宁夏植被覆盖时空变化对气候因素的响应

Spatio-temporal response of vegetation cover to climatic factors in Ningxia

【目的】植被是衡量生态环境优劣的重要部分,通过研究宁夏植被覆盖的大小以期为区域的生态改善提供理论依据。【方法】利用2001~2021年MODIS-NDVI数据集、气象数据,用最大值合成法、均值法、趋势分析法、相关分析法等分析宁夏植被覆盖时空演变特征,探讨植被时空变化与气候因素的关系。【结果】2001~2021年宁夏植被覆盖呈波动增加趋势,增长速率为0.001 4,夏季NDVI的变化速率为0.002 4,植被改善较明显。从空间上看,2001~2021年南部地区植被显著增加,占总面积的27.75%,在中部地区植被覆盖基本不变,占总面积的39.21%,而北部地区植被覆盖显著减少,面积占比较小。南部地区植被覆盖与气温呈负相关、与降水呈正相关。北部地区植被覆盖与气温呈正相关、与降水呈负相关。【结论】2001~2021年间宁夏植被覆盖状况呈现逐步变好的趋势,生态环境逐步改善,这与研究区域近20 a气温升高和降水增加有一定的相关性。

【Objective】 Vegetation is an important part of measuring the quality of the ecological environment.Studying the extent of vegetation cover can provide a theoretical basis for regional ecological improvement,so that appropriate measures can be taken to improve the ecological environment.【Method】 Using the MODIS-NDVI dataset and meteorological data from 2001 to 2021,the spatio-temporal evolution of vegetation cover in Ningxia is analyzed by maximum value synthesis method,mean value method,trend analysis method and correlation analysis method,and the relationship between spatio-temporal vegetation change and climatic factors is discussed.【Result】 From 2001 to 2021,the vegetation cover in Ningxia showed an increasing trend of fluctuation,the growth rate was 0.0014,the change rate of summer NDVI was 0.002 4,and the vegetation improvement was obvious.In terms of area,from 2001 to 2021,the vegetation cover in the southern region increased significantly,accounting for 27.75% of the total area;in the central region,the vegetation cover remained basically unchanged,accounting for 39.21% of the total area;in the northern region,the vegetation cover decreased significantly,accounting for a relatively small area.In southern China,vegetation cover was negatively correlated with temperature and positively correlated with precipitation.In northern China,vegetation cover is positively correlated with temperature and negatively correlated with precipitation.【Conclusion】 From 2001 to 2021,the vegetation cover in Ningxia showed a gradual improvement trend and the ecological environment gradually improved,which was related to the increase in temperature and precipitation in the study area in the last 20 years.