石羊河流域水文要素变化特征分析

选取石羊河流域永昌、肃南、天祝、古浪、武威、民勤6个气象站1961～2000年的降水、蒸发资料及黄羊河水库、杂木寺、南营、四沟嘴、古浪、沙沟寺、插剑门、大靖峡水库、红崖山水库9个水文站1961～2000年的径流资料,运用距平分析法和Kendall秩次相关法对流域水文要素的时程变化特征进行了分析。研究结果表明:石羊河流域降水、蒸发年内分配不均,但年际变化不大;降水集中于6～9月份,占全年的65%以上,蒸发集中于5～8月份,占全年的54%。径流的年内分配与降水一致,集中于6～9月,占全年的58%。径流的年际变化呈明显减少趋势,尤以红崖山水库入库流量减少最为显著。

Analysis of the Variety Characteristics of Hydrologic Factors in Shiyang River Basin

Based on the data of rainfall and evaporation from 6 observatories of Yongchang,Sunan,Tianzhu,Gulang,Wuwei and Minqin in the Shiyang River Basin from 1961 to 2000 and the data of river-flow from 9 hydrometric stations of Huangyanghe Reservoir,Zamusi,Nanying,Sigouzui,Gulang,Shagousi,Chajianmen,Dajingxia Reservoir and Hongyashan Reservoir from 1961 to 2000,the variety characteristics of hydrologic factors in the Shiyang River Basin were analyzed by using the method of analyzing the departure from the average and Kendall correlated analytical method.The results shows that there is uneven distribution of rainfall and evaporation in a year,but there is no large change among years.Nearly about 65% of the rainfall in whole the year concentrate from June to September,while about 54% of evaporation in the whole year concentrate from May to August..The distribution of river-flow in a year correspond with the rainfall,concentrating from June to September,which is about 58% of that in the whole year.The variety among years presents obvious decreasing trend,especially the inflow to the Hongyashan Reservoir.