水土保持措施对密云板栗林坡面产流产沙的影响

以北京市密云板栗林为研究对象,设置植物措施、工程措施和植物+工程措施处理(裸地作为对照)分析不同水土保持单一措施及其组合措施对坡面产流产沙及水沙关系的影响,以期为密云区板栗林水土保持措施的制定提供科学依据。结果表明:植物措施方面,卷柏处理的减流率和减沙率分别为62.8%,88.3%,减流减沙效果优于椰丝毯、狗牙根和结缕草处理;工程措施方面,水平阶处理的减流率和减沙率分别为83.2%,92.9%,减流减沙效果优于鱼鳞坑处理;组合措施方面,水平阶+卷柏处理的减流率和减沙率分别为86.7%,96.1%,水土流失防治效果最好。不同水土保持措施对径流量和产沙量的影响还取决于降雨量和降雨强度。综上,考虑到植物+工程组合措施的减流减沙效果略强于工程措施,但差异不显著,因此在综合考虑经济效益和生态效益的基础上,建议采用工程措施进行板栗林水土流失防治,具体采取水平阶作为研究区的主要水土保持措施。

Effects of Soil and Water Conservation Measures on Runoff and Sediment Yield on Slopes of Miyun Chestnut Forest

Taking the chestnut forest in Miyun District of Beijing as the research object, plant measures, engineering measures, and plant + engineering measures were set up to analyze the impact of different single and combined soil and water conservation measures on the runoff and sediment yield and the relationship between runoff and sediment on the slope, with the aim of providing scientific basis for the formulation of soil and water conservation measures in chestnut forests in Miyun District. The results showed that in terms of plant measures, the runoff and sediment reduction rate of Selaginella tamariscina treatment was 62.8% and 88.3%, respectively. The reduction effect of runoff and sediment of S. tamariscina treatment was better than that of coconut silk blanket, Cynodon dactylon and Zoysia japonica treatment. In terms of engineering measures, the runoff and sediment reduction rate of level terrace treatment was 83.2% and 92.9%, respectively, which was higher than that of fish-scale pits treatment. In terms of the combined measures, the runoff and sediment reduction rate of level terrace + S. tamariscina treatment was 86.7% and 96.1%, respectively, indicating the best effect of soil erosion prevention and control. The impact of different measures on runoff and sediment also depended on rainfall amount and intensity. In summary, the combined measures plant + engineering measures had slightly stronger control effects of runoff and sediment than engineering measures, but the difference was not significant. Therefore, on the basis of comprehensive consideration of economic and ecological benefits, it was recommended that engineering measures should be adopted to prevent and control soil and water loss in chestnut forests in this study area. Specifically, level terrace should be taken as the main soil and water conservation measures in the study area.