Recharge

The data item Total recharge to SZ (positive for downwards flow) is stored on the UZ storing time step interval. It is a Step Accumulated value stored in the results file: _2DUZ_AllCells.dfs2. The calculated Recharge includes the fol­lowing items:

·         Exchange between UZ and SZ, calculated by the UZ solver

·         Recharge from Bypass or Macropores if included

·         Direct flow between SZ and overland (when groundwater table is above ground)

·         Transpiration from SZ (when the roots reach the groundwater)

So neither baseflow (SZ-M11) nor drain flow is included. These items can be found in the two data items:

·         - SZ exchange flow with river (positive when flow from SZ to M11, nega­tive the other way)

·         - SZ drainage flow from point (positive drainage, only one way)

The Total recharge to SZ should correspond with the water balance items, but note the sign. The easiest way to check this is to look at a Saturated zone water balance, table type:

·         Recharge: exchange between UZ and SZ + Bypass flow or Macropore recharge if included + direct flow between SZ and Overland + transpira­tion from SZ, all POSITIVE UPWARDS

·         Drain: Drainage flow from point

·         SZ->River: SZ exchange flow with river, positive for flow to the river

Note the various units. The total recharge result type is a flux (i.e. mm/d, mm/h, m/s, etc) depending on the chosen user unit for Recharge. Whereas, the SZ river exchange and Drainage are flows (i.e. m3/s or similar). The Water balance output is in units of Storage depth (mm). That is, it is normal­ized with the catchment area (using the area inside the outer boundary), or the subcatchment area if a sub-catchment water balance has been extracted.