三峡库区坡地林草植被阻止降雨径流侵蚀

为了研究林草调控措施对坡面降雨径流侵蚀的影响及其对坡面侵蚀动力的调控效果,该文在重庆开县选择栾树+黄花槐、传统农作、植物篱、封山育林、自然恢复、经济林以及裸地对照7种林草治理措施并修建标准径流小区,通过观测产流产沙状况,分析比较其水土流失特征。结果表明:林草调控措施深刻影响降雨侵蚀动力,并对坡耕地径流侵蚀量产生较大的影响。林草调控措施中,均以裸地对照样地产流、产沙量最大,而以栾树+黄花槐和植物篱措施的产流、产沙最小,水土保持效果最为明显。以洪峰流量模数和径流深表示的坡面径流侵蚀功率与侵蚀产沙量呈正相关关系,说明径流侵蚀功率能够较好的模拟侵蚀动力;以径流侵蚀功率/侵蚀量表示不同林草调控措施对侵蚀结果的影响,可以成为评价植被侵蚀动力调控效应的指标。在未来三峡库区植被恢复与生态环境建设过程中,通过各种林草调控措施的逐步实施,重视和发展植被的恢复与重建,对于当地生态环境的改善和水土流失的治理具有重要的意义。

Effects of slope forest and grass vegetation on reducing rainfall-runoff erosivity in Three Gorges Reservoir Region

The study on the relationship between biological regulating measures and soil and water losses, is of great significance to the soil and water conservation and the ecological reconstruction of the environment in Three Gorges Reservoir Area. Seven standard runoff plots were built on the seven natural slopes with different biological regulating measures for observing the runoff and sediment yield produced under these slope biological regulating measures (Koelreuteria bipinnata + Cassia suffruticasa, traditional planting, hedgerows, closed forest, natural restoration, economic forest and control plot). The results showed that the treatments of biological regulating measures affected runoff and sediment generation significantly. Runoff and sediment yield reduced rapidly with the biological regulating measures, the values in control plot were higher, but lower in Koelreuteria bipinnata + Cassia suffruticasa plot and hedgerows plot. Runoff erosion power was positively related with sediment yield. It was suggested that runoff erosion power can be used to better simulate erosion dynamics. The presentation of the effect of different biological regulating measures on erosion by the ratio of runoff erosion power/erosion volume reflects the existence of critical biological regulating measures, which can be used to evaluate regulatory effects of biological regulating measures on soil erosion dynamics.