Hydraulic parameters which describe the rock framework are hydraulic conductivity, transmissivity and specific storage (yield). River with additional resistance as a colmation layer Main types of boundary conditions TypeĪquifer border (Q=0), barrier, recharge, pumping wellsįlux as function of potential (mixed condition) Table 1 gives an overview of the three available main boundary conditions including examples when those boundary conditions are generally used: No allocation is needed to indicate no flow at the edge of the model area as MODFLOW does not compute inter-cell flow through the outside edges of the grid (including bottom and top). In MODFLOW constant-head and no-flow cells are used to represent conditions along various hydrologic boundaries inside the grid. These boundaries need to be approximated in the model. sharp changes in hydraulic conductivity) or hydraulic (e.g. In a natural system boundaries can be physical (e.g. Figure: Discretization of model domain in MODFLOW (Harbaugh, 2005).īoundary conditions are necessary to define how the user-specified model interacts with the surrounding flow system. Inactive cells (Figure, circle) are ignored. Only active cells (Figure, filled points) are regarded in the calculation. For each cell the head is calculated in the center of the cell (node). The flow domain is discretized by a grid containing cells. MODFLOW is a modular finite-difference model solving the groundwater flow equation in three dimensions and it is used to simulate the flow of groundwater through aquifers. MODFLOW-2005 is based on the Darcy equation (Darcy, 1856): THEORETICAL BACKGROUND Flow model (MODFLOW) The INOWAS platform furthermore provides optimization algorithms to find the best location for an ASR well using a calibrated groundwater flow and solute transport model. Solute transport (MT3DMS)) as well as variable-density flow (see T03c. In addition, solute transport using MT3DMS can be added to the groundwater flow model (see T03b. The tool is based on MODFLOW-2005 (Harbaugh, 2005) and FloPy (Bakker et al., 2016) and enables the user to create, write and read input and output files as well as calculate models. The INOWAS tool helps to setup a new MODFLOW model for a study area in order to better understand the local groundwater flow system or as a basis for further scenario analysis (see T07.

The most widely applied numerical model for MAR assessment is MODFLOW which is a numerical groundwater flow model developed by the USGS (Harbaugh, 2005 Ringleb et al., 2016). This tool can be used for setting up a new numerical groundwater flow and solute transport model.

Online Guide To Modflow