秦岭-黄淮平原交界带河流水沙关系分析

ANALYSIS ON RIVERS′ DISCHARGE_SEDIMENT CORRELATIONS IN THE JOINT ZONE BETWEEN QINLING MOUNTAINS AND HUANGHUAI PLAIN

对秦岭－黄淮平原交界带河流水沙关系及其成因的分析表明，水沙年际变化趋势具有２个特征：各站径流过程曲线和输沙过程曲线走势大致相同；各站水沙变化趋势基本一致。年内水沙关系具有３个特征：相关曲线呈顺时针绳套关系；上半年内同流量的含沙量１～４（５）月小于５（６）月，呈现出逆时针型的相关趋势；５～６月份月平均径流量明显减少，而月平均含沙量明显增加。

Rivers′ discharge_sediment correlations are the judging indexes of the matching relations of rivers′ discharge and sediment.The study of the correlations is significant to light the sources,distributional laws of time and areas and depositional features of rivers′ discharge and sediment,and is helpful to make the measurements of realigning rivers.Using the methods of statistics,this paper analyses the features and its causes of formation of rivers′discharge_sediment correlations ( Q m- P m) in the joint zone between Qinling mountains and Huanghuai plain There are tow features about annual variation of discharge and sediment;the trends of the discharge hydrography and sediment hydrography of one river are similar;the trends of discharge and sediment variation of all rivers are similar too.There are three features about annual discharge_sediment correlations:the correlation diagram shows clockwise correlations; in the first semiyear,the silt content under the same discharge at January to April (May) is less than that at May(June)and shows counterclockwise correlations; from May to June ,the discharge decreases obviously,but the sediment increases clearly.