Remote Sensing And GIS Based Data Mining And Assessment For Degree Of Land Degradation

At present, land degradation is a most attention-getting problem on environment, which has been affecting the world's community and economy badly. China is one of the most serious land degradation Countries, where nearly one-third of the land is suffering from the threat of land degradation. In view of the enormous harm of land degradation in agricultural production and development of economy, this paper, supported by the scientific research project of China Land Surveying & Planning Institute, mainly based on the data including remote sensing, topographic maps and so on in Hengshan Country ShanXi Province, evaluates the extent of land degradation , and compares the degradation extent of 1990 and 2002 to reflect the development of land degradation among 12 years in this area, which can provide reference for local government to manage the land degradation.Based on remote sensing and Geographic Information System technology, an evaluation indicator system is established which includes six indicator images obtained by different sources of remote sensing data, and then the monitoring and assessment of land degradation in the study area is carried out. The main conclusions are as following:1. Based on ETM+ data of Lei-longwan area in 2002, with the help of retrieval of albedo images, extracting the image of a normalized difference vegetation index (NDVI) and humidity, a model about land degradation degree index (DDI) is established, which makes the image of land degradation's degree in study area. The results indicate that there is high relativity between DDI and the type of land use, and the DDI model can be used practicality and feasibility.2. Based on the method of literature analysis, the application situation of land degradation assessment indicators is discussed. The outcomes make out the high application frequency indicators including: vegetation cover, slope, organic matter content, land-use types, income levels, biology diversity, content of water and so on. Thereinto, vegetation cover and slope have the relatively high application rate, reaching 68 percent and 20 percent. The results of the stat. can be used for establishing assessment indicator system.3. Monitoring and assessment index system which including the indicators of vegetation cover, slope, organic matter content, land-use types, soil moisture, the sand covering is established, and the indicator images are obtained based on RS and GIS, then those images are recoded from one to five, homologous the degree of land degradation is separated into five types. Finally, a model of land degradation is established, which includes the indicators used in the monitoring and assessment indicator system.4. The result of synthetic information assessment on land degradation in 1990 and 2002 shows that: land degradation degree of the study area in 12 years has improved, which profits from the local climate, economic situation, certainly correlated with the policy of government which encourage protecting the forest in the northern regions of Shanxi province.