| Semi-karst region is a special division of the ecological region of karst area such as Guizhou Province. The characteristics of the development of karst and the degree of rocky desertification are obviously different from that of common karst. And Qianzhong area is a key economic development zone in Guizhou Province which has larger distribution area of "semi-karst" than other regions.By using multi-scale space unit and spatial autocorrelation analysis technology, the paper makes partition of semi-karst and karst region in Qianzhong area and makes quantitative description of rocky desertification development situation.We use karst rocky desertification index and combine calculation methods of landscape pattern based on the remote sensing image data of Qianzhong area in 2010.The research showed that compared with semi-karst and karst region, the latter’s rocky desertification situation is more serious and the landscape spatial heterogeneity is larger, and the whole landscape pattern is more broken. Although the former’s rocky desertification is in good condition, its ecological environment is sensitive and vulnerable to human disturbance. On the basis of this, the control strategy of rocky desertification was put forward according to the different conditions, The purpose of this paper is to take further research on different regions of rocky desertification and promote the harmonious development of ecology. The main conclusions are as follows:(1) From the point of view of spatial distribution, the rocky desertification in semi-karst district is better than that of karst district. The continuous limestone in karst ditrict has the most prone to rocky desertification and the most serious development, and with the increase of clastic rock composition, the occurrence rate of rocky desertification in limestone district is decreased. On the contrary, the dolomite district has the opposite trend. The self condition of semi-karst region has made the whole better rocky desertification situation, and the district is mainly distributed with mild rocky desertification.(2) From the point of view of spatial differentiation, there is a stronger spatial clustering of rocky desertification index in karst region, and the "hot spots" area of rocky desertification is mainly distributed in the area of severe rocky desertification. Compared to semi-karst region, the spatial pattern of rocky desertification in the former is more uneven and complex. With the decrease of the ecological units, the overall spatial autocorrelation of the two partition is enhanced.(3) From the view of landscape pattern, the rocky desertification landscape of Karst district is more broken, in which the continuous limestone zone is the most broken. For different grade rocky desertification, development of high degree of rocky desertification is scattered and has higher degree of fragmentation. Although the semiKarst’s own natural environment is better, but the ecological environment to a certain extent is more sensitive to human activity. The rocky desertification landscape index has different characteristics of grain effect.(4) There is a close relationship between the development degree of rocky desertification and basement of lithology. Development of desertification in different districts of karst district have different characteristics. Although there are some difficulties in the control of rocky desertification, for regions with different partitions or levels, in order to achieve a better control effect, we should take different measures to rocky desertification prevention and control work according to local conditions. |
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