SCS-CN (Soil Conservation Service Curve Number) 模型是广泛应用经验性水文模型，其模型参数的确定与空间尺度效应对径流模拟结果有着重要的影响。选取淮河上游为研究区，分析SCS-CN模型参数的敏感性并对模型进行改进，探讨了9种栅格尺度（100～2 000 m）下径流模拟结果的空间尺度效应。研究结果表明：SCSCN模型输入参数中，系数b的敏感性高于初损系数(λ)，将参数b值作为模型需要修正的参数；随着空间尺度增加，下垫面各要素的尺度变化使得参数b呈指数递减趋势；模型模拟精度的最佳空间尺度范围是250～500 m尺度。

The Soil Conservation Service Curve Number (SCS-CN) method is a widely used empirical hydrologic model.Determination of its parameters and spatial scale effect of parameters have important influences on the accuracy of runoff simulations.With the upstream area of Huaihe River as the research area,we analyzed the sensitivity of SCS-CN model [JP]parameters and further modified the model.Spatial scale effects of parameters were analyzed based on the runoff simulation results at nine spatial resolutions (100 m～2 000 m).The results show that the sensibility of the basin water storage capacity parameter b was higher than that of the initial abstraction ratio (λ),which should be calibrated in the model.The spatial resolutions of underlying surface features had an important effect on the calibrated parameter b,which showed an exponential decreasing trend as the pixel scale increased.The optimal spatial resolution of the modified SCS model was 250500 m.

国家自然科学基金（41801075）；中国科学院流域地理学重点实验室开放基金（WSGS2017009）；江苏省高等学校自然科学研究项目（18KJB170002）；中国博士后科学基金（2018M642349）