黄土高原森林植被对流域径流的调节作用

对黄土高原腹地子午岭典型森林流域与非森林流域年径流变化的对比分析结果表明，森林流域径流年内分配比非森林流域相对均匀，汛期（6～9月）总径流量减少了8.9mm（葫芦河比蒲河）和7.1mm（合水川比东川），枯季径流与汛期降水及枯水季节降水的回归分析可见，森林植被能将雨季蓄积的部分降水转化为地下径流，增大枯水季节的径流量，但由于黄土区土层深度，植被蒸腾耗水强烈，森林植被对枯水期河川径流的调节作用十分有限，森林植被对10～12月径流总的补枯效应仅为1.69mm（葫芦河比蒲河）和0.5mm（合水川比东川），对1～4月径流无调节作用，说明森林植被拦蓄的大部分降雨被植物吸收利用，消耗于蒸腾，从而揭示了森林植被对河川径流的削洪补枯效应及其机理。

Regulation effect of forest vegetation on eatershed runoff in the Loss Plateau

The runoff and rainfall data of typical forested and non-forested watersheds in Ziwuling region,which is located in the hinterland of the Loess Plateau,were used to analyze their annual runoff variation comparatively. The result showed that the annual distribution of runoff in forested watersheds was uniform,compared with that in non-forested watersheds. The total runoff in flood season dereased by 8\^88 mm and 7\^1 mm. Regression analyses between runoff in dried-up season and rainfall in flood season or in dried-up season showed that the rainfall in flood season in forested watersheds could be changed into underground runoff by forest vegetation,and increased the runoff in dried-up season. The annual variation of runoff also indicated that the total effect of forest vegetation on dried-up runoff complement from October to December was 1\^69 mm and 0\^5 mm,and that from January to May was not significant.