The Research Of The Benefit Evaluation On Small Watershed Comprehensive Management In Loess Hilly And Gully Area

Based on the investigation and study,the paper explored the benefit assessment methodto the shu-erliang small watershed comprehensive management, one of the typical hilly-gullyloess areas, so as to provide the reference for benefit evaluation methods of the Loess Hillyand gully area small watershed comprehensive control.This study first used the frequency statistics analysis on the predecessors selected indexfor the primary selection, the experts experience method is used to determine to10evaluationindicators which are better accord to the research area. Then in the view of the characteristicsof small watershed comprehensive management benefit, through to the Lord, objectiveweighting method of comparative analysis, combining the analytic hierarchy process (AHP)with expert experience method to determine the weight of indicators. Finally, combined withthe characteristics of small watershed comprehensive management benefit, the the paper usedthe method of fuzzy comprehensive evaluation to evaluate comprehensively comprehensivemanagement benefit of the shu-erliang small watershed.The results of the comprehensive evaluation showed: after the comprehensive treatment,ecological, economic and social benefits shu-erliang small watershed have improved,ecological efficiency was improved obviously, this result is in good agreement with the fieldsurvey, the analysis is carried out because dam system project has good water and sedimentreduction effects; But economic benefit increase is especially not obvious,this also coincideswith local villagers evaluation, mainly because the project implementation time is not long,the short-term economic efficiency is not very obvious.Among the benefit evaluation indexes on the effect of the shu-erliang small watershedcomprehensive management benefit, through the calculation of weight we can know percapita annual net income C4, soil erosion modulus C3and C6on land productivity whichhave made the greatest contributions for the comprehensive management benefit, and thesethree weights are more than60%. This showed that shu-erliang small watershed comprehensive management benefit mainly manifested by the per capita annual net income,soil erosion modulus and land productivity, this is also consistent with the actual situation.So that, this benefit assessment method, organically combined the frequency statisticsanalysis and expert experience method, the analytic hierarchy process with fuzzycomprehensive evaluation method to evaluate the benefits of the small watershedcomprehensive management on shu-erliang small watershed, is fit for shu-erliang smallwatershed, which is practical and feasible in this area. Taking into account the representativeof shu-erliang small watershed in Loess Hilly and gully region, we can see this method is alsosuitable for the small watershed comprehensive management benefit evaluation in Loess Hillyand gully region.