陕北黄土邱陵区面积为八○、○○○平方公里,包括绥德、榆林、延安三个专区和宝鸡、渭南两个专区的一部份。这些地区由于长期地遭受严重的水土流失,地形已成为光山秃岭,千沟万壑。根据绥德韮园沟大型土坝四年观测记录,平均每年 Northern Shaanxi Qiu Ling area covers an area of ​​80,000 square kilometers, including Suide, Yulin, Yan’an three special areas and part of Baoji, Weinan two prefectures. Due to the long-term serious soil erosion in these areas, the terrain has become a bald ridge of mountains and valleys. According to the Suide Jiuyougou large earth dam four-year observation records, an average of each year