A Long-Term and Comprehensive Assessment of the Ecological Costs Arising from Urban Agglomeration Expansion in the Middle Reaches of the Yellow River Basin

Abstract

The Yellow River Basin (YRB) stands as one of China’s most significant river basins, and the maintenance of its ecological functionality is of paramount importance for national well-being. The Guanzhong Plain Urban Agglomeration (GPUA), situated in the middle reaches of the YRB, represents the central hub of human activities. The rapid expansion of cities within this region poses formidable challenges to the ecological security framework of the highly sensitive middle reaches of the YRB. In this study, the dynamic equivalent coefficient method was employed to evaluate the changes in Ecological Service Values (ESVs) within the GPUA from 1990 to 2020, as well as the ecological costs incurred due to urban expansion. The results indicate the following: (1) Over the past three decades, the land-use pattern within the GPUA has undergone significant transformations. The area designated for urban development has expanded by a factor of 1.16 compared to its original extent, while the areas encompassing forests, shrubs, agricultural land, grassland, wetland, and bare land have experienced continuous reductions. (2) The ESV of the study area displays a declining trend initially, followed by a subsequent increase over the 30-year period. Forests play a predominant role in contributing to the ESV of the GPUA, with regulating services and supporting services standing out as the primary ecosystem functions. (3) The expansion of the GPUA between 1990 and 2020 has resulted in a net loss of 3772.10 km2 of ecological land. The ecological costs associated with urban expansion soar to an astonishing CNY 2.54 billion, with the highest costs attributed to the loss of hydrological regulation and soil conservation services; this issue demands significant attention. The outcomes of this research contribute to a better comprehension of the ecological costs and benefits that accompany the development of urban agglomerations in the middle reaches of the YRB. Furthermore, they provide invaluable insights for decision makers seeking to implement more effective strategies for sustainable land-use management.