半湿润半干旱流域降雨径流关系及下垫面相似性

Research on rainfall-runoff relationship and similarity of underlying surface in semi-humid and semi-arid basins

以半湿润半干旱地区的5个流域为研究对象,建立并综合各流域降雨径流相关图,发现其中3个地理位置相距较远的流域可以采用一个共同的降雨径流关系图描述,误差在许可范围内且精度等级在乙级以上。采用相似性指标、相对均方根误差和地形指数分布曲线综合定量评价流域的下垫面条件,发现这3个流域的下垫面条件较为相似。结果表明,下垫面条件较为相似的流域,尽管地理位置相距较远,仍可以用一个共同的降雨径流相关图描述;相对均方根误差和地形指数分布曲线更适用于评价半湿润半干旱流域下垫面条件的相似性。

Rainfall-runoff relationships were developed and comprehensively assessed for five basins located in semi-humid and semi-arid areas. It was shown that a common rainfall-runoff relationship can represent that of three basins far away from one another. The error was allowable and the accuracy was high. Three evaluation metrics,including the similarity index,the relative root mean square error,and the topography index,were employed to quantitatively assess the similarity of the underlying surface in selected basins. Results show that a common rainfallrunoff relationship can describe different basins with similar underlying surface conditions,even though they are far from one another. It was concluded that the relative root mean square error and the distribution curve of the topography index are more suitable for assessing the similarity of the underlying surface in semi-humid and semi-arid basins.