喀斯特地区枯落物层对地表径流和土壤侵蚀的影响研究

以枯落物层质量和雨强为影响因素进行室内人工模拟降雨试验,探讨喀斯特地区枯落物层对地表径流和土壤侵蚀的影响规律。结果表明:(1)地表无枯落物覆盖的情形下,除雨强为40mm/h无地表径流外,其它雨强的情形均有产流;且均随着雨强的增加,初始产流时间提前,地表产流产沙量增大。(2)在有枯落物覆盖情形下,初始产流时间有所延缓,在40mm/h雨强下,枯落物层明显影响了地表径流的产生,但随着降雨强度的增加,减少径流效果越来越不明显;(3)枯落物覆盖对减少土壤流失效果显著,其中降雨强度为90mm/h时,枯落物保沙效率约99%,当降雨强度为140mm/h时,达到94%。研究表明,喀斯特地区枯落物层对延缓地表径流和减少土壤侵蚀具有重要作用。

Influence of Litter Coverage on Surface Runoff and Soil Erosion in Karst Area

The influence of litter coverage on surface runoff and soil erosion are significant, but the characteristics of this in theKarst area are not yet clear. By doing indoor artificial simulated rainfall experiment with taking quality of litter layer and rain intensityas its influencing factors, the influence of litter layer on surface runoff and soil erosion in Karst area were studied. The resultsshow that: (1) In the case of no litter coverage, there are no surface runoff. When rain intensity is 40 mm/h and there aresurface runoff with other higher rain intensity; And, with the increase of rain intensity, the initial runoff time advance and surfacerunoff and sand producing both increased. (2) In the case of there are litter coverage, the initial runoff time delay. When rain intensityis 40 mm/h, litter coverage influence initial surface runoff significantly, but the influence become less obvious when rain intensitybecome higher. (3) The effect that litter cover reduce soil erosion is significant. When rain intensity is 90 mm/h, the efficiencyof litter protecting sand is about 99%, and which is 94% when rain intensity is 140 mm/h. These results suggest that littercoverage in Karst area plays an important role in delaying surface runoff and reducing soil erosion.