Potential Impact of Climate Change on Area Affected by Waterlogging and Saline Groundwater and Ecohydrology Management in Northeast Thailand

Modeling approach was employed to predict potential impact of climate change on waterlogging and salinity distribution with the ecohydrology options for land management under the projected climate conditions in Huai Khamriam subwatershed in the northeastern region, Thailand. The prediction was simulated using the variable density groundwater model SEAWAT supported with recharge estimation model HELP3 under the projected weather data from PRECIS RCM scenario A2. As the result of the higher precipitation simulated by PRECIS RCM scenario A2, the predicted groundwater recharge was likely to be higher in the middle of this century onward. The areas affected by shallow saline groundwater were found to increase with the climate change scenario as well as for the base case. Based on scenario simulation, climate change did not have substantial impact on salinity distribution, but it was significant impact to the expansion of waterlogging areas. Management option using ecohydrology simulation approach was performed to reduce the recharge water to groundwater system, which consequently minimizes the impact of the higher precipitation in the future. The results indicated that establishment of the fast growing tree integrated with the shallow groundwater interception in the recharge areas could reduce the expansion of waterlogging and salinised areas under the climate change condition.