黄河中游河口镇—龙门区间属黄土高原区，是黄河流域水土流失最为严重的地区，也是黄河暴雨的多发区和主要产沙区。该区域的降雨产流方式属于典型的超渗产流，影响产流量和洪峰流量的主要因素是降雨强度，相同的日降雨量，时空分布不同，所产生的洪水量级也不同，不能用月或年的降雨量与径流量的相关关系来分析该区水沙关系的变化。随着水土保持等人类活动的影响，一般降雨情况下的径流量和来沙量明显减少，但当发生稀遇的大暴雨时，该区间仍可能出现大流量高含沙洪水。%Hekouzhen-Longmen reach on the middle reaches of the Yellow River belongs to Loess plateau area. This region is the most serious soil erosion area,as well as the storm and the main sediment producing area. Since this region is the typical runoff generation over infiltration area,the precipitation intensity is the main factor affecting the runoff discharge and peak flow. Due to the different spatial and temporal distributions,the magnitudes of flood vary greatly even under the same daily precipitation,no mention to analyze the relationship of water and sediment using the correlation between monthly or annual precipitation and runoff. The amount of runoff and sediment under general rainfall reduced with the influences of human activities such as soil and water conservation. However,it is still possible to have a big flood with high sediment concentration in this area when rare strong storm happened.
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