Final Technical Report - weADAPT

5.2.2 Results: Impact of climate change on discharge of Mekong River’s tributaries in
Lao PDR and Thailand
After the VIC hydrological model had been calibrated, the future climate data
from climate scenario, which was simulated from CCAM climate model, was used as
input to simulate future tributary’s run-off under influence of climate change. As CCAM
climate model generates 10 years climate data at each atmospheric CO 2 concentration
condition (360ppm, 540ppm and 720ppm), climate data from the wettest year and driest
year of the decade were used in the hydrological simulation, in order to understand the
range of change in future hydrological condition in these watersheds.
The VIC model runs one grid cell at a time over a desired period (any subset of
the period spanned by the model forcing data), to produce time series of runoff, base flow,
evaporation, and other physical variables for each grid cell. These time series are then
routed by the VIC routing model to produce stream flow at points of interest in the
watershed. The simulation of tributary discharge was based on the calculation of run-off
at the river mouth before it flows into Mekong River main stem. The locations of the
routing are as per Figure 21 below:
(For the result of simulation of each sub-basin, see Appendix 3: Simulation Result
of Hydrological Regime of major Sub-basins of Mekong River in Lao PDR and Thailand
under Different Climate Scenarios).
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