2022 Fiscal Year Annual Research Report
Environmental assessments of aquifer storage and recovery for decentralized wastewater management
| Project/Area Number |
21F21787
|
|---|
| Research Institution | The University of Tokyo |
|---|
| Co-Investigator(Kenkyū-buntansha) |
劉 佳奇 東京大学, 大学院新領域創成科学研究科, 助教 (00885577)
|
|---|
| Project Period (FY) |
2021-09-28 – 2024-03-31
|
| Keywords | Urban flood / Drywell / Numerical modeling |
|---|
| Outline of Annual Research Achievements |
During FY2022, we utilized an integrated surface-subsurface flow modeling approach to evaluate the effectiveness of drywells in reducing urban runoff at a catchment scale. A 3D model with HydroGeoSphere was developed, characterizing a synthetic unconfined aquifer covered by a layer of low-permeability materials. Sensitivity analyses of parameters such as land surface conditions, aquifer properties, drywell designs, and rainfall conditions were performed. Model results indicated that drywells are more effective in reducing runoff when the land surface has a higher Manning roughness coefficient or the aquifer material has a higher hydraulic conductivity. To achieve optimal performance, drywells should be situated beneath drainage routes that have high runoff flux. Increases in drywell radius or depth enhance the infiltration capacity, but deeper drywells can contaminate groundwater through infiltrating stormwater. Drywell performance declines with higher rainfall intensity, emphasizing the need for local rainfall intensity, duration, frequency (IDF) data to inform the design level of drywells in specific catchments
|
| Current Status of Research Progress |
Current Status of Research Progress
2: Research has progressed on the whole more than it was originally planned.
Reason
The numerical modeling approach that has been proposed in the study has been rigorously tested through catchment scale applications. The results have been promising. The authors expect that the approach can be applied to realistic catchments, which would provide more practical insights.
|
| Strategy for Future Research Activity |
The proposed modeling approach is scheduled to be applied to a real-world site, specifically Koganei City, Japan. The model will play a crucial role in analyzing the impact of installed drywells on groundwater storage and their efficacy in controlling urban flooding. The results of this analysis will be presented at the International Association of Hydrogeologists (IAH) meeting and submitted to a reputable journal to be shared with the wider scientific community. The outcomes of this research are expected to provide valuable insights into improving urban water management and flood prevention strategies.
|
