| 研究実績の概要 |
During FY2021, a series of numerical simulations were conducted based on a conceptual unconfined aquifer to investigate the performance of drywells for aquifer recharge and flooding control in urban areas. Numerical simulations were conducted using a coupled surface-subsurface flow modeling approach. A modeling strategy was developed that could explicitly describe the drywell geometry in the model domain. Sensitivity analysis were conducted to explore to the effects of parameters including drywell designs (location, depth, radius, and number), aquifer properties (hydraulic conductivity and its heterogeneity), and rainfall patterns (intensity and duration). Results showed that installing drywells can enhance groundwater recharge and reduce urban runoff during heavy rainfall events. The infiltration capacity of drywells were found to depend on two factors, initial storage and infiltration, which can be affected by drywell designs and aquifer properties in different ways under different rainfall scenarios.
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| 今後の研究の推進方策 |
The research activities in FY2022 will focus on two targets:
(1) The coupled surface-subsurface flow model developed in FY2021 will be integrated with reactive mass transport modeling techniques in order to understand the impacts of drywells on groundwater quality and elaborate relevant hydrogeochemical processes.
(2) The developed numerical modeling strategy based on the conceptual aquifer will be applied to a realistic field case, Koganei City, Japan, in order to assess the performance of installed drywells for aquifer recharge. Fieldwork will be conducted to install sensors in existing drywells and monitoring wells for collecting information on infiltration rate and groundwater level dynamics.
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