基于水土保持的延河流域治理水文响应模型

 以建立一种科学的较简单的评价方法为目的,以延河流域水文站20世纪50-80年代30余年降水、径流、水土保持主体措施面积(梯田、造林、种草、淤堤坝)资料为基础,运用相关分析、因子分析等方法,建立了流域雨量站各月降雨量权重指标体系、流域4大水土保持措施面积权重指标值,并构建了以水土保持面积指标、降雨量指标为参数的流域水文响应评价模型,进而分析水土保持措施对流域径流量的效应。结果表明:水土保持措施拦蓄径流量的作用,在过去30余年逐渐增强,水土保持措施拦蓄径流量,占降雨径流量各时段平均值为6.48％。各年代分别为:50年代0.74％,60年代3.11％,70年代8.84％,80年代16.52％。20世纪70年代,由于降雨量减少引起的径流量减少幅度为12.9％,80年代为14.0％。而水土保持措施加强与降雨量减少,使径流量在20世纪70年代较50-60年代为基期减少了20.6％,80年代初则减少了28.2％。

Hydrological Response Model On Soil and Water Conservation in Yanhe River Basin

Based on data of Yanhe river basin's hydrological stations on precipitation, runoff, soil and water conservation measure area sizes (terrace land, forestation land, grassed land, and silted dam land) from 1950s'-1980s' , the basin's monthly precipitation station weightiness indexes and the four main measure areas weightiness indexes through correlation analysis and factor analysis were built. Authors then calculated out the composed area of soil and water conservation measures and then basin' s average precipitation. Then a model based on the two new factors had been set out which is the hydrological response model on soil and water conservation. Through the model the runoff of Yanhe River responded on soil and water conservation activity had been analyzed. The result shows that the soil and water conservation activity could store more water of rainfall therefore reduce runoff. This function had been being stronger and obvious in the latest 30 years from 1950s'-1980s' . The stored water accounted for 6.48% of precipitation induced runoff amount on average of historical period. The decade averages are respectively as 0.7 % in 50s' , and 3.11% in 60s' , 8.84 % in 70s' , and 16.52% in 80s' . In 70s' of 20th century the reduction of precipitation resulted in a 12.9% down in runoff, that amount increased to 14% in 80s' . The strengthen of soil and water conservation combined with the decreased precipitation brought out further decrease in runoff of river that would be 20.6% in 70s and 28.2% in 80s' respectively comparing to runoff in 50-60s' in 20th century.