Final Technical Report - weADAPT

4.3.2 Change in future precipitation in lower Mekong River basin
The result from the simulation shows trend of increasing precipitation throughout
the region in the future. The increasing in precipitation will be prominent in Lao PDR as
well as Mekong River delta in Viet Nam. However, the length of rainy season seems to
be unchanged (see Appendix 1: Rainy Season Pattern at Selected Cities in lower Mekong
River Basin under Influence of Climate Change). The illustration below shows 10-year
average precipitation of the baseline condition and the future change under climate
condition at atmospheric CO 2 of 540ppm and 720ppm.
Figure 18: Average annual rainfall in the lower Mekong River region –
Baseline condition and future change.
The change in regional precipitation will vary from year to year under influence
of climate variability. In the wettest year of the decade, precipitation in Lao PDR will
increase by slightly over 10% under climate condition at atmospheric CO 2 of 540ppm
and almost 30% under climate condition at atmospheric CO 2 of 720ppm. The Mekong
River delta will also have higher annual rainfall by approximately 10%. However, on the
contrary, there seems to be almost no change on annual precipitation in Thailand
throughout the future under wet year scenario.
Final technical report – AIACC AS07 39