Spatial characteristics and driving forces of the morphological evolution of East Lake, Wuhan

The shapes of the urban lakes in Wuhan city have been strongly influenced by the rapid industrialization and urbanization experienced in recent decades. Based on topographic maps and remote sensing images, the temporal and spatial changes of East Lake, Wuhan city, over the past two decades were analyzed. The landscape shape index(LSI) and centroid method were applied to analyze the evolution of lake morphology and its causes. Several key results were obtained.(1) The surface area of East Lake decreased sharply by 2.13 km2from 1995 to 2005, and slightly by 1.00 km2from 2005 to 2015. The shoreline length of East Lake displayed a continuous trend of decline during the study period: The length reduced by 21.89 km from 1995 to 2005, and by 0.67 km from 2005 to 2015. The LSI values, 7.04(1995), 6.46(2005), and 6.28(2015), displayed an accelerated downward trend, indicating a reduction of complexity in East Lake and the intensification of manual interventions in the water body.(2) The changes to East Lake displayed a clear temporal and spatial heterogeneity. The centroid of East Lake moved northeast from 1995 to 2005 and southeast from 2005 to 2015.(3) The reduction in the area of East Lake was mainly affected by human activities. A lake area of about 4.8 km2was converted to other land uses during 1995–2005, most of which was unused land, whereas from 2005 to 2015, 0.43 km2of the lake area was converted into built-up land, and 0.25 km2was converted into other land uses. The reduction in area was caused by infrastructure construction by the government, the development of the real estate industry, illegal construction by villagers, and the development of scenic spots for tourism. The driving forces of this reduction included Wuhan’s growing population, and the rapid development of the economy and urbanization between 1995 and 2015, which has resulted in a large demand for land. Finally, a formation mechanism model was constructed by analyzing the causes of East Lake’s morphological evolution.