Remote Sensing Monitoring Analysis of the Impact of Urban Expansion Patterns on Forest Fragmentation:A Case Study of Chengdu City
Based on Landsat-5 TM and Landsat-8 OLI satellite images from 1991 to 2021,using the global 30 m fine ground cover dynamic monitoring products from 1985 to 2020,the transfer matrix,landscape pattern index,center of mass and standard deviation ellipse,and urban expansion index in Chengdu were calculated by the object-oriented retrospective classification technique,revealing the influence of urban expansion direction,type and pattern on forest fragmentation.The results showed that the forest area in Chengdu decreased by more than 200 km2 over the past 30 years,and the rate of reduction has gradually slowed down.The degree of separation between the forest and the city,the index of patch cohesion showed a significant negative correlation,and the degree of fragmentation of the forest deepened year by year and was closely related to the urban expansion.The center of mass of the forest area in Chengdu shifted to the northwest year by year,the center of mass of the city shifted to the southwestern direction,and the urban expansion had a direct influence on the forest change.The marginal expansion of impervious surfaces encroached seriously on the forest,the enclave expansion tended to cause forest fragmentation,and the infill expansion has the least impact on the forest and did not hinder the upgrading of the urban level.
万方数据
