矿山废弃地灌草植被不同层次的水土保持效应

在北京市首云铁矿选择灌草覆盖的弃渣坡面,通过野外人工模拟降雨的方法,分析了在雨强0.5mm/min,连续30 min的人工降雨条件下,植被不同层次(灌木层地上和地下部分、草本层地上和地下部分)的水土保持效应.结果表明,植被在水土保持过程中发挥着重要的作用,可以减少57.65%的地表径流和93.55%的土壤流失.灌木的蓄水效应和减蚀效应分别是草本植物的7.4倍和30.9倍,这不仅与灌木在植被中所占的比重大有关,还与其形态结构特征有关.植物地上部分的蓄水效应是地下部分的1.65倍,说明植物的地上部分在保水方面发挥的作用较大.而地下部分的减蚀效应是地上部分的1.52倍,说明植物地下部分在固土方面发挥的作用更大.

Soil and Water Conservation Effects of Shrub-grass Vegetation at Different Levels on a Mining Wasteland

Soil and water conservation effects of the vegetation at different levels(aboveground and underground parts of shrub and herb layers) were investigated under field simulated rainfall of 0.5 mm/min rainfall intensity and successive 30 min rainfall duration on spoil slope with shrub-grass covered in Beijing Shouyun Iron district. Results showed that vegetation which plays an important role in soil and water conservation reduced surface runoff of 57.65% and soil loss of 93.55%. The effects of impoundment and erosion reduction by shrubs were 7.4 times and 30.9 times the effects by herbs,respectively. This was not only relevant to major ratio of shrubs in the vegetation,but also relevant to morphological structure of shrubs. The impoundment effect of the aboveground part of vegetation was 1.65 times the underground part of vegetation,which indicated that the aboveground part of vegetation played a great role in water conservation. While the erosion reduction effect of the underground part of vegetation was 1.52 times the aboveground part of vegetation,which illuminated that the underground part of vegetation played a great role in soil reinforcement.