Evolution path identification and process analysis of surface vegetation-soil state in dryland system of China

doi:10.13474/j.cnki.11-2246.2024.1225

Abstract

Abstract: As typical fragile ecosystems, dryland systems exhibit nonlinear evolution of their surface states, profoundly affecting ecological balance and human well-being. However, existing studies have yet to fully uncover their complex dynamic evolution processes. Based on monthly time-series products of vegetation and soil endmember fractions from 2001 to 2022, this study employs a trend and breakpoint detection algorithm based on discrete wavelet transform to identify the evolution paths of vegetation-soil states in dryland systems and analyze their dynamic changes. The results indicated that: ①From 2001 to 2022, the fractions of photosynthetic vegetation and non-photosynthetic vegetation endmembers in China's dryland systems showed a significant increasing trend, while the fractions of soil endmembers exhibited a significant decreasing trend.②The sudden increase, A-shaped increase, and V-shaped increase state evolution paths for photosynthetic vegetation accounted for 9.9%, 16.8%, and 21.9% of the total dryland area, respectively, while the corresponding state evolution paths for non-photosynthetic vegetation accounted for 9.1%, 12.6%, and 28.8%, respectively.③Overall, vegetation restoration in dryland had promoted the reduction of soil exposure, but in local areas, water scarcity and human activities had led to vegetation degradation. This study provides a new perspective for understanding the surface state evolution and its response mechanisms in China's dryland systems and offers scientific evidence for land degradation monitoring and ecological restoration.

Key words: dryland systems, vegetation-soil state, endmember fractions time series, discrete wavelet transform, evolutionary path

CLC Number:

P208

TIAN Yihe, JIAO Xin, SUN Qiangqiang, SUN Danfeng. Evolution path identification and process analysis of surface vegetation-soil state in dryland system of China[J]. Bulletin of Surveying and Mapping, 2024, 0(12): 149-154.

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