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黄河中游三門峽以上,占流域面积78％的黄土高原区,水土流失十分严重。这里雨量小而集中,又多暴雨,每年都有大量的土壤被水冲走,使肥沃的黄土高原变成瘦瘠的丘陵、沟壑,耕地面积不断縮小,土壤肥力日益降低,人民生活极为貧困。中游地区的土壤被水冲到河里,带到平緩的黄河下游又大量地沉积下来,使河身不断抬高,成为“地上河”,加重了整个黄河下游的危机,一遇較大洪水,就要发生决口、
The middle reaches of the Yellow River Sanmenxia above, accounting for 78% of the basin area of the Loess Plateau, soil erosion is very serious. The rainfall here is small and concentrated. There are also heavy rains. Every year, a large amount of soil is washed away by water. The fertile loess plateau is turned into a thin barren hills and ravines. The area of cultivated land is constantly shrinking, soil fertility is decreasing day by day, and the people’s living conditions are extremely poor. The middle reaches of the soil rushed into the river water, brought to the lower reaches of the Yellow River and a large number of sediments deposited, so that the river continued to rise, as a “ground river”, aggravating the crisis throughout the lower reaches of the Yellow River, a larger flood, It is necessary to burst the verdict,