论文部分内容阅读
近几年,黄河来沙量锐减原因成为人们普遍关注的热点问题。本文以天然产沙量约占流域入黄沙量90%的黄河潼关以上主要产沙区为研究范围,优选了降雨因子和模型的函数型式,改进或构建了各支流在天然时期的降雨~产沙相关模型,进而分析了该区近35年不同时段的降雨和下垫面因素的减沙作用。研究表明,若以各支流1956—1975年前后的降雨-产沙响应关系为基准,1980年以来下垫面减沙作用越来越大,近十多年最为突出。近10年研究区降雨总体偏丰、其中近5年明显偏丰,因此降雨变化不是黄河该时段来沙锐减的原因;2005—2014年和2010—2014年,下垫面因素的实际总减沙量分别为13.87~15.45亿t/a和15.70~18.70亿t/a。
In recent years, the sharp drop in the Yellow River sediment has become a hot issue of general concern. In this paper, the natural sediment yield of about 90% of the sediment into the Yellow River above the Tongguan above the main sand production area for the study, the preferred rainfall factors and model function type, improve or build the tributaries of natural rainfall Sand correlation model, and then analyzed the sediment reduction effect of rainfall and underlying factors in different periods in the past 35 years. The study shows that if the correlation between rainfall and sediment response of each tributary from 1956 to 1975 is taken as reference, the sediment reduction effect of underlying surface will be more and more obvious since 1980, which is the most prominent in recent ten years. In the past 10 years, the rainfall in the study area was generally over abundance, of which the past five years were obviously over-abundance. Therefore, the change of rainfall was not the reason for the sharp drop of the Yellow River sand during this period. In 2005-2014 and 2010-2014, the actual total reduction The amount of sediment is 13.87-1545 million t / a and 15.70-1.87 billion t / a respectively.