Multi-objective decision-making considering future demands helps to delineate key areas for ecological restoration in Changsha-Zhuzhou-Xiangtan urban agglomeration, China

Abstract

ecological restoration is an effective method to address land degradation and ecosystem deterioration of urban agglomeration with rapid development. However, previous efforts neglect socio-economic goals for ecological restoration and the land use demand in the future, leading to a disconnect between ecological restoration and the support for social and economic development. Here we explore the identification of key areas for ecological restoration (KAsER) according to a multi-objective view of the urban agglomeration, as well as future demand. Chang-Zhu-Tan urban agglomeration (CZTUA), playing a vital role in the implementation of strategy for the rise of central China, is facing the contradiction between ecosystem protection and development. Hence, taking it as a case study, four restoration scenarios, namely natural growth (NGS), ecological conservation (ECS), economic development (EDS), and comprehensive development scenario (CDS), were constructed. The potential restoration areas were identified integrating the historical land use change and the land demand for the future development initially. The ecological-economic-social objectives were to increase ESP, minimize restoration expenses, and improve the ES provision-demand match. Finally, the KAsER was determined based on the coupling value of triple objectives and it was further divided into ecological restoration zones according to the overlay analysis of multi-objectives. Results show that KAsER encompasses 640.32 (ECS), 415.75 (NGS), 332.00 (CDS), and 262.18 (EDS) km² respectively. There are eight zones for KAsER, and those with low-expense, high-benefits, and low-match of ES provision-demand should be prioritized for restoration regardless of scenarios. These findings provide a scientific foundation for reasonable and efficient ecosystem management facing uncertainties of future development for cities in central China.