降雨-径流关系的区域规律

Regional pattern of rainfall-runoff relationship

以湿润、半湿润、半干旱以及干旱地区的15个典型流域为研究对象,分别建立其P+Pa～Rs相关关系,然后对其中3个嵌套流域的P+Pa～Rs相关关系进行分析与验证,比较各流域嵌套前后的P+Pa～Rs相关关系变化。采用相对平均误差和Cv为评定指标,对不同自然地理条件下降雨径流相关关系的区域性规律进行探讨。研究发现,嵌套流域的P+Pa～Rs相关关系线适用于该嵌套流域内的任何子流域。以蓄满产流为特点的降雨径流相关预报方法在湿润和半湿润地区的精度较高,在半干旱和干旱地区的精度较低。在半干旱流域,如果相对平均误差大于20%,Cv>1.1,流域的降雨-径流相关关系较差。

This study was conducted in 15 typical watersheds in humid,semi-humid,semi-arid,and arid regions.The correlation between P＋Pa and Rs for each watershed was established.Then,the correlations between P＋Pa and Rs for three nested watersheds were analyzed and verified,and the correlations before and after the watersheds were nested were compared.The relative mean error and Cv were regarded as evaluation indicators to explore the regional pattern of the rainfall-runoff relationship under different natural and geographical conditions.It was found that the correlation between P＋Pa and Rs was applicable to all sub-watersheds within the nested watersheds.The forecasting method of the rainfall-runoff relationship,which was based on the concept of runoff formation on repletion of storage,had higher precision in humid and semi-humid regions than in semi-arid and arid regions.In semi-arid watersheds,if the relative mean error was greater than 20% and Cv was greater than 1.1,the rainfall-runoff relationship was insignificant.