Remote Sensing Survey And Driving Factors Analysis On Water Erosion Desertification

Water desertification is a new issue in the area of desertification research in recent years. The water erosion desertification’s development trend of the Three Rivers Region is growing increasingly, particularly acute in Yunnan region. Therefore, to Yunnan Province’s even the Three Rivers Region’s ecological environment, socio-economic and sustainable development of people’s lives, researching the water desertification’s status, change and its driving factors of the region has important research meaning and practical value by the means of combined with the use of remote sensing and GIS.With remote sensing based data sources(MSS, TM and ETM+) of three periods, this article constructed a multi-feature space to extract the information of water erosion desertification and used GIS platform for spatial analysis and processing combined with profiles and characteristics of the study area. Then combined with the regional data of the study area, it analysed the impact of the change of the driving factors. The main results obtained through research are as follows:1、According to the water erosion desertification grade evaluation system formulated by the State Forestry Administration, considering various factors which impacted the development level of water erosion desertification, a multi-feature space composed of the vegetation cover, slope and gully density was constructed, combined with remote sensing images can accurately extract the water erosion desertification classification information.2、In the interpretation process, the accurate extraction of the various features information is the key of water erosion desertification classification information extraction. This article extracted vegetation coverage information by using normalized vegetation index and the pixel dichotomy, and slope and gully density by using DEM.3、This article graded water erosion desertification information by application of multi-feature space and used GIS platform for spatial analysis, the results are as follows: From 1970 to 2000, water erosion desertification of the study area showed a trend of rapid development;from 2000 to 2008, it increased slowly. In general, the land of water erosion desertification distributed widely and concentrate contiguously but the trend of growth rate decreased year by year.4、Through the technical means combined with Remote Sensing and GIS, the achieved research results and the geological maps of the region were overlaid and supported by hydrology, climate and other statistical data to conduct spatial analysis and comprehensive study. The driving factors which influenced the change of water erosion desertification land of the study area are as follows: including geological factors, natural factors and human factors, etc. Among them, geological factors included the geological environment, stratigraphy and other factors; natural factors included climate and soil factors; human factors included population growth and industrial activities such factors. These driving factors affected the water erosion desertification’s formation and development of Yunnan Province Domestic Area of the Three Rivers Region in varying degrees.