Construction of ecological security pattern based on remote sensing urban ecological index and circuit theory: a case study of Guangzhou City, Guangdong Province of southern China

Objective In recent years, the rapid development of urbanization has made the contradiction between economic development needs and ecological protection increasingly prominent, and the construction of an ecological security pattern is of great significance for realizing the harmonious coexistence between man and nature and the optimization of spatial structure of the national territory.

Method Taking Guangzhou City, Guangdong Province of southern China as an example, the ecological source sites were selected using the remote sensing ecological index (RSEI), and ecological corridors, ecological pinch points and barrier points were extracted by the minimum cumulative resistance model and circuit theory, so as to construct the ecological safety pattern of Guangzhou City.

Result  (1) The ecological and environmental quality of Guangzhou City from 1990 to 2020 was relatively good, with the average value of RSEI decreasing from 0.60 to 0.58 and then increasing to 0.60, showing a trend of first decreasing and then increasing, but the difference between the habitat quality in the southern part and the northern part was large. (2) A total of 25 ecological source sites were identified, with a total area of 1 511.26 km², accounting for 20.33% of the total area of Guangzhou City, mainly concentrated in the northeast of the study area, with only 3 ecological source sites in the south. A total of 50 ecological corridors were extracted, including 20 primary corridors with a total length of 114.06 km, 22 secondary corridors, and 8 potential corridors. (3) A total of 48 ecological pinch points were identified, with the current land use types mainly being forest land, farmland and construction land, of which the largest area was 19.09 km², located in the area of Lianhua Mountain in Panyu District, and the smallest pinch point was only 0.11 km² in area. A total of 12 ecological barriers were identified, mainly in Huangpu District and Conghua District, where the current land use was mainly arable land and construction land, with the largest area of 0.42 km² located in the north of Dongpu Farm in Conghua District, and the smallest area of 900 m². 63 fracture points were identified, mainly in Baiyun District and Huangpu District in central Guangzhou.

Conclusion The research results can provide data support for the optimization of the future urban spatial pattern and ecosystem restoration in Guangzhou City, and at the same time, provide a reference for the construction of the ecological security pattern of other super-large cities.