近20年黄河流域甘肃段植被覆盖度变化与驱动因素分析

Fractional Vegetation Cover Change and Driving Factors in Gansu Section of Yellow River Basin

摘要:

黄河流域甘肃段作为我国重要水源涵养区和北方防沙带建设区，掌握其植被变化及驱动力对流域生态保护和高质量发展具有重要意义。基于2001—2022年MODIS NDVI数据集，利用像元二分法、变异系数、趋势分析法、Hurst指数和地理探测器，分析了近20年来黄河流域甘肃段植被变化趋势及驱动力。结果表明：2001—2022年黄河流域甘肃段FVC在波动中呈上升趋势，植被生长呈向好趋势。近20年间黄河流域甘肃段近1/2区域具有相对高-高波动性，主要集中分布在流域北部的黄土高原区，中波动性、相对低-低波动性主要分布在甘南高原区和陇南山地等区域。黄河流域甘肃段大部分地区植被呈改善趋势，少部分区域表现为退化，未来植被变化将呈反持续性。驱动力分析表明降水量、植被类型和土壤类型对黄河流域甘肃段植被覆盖起主导作用。

Abstract:

The Gansu section of the Yellow River Basin, a crucial ecological security barrier in China, plays a vital role in water conservation and northern desertification control. Understanding the vegetation changes and driving forces is crucial for the ecological protection and high-quality development of the basin. Based on the MODIS NDVI dataset from 2001 to 2022, the vegetation change trend and driving force in the Gansu section of the Yellow River Basin over the past 20 years were analyzed by using pixel dichotomy, coefficient of variation, trend analysis, Hurst index and geographic detector. The results showed that the FVC in Gansu section of the Yellow River Basin showed an increasing trend during 2001—2022, indicating a positive vegetation growth. In the past 20 years, nearly 1/2 of the Gansu section of the Yellow River Basin had relatively high-high volatility, which was mainly distributed in the northern Loess Plateau region, while the medium volatility and relatively low-low volatility were mainly distributed in the Gannan Plateau region and the Longnan Mountain region. The vegetation in most areas of the Gansu section of the Yellow River Basin showed an improvement trend, while a few areas showed degradation, indicating a potential anti-sustainable trend in future vegetation changes. The analysis of driving forces indicated that precipitation, vegetation type and soil type were the predominant factors influencing vegetation cover in Gansu section of the Yellow River Basin.