Ecological security assessment based on ecosystem service value and ecological footprint in the Pearl River Delta urban agglomeration, China

Abstract

The ecological environment in the Pearl River Delta (PRD) urban agglomeration has been affected by the acceleration of industrialization and urbanization, such as the urbanization lags behind industrialization and the level of town construction is backward, resulting in ecological and environmental problems. Thus, this paper detected the ecological security (ES) in the PRD urban agglomeration through the ecological footprint (EF) method, providing a reference for regional ES evaluation. Equivalence factor and yield factor were first calculated based on the ecosystem services value (ESV) for EF calculation. Then, we established the ES evaluation index system through EF, including per capita ecological deficit (ED), ecological footprint diversity index (EFDI) and ecological pressure index (EPI). The results showed that the difference between equivalence factor and yield factor for various land type was observed in the study region. Water regions had the largest equivalence factor, with the value of 2.48, indicating that human activities were most affected by water. Grassland has the highest biological production capacity as the yield factor of which is the highest, with the value of 4.36 in 2020. Temporally, the per capita EF in the PRD urban agglomeration has been increased from 2000 to 2020, while the per capita ecological carrying capacity (ECC) has been decreased over time, indicating that the ecological pressure is rising because of human activities. Spatially, the per capita EF and the per capita ECC show a spatial pattern of “low in the middle and high around”. In addition, the per capita ED shows an increasing trend, reaching 0.11 hm2/capita by 2020. The EFDI has decreased by 0.26, indicating that the richness and fairness of the ecosystem are declining. The ES is in “not safe” and “extremely unsafe” level in 2020, which has threatened the ecological environment in the region. Therefore, the ecological environment in this region is deteriorating, restricting sustainable development. There is no doubt that the region needs to strengthen environmental protection and balance the relationship between economy and ecology. If ecology is not taken seriously, the ED will grow and the insecurity of the ecological environment will continue to increase. The current state of the ecological environment in the PRD urban agglomeration is only a microcosm of the ecology in many small and medium scale regions. The results of this paper are useful for providing ideas for EF and ES analysis of other regions.