Assessment of meteorological drought in the Vietnamese Mekong delta in period 1985-2018

Abstract

Drought is one of a major natural disaster that causes tremendous damage to the ecological environment and social-economic in the Vietnamese Mekong Delta (VMD). Drought characteristics are invaluable knowledge for better management of water resources and agriculture production, especially under climate change context. This study investigated the spatiotemporal trend, intensity, duration, and frequency of meteorological droughts over VMD by using the Standardized Precipitation Evaporation Index (SPEI). The SPEI at multiple time scales (3, 6 and 12 months) are determined by using the monthly precipitation and temperature data between 1985 and 2018 obtained from ten meteorological stations in VMD namely Ba Tri, Cang Long, Soc Trang, Bac Lieu, Rach Gia, Ca Mau, Chau Doc, Can Tho, Cao Lanh, and My Tho. SPEI detected ten extreme drought events from 1985-2018 that matches with the historical extreme drought events reported in VMD. It means SPEI could be a useful indicator to support for drought management and mitigation in the future. The extreme drought event from October 2013 to September 2016 was the highest intensity and most prolonged duration from 1985-2018. The El Niño is considered to strongly influence on extreme drought events in VMD as all extreme drought events are highly associated with El Niño periods. The intensity, duration and frequency of drought events increased from 1985 to 2018. Drought events are more severe in VMD in recent years. Extreme drought also tends to cover for over VMD region. Adaption measures are essential to cope with drought disaster, especially in the agricultural and aquacultural sectors.