Simulation of sponge city landscape pattern optimization based on the storm water management model (SWMM).

With the rapid urbanization and increasing urban impervious areas in China, urban water-logging has become increasingly serious. The concept of sponge city was proposed based on the low impact development (LID) idea. We analyzed the impacts of landscape pattern optimization scenario on urban surface runoff and rainwater control ability in central urban area of Shen-Fu New Town in Liaoning Province. The storm intensity formula was used to construct rainfall process in different return periods. The landscape patterns of the study area were optimized based on sponge city concept. The storm water management model (SWMM) was used to simulate the differences of surface runoff and rainwater regulation ability under the pre-planning scenario and the landscape pattern optimization scenario. The results showed that total runoff and runoff coefficient of the study area were increased with increasing rainfall return period. In the same rainfall return period, the runoff coefficient was significantly reduced. The reduction of total runoff gradually increased, being 2.94, 3.58, 3.72, and 4.19 mm during the 1-year, 3-year, 5-year and 50-year return period under landscape pattern optimization scenario. The corresponding reduction rate was gradually reduced, being 23.9%, 16.4%, 14.3%, and 9.3%, respectively. Landscape pattern optimization scenario could meet the requirements that the rainfall was controlled at 20.8 mm when the rainfall return period p=1 year, the rainwater pipe network would not overload when p=3 years, and the river channel would not overflow when p=50 years.

Landscape ecological planning of coastal industrial park based on low impact development concept: A case of the second coastal industrial base in Yingkou City, Liaoning Province, China.

Low impact development (LID) of industrial parks is an important component in the construction of China's sponge cities. We compared the methods of optimizing ecological spatial structure for rain and flood control in industrial parks, via analyzing the influence of landscape pattern on hydrological process. Firstly, according to the hydrological and geological conditions of the coastal area, the landscape pattern of the industrial park was optimized, with the water corridor system being structured and green patches being integrated. Then, the reasonable spatial allocation for the ecological infrastructure of the industrial park was realized, with the rain and flood control areas being divided based on the characteristics of the underlying surface. The runoff control indices of different control areas were determined, and the LID technical measures of different landscape nodes were selected. The results showed that the landscape pattern optimization strengthened landscape connectivity by constructing the ecological network within the industrial park. The runoff control rate of the park increased from 45% to 70% through the combination of various LID technologies, with the pervious pavement, submerged green space, rainwater garden, wet pond and grass ditch accounting for 1.3%, 1.9%, 0.2%, 0.2% and 0.1% of the total area, respectively. This study could provide new ideas and methods for the low impact development and construction of coastal industrial parks.