黄河多沙粗沙区分布式土壤流失模型研究

Study on the Distributed Forecast Model of Soil Loss in Sandy Areas of Yellow River

以侵蚀动力学、地貌学、水文学、泥沙运动力学的理论为基础,以黄河多沙粗沙区岔巴沟流域为研究区域,以地理信息系统为平台,构建了黄河多沙粗沙区小流域分布式土壤流失数学模型,可用于计算小流域梁峁坡、沟坡和沟槽三部分的土壤流失量,并达到了产汇流模型与产输沙模型的紧密耦合;提出了当量糙率系数的概念,初步解决了定量表达水土保持工程对产汇流的影响,使模型具备了预测评价不同水土保持治理方案效益的功能;利用3S技术实现了土壤流失预测模拟信息系统的自动提取。通过对岔巴沟流域和杏子河流域土壤流失实测资料的验证表明,本模型能基本正确反映黄河多沙粗沙区流域土壤流失规律。

Base on the theory of erosion dynamics, geomorphology, hydrology, mechanism of sediment trans- port, a distributed soil loss model was built and applied in Chabagou watershed in sandy areas of Yellow River by using GIS technique, the model could be used to count the amount of soil loss on watershed loess slope, gully and groove, the model is capable to coupling the runoff process and sediment transport, raised the concept of equivalence estimation roughness coefficient, preliminary solve the problem soil and water conserva- tion proieet to change runoff , so the model could forecast the benefit on different control plan of soil and wa- ter eonservation; the soil loss imitation forecast information were extracted use 3S technique; built the definition method of classification template in virtual reality environment to improve the classification precision of remote sensing image, prefect solve the problem to distinguish the phenomenon ＂ the different thing with same spectrum and the same thing with different spectrum＂. Compare to the soil loss amount measured in Chabagou and Xingzihe watershed, the model could rightly to mirror the rule of watershed soil loss in Yellow River sandy areas.