24. The Impact of Weather Variability on Rice and Aquaculture Production in the Mekong Delta

Understanding the impact of weather variability on current agricultural production systems is of great importance for the development of strategies for adapting to and mitigating the potential impact of climate change on food security in the Mekong Delta of Vietnam. This essay assesses the impact of short-term weather variability on rice and aquaculture production, documents ways in which farmers have dealt with weather anomalies, and suggests strategies to adapt to weather and climate variability in the future. Statistical series data (1990–2008) and information collected from previous projects were analyzed. The probabilities of occurrences of weather anomalies were calculated and multiple regression analyses were conducted to identify and estimate significant effects of various weather variables on yields of rice and fish or shrimp in both irrigated and coastal regions. The results showed that temperature and rainfall were the key weather variables that strongly influenced rice and shrimp production. Vulnerability levels to weather variability differed by crops, crop-development stages, cropping seasons, and regions. Rice production was found to be more sensitive to weather variability than was aquaculture, and shrimp production was more sensitive than was Pangasiuscatfish culture. The impacts became more severe during the early vegetative, flowering, and ripening stages of rice crops. The wet-season rice crop and the coastal region were more vulnerable to weather anomalies than the dry-season rice crop and the irrigated region, respectively. Local farmers have coped with temperature and rainfall anomalies in the past by applying appropriate farming techniques. Nonetheless, further measures for adapting to weather and climate variability are essential.