径流小区集流桶含沙量测量方法研究

径流小区是研究坡面土壤侵蚀的重要观测手段,含沙量的测定是准确计算土壤流失量的关键。用传统方法很难测到粗颗粒,使测到的含沙量明显偏小。试验在密云石匣示范区坡面径流试验小区下面的分流桶内进行,用人工在径流桶内加沙的方法制备约4,12,30,60,90,120kg/m3不同含沙量。然后分别用传统测量方法和改进的分层测量方法进行了粗沙区的含沙量观测,并将观测结果与实际含沙量进行了对比。研究结果表明,传统测量方法所测得的含沙量远小于实际含沙量,平均相对误差为-83.05%;而分层测量所测得的含沙量基本上接近于实际值,平均相对误差为-2.77%。

Sediment Content Measurement in Collecting Tanks of Runoff Plots

Runoff plots are very important for soil erosion study. The measurement of sediment content is a key part in the process of soil loss calculation. It is so difficult for traditional measurement method to measure sandy particle that sediment content measured is apparently less than true value. The study was conducted in collecting tank at Shixia watershed, Miyun county of Beijing city. The six different sediment content including about 4, 12, 30, 60, 90, 120 kg/m~3 were put into collecting tank with about 0.7 m deep water, respectively. The traditional measurement method and layered measurement were used to measure sand content. The measurement results of these two methods were compared with true sand content. The results show that traditional measurement method underestimated sand content and the relative difference was (-83.05%), while layered measurement method can precisely measure sand content and the relative difference was -2.77%.