气候变化影响下澜湄流域下游水稻生产用水量模拟与分析

Simulation and Analysis of Water Consumption for Rice Production in Downstream Lancanng-Mekong River Basin under the Influence of Climate Change

农业用水是社会经济用水的主要行业,气候变化对农业用水的影响可能改变区域的水资源供需情势。以澜沧江-湄公河流域下游为研究区,基于ERA5-Land数据集和最新的CMIP6气候预测数据,选用SSP1-2.6、SSP2-4.5、SSP5-8.5三种排放情景,AquaCrop模型将非生产性土壤蒸发和生产性作物蒸腾分离,将水稻生长期内蒸腾总量作为水稻生产用水量,模拟了澜沧江-湄公河流域下游历史和未来时期水稻生产用水量,分析了水稻生产用水量的变化情况及其与温度、降水和CO_(2)浓度之间的相关关系。结果表明:澜沧江-湄公河流域下游水稻生产用水量在空间上表现为北多南少,总体呈现逐年减少趋势,且在SSP5-8.5情景下趋势更加明显。SSP5-8.5情景下的未来远期,澜沧江-湄公河流域下游水稻生产用水量将减少29.7%。与温度和降水相比,水稻生产用水量和CO_(2)浓度之间的相关性最强。SSP5-8.5情景下的未来远期,在泰国的相关系数为-0.875,其余国家各季度下的相关系数均小于-0.9。

Agriculture water consumption is the main sector of socio-economic water consumption.The impact of climate change on agriculture water consumption may change the situation of water supply and demand in a region.The downstream Lancang-Mekong River Basin is selected as the study area.Based on the ERA5-Land dataset and the latest CMIP6 climate projection data,three emission scenarios(SSP1-2.6,SSP2-4.5,and SSP5-8.5)are selected in this study,and the AquaCrop model is used to separate non-productive soil evaporation from productive crop transpiration.The total transpiration during the rice growth period is taken as water consumption for rice production,and the historical and subsequent water consumption for rice production in the downstream Lancang-Mekong River Basin is simulated.The changes in water consumption for rice production and its correlation with temperature,precipitation,and CO_(2)concentration are analyzed.The results show that the water consumption for rice production in the downstream Lancang-Mekong River Basin is manifested as more water consumption in the north and less water consumption in the south and has an overall decreasing trend annually.The trend is more obvious under the SSP5-8.5 scenario.In the SSP5-8.5 scenario,water consumption for rice production will reduce by 29.7%in the downstream Lancang-Mekong Basin in the far future.Compared with temperature and precipitation,the strongest correlation is found between water consumption for rice production and CO_(2)concentration.In the far future of the SSP5-8.5 scenario,the correlation coefficient is-0.875 in Thailand and less than-0.9 in other countries in all seasons.