Download Rodel Lasco

Climate Change Impacts
and Potential Adaptation
Strategies in Watersheds
in the Philippines
Rodel D. Lasco
Professor
University of the Philippines
7 Steps of Climate Impacts and Adaptations
Assessment (UNEP, 1996)
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DEFINING PROBLEM
SELECT METHOD
TEST METHOD/SENSITIVITY
FORMULATE INPUTS ANDASSUMPTIONS
ASSESS BIOPHYSICAL AND
SOCIO-ECONOMIC IMPACTS
ASSESS AUTONOMOUS ADJUSTMENT
EVALUATE ADAPTATION STRATEGIES
APF Project Example (UNEP, 2003)
1. Scope project design
Engage
Stakeholders
2. Assess Current Vulnerability
3.Characterise Future Climate-related Risks
4. Develop Adaptation Strategy
5. Continue Adaptation
Process
Increase
Adaptive
capacity
Water Resources
Impacts of Climate Change on
Water Resources

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Increase in volume
Decrease in streamflow
Increase severity, frequency and
variability
Increase in soil erosion and
sedimentation
Increase in the demand for water
Table 1. Changes in precipitation, temperature, and runoff for Angat water
reservoir from three GCMs (based on 2xCO2)
GCM
CCCM
UKMO
GFDL
Change in
Precipitation
-6%
3%
15%
Source: Jose et al., 1996
Change in
Temperature
(°C)
+2.0
+3.1
+2.4
Change in
Runoff
-12%
5%
32%
Comparison of Observed and Calibrated Daily Streamflow
40.0000
35.0000
30.0000
Streamflow (m 2/s)
25.0000
20.0000
15.0000
10.0000
5.0000
0.0000
12/1/96
1/20/97
3/11/97
4/30/97
6/19/97
8/8/97
-5.0000
DATE
OBSERVED
CALIBRATED
9/27/97
11/16/97
1/5/98
2/24/98
Adaptation Strategies
Increase water supply
 Modify
vegetation
 Impoundment
 Reduce evaporation
 Water importation
Adaptation Strategies 2
Decrease water demand
 Decrease
water demanding activities
 Behavioral change
 Water reuse
 Recycling
 Economic instruments
Adaptation Strategies 3
Manage supply and demand
 Synchronize
cropping systems to
match water availability
 Maximize multiple use of water
Table 5 Supply and demand adaptation strategies for
the water resources sector of the Philippines
Supply Adaptation
Comprehensive watershed
management
Water allocation system and
procedures
Source: Cruz, 2002
Demand Adaptation
Enhanced irrigation efficiency
Low water use crops and
efficient farming practices
Recycling (reuse) of water
Improvement of monitoring and
forecasting systems for floods
and droughts
Water pricing policies and
structures
Enhanced awareness of
climatic change and variability
Forest resources
Impacts on Forest Resources in the
Philippines
most of the forest resources of the country
are in watershed areas
 tropical forests will likely expand as
temperature and precipitation increase
 Increased forest clearing due to:

 Droughts
and floods
 Inc population and dec in arable lands

Increase vulnerability to fires
T change may lead to a loss of a few
species of plants and animals
 changes in T and precipitation may result
to the outbreak of pests and diseases

Potential Adaptation Options
(IPCC, 2001)
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Forest management used to long term
decisions under uncertain future market and
biological conditions
Most adaptation will occur under managed
forests
Salvaging dead and dying timber
Replanting with species better suited to new
climate
Planting genetically modified species
Intensifying or decreasing management
Exotics vs indigenous species?
Biodiversity
conservation