Analysis of rocky desertification landscape pattern change in Karst plateau area based on GIS

As one of the most serious geo-ecological disasters in Karst areas in Southwestern China, rocky desertification has become one of the key and difficult research issues. Taking the Houzhaihe Valley in Puding County, Guizhou Province, Southwestern China as an example, the landscape pattern changes of Karst rocky desertification in the recent 18 years in Karst plateau area were studied from the perspective of different rocky desertification levels, based on 3 series of remote sensing images (TM images of 1987 and 1995 and SPOT-5 image of 2004), and applying GIS technique and statistics analysis methods. Results indicated that, as a whole landscape, the intensity and rate of rocky desertification land were increasing in the recent 18 years. The increasing rate of rocky desertification were 6.55 hm²/a from 1987 to 1995, and 29.64 hm²/a from 1995 to 2004. Different rocky desertification levels had shown different change tendencies. The area of light rocky desertification land reduced at first (from 1987 to 1995) and then increased (from 1995 to 2004), while the area of moderate and severe rocky desertification land increased continuously from 1987 to 2004.