甘肃省草地植被NDVI时空变化特征及驱动因素研究

本文基于甘肃省2000—2019年归一化植被指数（normalized different vegetation index，NDVI）数据及气象数据，研究了甘肃省草地NDVI时空变化特征及驱动因素。结果表明：近20年，生长季草地NDVI整体水平较低但呈波动上升趋势，增速为0.030·（10a）^-1，草地NDVI分布呈现东南高西北低的格局；20年间生长季NDVI呈显著增加趋势的面积占甘肃省草地的19.08%，主要分布在陇中黄土高原；甘南高原和祁连山地生长季NDVI保持稳定，其中高寒草甸NDVI整体较高且稳定性较强；生长季草地NDVI受夏季降水量的影响较大；人类活动主要促进了草地NDVI的增长。整体而言，甘肃省草地NDVI呈现增长趋势且稳定性较高，降水量对草地NDVI的影响较强。另外，生态工程也促进了草地NDVI增长，需长期实施。

Spatio-temporal Variation and the Driving Factors of NDVI of Grassland Vegetation in Gansu Province

This study used the NDVI and meteorological data of Gansu Province from 2000 to 2019 to find out the spatio-temporal variation and driving factors of NDVI. The results showed that,in the last 20 years,although the grassland growth season NDVI in Gansu Province was generally low but the annual average NDVI was increasing by 0.030·(10a)^-1 (P<0.05). The grassland NDVI was higher in southeast and lower in northwest of Gansu Province. Approximately 19.08% of grassland areas had a significant (P<0.05) increasing trend in the growth season NDVI,which were mainly located in the Loess Plateau region. The growing season NDVI remained stable in the Gannan Plateau and Qilian Mountains regions. Among the Alpine meadow which had a relatively high and stable NDVI. The grassland growing season NDVI was strongly influenced by summer precipitation. Human activities mainly contributed to the growth of grassland NDVI. In summary,the grassland NDVI in Gansu Province generally showed an increasing trend and was relatively stable in the last 20 years. And precipitation had a strong influence on grassland NDVI. In addition,ecological engineering have contributed to the growth of grassland NDVI,which needs to be implemented in the long term.