Changes in flood characteristics of the Mekong River Basin

Flooding in the Lower Mekong Basin (LMB) is an essential driver for ecosystem productivity and biodiversity. The impacts of future climate changes and dam construction are important to understand the possible future alteration of flood characteristics and prevent the possible risk and damage. In this study, climate change impact showed an increase in annual peak discharge by 25%, 33%, and 40% and inundation extent by 19%, 29%, and 36% for 50-year, 100-year, and 1000-year return periods, respectively in the projected period (2051–2110) compared to the baseline period (1951–2010) under 4K increase scenario. The different sea surface temperature scenarios indicated an increase of flooding between 13% and 20% in the future (2075–99) over the baseline in 1979–2003. The future change in the upstream flow of the MRB from 10% to 50% would affect the reduction of peak discharge in the LMB by 8–39.8%, peak flood extent 5.7–32.5%, and peak flood volume 7.7–37.8%.