Assessment of Potential Evapotranspiration in the Future over Northern Thailand
Keywords:
Potential evapotranspiration, Climate change, Regional climate modelAbstract
In this research, potential evapotranspiration (PET) changes across northern Thailand were estimated using the Thornthwaite method. The Weather Research and Forecasting (WRF) model was driven by the Community Earth System Model (CESM) during the baseline period (2000-2004) and the projected period (2050-2054) under the Coupled Model Intercomparison Project 5 (CMIP5). The results reveal that the simulated monthly mean temperatures were underestimated relative to the observed data across all stations, with root mean square errors (RMSE) ranging from 0.73 to 3.14°C and correlation coefficients (R) ranging from 0.72 to 0.89. The monthly potential evapotranspiration over northern Thailand peaks in April, corresponding to the summer months, a pattern consistent across both current climate conditions and future projections. Specifically, the lower northern region shows higher monthly potential evapotranspiration during the summer compared to other provinces in the region. Future projections under the RCP8.5 scenario indicate a consistent increase in monthly potential evapotranspiration across all study stations, implying an elevated risk of drought conditions relative to the current climate.
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