Assessing drought fluctuations in dry season using the RDIst drought index for the Tien river estuary in the context of climate change

Abstract

The Tien estuary area is an important agricultural region of the Mekong Delta in Vietnam. In this area, the contribution of agriculture, forestry and fishery accounts for 35% of the region's
economic structure. In this economic group, cultivation is highly dependent on the degree of drought, especially in the dry season. The RDIst drought index was calculated using the
multivariate regression method, charts, maps and research to build a chart of drought changes over time for the Tien river estuary in RCP 4.5 emission scenarios and RCP 8.5. The results
show that the drought level ranges has increased over the years 1978 - 2017, from “mild drought” to “moderate drought”. The future drought level ranges may be one and a half times
larger than the drought during 1987 - 2017. The development of a drought scenario in the dry season in Tien estuary area has practical implications for policy makers.