Multifactorial Discrepancies in the Spatiotemporal Driving Mechanisms of Urban Ecological Quality: Evidence from Shanghai, China

Abstract

Urban ecological quality (UEQ) suffers from dramatic changes due to influence factors from multiple sources such as intensified human activity and climate change. A comprehensive analysis of the driving mechanisms is imperative for targeted ecological management. However, existing studies lack a spatiotemporal perspective to explore the discrepancies in driving mechanisms among multiple factors in detail. To address this critical gap, we established a spatiotemporal sequence of remote sensing ecological index (RSEI) from 2000 to 2020 in Shanghai and employed Geographically and Temporally Weighted Regression (GTWR) to meticulously investigate the multiple driving factors. Additionally, we utilized the K-Means clustering to uncover differentiation in the driving characteristics and mechanisms among different factors. Our findings revealed profound insights: 1) The overall RSEI exhibited a marginal decline from 2000 to 2005, followed by an improvement from 2005 to 2020 in Shanghai. The UEQ was mainly driven by the vegetation communities and also influenced and disturbed by a combination of abiotic factors including human activities, climate, soil, and topography. 2) The clustering of UEQ evolution in Shanghai is consistent with a certain urban-rural gradient. Multiple factors' driving roles and characteristics differ in distinct clustering areas, forming differentiated driving mechanisms that jointly influence the trajectory of UEQ spatiotemporal evolution. 3) Human activities play the largest negative inhibitory role among all drivers. Climatic factors show highly fluctuating time serial characteristics. This case study taking Shanghai as an example, not only depicts the evolutionary trajectory of UEQ in the last two decades but also analyzes and reveals in detail multifactorial discrepancies in the spatiotemporal driving mechanisms. Our research can provide references for environmental observations, targeted ecological management, and planning in Shanghai and other urban areas