密云水库周边板栗林下不同水土保持措施效益评价

为探究密云水库周边板栗林下的土壤侵蚀规律以及适合于当地板栗林下的水土保持措施,选取发生于2021年8月的10次降雨事件作为研究样本,通过对比不同水土保持措施配置下产流产沙对降雨因子的响应,采用径流小区法对不同水保措施配置模式的水土保持效益进行了评价,进而筛选出水土保持效果更好的水土保持措施。结果表明:(1)在仅布设植被措施的条件下,减轻地表径流及泥沙运移作用最大的植被类型为卷柏,其次为自然坡面。(2)在同时布设植被措施与工程措施的条件下,工程措施相同、植被措施不同时,自然坡面减流减沙效果最好。工程措施不同、植被措施相同时,减流效果最好的为鱼鳞坑。(3)马齿苋+鱼鳞坑、自然坡面+鱼鳞坑的水土保持效益最佳。(4)对产流产沙量影响最大的因子为降雨量,其与径流量、泥沙量的相关系数分别为0.533,0.557(p<0.01)。由此可知,进行密云水库板栗林水土保持工作时,可优先种植卷柏、布设鱼鳞坑,或布设马齿苋+鱼鳞坑、自然坡面+鱼鳞坑等水土保持措施。

Evaluation on Benefits of Different Soil and Water Conservation Measures Under Castanea mollissima Bl. Forest Around Miyun Reservoir

In order to explore the soil erosion law of Castanea mollissima Bl. forest around Miyun Reservoir and the soil and water conservation measures suitable for local Castanea mollissima Bl. forest, the runoff plot method was used in this study. A total of 10 rainfall events occurred in August 2021 were selected as research samples. By comparing the response of sediment yield to rainfall factors under different water and soil conservation measures configuration, the benefits of soil and water conservation under different water and soil conservation measures configuration modes were evaluated, and the better soil and water conservation measures were selected. The results showed that:(1)Under the condition of vegetation arrangement only, the vegetation type of Selaginella tamariscina (P. Beauv.)Spring was the most important to reduce surface runoff and sediment transport, followed by the natural vegetation.(2)Under the condition of vegetation measures and engineering measures at the same time, the effect of sediment reduction on natural slope is the best when the engineering measures are the same and the vegetation measures are different. With different engineering measures and the same vegetation measures, the fish scale pit has the best effect on reducing flow.(3)Portulaca oleracea Linn. + fish scale pit and natural vegetation + fish scale pit had the best soil and water conservation benefits.(4)The most influential factor on sediment yield was rainfall, and the correlation coefficients with runoff and sediment yield were 0.533 and 0.557(p<0.01), respectively. In conclusion, the soil and water conservation measures such as planting Selaginella tamariscina (P. Beauv.)Spring and laying Portulaca oleracea Linn. + fish scale pit and natural vegetation + fish scale pit can be preferred in the soil and water conservation work of Castanea mollissima Bl. forest in Miyun Reservoir.