2001—2019年黄土高原植被覆盖度时空演化特征及地理因子解析

探究黄土高原植被覆盖度变化及其与地理因子之间的关系有助于区域植被恢复政策的优化以及人地关系的协调发展。因此，以MOD13 A1数据作为数据基础，采用趋势分析、标准差和重心迁移模型，研究2001—2019年黄土高原植被覆盖度FVC(Fractional Vegetation Cover)时空演化特征，并结合地理探测器和相关分析对影响FVC的地理因子进行解析。结果表明：(1)2001—2019年黄土高原植被覆盖度恢复状况较好，FVC平均增速为0.0095/a,呈东南高西北低分布，极显著、显著增加的区域面积占比为84.37%,研究区各年FVC重心位于陕北一带，19年向北推进55.1km;(2)各地理因子对FVC的解释力存在显著差异，降水、土壤类型、气温、土地利用类型和坡度是FVC空间分布的主要驱动因子，且各因子之间交互作用的解释力高于单因子；(3)FVC与气温、降水相关系数均以正相关为主；FVC均值与变化趋势存在地形、土壤、人口密度、土地利用分异特征；土地利用转移可体现人类活动特征，其退耕还林还草、未利用地绿化等积极效应促使区域植被得到显著改善，城市扩张等消极效应则抑制植被增长。

Spatio-temporal variations of vegetation coverage and its geographical factors analysis on the Loess Plateau from 2001 to 2019

Exploring the relationship between vegetation coverage change and geographical factors on the Loess Plateau is conducive to the optimization of regional vegetation restoration policies and the coordinated development of man-land relations. Therefore, based on MOD13A1 data, using trend analysis, standard deviation and gravity migration model, the temporal and spatial evolution characteristics of FVC (Fractional Vegetation Cover) in Loess Plateau from 2001 to 2019 were studied, and the geographical factors affecting FVC were analyzed with GeoDetector and correlation analysis. The results show that: (1) the vegetation coverage recovery of the Loess Plateau was good from 2001 to 2019, and the average growth rate of FVC was 0.0095/a, with a high distribution rate in southeast and low distribution rate in northwest, and the area proportion of extremely significant and significantly increased was 84.37%. The center of gravity of FVC in the study area each year was located in northern Shaanxi, and it advanced 55.1km northward in 19 years. (2) There were significant differences in the explanatory power of each geographical factor on FVC. Precipitation, soil type, air temperature, land use type and slope were the main driving factors of FVC spatial distribution, and the explanatory power of interaction among the factors was higher than that of the single factor. (3) The correlation coefficient of FVC with temperature and precipitation was mainly positive, and the mean value and trend of FVC were characterized by terrain, soil, population density and land use differentiation. Land use transfer can reflect the characteristics of human activities, and its positive effects, such as returning farmland to forest and grassland, greening unused land and so on, can significantly improve regional vegetation, while the negative effects, such as urban expansion, can inhibit vegetation growth.