Study On Ecological Benefit Evaluation Of Comprehensive Management Of Soil And Water Conservation In Small Watershed

Based on the analysis of the connotation of ecological benefit evaluation of soil and water conservation comprehensive management in small watershed,the basic theory and method of ecological benefit evaluation are systematically discussed.Taking water storage and soil conservation,ecological environment improvement and soil improvement as the criteria for ecological benefit evaluation of comprehensive management of soil and water conservation in small watershed,the evaluation indexes were selected by using the methods of literature frequency,expert consultation and field investigation,and the weight of each index was calculated by analytic hierarchy process(AHP).The index system for ecological benefit evaluation of comprehensive management of soil and water conservation in small watershed was established The ecological benefits of soil conservation comprehensive management were evaluated.In order to provide some reference for the comprehensive management of soil and water conservation in small watershed.The main conclusions are as follows:(1)According to the constituent factors of the total objective(ecological benefits),the evaluation indexes of ecological benefits of comprehensive management of soil and water conservation in small watershed are determined as follows:benefits of water storage and soil conservation,benefits of improving ecological environment and benefits of soil improvement.The weight of each subsystem(criterion layer)of the evaluation system is water and soil conservation benefit(0.5936),ecological environment improvement benefit(0.2493)and soil improvement benefit(0.1571).(2)Through the comprehensive implementation of various engineering measures and forest and grass measures,the benefits of water and soil conservation are as follows:the annual soil conservation is 113600 T,the new water storage is 3147400 m3,and the soil erosion reduction modulus is 42.41t/hm2.Improvement of ecological environment benefits:by adjusting the industrial structure,the forest grass coverage rate increased from 61.29%to 69.22%,the cultivated land area decreased by 14.74%,the forested land area increased by 32.77%,and the economic fruit forest increased by 76.62%.Soil improvement benefits:physical properties,soil bulk density decreased after treatment,the average value decreased from 1.21 g/cm3 to 1.18 g/cm3;after treatment,the average value of soil water content increased from 46.31%to 48.29%;chemical properties,total nitrogen 2.22 g/kg,total phosphorus 0.29 g/kg,total potassium 3.92 g/kg and organic matter 38.56 g/kg increased.(3)In the forest and grass measures,the amount of water and soil conservation of each forest species is as follows:closed control>economic fruit forest>soil and water conservation forest,the amount of water and soil conservation of closed control is 2038100 m3 and 13900 T;the amount of water and soil conservation of economic fruit forest is 725300 m3 and 28100 T;the amount of water and soil conservation forest is 268500 m3 and 13900 t.(4)The comprehensive score of ecological benefits of comprehensive management of soil and water conservation in Laoxi small watershed is 87.03,which improves the indicators of comprehensive management of soil and water conservation in the project area on the original basis,basically controls the soil erosion,and is conducive to the sustainable development of ecological environment.