基于黄土丘陵沟壑区第Ⅰ副区淤地坝淤积调查的土壤侵蚀模数计算

目的]探索适合黄土丘陵沟壑区不同沟道土壤侵蚀模数计算的新方法,为区域水土流失防治和水保规划提供数据支持。方法]以黄土丘陵沟壑区不同沟道74个不同坝型的淤地坝为基础,将其看作小流域的沉沙池,同时结合实地调查测量与分析计算,利用淤地坝赋存的泥沙信息获得不同级别沟道的土壤侵蚀量。结果](1)在地形复杂的黄土丘陵沟壑区,土壤侵蚀模数与不同沟道对应的淤地坝控制面积具有一定的负相关关系;(2)土壤侵蚀模数调查值较设计值显著降低,造成淤地坝空坝率上升,使淤地坝长期保持负效应。结论]利用闷葫芦坝淤积量推算坝体控制面积土壤侵蚀量,方法简单合理。同时小流域坝系可采用多种方法综合分析,相互印证,可较准确地确定小流域土壤侵蚀模数。

Calculation on Soil Erosion Modulus Based on Sedimentation Investigation of Check Dam in First Subdivision of Loess Hilly-gully Region

Objective] The study aimed to find a new method calculating soil erosion modulus in order to provide basic data for planning of check dams and dam system, which could also provide important reference value to soil and water loss prevention.Methods] Different levels of channel in loess hilly region has been chosen for research. Chose seventy-four different type of dam "check dam", which could also been seen as an aerated grit chamber. By the sediment information recorded of check dam, the amount of soil erosion of different levels of channel obtained. Meanwhile, combining field investigation and analysis calculation, try to explore a new method, which could get the accurate soil erosion modulus in loess region.Results] (1) In complex terrain of loess hilly region, there is a negative correlation between soil erosion modulus and controlled area, which is corresponding to different channel silt dam;(2) Compared with the design value, the droop value of soil erosion modulus reduced significantly, which made silt dam can not be used, and makes silt dam holding negative effects in long-term.Conclusion] Based on sedimentation volume of check dam, calculating the soil erosion modulus of controlled area is simple and reasonable. At the same time, a variety of methods could be used and comprehensive analysis, they confirm each other, so that we could calculate soil erosion modulus accurately.