Ponded water storage
Water on the ground surface belongs to the ponded water storage. Rainfall is added to ponded storage. Ponded storage evaporates, infiltrates or flows to the River.
The items listed in Table 6.3 are those found in the “Overland flow - detailed” water balance output in the water balance configuration file:
[WblTypeDefinition]
Name = 'OL_DETAIL'
DisplayName = 'Overland flow - detailed'
Description = 'Detailed Overland component water balance'
NoGroups = 23
Group = 'qpnet(ol.qpnet)'
Group = 'qirrdrip(ol.qirrdrip)'
Group = 'qeol(ol.qeol)'
Group = 'qh(ol.qh+ol.qhmp)'
Group = 'qolszpos(-ol.qolszpos)'
Group = 'qolszneg(-ol.qolszneg)'
Group = 'qsztofloodpos(-ol.qsztofloodpos)'
Group = 'qsztofloodneg(-ol.qsztofloodneg)'
Group = 'qolin(ol.qolin)'
Group = 'qolout(ol.qolout)'
Group = 'qolrivpos(ol.qolrivpos)'
Group = 'qolrivneg(ol.qolrivneg)'
Group = 'qoldrstoinfl(ol.qoldrstoinfl)'
Group = 'qoldrin(ol.qoldrin)'
Group = 'qfloodtorivin(ol.qfloodtorivin)'
Group = 'qfloodtorivex(ol.qfloodtorivex)'
Group = 'qoldrtoMouse(ol.qoldrtoMouse)'
Group = 'qolMousepos(ol.qolMousepos)'
Group = 'qolMouseneg(ol.qolMouseneg)'
Group = 'qOlExtSink(ol.qOlExtSink)'
Group = 'qOlExtSource(ol.qOlExtSource)'
Group = 'dolsto(ol.dolsto)'
Group = 'olwblerr(ol.olwblerr)'
EndSect // WblTypeDefinition[WblTypeDefinition]
The sign convention for a ponded water control volume is such that precipitation is negative (inflow), and boundary outflow, infiltration and evaporation are all positive (outflow). All of the Wbl Error items together should add to zero.
Note, however, the negative sign in front of some of the terms in the water balance definition above. This is because the SZ exchange to ponded storage is an upwards positive flow in MIKE SHE - making it a positive value in the MIKE SHE results files when flowing to ponded water and a negative value when infiltrating to SZ. Whereas, these flows must be the opposite sign in the water balance calculation.
Special considerations for water balances in Flood Code cells
Water on the ground surface belongs to ponded storage - except in active flood code cells. Active flood code cells are those where the cell is flooded and the water level is controlled by the water level in MIKE Hydro River.
There are four terms in the water balance related to flood codes: qSZToFloodPos/Neg, and qFloodToRivIn/Ex.
When the groundwater table is at or above the land surface, water can exchange directly between ponded water and the saturated zone. The unsaturated zone does not exist. If the land surface is an active flood code cell, then then the water is added to or removed from the storage available for exchange with MIKE Hydro River and the two terms qSZFloodPos and qSZFloodNeg may be non-zero.
The exchange between ponded water and MIKE Hydro River in active flood code cells is calculated based on the change of storage due to the various source/sink terms over the MIKE SHE overland time step. This includes overland flow between flooded and non-flooded cells, rainfall, evaporation, infiltration to UZ, direct flow between SZ and flooded cells when the groundwater table is above ground. Thus, in a flood code cell
1. At the beginning of the overland time step, the ponded water level is set equal to the corresponding water level in MIKE Hydro River (if this is above the MIKE SHE ground level) and the status of the cell is set to active.
2. At the end of the overland flow time step, MIKE SHE calculates the change in ponded water level and adds or subtracts this as lateral inflow to MIKE Hydro River over the next MIKE Hydro River time step(s), covering the period of the MIKE SHE Overland time step.
Thus, qsztoflood is not directly added as lateral inflow to MIKE Hydro River . But it’s one of the source/sink terms that contribute to the change in storage in flooded cells – which is then added to MIKE Hydro river as qfloodtoriv
The two terms, qFloodToRivIn and qFloodToRivEx, together are the net lateral inflow to MIKE Hydro River from active flood code cells. In other words, summed together, they are the actual exchange between flood code areas and MIKE Hydro River.
Table 6.3 OL - Overland flow items
|
Item
|
Description
|
Sign Convention in the Water balance
|
Included in Wbl Error
|
|
ol.qPnet
|
Canopy throughfall to ponded water.
This is the same value as ci.qPnet, but with the opposite sign.
|
Inflow - negative
|
yes
|
|
ol.qIrrDrip
|
Irrigation added to ponded water. This includes both drip irrigation and sheet irrigation, since both are added directly to ponded storage.
|
Inflow - negative
|
yes
|
|
ol.qEOL
|
Direct evaporation from ponded water
|
Outflow - positive
|
yes
|
|
ol.qH
|
Infiltration from ponded water into the UZ
|
Outflow - positive
|
yes
|
|
ol.qHmp
|
Infiltration from ponded water into the UZ macropores
|
Outflow - positive
|
yes
|
|
-ol.qOLSZpos
|
Direct flow up from SZ to OL.
This is a positive upwards flow in the MIKE SHE results files.
|
Inflow - negative
(Note sign change in water balance definition)
|
yes
|
|
-ol.qOLSZneg
|
Direct flow down from OL to SZ.
This is a negative downwards flow in the MIKE SHE results files.
|
Outflow - positive
(Note sign change in water balance definition)
|
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.
|
Inflow - negative
(Note sign change in water balance definition)
|
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.
|
Outflow - positive
(Note sign change in water balance definition)
|
yes
|
|
ol.qOLin
|
Inflow to overland storage across the boundary of the model, or inflow across the boundary of the water balance sub-area
|
Inflow - negative
|
yes
|
|
ol.qOLout
|
Outflow from overland storage across the boundary of the model, or outflow across the boundary of the water balance sub-area
|
Outflow - positive
|
yes
|
|
ol.qOLRivPos
|
Overland outflow to MIKE Hydro River
|
Outflow - positive
|
yes
|
|
ol.qOLRivNeg
|
Inflow from MIKE Hydro River to overland storage
|
Inflow - negative
|
yes
|
|
ol.qOlDrStoInfl
|
Overland storage that is added to the Overland drain storage.
|
Outflow - positive
This is an outflow in the OL WB.
It corresponds to the inflow to the OL Drain WB.
|
yes
|
|
ol.qOlDrIn
|
Inflow to Overland storage in a cell received from Overland drain storage.
|
Inflow - negative
This is an inflow in the OL WB.
It corresponds to the outflow in the OL Drain WB (ol.qOlDrOut) that is added to ponding in a cell.
|
yes
|
|
ol.qolrivneg
|
Overland inflow from MIKE 11
|
|
|
|
ol.qOlDrOut
|
Outflow of overland drain storage that is added to a cell or removed (i.e. to the boundary)
|
Outflow - positive
This is an outflow in the OL Drain WB.
In the OL WB, this is the part that is added to ponding in a cell.
It appears in the ol.q.OlDrIn term.
|
no
|
|
ol.qOCDr
|
Overland drain storage that is added to a river link - excluding any flow to a specified H-point or MIKE Urban node.
|
Outflow - positive
This is an outflow in the OL Drain WB.
This term does not appear in the OL WB.
|
no
|
|
ol.qocdrtoM11HPoint
|
Overland flow (from paved areas) directly to a MIKE 11 H-Point
|
|
|
|
ol.qoldrtoMouse
|
Overland flow (from paved areas) directly to a Mouse manhole
|
|
|
|
ol.qOCDrToM11HPoint
|
Overland drain storage that is added to a specified H-point in MIKE Hydro River.
|
Outflow - positive
This is an outflow in the OL Drain WB.
This term does not appear in the OL WB.
|
no
|
|
ol.qOLDrToMouse
|
Overland drain storage that is added to a specified Mouse/MIKE Urban manhole
|
Outflow - positive
This is an outflow in the OL Drain WB.
This term does not appear in the OL WB.
|
no
|
|
ol.qFloodToRivIn
|
Net lateral inflow exchange between active flood code cells and MIKE Hydro River nodes that are inside the current water balance area
|
Inflow (negative) or Outflow (positive)
|
yes
|
|
ol.qFloodToRivEx
|
Net lateral inflow exchange between active flood code cells and MIKE Hydro River nodes that are outside the current water balance area
This is always zero unless the water balance is being calculated on a sub-area.
|
Inflow (negative) or Outflow (positive)
|
yes
|
|
ol.qOLMousePos
|
Outflow from overland storage to Mouse/MIKE Urban
|
Outflow - positive
|
yes
|
|
ol.qOLMouseNeg
|
Inflow from Mouse/MIKE Urban to overland storage
|
Inflow - negative
|
yes
|
|
ol.qOLExtSink
|
Outflow to OpenMI sink
|
Outflow - positive
|
yes
|
|
ol.qOLExtSource
|
Inflow from OpenMI sink
|
Inflow - negative
|
yes
|
|
ol.dOLSto
|
Change in overland storage
|
Positive if storage increases
|
yes
|
|
ol.qolExtSink
|
|
|
|
|
ol.qolExtSource
|
|
|
|
|
ol.OLWblErr
|
OL water balance error
|
Positive if water generated (Dstorage + Outflow > Inflow)
|
|
