渭河流域植被动态监测与驱动力分析

Vegetation dynamics monitoring and driving force analysis in the Weihe River Basin

渭河流域是中国北方的重要农业区和生态区,植被覆盖变化对区域的生态环境和经济发展具有重要影响。本研究基于MODIS NDVI数据和气象数据,采用Theil-Sen趋势分析、Mann-Kendall趋势检验、Person相关性、Hurst指数等方法对渭河流域2000—2020年植被覆盖变化空间演变特征进行分析。研究表明,2000—2020年渭河流域NDVI整体以升高趋势为主,呈现由东南向西北逐渐递增的趋势;NDVI改善明显的区域占比为83.95%,NDVI退化明显的区域占比为2.62%。在未来特征趋势方面,NDVI主要呈现反向特征,以持续改善为主体,主要分布在榆林市、庆阳市、延安市、渭南市等地区;在气象因子方面,降水是渭河流域植被变化的主要驱动因素,二者呈现正相关关系。

The Weihe River Basin is an important agricultural and ecological area in northern China,and changes in vegetation cover have an important impact on the ecological environment and economic development of the region.Based on MODIS NDVI data and meteorological data,this paper uses Theil-Sen trend analysis,Mann-Kendall trend test,Person correlation method and Hurst index to analyze the spatial evolution characteristics of vegetation cover changes in the Weihe River basin from 2000 to 2020.The results show that from 2000 to 2020,NDVI in the Weihe River Basin is mainly increasing,showing a gradual increasing trend from southeast to northwest,and 83.95%of the areas shows obvious improvement in NDVI,while 2.62%of the areas shows obvious degradation.In terms of the characteristics of the future trend,NDVI mainly shows the reverse characteristics,and the sustained improvement accounts for the main body,which is mainly distributed in the cities of Yulin,Qingyang,Yan'an and Weinan.In terms of meteorological factors,precipitation is the main driving factor for vegetation changes in the Weihe River basin,showing a positive correlation with vegetation cover.