基于Copula函数的北京市气候变化及人类活动对NDVI影响的识别

Identification of the Impacts of Climate Change and Human Activities on NDVI in Beijing Based on Copula Function

在气候变化和人类活动的双重影响下,城市植被受到严重影响,识别气候变化和人类活动对植被的影响,对城市的生态建设具有重要意义。本文依据《北京市城市总体规划》,运用Copula函数的方法考虑气候变化和人类活动对植被的影响进行分析。结果表明:北京市的植被在各个季节都呈现出较好的增长趋势,且在生态涵养区的增长趋势更加明显。NDVI-P的最优Copula函数主要为Frank Copula和Clayton Copula,而NDVI-T的最优Copula函数主要是Frank Copula函数。根据Copula函数的依赖结构分析表明,气候变化主要是通过影响植被的生长期和促进植被的光合作用来影响植被的生长;人类活动对植被的影响主要是通过建设活动与政策来影响植被的分布。

Under the dual effects of climate change and human activities, vegetation in urban areas has been severely affected. Identifying the impacts of climate change and human activities on vegetation is of great significance to the ecological construction of urban areas. This paper analyzes the impacts of climate change and human activities on vegetation using the method of Copula function based on the Beijing Urban Master Plan. The results showed that the vegetation in Beijing showed a good growth trend in each season, and the growth trend in the ecological conservation area was more obvious. The optimal Copula functions of NDVI-P are mainly Frank Copula and Clayton Copula, and the optimal Copula functions of NDVI-T are mainly Frank Copula functions. According to the analysis of the dependent structure of the Copula function, climate change affect the growth of vegetation through affecting the growth period of vegetation and promoting photosynthesis of vegetation;the impacts of human activities on vegetation is mainly the through construction activities and policies.