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土地利用/覆被变化(LUCC)引起的径流响应研究不仅是流域水文学的一个热点,也是评估国家退耕还林战略实施效果的需要。选择黄土高原西部关川河流域为对象,依据流域出口大羊营水文站1993—2001年期间5—9月的径流资料,对SWAT模型进行参数率定。进而利用率定后的SWAT模型计算1980年、2000年两期土地利用下的径流量,分析土地利用变化的水文响应。结果表明:模拟率定期和验证期的决定系数R2和Nash-Sutcliffe效率系数分别为:0.85,0.78和0.86,0.84,说明模型对关川河流域汛期径流量模拟具有较高的适用性;关川河流域在实施了退耕还林草后,2000年较1980年耕地大面积减少而草地大面积增加。在气象条件相同的前提下,即气象输入数据不变的情况下,2000年土地利用下的月径流模拟值相比1980年土地利用下的月径流降低,9a内年均(5—9月份)径流量减少1.39m3/s。既在气候不变情况下,林草植被恢复将会引起流域径流趋于减少。
The study of runoff response caused by land use / cover change (LUCC) is not only a hot topic in basin hydrology, but also a need to evaluate the effectiveness of the national strategy of returning farmland to afforestation. Based on the runoff data of Dayangying Hydrometric Station during the period from 1993 to 2001 in the drainage area of the basin, the parameters of the SWAT model are determined. Then the SWAT model with the fixed rate was used to calculate the runoff of land use in 1980 and 2000 and to analyze the hydrological response of land use change. The results show that the coefficient of efficiency of R2 and Nash-Sutcliffe are 0.85, 0.78 and 0.86, 0.84, respectively. The results show that the model has high applicability to simulating flood season runoff in the Guanchuanhe River Basin. After the implementation of returning farmland to forest and grassland in the river basin, the area of arable land decreased in 2000 and the area of grassland increased in 2000. Under the same meteorological conditions, that is, the meteorological input data remain unchanged, the monthly runoff simulated value under land use in 2000 is lower than the monthly runoff under land use in 1980, and the average annual (May-September) Reduced runoff 1.39m3 / s. Both in the same climate, the restoration of forest and grass vegetation will lead to runoff tends to reduce.