Investigation And Research Of Remote Sensing To The Desertification In Lujiang Catchment, Yunnan Province

Recently, along with the deterioration of the mankind environment and pay attention to the ecosystem environment increasingly, the ecosystem environment (rocky desertification) has been concerned. The present study, supported by the project of China Geological Survey-Remote Sensing Investigation and Monitoring on the Key Karst Mountain Areas in Southwest China, focuses mainly on the Lujiang drainage catchment. Based on a large mumber of high-resolution remote sensing image and aided by the GIS technique to extract karst rocky desertification information, with the method of the multi-source data to multi-temporal data, the automatic extraction and human-machine cooperation and combine the integration study to the investigation. On the basis of the investigation by remote senseing, the present situation of rocky desert of 2005 in Lujiang catchment was basically revealed. The total area of rocky desert in the whole investigated region is approximately 957.30km2, accounting for 21% of the total investigation area and 38% of the karst mountain area.According to the map of spatial distribution of rocky desertification, the slope chart derived from DEM data and previous achievements in Lujiang catchment, this study mainly tried to find out the distribution characteristics of rocky desert with the overlaying analysis and research into the original mechanism of rocky desertification. Based on the analysed and research, we think the natural factor and human factor is the factor to karst rocky desertification, natural factor especially tectonics factor was the main factor to the karst rocky desertification. Human factor increase the development of the karst rocky desertification:①The tectonics was a controlling factor of the rocky desertification, the new tectonics movement was a important condition to the rocky desertification;②The lithology was a controlling factor of the rocky desertification, the distribution of lithology affected the distributed rules of rocky desert directly;③Slope is of the upmost important driving factor on rocky desertification. Based on the spatially analyze and the synthetically study on the distributive map of rocky desert and the map of slope in monitoring area, we foundthat the change of slope affected the degree of rocky desert,s forming. The higher the slope is, the more percentage of the rocky desert occupies within the study region;④Karst mountain region stratigraphy develop the fold and the fault, rock fragmentation, and promoted the karst rocky desert;⑤The karst geomorphology with the new tectonic movement has been a very important condition to karst rocky desert;⑥The human factor increased the development of the karst rocky desertification;⑦From the intensity of the Lujiang catchment, there were Shiping, Kaiyuan, Gejiu, Mengzi, Jianshui, the natural factor (fault) affected the Jianshui, Kaiyuan, Shiping, the natural factor and the human factor affected the Mengzi and Gejiu.