Lake Evolution and Its Response to Urban Expansion in Wuhan City in the Last Hundred Years Based on Historical Maps and Remote Sensing Images

Wuhan is dotted with lakes, known as “ City with Hundreds of Lakes”, the development of the city is inseparable from the river and lake waters, the evolution of the lakes has been affecting the construction and layout of the city. Since the 20th century, the lake evolution in the main urban area of Wuhan is the most intense and the urban development is also the most rapid. Therefore, based on the precious high-precision historical maps of Wuhan in the early and mid-20th century, combined with the information of lakes in Wuhan obtained from satellite remote sensing images, the evolution characteristics of lakes in Wuhan in the past 100 years (1920~2019) were investigated through the theory of landscape fractal, and the response mechanism of lake evolution to urban expansion was further explored by combining with the trajectory of urban expansion. The results show that the area of lakes in Wuhan declined from 2,133.5 km2 in 1920 to 550.8 km2 in 2019, with a total decrease of 1,582.7 km2, an area shrinkage rate of 74.18 % , and a strong amplitude of area change. The changes of fractal dimension and shoreline development coefficient of lakes in Wuhan city show synchronization as a whole, with occasional fluctuations, but on the whole the fractal dimension and shoreline development coefficient of lakes are getting smaller in a century. Specifically, the evolution of lakes in the Hankou area is mainly affected by the construction of dykes and lake filling, and most of the lakes are resolved and fragmented under the influence of urban expansion, whereas the evolution of lakes in Wuchang and Hanyang is mainly caused by the urban construction around the lakes, and many lake branches are cut for various urban constructions, and the shape of the lake tends to be simple and regular under the influence of urban expansion. This study is of great significance to fill in the history of lake evolution in Wuhan before the popularization of remote sensing, and to guide the rational development of lakes in Wuhan and the sustainable and healthy development of Wuhan.