2000-2022年庆阳市NDVI时空变化及影响因素研究OA

As a critical ecological conservation area in the Longdong region,the ecological management of Qingyang City is vital for ecological construction and sustainable development in Gansu Province.Using normalized difference vegetation index(NDVI),temperature,and precipitation datasets from 2000 to 2022,this study employed Theil-Sen trend estimation,the Mann-Kendall test,and correlation analysis to investigate the spatiotemporal variation of NDVI and its climatic factors.The results indicate that from 2000 to 2022:1)NDVI increased most rapidly in summer,with a decadal rate of 0.098,and spatially exhibited a pattern of higher values in the southeast and lower values in the northwest.Medium-high and high vegetation cover accounted for 21.46%of the region,and 89.06%of the area showed improved vegetation cover,reflecting a sustained positive ecological trend.2)The climate exhibited a warming and wetting trend,with the fastest temperature increase in spring(0.132℃per decade)and the fastest precipitation increase in summer(18.769 mm per decade).Spatially,NDVI was strongly and positively correlated with temperature(68.71%of areas)and precipitation(81.44%of areas).Temporally,a"time-lag effect"was observed between NDVI and climate factors,with precipitation showing a more pronounced lag,extending up to three months,than temperature.Overall,precipitation exerted a stronger influence on vegetation growth(r=0.991,P<0.01).These findings provide a scientific basis for ecological management and sustainable development in Qingyang City and Gansu Province.