Spatiotemporal dynamics of fractional vegetation cover and its relationship with climatic factors in the Yarkand River Basin

Abstract

The Yarkand River Basin, an ecologically fragile zone in arid northwest China, is critical for regional ecological management due to its sensitivity to environmental changes. This study examines the spatiotemporal dynamics of fractional vegetation cover (FVC) from 2000 to 2023 and its correlation with climatic factors, using the moderate resolution imaging spectroradiometer (MODIS) normalized difference vegetation index data and climate observations (temperature and precipitation). FVC was estimated using the pixel dichotomy method, with Sen+Mann-Kendall trend analyses, and Pearson correlation was applied to assess temporal trends and climate-vegetation relationships. MODIS land use data were reclassified to evaluate FVC variations across forestland, grassland, farmland, bare land, and other ecological types. Results revealed significant spatiotemporal heterogeneity in FVC. Spatially, Yecheng County exhibited higher FVC than Bachu County, driven by favorable topography. Temporally, FVC showed a significant upward trend post-2000, particularly in grasslands and croplands, stabilizing between 2010 and 2023. Climate analysis indicated divergent responses: farmland and forest FVC were negatively correlated with temperature (ranging from 8°C to over 9°C). In contrast, grassland and forest FVC were positively associated with precipitation (increasing by ~14 mm). A 1-2-month lag effect was observed in precipitation’s impact on FVC. The Hurst index suggested a sustained FVC growth in most regions. These findings highlight the role of climate change in driving FVC dynamics, providing a scientific basis for ecological conservation and sustainable water resource management in arid regions.

Keywords

Yarkand River Basin / Fractional vegetation cover / Land use types / Climatic factors / Ecological management

Funding

This work was supported by the Sub-project of the Major Science and Technology Special Project of Xinjiang Uygur Autonomous Region, China (Grant Number 2023A02012-1-3), titled “Research on the System for Optimal Allocation of Water Resources at the Watershed Scale.”

Conflict of interest

The authors declare that they have no conflicts of interest. The funders had no role in the design of the study; in the collection, analysis, or interpretation of data; in the writing of the manuscript; or in the decision to publish the results.

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