2000-2020年陕西省植被 NDVI时空变化及 气候因子探测.

[Objective] This paper reveals the spatiotemporal changes of vegetation in different ecosystems in Shaanxi Province, clarifies the influence mechanisms of different climatic factors and their interactions on the changes of vegetation, and provides a theoretical basis for regional ecological environmental protection. [Methods] Based on MODIS NDVI and annual average high temperature, annual average low temperature, annual average temperature, and annual total precipitation data, this paper analyzed the spatiotemporal variation characteristics of vegetation NDVI in each landscape partition from 2000 to 2020 by Theil-Sen Median trend, partial correlation, and geodetector, and the internal correlations and response mechanisms of vegetation NDVI changes with precipitation and temperature were investigated by combining variable separation. [Results] Vegetation NDVI in Shaanxi fluctuated and increased from 2000 to 2020 at a rate of 5.9%/per decade, among which the rate of vegetation NDVI decreased in the different landscape in the order: Northern Shaanxi＞Guanzhong＞Southern Shaanxi.The multi-year vegetation NDVI value of the province was 0.71, with high level in the south and low level in the north. Vegetation NDVI in 67% of the regions showed a significantly improved trend during the study period, and the proportion in different landscape decreased in the order: Northern Shaanxi＞Southern Shaanxi＞Guanzhong. The climate factors fluctuated over time in Shaanxi from 2000 to 2020, the change rates in different landscape decreased in the order: Shaanxi South＞Guanzhong ＞Shaanbei. The spatial trends of temperature factors showed the decrease in annual average high temperature, the increase in annual average low temperature, and the decrease in annual average temperature, and the increase in precipitation. The overall vegetation NDVI of Shaanxi and each sub-district from 2000 to 2020 was negatively correlated with annual average high temperature and positively correlated with annual average low temperature, annual average temperature, and annual total precipitation. The contribution of annual total precipitation was greatest in the province and northern Shaanxi, and the contribution of annual average high temperature was greatest in Guanzhong and southern Shaanxi. The interaction of annual average high temperature and total annual precipitation had the strongest influence on vegetation NDVI in the province, northern Shaanxi and southern Shaanxi, and the interaction between annual mean temperature and total annual precipitation had the strongest effect on vegetation NDVI in Guanzhong. The interaction of of precipitation with maximum and annual average temperatures significantly influenced the vegetation NDVI changes. [Conclusion] The vegetation in Shaanxi and the sub-regions had became better overall during the study period. The vegetation in each sub-region responded differently to climate, and the contribution of each factor and its interactions also differed. [ABSTRACT FROM AUTHOR]