陝北地区邱陵起伏,雨季集中,植被缺乏,耕作粗放,无一定的轮作制度,并对水土保持措施推广不夠普遍,因此造成严重的水土流失与干旱,土壤肥力逐漸减低,农作物产量不高。尤其境內黃河支流很多,夏季暴雨后发生洪水,泥沙大量流失,其中以北洛河,无定河,延河最为严重。 The ups and downs of the hilly area in northern Shaanxi, the concentrated rainy seasons, the lack of vegetation, the extensive cultivation and the lack of a certain crop rotation system have not popularized the soil and water conservation measures. As a result, serious soil erosion and droughts, soil fertility and crop yields are not high. In particular, there are many tributaries of the Yellow River in the country. Floods and heavy losses of sediment occurred after the heavy rains in summer, of which the most serious were the North Luohe River, the Wuding River and the Yanhe River.