Impact of Climate Change on Rice Water Demand and Food Security： Case of Thailand and Vietnam

Water plays an important role in food production especially rice. Rice productivity depends greatly on sufficient water to meet evaporative demand and soil moisture. It is certain thalL rice, the most important crop of Thailand and Vietnam, is vulnerable to climate change. This paper proposes an analysis on the impact of climate on rice water requirement and food security in Thailand and Vietnam. Water demand, yield and production of rice were computed under the changed surface air temperature for three time slices, namely 2020s, 2050s and 2080s. Food security was analyzed from rice supply （calculated milled-rice product, rice stock, and imports） and demand （domestic uses from population growth, exports to world market, domestic seed and other uses）. The result showed that, under the higher surface air temperature scenario, water requirement office in Thailand and Vietnam could increase by 1.8 times in the end of the 21 st century. Production of rice dropped by declined yield. Thailand and Vietnam which is the world largest rice exporter in last decades will face the rice shortage in 2080s and 2030s respectively.