Study On Benefit Evaluation Of Soil And Water Cornservation In Pengyang County Based On 3S Technology

Pengyang County,which is located in the second sub region of the Loess Hilly and gully region,was studied by using 3S technology,comprehensive evaluation method and grey relevance analysis.With the SPOT 5（2.5m）image of 2005,GF₂（lm）in 2015,2005 and 2015 TM（30 meters）remote sensing images.DEM,statistical data and so on as data sources,based on the status of the comprehensive control of soil and water conservation in Pengyang County in 2005-2015 years.and referring to the principles and methods of the index system for the evaluation index system at home and abroad,the evaluation index system of soil and water conservation benefit in Pengyang county was constructed from 3 aspects of ecology,economy and society,applying combination weighting method determines the weight of each index.ArcGIS,ENVI,and eCognition software were used to extract the basic information of soil and water conservation,evaluate the benefits of water and soil conservation in Pengyang County,and analyze the spatio-temporal characteristics of water and soil conservation benefits in Pengyang County from 2005 to 2015.The influence factors of the spatial differentiation of soil and water conservation benefit in Pengyang county are studied by the grey correlation analysis,and the soil and water conservation are used as soil and water conservation.It provided reliable data support for soil erosion control and soil and water conservation research,so as to provide scientific basis for soil and water conservation management and decision-making.The main conclusions are as follows:（1）The study comprehensively used 3S technology to extract basic information of soil and water conservation,Using GPS technology to quickly locate and accurately acquire data,conduct field investigations and establish Pengyang County’s land use remote sensing interpretation signs;The RS technology was used to preprocess the remote sensing image,extract the NDVI value from the TM remote sensing image,and extract the terrace information automatically based on object-oriented.Using GIS technology’s powerful spatial analysis capabilities to obtain soil erosion data,using spatial expression capabilities,visualizing the evaluation results,and visually reflecting the spatial distribution and spatial agglomeration characteristics of soil and water conservation benefits.The 3S technology has obvious advantages in terms of the research content of soil and water conservation benefits and spatial distribution characteristics in extracting the basic information of soil and water conservation,and provides reliable data support for soil erosion prevention and water and soil conservation scientific research quickly and accurately.（2）The study used theoretical derivation,expert consultation,literature frequency analysis and other methods,combining with the Nanshan eco-economic basin model and the actual situation of water and soil conservation construction in Pengyang County,from the three dimensions of ecological benefit,economic benefit and social benefit,11 indexes,such as soil erosion control degree.weighted average soil erosion modulus,grain yield.per capita livestock feeding,land productivity and land use structure,are selected,which constitute the index system of water and soil conservation benefit evaluation in Pengyang county.The combined weighting method was used to determine the weight of evaluation index,and the comprehensive evaluation model and spatial analysis method were used to calculate the comprehensive benefit,ecological benefit,economic benefit and social benefit of soil and water conservation in 12 townships in the study area,and the spatial and temporal changes of the benefits from 2005 to 2015 were analyzed.The evaluation results conform to the actual situation of soil and water conservation in Pengyang County,indicating that the selection and evaluation methods of evaluation indexes are suitable for the evaluation of soil and water conservation benefits in Pengyang county.（3）From the perspective of time changes,the scores of eco-efficiency,economic benefits,social benefits,and comprehensive benefits of all towns and villages in Pengyang County have increased from 2005 to 2015.The average score of comprehensive benefits increased from 1.31 to 1.66.The average score of ecological benefits increased from 1.41 to 1.68,the average score of economic benefits increased from 1.20 to 1.57,and the average score of social benefits increased from 1.30 to 1.71.Through the implementation of a series of soil and water conservation measures,the ecological benefits,economic benefits,and social benefits of water and soil conservation in Pengyang County have been improved,and water and soil conservation construction has achieved results.（4）From the perspective of spatial pattern,the comprehensive benefits of soil and water conservation in southern townships of Pengyang County are higher than those in northern townships.The Baiyang Town,Gucheng Town,Honghe Town,Xinji Township and other townships are located in the south with higher comprehensive benefits.The comprehensive benefit scores were all greater than 1.35 in 2005 and 1.70 in 2015;the comprehensive benefits were lower in the townships of Jiaotong,Luojing,Xiaojiao and Fengzhuang in the north,and the comprehensive benefit scores were all lower than 1.26 in 2005.In 2015,they were all below 1.60.The spatial patterns of ecological benefits,economic benefits,and social benefits are basically the same as those of comprehensive benefits.The overall southern township scores higher than the north.（5）The study used the grey correlation degree model to calculate the correlation degree of each factor reflects the influence degree of impact factor on the spatial differentiation of water and soil conservation benefits in Pengyang County.The results showed that the five factors of per capita income,multi-year average rainfall,slope,terrain relief and elevation,and the integrated benefits,ecological benefits,economic benefits,and social benefits are all greater than 0.8,which are the main factors affecting the spatial differentiation of water and soil conservation benefits.And the degree of impact:per capita income>average annual rainfall>elevation>topography relie>slope.