Author(s): Jana Glass; Constantinos Panagiotou; Ralf Junghanns; Catalin Stefan
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Keywords: No Keywords
Abstract: Managed aquifer recharge (MAR) combines various solutions for the interim storage of water underground for later usage or environmental benefits which encompasses infiltration basins and wells. Although MAR represents a viable solution for sustainable water resources management, its contribution to safe water supply at global scale is still limited. This is mainly caused by the lack of data on hydrogeological site-specific characteristics, technological costs and associated operational risks such as unpredictable quality and quantity of recharged and recovered water. Proper monitoring of MAR facilities in combination with simulation-based optimization can better describe the risks associated with MAR implementation, provide support for the optimization of operational management and therewith increase the level of public trust. The INOWAS platform is a compilation of free web-based empirical, analytical and numerical simulation tools for groundwater management tailored at MAR management (www. inowas. com, Glass et al, 2022). It includes tools for real-time monitoring and numerical groundwater flow and transport modelling to optimize the performance of MAR systems while satisfying economic and environmental constraints. Numerical models are frequently used to plan, assess and further improve the operational efficiency of MAR facilities, even though the optimal use of the modelling results is hindered, mainly because these models are only accessible to experts, and not frequently actualized and compared to present observation data. The INOWAS platform allows the web-based setup, run, calibration and analysis of numerical groundwater flow and transport models developed in widely used open-source code such as MODFLOW, MT3DMS, SEAWAT, as well as the direct integration of in-situ observation data into the numerical modelling scheme. Model data can be integrated on the INOWAS platform using the GeoJSON upload e. g. for the study area and locations of boundary conditions, the CSV upload for time series data such as pumping and recharge rates over time and the raster upload for the geological data such as top and bottom of layers, hydraulic conductivities and specific storage. Specific parameters such as a constant soil hydraulic parameter or MODFLOW solver package parameters such as the number of inner and outer iterations and the residual and head change criterion can be directly typed into the INOWAS user interface. The calculation of the model can be initiated via the web interface after which the model data is send and calculated on the servers. After the successful finish of the model run, MODFLOW calculation logs and all model files are displayed and can be downloaded. For results visualization, a map of groundwater heads and drawdowns for a selected layer and time step can be displayed as well as cross sections of specific rows and columns. Time series for specific cells and the volumetric flow budget can be visualized in a graph. The calibration functionality offers the analysis of the model statistics (e. g. maximum and minimum absolute residual, normalized root mean squared error), the display of the simulated versus observed heads, the weighted residuals versus simulated heads and the ranked residuals against normal probability. A distinctive tool for scenario management is also implemented to assess the behavior of the groundwater models under different numerical conditions, fostering the scientifically based decision-making for stakeholders.
Year: 2024