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坡面侵蚀临界水流能量是反映土壤抗蚀作用强弱的重要特征值。利用人工模拟降雨试验,定量研究了在45mm/h、87 mm/h和127 mm/h降雨强度下、20°陡坡面裸地、草地和灌木地的坡面侵蚀临界水流能量。结果表明,不同植被条件下坡面输沙率随径流切应力、单位水流功率和断面比能的增大而增大,有良好的响应关系。裸地、草地和灌木地坡面侵蚀的临界径流切应力分别为0.86 N/m2、2.86 N/m2和1.65 N/m2,临界单位水流功率分别为0.0036 m/s、0.0127 m/s和0.0169 m/s,临界断面比能分别为0.074 cm、0.11 cm和0.13 cm。在具有植被条件下,只有当水流具有更大的能量时,才会引起坡面土壤侵蚀。该研究对于揭示植被调控坡面产流产沙机理,为生态修复工程建设提供科学依据具有一定的科学意义。
The critical erosion energy of slope erosion is an important characteristic value reflecting the strength and weakness of soil erosion resistance. Using artificial simulated rainfall test, the critical erosion energy of slope erosion on nudity, grassland and shrub land of 20 ° steep slope was quantitatively studied under rainfall intensity of 45mm / h, 87mm / h and 127mm / h. The results show that the slope sediment transport rate under different vegetation conditions increases with the increase of runoff shear stress, unit flow power and section specific energy, and has a good response. The critical runoff shear stress of erosion on bare land, grassland and shrub land are 0.86 N / m2, 2.86 N / m2 and 1.65 N / m2 respectively, and the critical unit water flow power is 0.0036 m / s, 0.0127 m / s and 0.0169 m / s, critical section specific energy of 0.074 cm, 0.11 cm and 0.13 cm, respectively. Under vegetated conditions, erosion of the slope surface will only be caused when the water flow has greater energy. The research is of scientific significance to reveal the mechanism of runoff and sediment production by vegetation control and provide a scientific basis for ecological restoration engineering construction.