关键词: 地理单元, 辽河流域, 归一化植被指数, 植被变化, 气候因子

Abstract: Global climate change would affect regional vegetation changes. Clarifying the spatiotemporal variations of normalized difference vegetation index (NDVI) in a basin and its response to climate change can provide important insights into regional ecological environment construction and management. Based on the perspective of geographical micro-regional differentiation, we constructed geographical units with characteristics of Liaohe River Basin (Liaoning section). GIS and other software were used to analyze the MODIS-NDVI remote sensing data acquired from 2000 to 2022. The data of temperature and precipitation were collected during the same period. The methods of Theil-Sen + Mann-Kendall test, coefficient of variation and partial correlation analysis were employed to identify the spatiotemporal patterns and climate responsiveness of NDVI during the growing season in different geographical units. The average NDVI during the growing season in different geographical units showed an increasing trend, but with different growth rates and obvious spatial heterogeneity. The analysis of trend significance and variation coefficients showed that gentle slope luvisols on sunny/shady slopes had a positive interaction with vegetation, indicating that they are suitable for the growth of various vegetation types. Vegetation on gentle slope phaeozems had been restored to a good level, but there were still some areas with degradation. Plant community structure on steep slope luvisols on sunny/shady slopes was in a relatively stable state. NDVI in different geographical units had a weak correlation with temperature, and a significant positive correlation with precipitation. Our findings provide references for evaluating potential vegetation restoration as well as ecological restoration zoning and management in Liaohe River Basin (Liaoning section).

Key words: geographic unit, Liaohe River Basin, normalized difference vegetation index, vegetation change, climatic factor