多气候情景下中国主要粮食作物灌溉需求与发展潜力

Irrigation Demand and Development Potential of Major Food Crops in China under Multi-climate Scenarios

摘要:

灌溉是保障我国粮食增产稳产的重要途径,但未来多气候情景下主要粮食作物的灌溉需求及其发展潜力仍有待进一步研究。本研究选取SSP2-45、SSP3-70和SSP5-85 3种气候情景,利用降水量与作物需水量计算2030、2040、2050年中国耕地灌溉需求指数（IRI）;结合净灌溉需水量和可利用灌溉水资源量,量化主要粮食作物灌溉发展潜力。结果表明：2030-2050年,玉米、水稻和小麦灌溉需求均呈上升趋势,3种作物分别在SSP5-85、SSP3-70和SSP5-85情景下灌溉需求程度最高。空间分布上,西南和西北地区是3种主要粮食作物灌溉需求较高区域,此外华中地区玉米农田以及华北和华中地区小麦农田灌溉需求程度也较高。灌溉发展潜力由大到小依次为水稻、玉米、小麦。在3种气候情景下,玉米可充分灌溉地区占比从2030年的18.8%~21.8%降至2050年的4.0%~6.2%,集中收缩至川渝及华中地区;水稻可充分灌溉地区占比从30.0%~34.6%降至7.1%~8.2%,保留在长江中下游省份;小麦可充分灌溉地区占比从2.7%~4.1%降至1.5%,仅集中在西藏。针对灌溉需求与发展潜力的区域差异,玉米可通过推广节水技术提高用水效率缓解灌溉需求;水稻需通过加大农业水利工程建设,加强水资源精准分配;小麦主产区则需通过跨流域调水、节水技术集成和种植规模调控构建多维缓解机制。研究结果可为制定气候适应型粮食生产空间布局规划提供参考。

Abstract:

Irrigation plays a critical role in ensuring stable and increased grain production in China. However,under multiple future climate scenarios,the irrigation demands and development potential of major cereal crops remain insufficiently understood. The irrigation requirements and potential for maize,rice,and wheat in China under three climate scenarios,SSP2-45,SSP3-70,and SSP5-85 were evaluated by calculating the irrigation requirement index (IRI) based on precipitation and crop water requirements in 2030,2040 and 2050. In addition,irrigation development potential was quantified by integrating net irrigation requirements with regionally available irrigation water resources. Results indicated a consistent increase in irrigation demand for all three crops from 2030 to 2050. Among the scenarios,the highest irrigation demand was observed under SSP5-8.5 for maize and wheat,and under SSP3-70 for rice. Spatially,southwestern and northwestern China emerged as shared high-demand regions for all three crops. Moreover,maize farmlands in central China and wheat fields in both northern and central China exhibited particularly high irrigation requirements. Rice exhibited the greatest irrigation development potential,followed by maize and then wheat. From 2030 to 2050,the proportion of maize cropland with sufficient irrigation capacity declined from 18.8%~21.8% to 4.0%~6.2%,becoming increasingly confined to the Sichuan-Chongqing region and central China. For rice,this proportion dropped from 30.0%~34.6% to 7.1%~8.2%,with adequate irrigation maintained primarily in the middle and lower Yangtze River Basin. For wheat,it fell from 2.7%~4.1% to 1.5%,becoming limited to the Tibet Autonomous Region. Given these regional disparities,differentiated adaptation strategies were required. For maize,improving irrigation efficiency through water-saving technologies was key. Rice production should prioritize enhanced investment in agricultural water infrastructure and more precise allocation of water resources. In major wheat-producing areas,a multi-dimensional strategy integrating inter-basin water transfer,advanced water-saving technologies,and optimized planting scales was essential. These findings can provide scientific support for climate-adaptive spatial planning of cereal production in China.