Dynamic Evolution Analysis And Simulation Of Desertification In Jinghe Oasis Of Aibi River Basin

In the global environmental studies, land desertification is increasingly being considered urgent research topic, its development speed of desertification and severe disaster caused widespread concern in the international academic community. Jinghe oasis Aibihu Lake Basin was taken in this study area, using GIS and CA(cellular automata) model to simulate and predict the changes of desertification in the study area. Firstly, the study area based on desertification field research status and different time(1984 Landsat5-TM and 2014 Landsat8-OLI) sensing image, using the normalized difference vegetation index(NDVI) and desertification highly correlated to NDVI as quantitative assessment of desertification and land desertification based divide, and made a more comprehensive discussion of the characteristics of desertification in the study area.Then, this paper comprehensively quantitative got the relationship between desertification and between the various driving factors, revealed the study of land desertification main drivers based on field research and remote sensing dynamic monitoring and evaluation, combined with multivariate data and information base of existing research results of the study area, the use of powerful GIS spatial analysis functions and probability and statistics, principal component analysis, hierarchical analysis, mathematical methods. On this basis, the existing desertification distribution of 1984, 2014 as the reference and test data was used, the 3S technology combined with cellular automata model was used to achieve the desertification evolution mathematical model: Geo CA-Desertification model, and use this model the study area in 2024 evolution trend of desertification were simulated and analyzed, discussed the research area of desertification spatial and temporal distribution. Finally, desertification in the study area is characterized by the occurrence and development, systematically presented desertification prevention recommendations.The results showed that:(1) The scale of desertification in the northwest is still evolving. From 1984 to 2014, and the extent of desertification area were tested to increase. Desertification area from 1984 to 15.228 × 104 ha, increased in 2014 to 21.319 × 104 ha, and an annual growth rate of 1.87 %. Percentage of the total area very severe desertification area accounts decreased from 78.75% in 1984 to 78.41 % in 2014.(2) Changes in the area during 1984- 2014, except for the unchanged portion of 65.08%, the largest proportion of the type of deterioration level, an area of 16.81 × 104 ha, 17.30% of the total area; followed by reversal, reversal of the strong signs of improvement type, total area is 15.41 × 104 ha, 15.82% of the total area; strong deterioration area is not dominant, has reached 0.09 × 104 ha, 0.09% of the total area.(3) CA model simulations to evaluate the accuracy, index value of Kappa is 0.832. According to remote sensing image analysis, desertification evolution mechanism and mathematical model results analysis, the study area extended desertification overall direction was from north to south, moving from west to east. Jinghe County and surrounding towns always been affected by desertification edge.