黄丘一区水土保持单项措施及综合治理减水减沙效益研究

通过对大量实测与调查资料进行分析,得出了水土保持单项措施水平梯田、造林、种草的减水效益分别为86.0％、63.5％、33.7％,减沙效益分别为94.8％、83.0％、74.6％,年拦蓄径流量分别为213m~3/hm~2、154m~3/hm~2、105m~3/hm~2,年拦蓄泥沙量为94.0t/hm~2、63t/hm~2、45t/hm~2。淤地坝是主要的治沟工程措施,平均每公顷坝地的拦泥指标为6万m~3。11条综合治理的小流域,无论其治理措施实施年代的长短,均具有明显的减水减沙效益,减水效益平均为45.41％,减沙效益平均为59.22％。

A Study on the Benefits of Reduction of Water and Sediment Runoff of Individual Measure and Cmprehensive Harnessment in the First Subregion of Gullied Hilly Loess Region

Through analysis of large amount of materials both measured on the spot and investigated, the reduction of water runoff of individual soil and water conservation measure of bench terraces, afforestation and planting grasses are 86. 0%, 63. 5%, 33. 7% respectively, reduction of sediment load are 94. 8%, 83. 0%, 74. 6% respectively. The annual retained water runoff are 213m~3/hm~2, 154m~3/hm~2, 105m~3/hm~2 respectively, and the annual retained sediment are 94t/hm~2, 63t/hm~2, 45t/hm2 respectively. The average quota of sediment traped by desilting dam is 60000m~3 per hectare of desilted land. In the 11 comprehensive controlled small watersheds, no matter how long these control measures are carried out, obvious benefits of reduction of water and sediment runoff are obtained. In average, water runoff is reduced by 45. 4%, and sediment is re- ducedby 59.2%.