Page 228 - AJWEP-22-6

Qin, et al.

1. Introduction sustains such growth, indirectly affecting vegetation.
6
Other key factors include land use and human
Fractional vegetation cover (FVC), a standardized activities. As an integral part of the Tarim River
7
ecological indicator, serves as a critical measure for Basin, the vegetation dynamics of the Yarkand River
quantifying the extent of surface vegetation, playing an Basin are shaped by complex terrain—encompassing
indispensable role in ecosystem material cycles, energy alpine glaciers, oasis agricultural zones, and desert
balance, and regional climate regulation. As a key ecosystems—and diverse vegetation types, including
1
parameter reflecting vegetation growth status, FVC not grasslands, shrubs, croplands, and sparse vegetation.
8
only visually delineates spatial distribution patterns of Since 2000, global warming has driven temperature
vegetation but also provides essential data for assessing increases and altered precipitation patterns, profoundly
ecosystem service functions, such as carbon sequestration affecting vegetation growth and distribution. Previous
9
and soil conservation. Against the backdrop of global studies have highlighted that FVC in arid areas typically
climate change, climatic factors, such as temperature correlates positively with precipitation, while rising
and precipitation, exert a significant influence on FVC, temperatures may inhibit growth through enhanced
with arid and semi-arid regions displaying heightened evapotranspiration. 10,11 Human interventions, such as
sensitivity to these variations. The fragile ecosystems agricultural irrigation, urbanization, and ecological
2,3
in these areas amplify the ecological consequences, restoration projects, further influence these dynamics. 12,13
where even subtle FVC fluctuations can trigger However, existing research, often limited to shorter time
cascading effects on processes, such as carbon cycling scales or single vegetation types, lacks a comprehensive
and surface albedo, ultimately influencing regional and analysis of long-term FVC spatiotemporal variations,
global climate systems. This underscores the urgency county-level differences, and the response mechanisms
of monitoring and understanding FVC dynamics to of diverse vegetation types from 2000 to 2023. 14,15 This
support sustainable environmental management. gap highlights the need for an in-depth investigation
Remote sensing technology has emerged as a into these aspects.
cornerstone for studying FVC, leveraging its high This study, based on remote sensing data from
spatiotemporal resolution and extensive coverage 2000 to 2023, employs CV, Sen+Mann–Kendall trend
to monitor vegetation dynamics effectively. Core analysis, and Pearson correlation to systematically
4
indicators, such as the normalized difference vegetation explore the spatiotemporal variation characteristics of
index (NDVI) and its derivative, FVC, derived from FVC in the Yarkand River Basin and its relationship
datasets including the moderate resolution imaging with temperature and precipitation. This study utilizes
spectroradiometer (MODIS) and Landsat, have yielded the latest MODIS NDVI data (MOD13Q1 V6) spanning
significant insights across various river basins. the extended period from 2000 to 2023 to capture
5
Common methodologies include the coefficient of long-term FVC trends and analyzes FVC spatial
variation (CV) to assess temporal stability, Sen+Mann– heterogeneity at the county and land use type scales.
Kendall trend analysis for detecting long-term trends, The significance of this work lies in: (i) enhancing
and Pearson correlation analysis to explore climatic the understanding of vegetation dynamics and climate
relationships. These approaches, widely validated in response mechanisms in the Yarkand River Basin,
arid region studies, provide a robust framework for offering a reference for regional ecosystem research;
analyzing FVC spatiotemporal patterns. Building on this (ii) providing a scientific foundation for ecological
foundation, this study employs CV, Sen+Mann–Kendall protection and climate adaptation management in arid
trend analysis, and Pearson correlation to investigate regions; and (iii) supporting data-driven water resource
FVC dynamics in the Yarkand River Basin, thereby management and sustainable development initiatives.
enhancing the precision and scope of FVC research.
The Yarkand River Basin, located in the northern 2. Materials and methods
Tarim Basin of Xinjiang, China, is a core arid region
characterized by a fragile ecological environment. 2.1. Overview of the study area
Changes in its FVC significantly impact regional The Yarkand River Basin (36°02’–41°22’ north,
balance in ecology and are intricately linked to several 75°14’–81°47’ east), as shown in Figure 1, is located
key factors, such as water resources. The water resources in the northern part of the Tarim Basin in Xinjiang,
not only supply the necessary moisture for vegetation China, with a total area of approximately 110,000 km ,
2
growth but also influence the soil environment that accounting for about 10.7% of the area of the Tarim

Volume 22 Issue 6 (2025) 222 doi: 10.36922/AJWEP025350269