陕西省植被生长与地表水分状况演变及驱动机制OA

This study assesses the synergistic evolution of regional vegetation restoration and surface moisture supply within the context of major ecological engineering initiatives.We developed a multidimensional assess-ment framework incorporating vegetation quantity(NDVI),growth quality(VCI),and surface water restriction(TVDI).Using high-resolution MODIS V6.1 data from 2000 to 2024,we analyzed the spatiotemporal evolution,interannual stability,and nonlinear driving mechanisms of vegetation growth and surface moisture in Shaanxi Province.Our analysis employed Theil-Sen trend analysis,the coefficient of variation(Cv),and the geographical-ly weighted regression model.The key findings are as follows:(1)Over the past 25 years,Shaanxi Province ex-hibited highly significant improvements in both vegetation greenness and physiological health(P<0.001).The av-erage annual growth rates for NDVI and VCI were 0.0049 and 0.4866,respectively.The surface moisture deficit(TVDI)showed a nonsignificant downward trend(-0.0008·a-1,P>0.05),suggesting that regional water condi-tions remained stable despite large-scale greening.(2)Regional ecological restoration displayed significant spa-tial heterogeneity and functional mismatch.In the northern Loess Plateau,over 98%of the area showed vegeta-tion improvement,but it also exhibited the highest interannual variability,reflecting"high restoration rates but low ecological stability."The Guanzhong Plain,affected by intense human interference,emerged as the primary zone for vegetation degradation and surface moisture deficit risks.By contrast,the Qinba Mountains in southern Shaanxi demonstrated the highest ecosystem resilience and stability.(3)The driving mechanisms varied signifi-cantly across different climatic zones.In semi-arid northern Shaanxi,precipitation was the dominant positive driv-er for vegetation improvement.However,in the Guanzhong Plain,a significant negative correlation was observed between precipitation and the vegetation index.This anomaly is primarily attributed to the"cloud-shading ef-fect,"where increased precipitation reduces effective sunshine hours,making light limitation the key constraint on vegetation photosynthesis in this region.In southern Shaanxi,vegetation growth was jointly driven by hydro-thermal conditions,with surface drought primarily controlled by potential evapotranspiration.(4)Human activi-ties more significantly affected the surface moisture environment than vegetation cover.In urban built-up areas,urbanization,characterized by impervious surface expansion and the heat island effect,was the primary physical mechanism inducing local surface moisture deficits.The Nighttime Light(NTL)index(q=0.069)demonstrated significantly greater explanatory power for TVDI than did population density(POP,q=0.025).This suggests that continuous increases in vegetation greenness may be accompanied by potential risks of ecosystem instability and moisture imbalance.These findings offer a scientific basis for regional ecological management to transition its fo-cus from quantitative expansion to enhancing the quality,stability,and water-resource adaptability of restored eco-systems.Recommended regional strategies include promoting"sponge cities"in the Guanzhong Plain and opti-mizing water-adaptive vegetation configurations in the Loess Plateau.