ASSESSMENT OF CLIMATE CHANGE IMPACTS TO THE FLOW MODE OF BA RIVER BASIN

Abstract

The climate change scenario for Viet Nam has officially been published by the Ministry of Natural Resources and Environment in 2016, in which, the meteorological, climatic factors as well as hydrological regime and flows in the Ba river basin has indicated significant influences future changes. The research results show that the annual average, the highest and lowest average temperature tend to increase over time in two scenarios RCP4.5 and RCP8.5 at stations in the river basin. The changing trend of temperature entails an increase in evaporation, as well as the average annual rainfall at most stations tends to increase compared to the average annual rainfall of the baseline scenario. Nevertheless, the variation in rainfall between months and seasons tends to vary differently during the year. Specifically, the precipitation at stations shows increases in summer, autumn and decreases in winter and spring. However, the changing level among stations is different in the Ba river basin. The calculation results of the future flow in the Ba River basin reveal that the flow changes according to the months of each season. As a consequence, climate change scenarios have significant impacts on flows at An Khe and Cung Son station with the RCP4.5 and RCP8.5 scenario. The flow tends to decrease in dry season with largest reduction in June and July, and increase in flood season with the biggest flow in October and November. Therefore, the climate change impact on flows in dry season is greater than flood season.