Saturated Zone storage

The Saturated Zone storage includes all water below the water table. All groundwater pumping is from the saturated zone, including irrigation extraction from groundwater.

The items listed in Table 6.5 are those found in the “Saturated Zone - detailed” water balance output in the water balance configuration file:

[WblTypeDefinition]

Name = 'SZ_DETAIL'

DisplayName = 'Saturated Zone - detailed'

Description = 'Detailed Saturated ... balance (depth-integrated)'

NoGroups = 28

Group = 'qszprecip(sz.qszprecip)'

Group = 'qrech(uz.qrech)'

Group = 'qrechmp(uz.qrechmp)'

Group = 'qolszpos(sz.qolszpos)'

Group = 'qolszneg(sz.qolszneg)'

Group = 'qetsz(sz.qetsz)'

Group = 'qszin(sz.qszin)'

Group = 'qszout(sz.qszout)'

Group = 'dszsto(sz.dszsto)'

Group = 'qszabsex(sz.qszabsex)'

Group = 'qszdrin(sz.qszdrin)'

Group = 'qszdrout(sz.qszdrout)'

Group = 'qszdrtorivin(sz.qszdrtorivin)'

Group = 'qszdrtorivex(sz.qszdrtorivex)'

Group = 'qszdrtoM11HPoint(sz.qszdrtoM11HPoint)'

Group = 'qszrivneg(sz.qszrivneg)'

Group = 'qszrivpos(sz.qszrivpos)'

Group = 'qszfloodneg(ol.qsztofloodneg)'

Group = 'qszfloodpos(ol.qsztofloodpos)'

Group = 'qgihbpos(sz.qgihbpos)'

Group = 'qgihbneg(sz.qgihbneg)'

Group = 'qirrwell(sz.qirrwell)'

Group = 'qszdrtoMouse(sz.qszdrtoMouse)'

Group = 'qszMousepos(sz.qszMousepos)'

Group = 'qszMouseneg(sz.qszMouseneg)'

Group = 'qSzExtSink(sz.qSzExtSink)'

Group = 'qSzExtSource(sz.qSzExtSource)'

Group = 'Error(sz.szwblerrtot)'

EndSect // WblTypeDefinition

The sign convention in the SZ water balance is such that infiltration from the unsaturated zone is negative (inflow) and discharge to overland flow is positive (outflow). All of the items together should add to zero.

The use of negative signs in the SZ water balance is avoided by explicitly including both inflow (negative) and outflow (positive) terms. For example, sz.qOlSzPos is the flow from the saturated zone directly to ponded water when the groundwater table is at or above the ground surface. In the MIKE SHE results, this is a positive upwards flow, and in the water balance it is a positive outflow. Similarly, sz.qOlSzNeg is the downward flow from ponded water directly to the saturated zone, which is a negative downward flow and a negative water balance inflow to SZ.

Table 6.5 SZ - Saturated Zone - all layers
Item	Description	Sign Convention in the Water balance	Included in Wbl Error
sz.qSzPrecip	Precipitation added directly to the SZ layer. This can only be non-zero when the simulation does not include UZ. If UZ is included, but the groundwater table is at the ground surface (no UZ cells), the precipitation to SZ is included in the term sz.qOlSzNeg. Can be an outflow if the negative precipitation option specified in the Extra Parameters (Negative Precipitation (V1 p. 737)). In this case, negative precipitation can be removed from multiple SZ layers.	Inflow - negative Can be positive (outflow) if negative precipitation option specified.	yes
sz.qszin (per layer)	SZ flow into the subcatchment	Positive out of SZ (always negative, but printed as a positive value in the WB table)
uz.rech	Recharge out of the bottom of the UZ soil column to SZ via the UZ soil matrix. In the MIKE SHE results, recharge is a vertical downward flow, thus in the negative direction. This is the same sign as the water balance convention of negative inflow.	Inflow - negative	yes
uz.rechmp	Recharge out of the bottom of the UZ soil column to SZ via the UZ macropores or by-pass flow. In the MIKE SHE results, recharge is a vertical downward flow, thus in the negative direction. This is the same sign as the water balance convention of negative inflow.	Inflow - negative	yes
sz.qOlSzPos	Upward flow directly from SZ to ponded water. This is non-zero only when the groundwater table is at or above the ground surface. The sign is positive upwards which is the same as the positive outflow water balance sign convention.	Outflow - positive	yes
sz.qOlSzNeg	Downward flow directly from ponded water to SZ. This is non-zero only when the groundwater table is at or above the ground surface. The sign is positive upwards which is the same as the negative inflow water balance sign convention.	Inflow - negative	yes
sz.EtSz	Evapotranspiration directly from SZ.	Positive - outflow	yes
sz.qSzIn	Inflow to SZ storage across the boundary of the model, or inflow across the boundary of the water balance sub-area. Inflow from internal fixed head cells is also included in this term.	Inflow - negative	yes
sz.qSzOut	Outflow from SZ storage across the boundary of the model, or outflow across the boundary of the water balance sub-area. Outflow to internal fixed head cells is also included in this term, as well as drainage to local depressions that contain a fixed head boundary condition.	Outflow - positive	yes
sz.dSzSto	Change in SZ storage	Positive when storage increases	yes
sz.dszsto_dead (per layer)	how can this be by layer?????
sz.szsto
sz.qSzAbsEx	Groundwater pumping from SZ. This does not include irrigation wells and shallow irrigation wells, but includes outflow to fixed head drain internal boundary conditions.	Outflow - positive Can be negative (Inflow) if injection specified for wells.	yes
sz.qUZfeedback	how can this be by layer?????
sz.qSzDrIn	SZ drainage to local depressions in the current water balance area from areas outside of the current water balance sub-area. This term also includes inflow to the SZ drainage system added via OpenMI.	Inflow - negative	yes
sz.qSzDrOut	SZ drainage to the model boundary, SZ drainage removed directly from the model. This term also includes SZ drainage to local depressions located outside of the current water balance sub-area.	Outflow - positive	yes
sz.qSzDrToRivIn	SZ drainage to MIKE SHE River Links inside of the water balance sub-area.	Outflow - positive	yes
sz.qSzDrToRivEx	SZ drainage to MIKE SHE River Links outside of the water balance sub-area. This can only be non-zero if the water balance is calculated for a sub-area.	Outflow - positive	yes
sz.qszdrtoM11HPoint	SZ drainage to specified MIKE 11 H-points
sz.qSzDrToM11HPoint	SZ drainage to specified MIKE Hydro River h-points. These are specified in the Extra Parameter option in SZ Drainage to Specified MIKE Hydro River H-points (V1 p. 758)	Outflow - positive	yes
sz.qSzRivPos	Baseflow from SZ to MIKE SHE River Links	Outflow - positive	yes
sz.qSzRivNeg	Infiltration from MIKE SHE River Links to SZ	Inflow - negative	yes
ol.qSZToFloodPos	Direct flow upwards from SZ to an active flood code cell (active means that it is actually flooded and the water level is controlled by the water level in MIKE Hydro River). This is a positive upwards flow in the MIKE SHE results files. Only non-zero when the groundwater table is at or above the ground surface.	Outflow - positive (Note sign change compared to detailed Ponded Storage water balance)	yes
ol.qSZToFloodNeg	Direct flow downwards from an an active flood code cell to SZ. (active means that it is actually flooded and the water level is controlled by the water level in MIKE Hydro River). This is a negative downwards flow in the MIKE SHE results files. Only non-zero when the groundwater table is at or above the ground surface.	Inflow - negative (Note sign change compared to detailed Ponded Storage water balance)	yes
sz.qGihbPos	Outflow from SZ storage to internal general head boundaries (GHB cells)	Outflow - positive	yes
sz.qGihbNeg	Inflow from internal general head boundaries (GHB cells) to SZ storage	Inflow - negative	yes
sz.qIrrWell	Groundwater pumping from irrigation wells. This includes both specified irrigation wells and shallow wells.	Outflow - positive	yes
sz.qSzDrToMouse	SZ drainage to specified MOUSE/MIKE Urban manholes. These are specified in the Extra Parameter option in Time varying SZ drainage parameters (V1 p. 761)	Outflow - positive	yes
sz.qSzMousePos	Outflow from SZ storage to Mouse/MIKE Urban pipes	Outflow - positive	yes
sz.qSzMouseNeg	Inflow from Mouse/MIKE Urban pipes to SZ storage	Inflow - negative	yes
sz.qSzExtSink	Outflow to external sinks specified via OpenMI	Outflow - positive	yes
sz.qSzExtSource	Inflow from external sources specified via OpenMI	Inflow - negative	yes
sz.qSzExtSink (per layer)
sz.qSzExtSource (per layer)
sz.szWblErrTot	Aggregated SZ water balance error for all layers	Positive if water generated (Dstorage + Outflow > Inflow)
sz.qsztofloodpos	Upward flow from SZ to flooded areas (not in list)	Positive up (always positive)
sz.qsztofloodneg	Downward flow from flooded areas to SZ (not in list)	Positive up (always negative)

Saturated Zone layers

The Saturated Zone water balance can also be calculated by numerical layer. This means that all of the items in Table 6.5 are repeated for each numerical layer. However, in this case the water balance error term, sz.szWblErrTot is replace by a water balance error for each layer.

The layer water balance is slightly more complicated. It includes terms for the exchange between layers, and the upper layer includes the terms for the exchange with UZ and ponded water.

In particular, the output for each SZ layer water balance only includes the exchange with the layer above. This is found in the two additional layer water balance terms qSzZpos and qSzZneg.

The first term, qSzZpos, is the flow from the current layer upwards to the layer above. In the results files, this term is in the positive (upwards) direction. In the water balance, the term is also a positive outflow.

The second term, qSzZneg, is the flow from the layer above downwards into the current layer. In the results files, this term is in the negative (downwards) direction. In the water balance, the term is also a negative inflow to the current layer.

Note: The layer water balance error includes the flows to and from the layers above and below. However, when summing up the flows, the sign must be changed for the qSzZpos and qSzZneg terms that originate from the layer below.

Table 6.6 SZ - Saturated Zone - specified by layers
Item	Description	Sign Convention in the Water balance	Included in Wbl Error
sz.qSzZpos	Upward SZ flow from the current layer to the layer above Only available for LAYER water balances	Outflow - positive	yes
sz.qSzZNeg	Downward SZ flow from the layer above to the current layer. Only available for LAYER water balances	Inflow - negative	yes
sz.qSzExtSink (per layer)
sz.qSzExtSource (per layer)
sz.szWblErr	SZ water balance error for the current layer only available for LAYER water balances	Positive if water generated (Dstorage + Outflow > Inflow)
sz.qsztofloodpos	Upward flow from SZ to flooded areas (not in list)	Positive up (always positive)
sz.qsztofloodneg	Downward flow from flooded areas to SZ (not in list)	Positive up (always negative)

Saturated Zone Linear Reservoir water balance

If the linear reservoir method is used for the saturated zone, the water balance terms are basically the same but are slightly less transparent.

The layer output for the linear reservoir method divides the SZ into two layers - the interflow reservoirs and the baseflow reservoirs. For the linear reservoir layers, there is no distinction between the two parallel baseflow reservoirs, or the cascading interflow reservoirs.

The items listed in Table 6.7 are those found in the “Saturated Zone - layers(Linear Reservoir)” water balance output in the water balance configuration file:

[WblTypeDefinition]

Name = 'SZ_LAYER_LR'

DisplayName = 'Saturated Zone - layers(Linear Reservoir)'

Description = 'Saturated zone water balance for linear reservoir'

NoGroups = 13

Group = 'recharge(uz.qrech+uz.qrechmp)'

Group = 'evapotranspirationSZ(sz.qetsz)'

Group = 'lateral IN(sz.qszin)'

Group = 'lateral OUT(sz.qszout)'

Group = 'percolation(sz.qszzneg)'

Group = 'To river(sz.qszrivpos)'

Group = 'From river(sz.qszrivneg)'

Group = 'storagechange(sz.dszsto)'

Group = 'deadzonestoragechange(sz.dszsto_dead)'

Group = 'pumping(sz.qszabsex)'

Group = 'Irr.pumping(sz.qirrwell)'

Group = 'feedbackUZ(sz.qUZfeedback)'

Group = 'Error(sz.szwblerr)'

EndSect // WblTypeDefinition

Table 6.7 SZ - Saturated Zone - Linear Reservoir all layers
Item	Description	Sign Convention in the Water balance	Included in Wbl Error
recharge (uz.qrech+uz.qrechmp)	This is the total recharge into the interflow reservoirs. If UZ is not simulated, then uz.qrech is still calculated based on the infiltration from OL.	Inflow - negative	yes
evapotranspirationSZ (sz.qetsz)	This is the direct ET from the water table. In the LR SZ method, the water table is constant and fixed at the beginning of the simulation. If the root zone reaches the water table, then ET will be taken from the water table as an infinite sink when the reference ET is not satisfied by the other sources.	Outflow - postitive	yes
lateral IN (sz.qszin)	In the LR SZ model, infiltration to the interflow reservoirs and percolation to the baseflow reservoirs is distributed equally to the entire reservoir. When you calculate the water balance in a sub-area, sz.qszin is the amount of recharge/percolation that is distributed into the sub-area. For example, if all your recharge occurs outside of your sub-area, this is the increase in groundwater storage that occurs inside your sub-area. This can only be non-zero for sub-area water balances.	Inflow - negative	yes
lateral OUT (sz.qszout)	In the LR SZ model, infiltration to the interflow reservoirs and percolation to the baseflow reservoirs is distributed equally to the entire reservoir. When you calculate the water balance in a sub-area, sz.qszout is the amount of recharge/percolation that is distributed to areas outside of the sub-area. For example, if all your recharge occurs inside your sub-area, this is the increase in groundwater storage that occurs outside your sub-area. This can only be non-zero for sub-area water balances.	Outflow - positive	yes
percolation (sz.qszzneg)	Infiltration from interflow reservoirs to baseflow reservoirs. This is defined only for the lower (baseflow) layer in the water balance output, but is used in the water balance error calculation of the interflow reservoirs with the opposite sign. The term sz.qszzpos is not included here because the LR method does not allow any transfer of water from the baseflow reservoir upwards to the interflow reservoir.	Inflow - negative (to the baseflow reservoir)	yes
To river (sz.qszrivpos)	Outflow from interflow and baseflow reservoirs to MIKE SHE River Links.	Outflow - positive	yes
From river (sz.qszrivneg)	Inflow from MIKE SHE River Links to the baseflow reservoir. For the interflow reservoirs, this is always zero because MIKE Hydro River only discharges to the baseflow reservoirs.	Inflow - negative (to the baseflow reservoir)	yes
storagechange (sz.dszsto)	Change in storage in the interflow and baseflow reservoirs.	Positive if storage increases	yes
deadzonestoragechange (sz.dszsto_dead)	Change in storage in the deadzone storage. This is calculated as a change in storage, but it is equal to the outflow to dead zone storage because there is no option in MIKE SHE to reduce the dead zone storage.	Outflow - Positive	yes
pumping (sz.qszabsex)	Groundwater pumping from the baseflow reservoirs. This is always zero for the interflow reservoirs.	Outflow - positive But, can be negative if injection rates specified in wells	yes
Irr.pumping (sz.qirrwell)	This is the sum of groundwater pumping for irrigation - irrigation wells + shallow irrigation wells.	Outflow - positive	yes
feedbackUZ (sz.qUZfeedback)	This is a fraction of the discharge from the baseflow reservoirs to MIKE Hydro River to account for discharge to riparian zones that is lost to ET.	Outflow - positive (from baseflow reservoirs only)	yes


Error (sz.szwblerr)	SZ water balance error for the current layer only available for LAYER water balances	Positive if water generated (Dstorage + Outflow > Inflow)
Error (sz.szwblerrtot)	SZ water balance error for the both the interflow and baseflow reservoirs combined. This is only available for the total water balance option.	Positive if water generated (Dstorage + Outflow > Inflow)
sz.qsztofloodpos	Upward flow from SZ to flooded areas (not in list)	Positive up (always positive)
sz.qsztofloodneg	Downward flow from flooded areas to SZ (not in list)	Positive up (always negative)