Impact of urbanization on the spatial and temporal evolution of the water system pattern: A study of the Wuhan metropolitan area in China

Abstract

With the rapid economic development and continuous urbanization, the status of river ecosystems is undergoing profound changes. Therefore, quantitative assessment of the impact of urbanization on the water system is highly desirable. Considering Wuhan metropolitan area as the study area, this study constructed an indicator system and used the entropy technique for order preference similarity to ideal solution (TOPSIS) method to quantify the urbanization level of each city. The urbanization process was divided into four periods based on the results of the urbanization level measurement. Then, the theory of landscape ecology was used to establish the evaluation index system of the water system pattern. Finally, the study used the grey relational analysis model to analyze the relationship between urbanization and evolution of water patterns under different periods. The results indicate that (1) from 2000 to 2019, the urbanization level of Wuhan metropolitan area exhibited an increasing trend, while the four indicators of the quantitative attribute and the two indicators of complexity showed a decline. (2) A negative correlation was observed between urbanization level and water system pattern indicators, with the correlation ranging from 0.55 to 0.62 (maximum value is 1). The urbanization process shows the most significant impact on the quantitative characteristics of water systems. (3) After classifying the urbanization stages, the correlation further increased between 0.55 and 0.95. (4) The four indicators of water patterns with the highest correlation with urbanization in the given periods are class area, area-weighted mean patch fractal dimension, edge density, and number of patches. Management can judge the corresponding human activities in relation to the current stage of the urbanization process and targeted protection of the water systems.