Attributes: VORF [m NN], ABRI [m]
The constant potential head of the receiving water course is required to compute the potential difference hvorf - h and the corresponding leakage rate (linear relationship). Water course levels are always assigned to nodes.
'F' in column 15 means that the receiving water course level is not considered in the calculation with terrain settings. (In case of a transient calculation with transient terrain settings the water course level is charged with the transient settings. The character 'F' is in this case meaningless.) The boundary condition VORF can also be defined as transient boundary condition (transient VORF data).
The attribute VORF is effective only in conjunction with a leakage coefficient.
Attribute ABRI:
To take reduced infiltration conditions into account a value can be defined at a node at which the maximum possible amount of infiltration is achieved, i.e. the flow stops. This value is obtained when the groundwater level (hGW) falls below the difference bottom height (hbottom) - ABRI. In this case the leakage rates are calculated on the basis of the potential difference of hVorf - hbottom, in this hbottom corresponds to the ground level.
ABRI conditions can also be defined as transient conditions (transient ABRI data).
The following representation shows the relationship between the height of the water level and the tear-off height:
Relationship between the height of the water level and the tear-off height