Belastungsdefinition/ Modellinput/en

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Pollution affects a water management system in the form of precipitation, temperature, evaporation, inflow, substance input and withdrawals.

System elements that bring about a water input into the system are in particular point source and catchment area. Consumer und reservoir can also bring additional flow into the system: Consumers via the input of subsidies, reservoirs via an assigned precipitation, which, scaled with the current reservoir surface, also brings water input into the system (especially relevant for dams with large water surfaces).

Substance entries into the system can only be made using the point source element.

An entry/loss of thermal energy as such is currently not possible in the surface. However, the transport reach can already be used at the file level for heat entry/loss. A water temperature at the outlet of the transport element can be defined and the heat exchange between the water surface and the air can be calculated. For more details see: Temperature Modelling. In the surface, temperature data only play a role in the evaporation and snow calculation and thus for the water balance. Water temperatures of the system elements are not simulated.

Losses of water, substances or thermal energy can be made via the elements consumer and diversion. Reservoir elements can also withdraw water from the system if the evaporation calculation is activated. Via the discharge splitting of the catchment area elements it is possible to discharge individual discharge components from the system in addition to the evaporation term (e.g. urban surface runoff or deep base runoff).

Depending on the simulation type and system element, there are different possibilities for entering loads:

Simulation type long-term simulation

- Hydrographs

- Time series

Simulation type short-term forecast

- model rain

- flood waves from flood characteristics

Hydrographs: Yearly, weekly, daily course

If charts are chosen as input option for a load, a constant value can be scaled with a recurring constant yearly and/or weekly and/or daily course. For daily courses, a value can be defined for each hour of the day, for weekly courses a constant value for each day of the week and for annual courses, either constant monthly values can be defined or variable limits can be drawn via concrete date entries. In the datasheets of system elements only the assignment of hydrographs is done. The hydrographs are created independently from single system elements in the respective hydrograph window.

Time series

thumb|Interpretation of time series Time series are time sequences of data, i.e. ascending date and time stamps are assigned to values. Both measurement time series and simulated time series can be used as model input.

Wichtig ist, dass die Zeitreihen, über den Simulationszeitraum lückenfrei sind. Eventuell vorhandene Lücken in den Zeitreihen, müssen vorher geschlossen werden (z.B. über Regressionen zu ähnlichen Zeitreihen oder durch andere Annahmen). Idealerweise aber nicht zwingenderweise liegen die Zeitreihen äquidistant in mindestens der Auflösung des Simulationszeitschrittes vor. Abgesehen von den Datums- und Zeitreihenwert ist für die Simulation auch die Interpretation der Zeitreihe entscheidend. Außerdem muss darauf geachtet werden, dass Zeitreihen in der passenden Einheit angegeben sind (z.B. m³/s für den Abfluss oder mg/l für die Konzentration). Manche Systemelemente bieten die Option Zeitreihen mit einem zusätzlichen Faktor zu skalieren.

In den Datenblättern der Systemelemente erfolgt lediglich die Zuordnung der Zeitreihen. Die Zeitreihen werden unabhängig von einzelnen Systemelementen und sogar unabhängig von den Varianten und Projekten zentral in der Zeitreihenverwaltung erstellt und auf dem Server gespeichert, d.h. Zeitreihen eines Auftraggebers können in unterschiedlichen Projekten verwendet werden.