The Monitoring And Assesement Of Grassland Desertification In Zhenglan Banner Of Inner Mongolia Based On RS And GIS

Desertification is nowadays a big environmental and social issue the mankind faces. The desertification in the Northern China is mainly shown as the grassland desertification, Which has been the main factor of restriction for utilizing grassland resource and sustainable development of economy in Northern China. For better constituting countermeasure and measure for preventing grassland desertification, building regional project to combat desertification reasonably, utilizing and protecting grassland resource scientifically and guaranteeing the sustainable development of the animal husbandry, it is very important to appraise the degree of grassland desertification accurately. This research takes Zhenglan Banner as an example, based on RS and GIS and by field investigation, have studied the spatial pattern, the trend and the law of development of grassland desertification during four periods of the past 13 years in Zhenglan banner, and under the direction of theory of landscape ecology analyze and predict the trend of the change of landscape pattern of grassland desertification . The results are as following:The area of desertification grassland accounts for 70.49% of the total land area in Zhenglan banner by the year 2004 and the moderate desertification type account for 32.19%, severe and extremely severe desertification type account for 23.70% and slight desertification type accounts for 14.59%. The spatial distribution characteristic is that extremely severe, severe type tend to join together while the slight and moderate type distribute scattered .The results indicates that the total area of the grassland desertification increased by 8.83% from 1991 to 2004 and the degree of grassland desertification tend to be more serious. The area of moderate type have the tendency to reduction slowly, but extremely severe, severe types trend to increase.The characteristics of desertification spatial change is that stable type is the main body and the upgrading is more than degrading. The main form of stable type is extremely severe and moderate, the main form of upgrading type is slight upgrading ones, the main form of degrading type is slight degrading. The main form of degrading types is serious desertification to moderate and moderate to slight desertification and the main form of upgrading types is serious desertification to moderate and moderate to slight desertificationfrom slight to moderate desertification. From the main change forms we conclude that people focus on combating serious grassland desertification but neglect the slight and moderate grassland desertification, which is the cause of the expansion of grassland desertification.The dynamic change of grassland desertification was predicted by Markov's model .The results indicate that the area proportion of moderate and extremely severe desertified grassland increase and the proportion of area of non-desertification land have the tendency of certain reduction, which shows that with the impact of mankind the grassland desertification is developing in zhenlan banner.The analyses of landscape pattern from 1991 to 2004 shows that the landscape diversity tends to increase, which shows the difference of the proportion of different desertified grassland types become reduced, while the dominance have the tendency of reduction, which indicate that the control ability of moderate and slight desertified grassland weaken. Homogeneity increase slightly, which shows that desertification landscape develop homogeneously. The fraction dimension of patch decrease from 1.23 in 1991 to 1.22 in 2004,which shows that the shape of patches composed the grassland desertification landscape tend to be simple and regular under the disturbance of mankind. Among all the patches types the fractional dimension for slight and moderate type is least ,which indicate that the shape of the two type patch is affected by mankind mainly.The cause of the expanding of grassland desertification in Zhenlan banner is for man to utilize the grassland resources unduly, such as population expansion, livestock i...