Spatio-Temporal Evolution Pattern and Optimization Strategies of Water–City Integration in Waterfront Cities from a Symbiosis Perspective: A Case Study of Suzhou, China

Waterfront cities face growing strain from urbanization, complicating the relationship between water bodies and urban development. This study aims to understand the evolving water–city relationship in such areas by applying symbiosis theory, offering a framework for sustainable spatial governance. Using Suzhou as a case study, a “water-city-environment” evaluation system was constructed based on multi-source spatiotemporal data and the Lotka-Volterra model to analyze the period from 2010 to 2020. The key findings include: (1) All symbiotic systems showed growth trends in most areas of Suzhou during 2010–2020; (2) the symbiosis modes gradually shifted towards benign interactions. The city pattern evolved from being dominated by parasitism and mutual detriment in the early stages to commensalism and mutualism; (3) The symbiosis degree index demonstrated spatial convergence and improvement, fluctuating upwards over time. In conclusion, the study provides a dynamic identification framework that supports coordinating urban development with water conservation, contributing to the sustainable planning of waterfront cities.