基于SWAT模型和SUFI-2算法的石羊河流域月径流分布式模拟

Distributed Simulation of Monthly Runoff Using SWAT and SUFI-2 Algorithm in Shiyang River Basin

[目的]揭示石羊河流域径流量对土地利用变化的响应机制,为旱区水资源的合理配置和优化利用提供理论依据。[方法]利用石羊河流域DEM、气象、土壤、1995与2000年2期土地利用等数据,结合RS和GIS技术,构建SWAT分布式水文模型。基于SWAT模型及SUFI-2算法,对石羊河流域1980—2009年的月径流过程进行模拟。[结果]流域内1995与2000年土地利用均以耕地、林地、城乡工矿居民用地面积显著增加,草地、水域、未利用地减少为主;影响SWAT模型模拟效果前3位的参数分别是CN2,Alpha_Bf,Timp;校正期和验证期月流量的模拟值和实测值拟合较好,其Nash Suttcliffe系数Ens和相关系数R2均大于0.8,相对误差|Re|均小于10%。[结论]采用SUFI-2算法的SWAT模型在石羊河流域月径流模拟中具有一定程度的适宜性。

[Objective] The objective of this study is to reveal the response mechanism of runoff to land use changes in Shiyang river, in order to provide theoretical basis for reasonable allocation and optimization of water resources in arid areas.[Methods] Using various data derived from watershed DEM（digital elevation model）, land use, soil and meteorology and combined with GIS（geographic information system） and RS（remote sensing） technology, we developed a distributed hydrological model with SWAT（soil and water assessment tool）. Based on SWAT Model and SUFI-2 algorithm, we simulated monthly hydrograph in the Shiyang river basin from 1980 to 2009.[Results] The top three sensitive parameters influencing model were CN2, Alpha_Bf and Timp. The simulated values of calibration and validation periods were in accordance with actual values, Nash-Sutcliffe and R2 efficiency coefficient Ens were higher than 0.8, the relative errors｜Re｜were all less than 10%.[Conclusion] The result of the present work implied that the SWAT model of SUFI-2 algorithm is suitable for the simulation of the monthly runoff in Shiyang river basin.