喀斯特区石桥小流域不同条件的坡面径流的产流特征分析

Analysis on Runoff Yield Characteristics of Slope Surface Runoff under Different Control Measure Conditions in Shiqiao Small Watershed of Karst Area

[目的]研究喀斯特区石桥小流域不同条件的坡面径流的产流特征。[方法]在喀斯特区石桥小流域水土流失综合治理试验区,按不同治理措施条件设置了23个径流小区、3个固定植物群落样地,通过长期定位观测,收集了小流域2005年以来的基础数据和2006至2009年小流域综合治理实施后的监测数据,分析不同条件下坡面径流的产流产沙特征。[结果]不同坡度对径流深的影响依次为:坡度为5°时径流深为392 mm<坡度10°的404 mm<坡度15°的423 mm=坡度20°的423 mm<坡度25°的424 mm<坡度30°的438 mm<坡度40°的442 mm;不同坡度对土壤侵蚀模数影响依次为:坡度5°时土壤侵蚀模数为38.08 t/km2.a<坡度10°时的83.90 t/km2.a<坡度15°时的120.50 t/km2.a<坡度20°时的136.21 t/km2.a<坡度25°时的210.50 t/km2.a<坡度30°时的272.71 t/km2.a<坡度40°时的308.08 t/km2.a。[结论]径流深和土壤侵蚀模数均随坡度增加而增大;坡长与径流深密切相关。

[Objective] The aim was to study the runoff yield characteristics of the slope surface runoff under different control measure conditions in Shiqiao small watershed of Karst area.[Method] In the test area with the comprehensive control for waster and soil loss in Shiqiao small watershed of Karst area,23 runoff plots and 3 plots of fixed co mmunities were set up according to the different control measure conditions,through long-term positional observation,the basic data from 2005 and the monitoring data in 2006～2009 after conducting the comprehensive control of small watershed were selected and the runoff yield characteristics of the slope surface runoff under different control measure conditions were analyzed.[Result] The effects of different slope degree on the runoff depth were in order of the runoff depth of 392 mm at 5° 〈 that of 404 mm at 10° 〈 that of 423 mm at 15°= that of 423 mm at 20° 〈 that of 424 mm at 25° 〈 that of 438 mm at 30° 〈 that of 442 mm at 40°.The effects of different slope degree on the soil erosion modulus were in order of the soil erosion modulus of 38.08 t/km2·a at 5°〈 that of 83.90 t/km2·a at 10° 〈 that of 120.50 t/km2·a at 15° and that of 136.21 t/km2·a at 20° 〈 that of 210.50 t/km2·a at 25°〈 that of 272.71 t/km2·a at 30° 〈 that of 308.08 t/km2·a at 40°.[Conclusion] The runoff depth and the soil erosion modulus were all enhanced with the increase of the slope degree,and the slope length was closely correlated with the runoff depth.