Measurement and evaluation of suitable ecological land based on the minimum cumulative resistance model: A case study in Shanghai, China

Abstract

Driven by rapid urbanization in China, land use change has become one of the most significant factors influencing the provision of ecosystem services. The conversion of ecological land, especially cropland, to the built-up area is the most significant change in the process of urbanization. Measuring the quantity and pattern optimization of urban ecological land is critical to guaranteeing urban ecological security and realizing urban sustainable development. In this study, the Chinese city of Shanghai, a very famous and important megacity in China, was selected as the case study to explore the land use changes from 1995 to 2017 and calculate the suitable amount of ecological land to meet the needs of socioeconomic development of Shanghai. Remote sensing and GIS-based techniques were used to map spatial distribution and changes in ecological land from 1995 to 2017. Results showed a continuing spatial expansion of the built-up area and decline in the ecological land. From 1995 to 2017, the proportion of ecological land in Shanghai dropped from 84.41% to 59.15%. Also we applied the minimum cumulative resistance model (MCRM) to calculate the amount of ecological land for Shanghai. Considering the potential source of ecological land and comparing the current land use status with the model simulation results, we proposed the suitable ecological land area for Shanghai should be no less than 3487.6km2, which is 51.2% of the total area of Shanghai, and is mainly distributed in Chongming County, Changxing Iland, Hengsha Iland and Jiuduan Iland. Our findings suggested that optimal land use strategies should be implemented in the urban construction process. For urban ecological land, further positive protection measures should be implemented. For ecotones between urban built up the area and ecological land, protection should be given priority and spatial expansion of built up area should be strictly controlled. For built up area, reasonable land use intensity should be kept to improve the land use efficiency.