Simulation method of water quantity and quality in urban built-up areas based on landscape pattern
Landscape diversity helps to improve urban resilience,but the fragmentation of permeable patches and the change of corridor connectivity caused by landscape diversity will affect the generation and transport characteris-tics of non-point source pollution in urban areas.The traditional quantitative assessment of non-point source pollu-tion neglects the influence of landscape pattern(shape,proportion and spatial configuration)on material transport in catchment unit,which is the main reason for the low simulation accuracy.To solve this problem,this study combined remote sensing image and urban landscape pattern distribution characteristics,and built a landscape pat-tern based catchment unit division method(landscape pattern method).SWMM model was used to study Shwuli River,a first-level tributaries of the Chaohu Lake.The results show that:(1)Based on the measured data,the NSE of each index(water volume,COD,TP and NH3-N)simulated by landscape pattern method is greater than 0.7,and the results are reliable;(2)Compared with the traditional method(Tyson polygon division of catchment units),the precision of water quantity simulation(NSE)increased by 8％,and the precision of water quality sim-ulation increased by 6％;(3)Compared with the Tyson polygon method,the landscape pattern method weakened the total water flow into the river and the total pollution load,and had a lagging effect on the peak pollutant concen-tration;(4)By changing the hydraulic connection between catchment units,the landscape pattern method weak-ened the pollutant scour process,thus reducing the initial rain scour effect.Moreover,with the increase of the re-currence period,the effect of reducing the initial rain scour intensity becomes more obvious,indicating that to a certain extent,the diversification of landscape types can help to alleviate the impact of instantaneous high-intensity pollution.The method constructed in this study fully considers the landscape pattern distribution characteristics and hydraulic linkages within urban patches,which can provide a new assessment method for urban non-point source pollution output control.
万方数据
维普
