Analysis of flood and drought variability in the Mekong River Delta in the last 20 years.

Abstract

The Mekong River Delta in Vietnam is the region receiving the whole Mekong River’s water before flowing into the East Sea. Climatically, this area has only two distinct seasons: the rainy season and the dry season. The last months of these two seasons are the extreme events of river hydrology: floods and drought occurred. These meteorological and hydrological features greatly affect not only agriculture and aquaculture cultivation, but also the residential habits throughout the delta.
Over the past two decades, the Mekong River basin in general and the Mekong Delta in particular, have witnessed many extremely climatic phenomena, breaking the previously recorded meteorological and hydrological regulations. This paper analyses some of the climate changes, focusing on the past 20 years’ data on flooding peak levels and drought situation causing saline intrusion in the delta. The results show that, over the past two decades, there has been a trend in reducing the number of years with heavy floods and increasing the number of small flood years, and the salinity isolation have been deeper in the coastal areas.