北京市门头沟地区不同水土保持措施的减水减沙效益

目的]评价北京市门头沟区水土保持措施的减水减沙效益,为区域水土保持措施的环境效益评估和土壤侵蚀预报参数选择提供依据。方法]根据2005—2009年北京市门头沟区龙凤岭水土保持科技示范园内8个径流小区的产流产沙数据,对不同水保措施的蓄水减沙效益进行分析。结果]坡长不同的径流小区年径流深和土壤侵蚀模数差异显著;梯田和树盘都具有很好的水土保持效益,其减水效益分别达到77.6%和81.0%,减沙效益分别达到84.3%和77.4%;梯田和树盘的影响因子分别为0.17和0.23,玉米、大豆和京白梨的影响因子分别为0.97,0.35和0.85。结论]研究区内工程措施较植物措施具有更好的水土保持效益,且两者相结合的水土保持效益最佳。

Benefits of Runoff and Sediment Reductions of Different Soil and Water Conservation Measures in Mentougou Area of Beijing City

Objective] The reductions of runoff and sediment by the soil and water conservation measures in Beijing mentougou district were evaluated in order to provide some references for soil erosion prediction and environmental effects evaluation upon soil and water conservation. Metheds] The benefits produced by different measures of soil and water conservation on reducing runoff and sediments were analyzed with the data from runoff plots(2005-2009) in the synthetic science demonstration park of soil and water conservation. Results] There existed significant differences of runoff depth and soil erosion modulus among the runoff plots with different length; The benefits of terrace and tree disk mensure had good effects of soil and water conservation, they reduced runoff about 77.6% and 81.0%, respectively; and reduced sediment about 84.3% and 77.4%, respectively. The biological impacting factors of terrace and tree disk mensure were 0.17 and 0.23, respectively; the engineering factors of corn, soybean and developing pear were 0.97, 0.35 and 0.85, respectively. Conclusion] As compared with biological measures, the benefits of engineering measures behaved better, and the combined benefits of the two measures would be the best in the study area.