中德合作交流项目“城市洪涝高分辨率数值模拟和预报方法” (M-0427)； 国家自然科学基金项目(52079106，52009104)； 陕西省重点研发计划(2021SF-484)
[目的] 研究渭河中上游流域不同土地利用情景下径流的响应规律，为渭河中上游流域的发展规划及水资源管理提供科学支撑。[方法] 基于1980—2020年土地利用数据，分析流域40 a的土地利用变化特征，并结合SWAT模型，设置5种历史土地利用情景、两种综合土地利用情景和3种极端土地利用情景，探究径流在不同土地利用情境下的响应。[结果] ①流域40 a间耕地、水域及未利用土地面积逐渐减小，林地、草地和居民用地面积逐渐增加。②1980—2020年共5个时期模拟年均径流深分别为72.24，72.27，72.31，71.86，72.25 mm，退耕还林、退耕还草、耕地型、林地型及草地型模拟年均径流深分别为68.59，69.70，72.60，64.81，66.82 mm。[结论] 40 a间土地利用类型的变化对渭河中上游流域径流的影响小于10%；退耕还林、退耕还草对径流主要起抑制作用。在3个极端土地利用情境下径流大小为：耕地型＞草地型＞林地型，且耕地型与林地型、草地型情境下的差异明显。
[Objective] The response law for runoff under different land use scenarios in the middle and upper reaches of the Weihe River was analyzed in order to provide scientific support for development planning and water resource management of the middle and upper reaches of the Weihe River. [Methods] Based on land use data from 1980 to 2020, the characteristics of land use change in the Weihe River basin over the past 40 years were analyzed. the SWAT model was used to set up five historical land use scenarios, two comprehensive land use scenarios, and three extreme land use scenarios in order to determine the response of runoff under different land use scenarios. [Results] ① During the past 40 years, the areas of cultivated land, water, and unused land gradually decreased, while the areas of forest land, grassland, and residential land gradually increased. ② From 1980 to 2020, the simulated annual average runoff depths were 72.24, 72.27, 72.31, 71.86 mm, and 72.25 mm in five periods, respectively. The average annual runoff depths were 68.59 mm, 69.70, 72.60, 64.81, and 66.82 mm, respectively. [Conclusion] The SWAT model had good adaptability for the middle and upper reaches of the Weihe River. The impact of land use type changes on runoff in the middle and upper reaches of the Weihe River was less than 10%. Returning farmland to forest and grassland was mainly responsible for inhibiting runoff. In the three extreme land use scenarios, runoff size followed the order of cultivated land type＞grassland type＞forest type, and the differences between cultivated land and forestland and grassland were obvious.