Dynamic Change Analysis of Desertification Land in Key Project Desertification Control Area in Litang County Based on RS and GIS

Based on the landsat8 remote sensing images in 2013 and 2018 as data sources, with the support of remote sensing (RS) and geographic information system (GIS) technology, the dynamic changes of desertification land in the key project desertification control area in Litang county were monitored. The results showed that the reversal trend of desertified land was obvious in the study area from 2013 to 2018, and the area of extremely severe and moderate sandy land decreased significantly, showing a gradual reversal trend of "extremely severe sandy land → severe sandy land → moderate sandy land → light sandy land". The total area of moderate, severe and extremely severe sandy land with relatively serious desertification decreased by 26.38%, indicating that the relevant desertification control projects in the study area had achieved remarkable results. It was concluded that the model of artificial grass planting (low dosage) was suitable for mild sandy land control. The model of artificial grass planting (high dosage) was suitable for mild and moderate sandy land control. The model of artificial shrub and grass planting was suitable for mild and moderate sandy land control, and also had certain effects on severe and extremely severe sandy land control. The model of guest soil+artificial grass planting and guest soil+artificial shrub and grass planting were suitable for moderate, severe and extremely severe sandy land control. The model of sand barrier+artificial shrub and grass planting could effectively prevent further degradation of severe sandy land. In the future, it is necessary to strengthen the selection of tree species and grass species, increase the diversity, and combine with engineering measures to control severe desertification areas.