The average contributive ratio affecting soil erosion by human activities is 65.6%, and at the same period the contributive ratio by runoff and rainfall is 34.4%.

• 通过数学模型定量的计算了大沙河流域人类活动对泥沙输移减少的贡献率平均为65.；6%25，而同期径流和降雨对泥沙减少的贡献率平均则为34