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Updated: Jun 28, 2026
Measuring and Mapping Patterns of Soil Erosion and Deposition Related to Soil Carbonate Concentrations Under Agricultural Management
Published on: September 12, 2017
Unveiling the nonlinear impact of urban-rural impervious surface expansion on ecosystem carbon sinks in China: Toward
Qiao Zhao1, Yaobin Liu2, Shuoshuo Li3
1School of Digital Economics, Jiangxi University of Finance and Economics, Nanchang, 330013, China; Technical Innovation Center for Land Spatial Ecological Protection in Large Lake Basins, Ministry of Natural Resources, Nanchang, 33025, China.
Abstract:
Global climate governance makes ecosystem carbon sinks (ECS) increasingly important for tackling climate change and ecological security. However, impervious surface expansion (EIS) threatens their stability. Many studies ignore the spatially heterogeneous impacts of EIS on ECS across urban-rural and geographical contexts and overlook possible nonlinear relationships. Therefore, this study measures ECS and the proportion of impervious surface area (PIS) across 365 Chinese cities from 2001 to 2023, and analyses their spatiotemporal patterns. Then, a hierarchical analytical framework encompassing "overall-urban-rural" and "overall-clustering" dimensions was constructed. Econometric models and machine learning algorithms are combined to pinpoint impact mechanisms and critical thresholds of EIS on ECS. This provides a scientific basis for targeted spatial zoning policy. The results show that: (1) ECS increased from 5.167 Mt to 7.543 Mt, forming a stable pattern featuring "high values at both ends, decreasing in a gradient manner" along the Hu Huanyong Line. (2) PIS rose from 4.198% to 7.239%, with high-value areas southeast of the Hu Huanyong Line and northeast of the Bole-Taipei Line. (3) EIS significantly reduces ECS, with an impact coefficient of -0.259. When PIS exceeds 2.83%, it notably diminishes ECS capacity. Heterogeneity analysis reveals that the influence effect and critical threshold differ across clusters. And, the threshold is much higher in urban than in rural areas. Identifying critical EIS thresholds provides a scientific basis for ecological protection and improved spatial planning. Finally, based on the 2.83% upper limit of PIS and differentiated urban-rural thresholds, this study proposes hierarchical and classified spatial management strategies, including the delineation of ecological restoration priority areas, release of gray space, removal of hardened surfaces, and coordinated urban-rural planning.
