摘要
Abstract
[Background] The estimation of regional soil erosion is an important but difficult topic for soil erosion research.During the past years,artificial survey method had been used to make national soil erosion survey,classifying the soil erosion intensity in the topographic map according to vegetation coverage and slope gradient was time-consuming.The national soil erosion investigation based on remote sensing image and GIS technology in large scale had also be conducted,the soil erosion type and intensity were evaluated only according to vegetation coverage and slope,but without rainfall,soil erodibility and other important factors.Thus,how to present the regional spatial distribution of soil erosion quickly and accurately is an urgent issue.[Methods] In order to study method of estimating the regional soil erosion by survey data,Liaoning Province was taken as the study area,soil erosion factors (rainfall erosivity,soil erodibility,topography,soil and water conservation measures) and soil erosion modulus in 2011 were estimated using Chinese Soil Loss Equation (CSLE) based on GIS technology and sampling data from the first nationwide water resources survey in 2011.The soil erosion intensity of the whole Liaoning Province were graded,and compared with the statistical results in sampling plots.[Results] The results showed that the estimated soil erosion factors were relatively consistent with the sampling results apart from slope length and gradient.And the difference of scale accuracy of the topographic data mainly contributed to the difference of slope length and gradient between the whole Liaoning Province and sampling plots.The data from sampling plots and the whole province both showed the similar results that the intensity of soil erosion in Liaoning Province were mostly slight and light.Every year the intensity less than 1 000 t/km2 accounted for about 85％ of the area,while the one greater than 5 000 t/km2 accounted for only 2％ of the area.The soil erosion modulus of other land was the largest (1 777.65 t/km2),folllowed by the dryland (842.20 t/km2) and grassland (794.87 t/km2),the urban residence (11.69 t/km2),paddy field and water areas (17.14 t/km2) were the smallest.Compared to the estimated results of the whole province,the erosion modulus of sampling plots in the independent industrial and mining area,other garden and other land were larger with average values of 3 974.89 t/km2,1 656.95 t/km2 and 807.74 t/ km2 respectively,while the erosion modulus of sampling plots in grassland and other woodland were smaller with average values of 551.48 t/km2 and 197.55 t/km2 respectively,and these differences might resulted from the different resolutions of DEM data between the whole province and sampling plots [Conclusions] The research suggests that it is highly credible to estimate regional soil erosion modulus relying on sampling survey data and soil erosion model.And it can provide a reference for the estimation of regional soil erosion using sampling survey data.关键词
抽样调查资料/中国土壤流失方程(CSLE)/GIS应用/区域土壤侵蚀/辽宁省Key words
sampling data/CSLE/ArcGIS/regional soil erosion/Liaoning Province分类
农业科技
