Dynamic changes in the landscape of bare sand patches in sandy grasslands

Desertification is a major environmental problem in arid and semi-arid areas with fragile ecosystems and land degradation. Desertification of sandy grasslands in the arid and semi-arid areas of northern China is characterized by vegetation degradation and bare sand patches. The overall landscape of the sandy grassland is characterized by a mosaic distribution of vegetation patches and bare sand patches. This article selects 8 sample areas in two areas that are both located in sandy grasslands but have different landform expressions and uses Landsat data from 7 periods in 1990, 1995, 2000, 2005, 2010, 2015, and 2020. The distribution and changes of other landscape types such as bare sand patches in the past 30 years; further analysis of their landscape index; comparative analysis of dynamic changes of bare sand patches in the two regions using climate elements and socioeconomic data in the same period. The results show that: (1) In the past 30 years, the area of ​​bare sand patches dominated by dunes has decreased while the area of ​​bare sand patches dominated by blowout has increased (2) Index changes of bare sand patches dominated by blowout The amplitude is greatly expanded and the connectivity is more obvious. (3) Both areas are greatly affected by human activities. These findings can provide an important method for comparing the desertification process of the desert and also meaningful information for the prevention and control of desertification and sustainable development for the arid regions.

Keywords: Bare sand patch, Landscape, influencing factors.