Degree of desertification based on normalized landscape index of sandy lands in inner Mongolia, China

Abstract

Desertification is one of the most serious ecological environmental problems over the past several decades in the arid regions. The quantitative assessment of the desertification degree in sandy lands has also been an essential part of landscape ecology. Based on the character of relief, we proposed a new indicator system, i.e., Normalized Landscapes Index (NLI) to calculate the dynamic trend of the desertification process. The data from three periods of Mu Us sandy land and Kubuqi sandy land in Inner Mongolia were used to verify the accuracy of this method. The results show that, from 1990s to 2010s, the NLI change amount of fixed sandy land and semi-fixed sandy land all had positive values while bare sandy land and water had all negative values for both regions. Over the past 20 years, the desertification reversal phenomenon occurs in Mu Us with the desertification process (DP) of −0.36%, while a positive development of desertification in Kubuqi with the DP of 0.01%. The NLI dynamic degree of two sandy lands had the same trend as land use dynamic degree, while NLI was more accurate than the landscape dynamic degree. These findings can provide an important method for comparing the desertification process of the desert and also the meaningful information for prevention and control of desertification and sustainable development for the sandy lands in the arid regions.