cultivation with very short fallow period is predominant.
Recommendations
•
The deforestation of forests in the dry zone has to be controlled which are heavily subjected to
unsustainable agriculture practices.
•
Forest protection strategies should be taken without hampering the livelihood of the rural community who
are highly depend on agriculture as their livelihood.
•
Implementation of properly designed REDD+ programs would brings substantial forest related benefits as
well as co-benefits such as poverty alleviation, reduce food insecurity and improve rural livelihoods.
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