Spatial evolution simulation of karst rocky desertification based on Logistic-CA-Markov models

In order to reveal the occurrence and evolution of rocky desertification in karst area, the rocky desertification data in 1990, 2000 and 2010 were obtained from the study area: Liuzhi, Guizhou Province. The driving factors and the transformation between all the types of the rocky desertification were assessed by using Logistic-CA-Markov models. The spatial distribution of the rocky desertification in 2020 was simulated in two scenarios. The results show that firstly using regression analysis of Logistic model to analyse the driving factors well reflects the probability distribution of the factors, while the result of CA-Markov coupling model can reflect the complexity and randomness of spatial variation of the regional rocky desertification. Secondly,except for the extremely strong rocky desertification, topography and land use types greatly influence on the development of various types of rocky desertification. Therefore, the occurrence and distribution of rocky desertification is strongly dependent on topographic features and result of different land uses. Thirdly, for scenarioⅠwhere a rocky desertification rate is as quick as currently observed, both environmental restoration and deterioration meanwhile occur in the areas with moderately, lightly and potentially rocky desertification. For scenarioⅡ(areas with eco-reconstruction and land reforestation), the trend of environmental restoration becomes predominant, in which the effect of lightly and moderately rocky desertification controls are noticeable. Accordingly, it is suggested that the key regions for desertification control should focus on the areas with lightly and moderately rocky desertifications;and the effective control measures should be complete reforestation in moderately rocky desertification areas.In the meantime, more attentions need to be paid to coordinating human-land conflict to avoid the deterioration of eco-environment in case of land use in rocky desertification areas.