Desktop Study on - Regional Climate Change Adaptation ...

<strong>Desktop</strong> <strong>Study</strong>
evapotranspiration. The fresh groundwater storage
is estimated at 5,000 billion m3 (MOSTE, 2000)
Range of Studies Reviewed and
Methods Applied
A range of studies and applied methods were
reviewed for analyzing the Indonesian water sectors’
situation in view of climate change and are shortly
presented in the following.
A regional hydrologic-atmospheric model of
Peninsular Malaysia called ‘Regional Hydroclimate
Model of Peninsular Malaysia (RegHCM-PM)’ was
developed by the National Hydraulic Research
Institute of Malaysia (NHRIM) to downscale the
global climate change simulation data (Canadian
GCM1 current and future climate data) that are at very
coarse resolution (~ 410km), to Peninsular Malaysia
at fine spatial resolution (~9km) and to be able to
quantify the impact of the complex topographical
and land surface features of Peninsular Malaysia
on its climate conditions (Zakaria and Jamalluddin,
2007).
In the climate change scenarios developed by
the Malaysian Meteorological Department, the
impact of global warming on the monsoons over
the Malaysian region is studied by using twelve
coupled Atmosphere-Ocean General Circulation
Models (AOGCMs). However, for temperature and
rainfall analysis, only nine different AOGCMs were
chosen in this study. The AOGCMs used in this study
are from the contribution of the Coupled Model
Inter-comparison Project (CMIP) to the IPCC 4th
Assessment Report. The AOGMs and the institution
which developed them are: CNCM3 by Meteo-France,
MRCGCM by the Meteorological Research Institute
from Japan, FGOALS by the Institute of Atmospheric
Physics from China, FCM20 by NOAA/GFDL from
USA, HADCM3 by Hadley Centre from UK, MIHR by
JAMSTEC form Japan, MPEH5 by Max Plank Institute
from Germany, NCPCM by NCAR form USA, CSMK3
by CSIRO Atmospheric Research, CGMR by Canadian
Centre for Climate Modelling & Analysis, and MIMR
by University Of Tokyo. All the models start their
integration from the ‘20th Century Climate in
Coupled Model’ (20C3M) run, in which the level of
anthropogenic forcing is based on historical data of
the late 19th century through the 20th century.
Impacts on the Water Sector
The Initial National Communication gathers some
of the main impacts on water resources because of
the change on climate that result for the data of the
models described before. Under the 2 x CO2 scenarios
there may be an increase of 10% to 20% in storm
magnitude that would result in double designed
storm frequency or return period. These preliminary
results provide at least a qualitative trend of the
climate change induced impact on rainfall intensities
that will end up in more frequency and severity of
floods due to extreme events. Taking into account
that erosion and sedimentation rates increase during
and after strong storm, there will be a higher risk
of slope failures of riverbanks and hills, faster rate
of sedimentation of reservoirs and channels, and
more extensive loss of soil nutrients. For example, in
the Kelantan River, a 20% of increase on discharge
would cause a sediment load increase of 33%. In
Sabah and Sarawak, an increase of 20% in high flow
magnitudes and frequencies will translate to a 44%
surge in sedimentation loads (MOSTE, 2000). There
are aspects of land use and climate change in the long
term such as, soil erosion or chemical poisoning that
combined with some others related to daily quality
of life such as, water pollution, shortage of food or
resources, produce effects difficult to predict such
as, natural and environmental catastrophes in recent
times- floods, landslides, long periods of drought etc.
The floods incidence happened in the southern states
of Malaysia, involving Negeri Sembilan, Melaka,
Johor and Pahang. Johor was the worst affected,
heavy rainfall in Southern Malaysia, was exaggerated
because of with poor drainage systems. Without
adequate measures floods may cause displacement
of people, damaged infrastructures and losses of
agricultural production from eroded and inundated
lands (Kamal, 2007).
Annual rainfall will increase a 10% for Kelantan,
Terengganu and Pahang and decrease 5% for Selangor
and Johor. Also is expected an increase in mean
monthly rainfall over the North East Coastal region
and over Kelantan while over Selangor and Johor
a decrease is expected (Zakaria and Jamalluddin,
2007). Because of changes in climate conditions, the
total surface runoff will also be affected inducing at
the same time variations on water availability. In the
Initial National Communication is set that for a 1°C
increase in temperature there is an increase in the
potential evapotranspiration (PET) of between 3%
and 9%; for a 3°C the PET is expected to rise from 9%
to 13%, which represents potentially about 170 mm
of extra moisture loss. In wet months, for an increase
of 1ºC to 3ºC, the long-term runoff will be reduced
between 1% and 5% and between 2% and 17%,
respectively, but in dry months, the scenarios show
a reduction between 1% and 16% and between 1%
and 24% respectively. With a reduction in rainfall
of 10%, the runoff will be reduce between 12% and
142