广西西林县非石质山区小流域水土保持综合治理效益评价

Benefit Evaluation of Comprehensive Control of Soil and Water Loss in Small Watershed of Non-rocky Mounta in Areas in Xilin County in Guangxi

对同一区域内不同小流域综合治理效益评估并进行对比分析,可以为挑选适宜该区域更有效的治理方式和以后水土流失治理工作提供参考依据。由统计和监测数据对西林县实施了水土保持综合治理工程的龙英、八阳、普驮3条小流域评估分析,结果表明3条小流域治理后水土流失被有效的控制,土地利用结构得到调整与优化,农民生活水平提高。通过引进土壤侵蚀模数降低率(Z)、水土流失面积治理率(Y)、林地面积增加率(X)、综合治理生态效益的参数(H)4个因子,运用加权求和得到龙英、八阳、普驮小流域综合治理生态效益的参数H1、H2、H3分别为0.924、0.574、0.479。效益具体等级评价分别为“优”“良”“良”。运用静态分析法求得3条小流域经济参数——计算效益期内净效益、效益费用比、经济效益系数、还本年限、敏感性分析5个指标值后分析。结果表明3条小流域治理投资在经济上是可行的,3条小流域数据体现优势各异。

The benefit evaluation and comparative analysis of integrated management of different small watersheds in the same region can provide reference for selecting more effective control methods and controlling water and soil loss in future in this region.Based on monitor data,this paper evaluates and analyzes Longying,Bayang and Putuo small watersheds in the project of comprehensive control of water and soil loss,the results show that the water and soil loss was effectively controlled after the three small watersheds were treated.At the same time,the structure of land use was adjusted and optimizedand the standards of farmers' lives were improved.By calculating four factors of soil erosion modulus reduction rate ( Z ),water and soil loss area control rate ( Y ),forest area increase rate ( X ) and comprehensive ecological benefit parameter ( H ),the parameters H1,H2 and H3 of comprehensive ecological benefit in Longying,Bayang and Putuo small watersheds are 0.924,0.574 and 0.479 respectively by weighted summation.The specific grades of benefit evaluation are “excellent”,“good” and “good” accordingly.By static analysis method,the economic parameters of three small watersheds,including net benefit,ratio of benefit to cost,coefficient of economic benefit,return period and sensitivity analysis inbenefit period are obtained.The results shows that the investment on control of the three small watersheds is economically feasible,and the three small watersheds have different advantages.