Spatiotemporal evolution of vegetation coverage in Beijing-Tianjin-Hebei and its response to natural anthropogenic changes
This study investigated the spatiotemporal changes of vegetation cover in Beijing-Tianjin-Hebei region using Sen trend analysis,Mann Kendall significance test and Hurst index analysis,in which FVC was synthesized using the maximum value of the like element dichotomous model based on the normalized difference vegetation index(NDVI)data from 2001 to 2020.In addition,this study also quantified the relative contribution rate of impact factors using meteorological factor data,correlation analysis and residual analysis.The results indicated that the vegetation construction in Beijing-Tianjin-Hebei region was good in the past 20 years.The average coverage was 64.5%in the whole region,and the vegetation change rate varied from-0.0597421/a to 0.039797/a.However,the vegetation cover fluctuated greatly,which showed obvious geographical differences.The spatiotemporal variation of FVC in this region can be affected by a multitude of factors.The distribution of FVC was negatively correlated with temperature,and its distribution area was close to the geographical boundaries,which was related to the urban heat island effect.Conversely,the FVC showed a positive correlation with precipitation,and its distribution followed ecological zones,predominantly regulated by geographical factors.The average residual error of human activities was-0.00105,mainly exhibiting negative impact.Furthermore,the relative contribution rates of natural factors and human factors were 31.33%and 68.67%,respectively.This revealed that human activities were the major driver of vegetation change.Although a positive trend is expected,a decrease in FVC is also predicted in urban areas.This study can guide the FVC monitoring at the junction of Beijing,Tianjin and Hebei,carry out positive human intervention,enhance the environmental quality of Beijing-Tianjin-Hebei,and boost the high-quality development of the regional ecological environment.
NETL
NSTL
万方数据
