An Assessment of Future Climate Change and Water Condition in Upper Ping River Basin under A2 and B2 Scenarios during 2015–2074

Abstract

According to research findings, due to global warming, an increase in the average temperature has been observed in the mountainous areas of the world, including the northern part of Thailand, and this is likely to affect water resources. This study aims to  investigate the impact of climate change on the variations in temperature and rainfall in Mae Rim watershed (MRW), a tributary of Ping River in Northern Thailand under the progress of A2 and B2 emission scenarios during 2015–2074, and to review
and evaluate the water conditions in future climate scenarios in the watershed, with an emphasis on rain fed agriculture. The results indicated that, in both A2 and B2 scenarios, maximum and minimum temperature (Tmax and Tmin) during the 2045–
2074 period will be higher than the 2015–2044 period, and the Tmin under A2 scenario will be greater than the B2 scenario. As for rainfall conditions, less changes are expected to be found in the rainy season, but there is likely to be an increasing trend in
the dry season. Upon using the drought indices of the generalized monsoon index (GMI) and the standardized precipitation index (SPI) to evaluate for the water condition in the watershed, it was found that SPI and GMI values under both A2 and B2 scenarios
followed a similar trend. The drought events in the 2015–2044 period were found to be greater than the 2045–2074 period.