基于RS和GIS的重庆市土壤侵蚀模型研究

The Study of Soil Erosion Models in Chongqing Based on RS and GIS

[目的]研究更简便、更精确的模型计算重庆市的水土流失量。[方法]以RS、GIS、e Cognition、SPSS等软件为平台,将基于RUSLE模型计算得到的2002年重庆市各区、县的年水土流失量数据与官方公布数据进行回归分析,建立重庆市土壤侵蚀模型。[结果]基于RUSLE模型计算得到的2002年重庆市各区、县的年水土流失量数据相对于官方公布数据,平均精度达72.38%,在多缓坡的区、县精度较高,在多陡坡的区、县精度较低。由建立的重庆市土壤侵蚀模型计算得到的2002年重庆市10个区、县的年水土流失量数据相对于官方公布数据,模拟精度达85.73%,较好地改善了RUSLE模型在陡坡地区精度较差的不足。重庆市土壤侵蚀模型相对于RUSLE模型,在重庆市10个验证数据的水土流失量计算中,计算结果的平均精度提高了10.6%。[结论]重庆市土壤侵蚀模型相对于RUSLE模型在重庆市水土流失量的计算中具有更好的实用性,可为重庆市水土流失量的计算提供参考。

[Objective]To explore a simple and more accurate model to calculate the amount of soil and water loss in Chongqing.[Method]Based on the RUSLE model,this paper took advantage of RS,GIS,eCognition,SPSS and other software.First of all,six factors that affect soil and water loss were calculated and the distribution of soil and water loss of Chongqing in 2002 was obtained by applying the overlay analysis function of GIS.Then,calculating the amount of soil and water loss in various districts and counties of Chongqing in 2002 and making regression analysis with official published data,finally established the model of soil erosion in Chongqing.[Result]With the standard of official data,the average accuracy of soil and water loss in districts and counties of Chongqing in 2002 which was calculated based on the RUSLE model reached to 72.38%.The accuracy was more accurate in districts which had more gentle slopes,and was poorer in steep districts.With the standard of official data,the simulation accuracy of soil and water loss in districts and counties of Chongqing in 2002 which was calculated based on the established model of soil erosion in Chongqing,reached to 85.73%.The established model of soil erosion in Chongqing improved the deficiencies of RUSLE model in steep lands.Compared with the RUSLE model,the established soil erosion model in Chongqing showed that the average accuracy of calculated results was improved by 10.6%in calculation the amount of soil and water loss in 10 validated data in Chongqing.[Conclusion]Compared with the RUSLE model,the model of soil erosion in Chongqing improves the calculation precision in the areas which have large gradient,and has better practicability in the calculation of soil and water loss in Chongqing.