Taking the Yangtze River Delta Ecological Green Integrated Development Demonstration Zone as an example, based on the hydrological hydrodynamic model of the Taihu Lake Basin, a series of scenarios of changes in drainage capacity and scheduling rules are set up, and a trial calculation is carried out by taking the 1999 southern-type design rainfall of the Taihu Lake Basin as an input to obtain the water level process data of the main river satin surface and the maximum water level data in m of the major river channels in the Yangtze River Delta Ecological Green Integrated Development Demonstration Zone. Based on these data, the impacts of flooding situation within and adjacent to the city due to changes in drainage capacity and rules are analyzed, and finally the mutual feedback effects of cross-regional urban drainage are quantified based on the constructed drainage response index.
City flooding capacity and scheduling rule changes can change the flooding situation within the city itself, Wujiang and Qingpu polder flood control pressure by the drainage capacity of the smaller, by scheduling water level adjustments to the impact of Jiashan is the opposite. Wujiang drainage capacity and Jiashan, Qingpu flood control pressure was positively correlated, drainage capacity changes, can significantly change the Jiashan, Qingpu dike outside the river flood control pressure; Qingpu and Jiashan drainage capacity changes in adjacent cities dike outside the river flooding situation to change the influence of smaller.
Adjustment of the scheduling level has almost no effect on the flooding situation of the river outside the dike in two districts and one county. The flooding response index of the three cities in the demonstration area was generally negatively correlated with the flooding capacity; the flooding situation in Wujiang, Jiashan, and Qingpu had the strongest sensitivity to changes in the flooding capacity of Wujiang District, followed by Jiashan County. Changes in flood discharge capacity in Qingpu District only had a significant effect on the river outside its own polder.
The data source of this dataset is from the calculation results of the hydrological and hydrodynamic model run in the Taihu Lake basin. There is a certain reliability.
Based on the latest subsurface data, study area polder drainage modulus, pumping station drainage capacity data, the model of the Taihu Lake basin was optimized and updated, and a series of study area flood control and flood removal schemes were set up. And selected the Taihu Lake basin 100-year “99 south” type design rainstorm simulation, obtained the cross-regional flood control and flooding mutual feedback law data set, analyzed the cross-regional inter-city flood control and flooding mutual influence law.
From the results of the Taihu Lake model rate determination, the simulated water level process at the model stations is relatively close to the measured water level process, and the maximum difference between the simulated maximum water level and the actual value is no more than 0.1m, and the relative errors between the simulated value and the actual value of the stations in the Yangtze River Delta Eco-Green Integration and Development Demonstration Zone are all less than 5%, which indicates that the simulation accuracy of the updated model of Taihu Lake is relatively high. indicates that the simulation accuracy of the updated Taihu Lake basin model is high.
When the governance standard of polders in a single area is improved, the water level of the river outside the polders shows a rising trend with the improvement of polders' governance standard, and the risk of flood control is increased and the change is in the form of “S”. The water level in the polder, the flood discharge power is enough to meet the flood demand, continue to increase the flood discharge power and will not significantly change the water level process, the water level in the polder will not produce large fluctuations, will only have an impact on the length of the retreat. Pike gate and pump scheduling rule changes can make significant changes in the water level within the pike.
The impact of flooding on neighboring areas, polder drainage capacity can increase the adjacent areas of flood control and drainage pressure, and polder drainage changes in neighboring areas of the degree of influence and geospatial location and distance between each other is closely related to the Wujiang polder drainage of flooding in neighboring areas of the greatest impact, Jiashan area, followed by the impact of the weakest in the Qingpu area. Changes in gate and pump scheduling rules in the polder have almost no effect on the flooding situation in neighboring areas.
| # | number | name | type |
| 1 | 2021YFC3000100 | Lower Yangtze River Flood Disaster Integration and Control and Emergency De-risking Technology and Equipment | National key R & D plan |
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CSTR:11738.11.NCDC.NHRI.DB6771.2025
10.12072/ncdc.nhri.db6771.2025