Unterteilung in Systemelemente/en: Unterschied zwischen den Versionen

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** Inflows
** Inflows
** Point sources
** Point sources
** Withdrawals
** Extractions
* Location of hydrological structures
* Location of hydrological structures
* Gauge stationing
* Location of gauging stations
* Type and geometry of watercourse
* Flow type and geometry


The result of this subdivision are digital catchment area boundaries and river sections. If the available data initially results in a rough subdivision, it can be subdivided even further, especially if, due to the problem at hand, certain processes in the water body can no longer be represented with a rough subdivision. In the following a high resolution water resources system is compared to a low resolution system:
The results of this division are digital catchment boundaries and river sections. If the available data initially results in a rough division, it can be subdivided even further, especially if, due to the problem at hand, certain processes in the waterbody can no longer be represented with the intitial division. In the following, a high resolution water resources system is compared to a low resolution water resources system:


{| class="wikitable"
{| class="wikitable"
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*As the accuracy of system mapping increases, the importance of hydraulics in waterbodies increases.
*As the accuracy of system mapping increases, the importance of hydraulics in the waterbodies increases.
*The parameters of the discharge concentration refer only to the surface discharge in the subarea, or interflow and base discharge.
*The parameters of the runoff concentration only refer to the surface runoff in the corresponding sub-catchments, resp. interflow and base flow.
*The illustration of the wave runoff in the water bodies is possible.
*The illustration of flood-routing within the waterbodies is possible.
||
||
*Simple approaches to the calculation of the runoff formation usually get along better with a rough system illustration.
*Simple approaches to the calculation of runoff generation usually manage better with a rough system illustration.
*Both the surface runoff in the subareas and the wave runoff that occurs in the water bodies are included in the parameters of the runoff concentration.  
*Both, the surface runoff in the sub-catchments and the flood-routing that occur in the waterbodies are included in the parameters of the runoff concentration.  
*The illustration of the wave runoff in the waters is hardly possible
*The illustration of flood-routing within the waterbodies is hardly possible.
|-
|-
|}
|}


[[Datei:Teilgebiet_Auswahl_Systemelemente.png|thumb| Subareas can be defined via a [[Einzugsgebiet|Rainfall-Runoff Model]][[Datei:Systemelement001.png|20px]] or can be visualised through a [[Special:MyLanguage/Einleitung|hydrograph]][[Datei:Systemelement002.png|20px]] at the output]]
[[Datei:Teilgebiet_Auswahl_Systemelemente.png|thumb| Sub-catchments can be defined via a [[Einzugsgebiet|Rainfall-Runoff Model]][[Datei:Systemelement001.png|20px]] or can be visualised through a [[Special:MyLanguage/Einleitung|hydrograph]][[Datei:Systemelement002.png|20px]] at the output]]




The next step is to decide which system elements are to be used to map the catchment areas, depending on the problem and the data basis. Besides the system element [[Special:MyLanguage/Einzugsgebiet|sub-basin]], which brings the load into the system via a precipitation-runoff simulation, [[Special:MyLanguage/Einleitung|point source]] can feed the runoff at the exit of the catchment area directly into the system via a runoff hydrograph. The latter is of course only possible if such a discharge hydrograph is available. Then it is the less computationally intensive variant, which in addition (with good quality of the input data) can illustrate most exactly the actually taken place discharge behavior. If, however, for example, a forecast is to be calculated under changed land use conditions or if the discharge hydrograph is not long enough, it is advisable to use the system element [[Special:MyLanguage/Einzugsgebiet|sub-basin]]. In Talsim-NG the selection of the system element for subcatchments can also vary from subcatchment to subcatchment.
The next step is to decide which system elements are to be used to map the sub-catchments, depending on the problem and the data basis. Alongside the system element [[Special:MyLanguage/Einzugsgebiet|sub-basin]], which brings the load into the system via a precipitation-runoff simulation, the system element [[Special:MyLanguage/Einleitung|point source]] can feed the outflow from the sub-catchment directly into the system via a hydrograph. The latter is of course only possible if a hydrograph is available. Then it is the solution using the fewest computational resources, which in addition (with good quality of the input data) also illustrates the actual outflow behavior in a realistic manner. If, however, for example, a forecast is to be calculated with changed land use conditions or if the hydrograph is not long enough, it is advisable to use the system element [[Special:MyLanguage/Einzugsgebiet|sub-basin]]. In Talsim-NG the selection of the system element for sub-catchments can also vary from sub-catchment to sub-catchment.


Once the system elements are defined, the [[Special:MyLanguage/Systemlogik|flow network]] is created, i.e. the flow relationships between the elements are defined.
Once the system elements are defined, the [[Special:MyLanguage/Systemlogik|flow network]] is created, i.e. the flow relationships between the elements are defined.




== Grid-based subdivision==
== Grid-based Division==


In grid-based subdivision, water is generally passed from one cell to the next according to its flow direction.  
In grid-based division, water is generally passed from one cell to the next according to its flow direction.  


The transfer from one cell to the next varies depending on the discharge component:
The transfer from one cell to the next varies depending on the flow component:
* Surface runoff is integrated into the runoff formation process of the next cell, i.e. is treated there like additional precipitation.
* Surface runoff is incorporated into the runoff generation process of the next cell, i.e. it is treated like additional precipitation.
* Interflow is fed into the storage cascade of the interflow of the next cell.
* Interflow is fed into the cascade of reservoirs of the next cell's interflow.
* Base flow is fed into the storage cascade of the base flow in the next cell.
* Base flow is fed into the cascade of reservoirs of the next cell's base flow.

Version vom 22. Dezember 2020, 14:06 Uhr

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In order to divide a water resources system into individual system elements it is vital to consider the problem which the model is used for and the existing data basis.

Basically there are two possible ways for the division of the system. It can be divided either catchment-based or grid-based. In addition, all hydrological structures relevant to the problem must be identified and represented by a suitable system element, e.g. dams by reservoir, extractions by consumer, etc. Often there are several feasible solutions.

The preliminary work for dividing a river basin is usually done with a GIS.


Catchment-based Division

Criteria for the division can be:

  • Catchment properties (topography)
  • Punctual changes of the outflow by
    • Inflows
    • Point sources
    • Extractions
  • Location of hydrological structures
  • Location of gauging stations
  • Flow type and geometry

The results of this division are digital catchment boundaries and river sections. If the available data initially results in a rough division, it can be subdivided even further, especially if, due to the problem at hand, certain processes in the waterbody can no longer be represented with the intitial division. In the following, a high resolution water resources system is compared to a low resolution water resources system:

System räumlich hochaufgelöst.png System räumlich geringaufgelöst.png
  • As the accuracy of system mapping increases, the importance of hydraulics in the waterbodies increases.
  • The parameters of the runoff concentration only refer to the surface runoff in the corresponding sub-catchments, resp. interflow and base flow.
  • The illustration of flood-routing within the waterbodies is possible.
  • Simple approaches to the calculation of runoff generation usually manage better with a rough system illustration.
  • Both, the surface runoff in the sub-catchments and the flood-routing that occur in the waterbodies are included in the parameters of the runoff concentration.
  • The illustration of flood-routing within the waterbodies is hardly possible.
Sub-catchments can be defined via a Rainfall-Runoff ModelSystemelement001.png or can be visualised through a hydrographSystemelement002.png at the output


The next step is to decide which system elements are to be used to map the sub-catchments, depending on the problem and the data basis. Alongside the system element sub-basin, which brings the load into the system via a precipitation-runoff simulation, the system element point source can feed the outflow from the sub-catchment directly into the system via a hydrograph. The latter is of course only possible if a hydrograph is available. Then it is the solution using the fewest computational resources, which in addition (with good quality of the input data) also illustrates the actual outflow behavior in a realistic manner. If, however, for example, a forecast is to be calculated with changed land use conditions or if the hydrograph is not long enough, it is advisable to use the system element sub-basin. In Talsim-NG the selection of the system element for sub-catchments can also vary from sub-catchment to sub-catchment.

Once the system elements are defined, the flow network is created, i.e. the flow relationships between the elements are defined.


Grid-based Division

In grid-based division, water is generally passed from one cell to the next according to its flow direction.

The transfer from one cell to the next varies depending on the flow component:

  • Surface runoff is incorporated into the runoff generation process of the next cell, i.e. it is treated like additional precipitation.
  • Interflow is fed into the cascade of reservoirs of the next cell's interflow.
  • Base flow is fed into the cascade of reservoirs of the next cell's base flow.