土壤学报2017，Vol.54Issue(5)：1136-1146,11.DOI:10.11766/trxb201611290469
延河流域三种土壤可蚀性K值估算方法比较
Comparative Study of Three Different Methods for Estimation of Soil Erodibility K in Yanhe Watershed of China
摘要
Abstract
[Objective]Soil erodibility K is an international index of soil susceptibility to erosion, and can be used as an important quantitative parameter in evaluating soil erodibility. The Yanhe Valley is located on the Loess Plateau,where soil erosion is very severe,and also very severe in soil erosion. In this case,it is particularly important to conduct research on soil erosion models for this region. In recent years, in studies on soil erodibility of loess,soil erodibility factor K is often used as an index for evaluation of soil erosion. Though certain progress has been made in the research on using the formula method to assess soil erosion factor K in the loess area,it is still infeasible to go on doing researches on estimating K values in some parts of the Loess Plateau due to limitation of data availability and inconsistency between standard plot and observation plot. Besides,the reliability of the formula method still need to be validated. So,it is necessary to design an equation that is workable for estimating soil erodibility K even when inadequate data of soil physical and chemical properties are available. The purpose of this study is to pick out of the three methods currently available for estimating soil erodibility K one that fits the special situation of the river valley.[Method]In this study,comparison was performed between the three methods,i.e. Torri.D model, EPIC model,and Shirazi formula in applicability to estimation of K for the nine catchments of the Yanhe Valley. Collection analysis and Model-based estimation methods were used to process and analyze the data and compare predicted K with measured K,so as to screen out the most suitable one.[Result]Results show that the contents of soil organic carbon,clay and silt gradually increased from north to south with the increasing vegetation coverage. In terms of mean weight diameter(DMW),the three types of vegetation in the valley followed an order of forest > forest-steppe > steppe,and DWM was positively related to the K predicted with the EPIC model and Shirazi formula method,but negatively to that with the Torri.D model,which means that soil aggregate increased in stability and the soil in erosion resistance as the vegetation turned from steppe to forest-steppe to forest. The three predicted Ks displayed an order of KTorri.D > KEPIC > Kshirazi. KTorri.D varied in the range of 0.068~0.1475,higher than the measured one(0.0312~0.0796). Compared with the other two,Torri.D model was the lowest in uncertainly,with mean absolute error(MAE),mean relative error(MRE),root mean square error(RMSE)close to 0,and dilution of precision(Af)close to 1, suggesting that Torri.D model is more suitable than the other two for use to evaluate soil erosion susceptibility and calculate soil loss.[Conclusion]To sum up,all the findings described above indicate that Torri.D model can be used to soil erosion susceptibility and predict soil loss of a region even when data of the region are incomplete or inadequate.关键词
延河流域/土壤可蚀性K值/Torri.D模型Key words
Yanhe Valley/Soil erodibility K/Torri.D model分类
农业科技引用本文复制引用
林芳,朱兆龙,曾全超,安韶山..延河流域三种土壤可蚀性K值估算方法比较[J].土壤学报,2017,54(5):1136-1146,11.基金项目
国家自然科学基金项目(41671280)、水利部公益性行业科研专项经费项目(201501045)和西北农林科技大学基本业务费专项(2452015092)资助 Supported by the National Natural Science Fund Project(No. 41671280),the Special Fund Projects of Public Welfare Industry of the Water Conservancy Ministry of People's Republic of China(No. 201501045)and the Fundamental Research Funds Project of the Northwest A&F University(No. 2452015092) （41671280）
