| Karst rocky desertification, following desertification in northwest area and soil erosion in loess area becoming the third-largest ecological problems in China, is becoming difficult and important ecological environment in South China karst region. In recent years, many experts and scholars pay high attention on it, and it become a research hotspot.In this paper, use the most complex and largest karst distribution area Guizhou as research target, discuss the evaluation system of karst rocky desertification grades , confirm desertification grade criteria , spectral characteristics of different lithology, different grades of rock desertification on remote sensing images had been analyzed. Use 2000 TM and 2005 ASTER satellite images for the data source, base on RS-GIS-GPS integration technology, according to enhanced vegetation index, soil index, slope information extracted rocky desertification, map the 2000 and 2005 rocky desertification of Guizhou province. Base on spatial analysis, transfer matrix studies and Markov prediction method, Analyse the distribution characteristics of rocky desertification of Guizhou, research Guizhou rock desertification variation and development trends. Study shows that:Different lithology, different grades of rock desertification have different spectral characteristics in remote sensing images and found that the spectral curve of carbonate rocks have standard spectrum character near 11.3um. Relative to limestone, dolomite have the moving short-wavelength features, relative to carbonate rocks, clastic rocks band characteristics is smaller, has lower reflectivity, no obvious regularity.Use original ASTER image, the enhanced vegetation index band, soil index band and the gradient information band synthetic image data, based on different types of rocky desertification has difference spectra characteristic curves, application tree-based information extraction method , according to vegetation index and soil index extracted rocky desertification. After verify accuracy, find that tree-based information extraction method is more accurate than the supervised classification method.There are 37597. 36km2 rocky desertification land in Guizhou province, accounting for 21.34% of the total area, accounting for 34.47% of the karst area, more than 1/3 karst area has been desert. Guizhou province has the largest area whether in karst area or rocky desertification area of China. Distribution of rocky desertification in Guizhou is lighter in western and eastern area, more severe in southern and northern part.By using the desertification map of 2000 and 2005, base on overlay analysis, dynamic transfer matrix access to dynamic changes. Statistical data show that desertification area has increased 2188 km~2 in the last 5 year period, the potential rocky desertification area reduced, other rocky desertification area increased. Rocky desertification in Guizhou dynamic transfer matrix display, rocky desertification conversion area is large, potential rocky desertification is the largest conversion type, changes area is 9135km~2, rocky desertification conversion is mainly from the low-grade to high-grade, there are none grade jump in little time.Transformation of the rock desertification wider distribution in Guizhou, but there are obvious centralized changes. Mainly in the southern and western Guizhou areas rocky desertification grades enhanced, but in northern and eastern parts of the region rocky desertification depressed.Assumption that Rocky desertification in Guizhou Province development with current trend, use Markov method forecasting each Rocky desertification area at 2030 and 2050. At the same time, in accordance with each treatment project effect, analysis various changes of rocky desertification. According to the combined effect of two factors, analysis of the future development of the rocky desertification in Guizhou. Data show that rocky desertification treatment project hace obvious effect. Potential and non-rocky desertification area significantly increased, while, the intensity desertification area change slow.Through the Markov forecasting method, in accordance with rocky desertification control project in Guizhou Province, analyse the development trends of rocky desertification in Guizhou. Data show that rocky desertification control project play important role of rocky desertification in Guizhou, none-rocky desertification area significant increase, the potential rocky desertification obvious reduce, but, the intensive rocky desertification area changes slowly. Rocky desertification control project, to a certain extent, limit the development trend of rock desertification in Guizhou, slowed down rocky desertification, reduce rocky desertification grades, Data shows that 2030 rocky desertification area in Guizhou Province from the current ratio of 21.34% down to 14.9% by 2050 reduced to 13.5%, but rocky desertification in Guizhou problem will exist for a long time.By research on Bijie, Qingzhen, Huajiang, Zunyi and Yanhe five demonstration zones rocky desertification features , changes and development trend of rocky desertification, after rocky desertification control governance, None-rocky desertification increase, rocky desertification area gradually reduce, but increase or decrease level differences. Karst plateau canyon and mountanious region were significantly higher than the karst plateau basin region of incidence of karst rocky desertification, from 2005 to 2007 changes in the demonstration zone data show that karst plateau basin rocky desertification annual change rate is the largest, but the Karst plateau canyon area is the lowest type.Rocky desertification Changes in Wujiang River Basin has the following characteristics: the lower reaches of Wujiang River rocky desertification grades is the highest. None-rocky desertification area and potential rocky desertification area both increase in the three demonstration zones, the other type of rocky desertification area reduced, rocky desertification annual change rate is the largest in the middle reaches of Wujiang River.There are obvious correlation of rocky desertification, soil erosion and land use type. Land-use types obvious influence the rocky desertification degree. Most of the Soil Erosion region are potential and mild rocky desertification area, at the same time, non-rocky desertification non-Karst soil erosion are also serious. Soil erosion occurs mainly in dry land, woodland and grassland.Rocky desertification has seriously affected production and living of local residents, directly threat to survival environment of mountain people in the southwest karst area, and the ecological security of the Yangtze River and Pearl River also been affected. Only strict control the population growth, organized labor export; to optimize the structure of land use, development characteristics industry; set down the overall plan for rocky desertification control, make the population, resources, environment harmony development, can rocky desertification region make a real sustainable development.
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