WaterWare On-line Manuals: Start nodes

WaterWare
Reference &
User Manual

WaterWare On-line Manuals

Release Level

6.2

Release Date

2010 05

Revision Level

1.0

Last modified on: Thursday, 20-May-10 18:09 CEST

WRM web version, node type: Start Node

A WRM scenario can include any number of start nodes. A start node is characterised by a time series of flow data, and a flow multiplier for easy scaling of the input data.

Start Node Types, subclasses:

The following start node types are supported; they have the same basic structure, but represent different sources of water (treated separately in the groundwater mass budget, for example) and with different data requirements for any cost-benefit analysis (not yet implemented).

Generic: can represent any type of water input, natural flow (a spring), pumped (groundwater wells), or piped or by channel (interbasin transfer), depending on which data are supplied;
Well: representing pumped flow from groundwater; with a cost structure depending on groundwater head, should be coupled to an aquifer;
Spring also from groundwater (should be coupled to an aquifer) but without pumping, thus a different economic evaluation;
Subcatchment:representing inflow from a sub-catchment, can be estimated with the
RRM rainfall-runoff model; structurally equivalent to inter basin transfer.
Transfer: representing inter-basin transfers.
Desalination: for coastal location, seawater de-salination is also an option.
Water harvesting: describes water harvesting schemes; they are characterised by
- an effective collection area,
- an efficiency % of precipitation collection,
- a precipitation time series and multiplier
Flow from a water harvesting node is calculate from the rainfall (in mm) on the coollection area, corrected by the efficiency.

Data Items

Name	Node Name
Sub-type	one of: generic, well, spring, catchment, transfer, desalination
META	META data block, consisting of author, ctreation and modification dates, free text description
OBJECT ID	optional link to a river basin OBJECT
Aquifer	optional link to an Aquifer (for sub-types well and spring)
flow_ts	time series of flow linked from the model TS data base;
fts_multiplier	scales the time series data, provides the possibility to convert data sets of different units to a common unit (m³/s for flow).
Economic (cost) data:	annualized investment costs; fixed operating costs (annual); variable, OM costs, proportional to the flow.

Dynamic output time series:

A StartNode generates no output other than mirroring its input (flow).

Reports and Statistics:

Statistics of a single flow time series; average, min, max, (SD., % of TOTAL inflow)

Development Notes:

To account for the cost of pumping (start,GWater), a unit cost per m3 pumped should be added to the node data structure as a first simplified representation. More exact estimates depending on the groundwater table (head) require the use of a simple groundwater accounting and local geological and well data also.
Start node types spring and pumped well should be coupled to Aquifers.
For pumped wells, a local analytical model of draw-down would make it possible to monitor wells falling dry; would require aquifer parameters of conductivity anmd storativity, and additional well data (depth).

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