Impact of water resources variation on winter–spring rice yield in the upper Vietnamese Mekong Delta: A case study of An Giang Province

Natural and socio-economic development under climate change has affected the distribution of surface water resources (SWRs) in many deltas worldwide. The dynamics in the SWRs has negatively impacted agricultural production, which is one of the growing issues in the Vietnamese Mekong Delta (VMD) as the national rice bowl. Our study aims to assess SWR dynamics related to its effects on rice production in the upper VMD. We applied Mann–Kendall, linear regression and Pettit tests to statistically determine trends of SWRs in terms of water level, total water volume and rainfall in 1996–2020. The findings show that high water level trends decrease significantly after 2011, and this reduction has been due to climate variability and dam development upstream of the Mekong River. Moreover, rice yield data analysis from 1996 to 2020 indicated a decreasing trend in the yield of the winter–spring rice crop in the An Phu district of An Giang Province after 2011. Our interviews with 33 water experts and 90 local farmers revealed 80% agreement that the decline in water resources has affected rice yield. This study provides empirical evidence and a platform for knowledge sharing and learning across different deltas and initiatives worldwide.