|
|||||
|
|
A two-layer model for studying 2D dissolved pollutant runoff over impermeable surfaces |
|
| Authors: | Taotao Zhang Yang Xiao Dongfang Liang Hongwu Tang Junzeng Xu Saiyu Yuan Nairu Wang Bin Luan |
| Institution: | 1. State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Hohai University, Nanjing, China
College of Water Conservancy and Hydropower Engineering, Hohai University, Nanjing, China College of Agricultural Engineering, Hohai University, Nanjing, China;2. State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Hohai University, Nanjing, China;3. Department of Engineering, University of Cambridge, Cambridge, UK;4. State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Hohai University, Nanjing, China College of Agricultural Engineering, Hohai University, Nanjing, China;5. State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Hohai University, Nanjing, China College of Water Conservancy and Hydropower Engineering, Hohai University, Nanjing, China;6. River Harbor Engineering Department, Nanjing Hydraulic Research Institute, Nanjing, China;7. College of Water Conservancy and Hydropower Engineering, Hohai University, Nanjing, China |
| Abstract: | Dissolved pollutants in stormwater are a main contributor to water pollution in urban environments. However, many existing transport models are semi-empirical and only consider one-dimensional flows, which limit their predictive capacity. Combining the shallow water and the advection–diffusion equations, a two-dimensional physically based model is developed for dissolved pollutant transport by adopting the concept of a ‘control layer’. A series of laboratory experiments has been conducted to validate the proposed model, taking into account the effects of buildings and intermittent rainfalls. The predictions are found to be in good agreement with experimental observations, which supports the assumption that the depth of the control layer is constant. Based on the validated model, a parametric study is conducted, focusing on the characteristics of the pollutant distribution and transport rate over the depth. The hyetograph, including the intensity, duration and intermittency, of rainfall event has a significant influence on the pollutant transport rates. The depth of the control layer, rainfall intensity, surface roughness and area length are dominant factors that affect the dissolved pollutant transport. Finally, several perspectives of the new pollutant transport model are discussed. This study contributes to an in-depth understanding of the dissolved pollutant transport processes on impermeable surfaces and urban stormwater management. |
| Keywords: | dissolved pollutant impermeable surfaces pollutant transport rainfall runoff rainfall simulation |