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Presentation of the plugin concepts#

The StarEau plugin helps to manage the data of underground water networks with QGIS and PostGIS:

  • drinking water networks (AEP, alimentation en eau potable),
  • sanitation networks (ASS, assainissement): wastewater, stormwater and combined sewers.

The data model is the StaR'Eau geostandard, published by the CNIG (Conseil national de l'information géolocalisée) and the ASTEE. The SQL files of the geostandard are available in the StaR-Eau repository: the plugin installs them and adds its own functions and triggers to keep the network topology consistent and to analyse the network.

Network types#

Each object of the network has a network type, stored in the field type_reseau (value list com_type_reseau):

Code Network
aep Drinking water
assaeu Wastewater
assaep Stormwater
assaru Combined sewer (réseau unitaire)
ince Fire fighting

The plugin tools work either on the AEP network (type_reseau = 'aep') or on the ASS network (all the other network types). A pipe is never linked to a node of the other network family.

Nodes and pipes#

The network is a graph made of network nodes and pipes:

  • a network node (nœud réseau) is a point: a valve, a manhole, a reservoir, a pumping station, etc.,
  • a pipe (canalisation) is a line linking two nodes:
    • its initial node (noeudinitial), at the start point of the line,
    • its terminal node (noeudterminal), at the end point of the line.

The direction of the line is meaningful: from the initial node to the terminal node. For a sanitation network, it is the flow direction, used to walk the network upstream and downstream.

When there is no node at the start or end point of a pipe, the field noeudinitial or noeudterminal contains the value non_renseigne: it is a missing node, which can be found with the algorithm Get missing nodes.

The links between pipes and nodes are maintained automatically by the database, see Network topology.

Table inheritance#

The StaR'Eau data model uses the PostgreSQL table inheritance:

  • the table stareau_principale.noeud_reseau is the parent of all the node tables: aep_vanne, aep_reservoir, ass_regard, ass_pompage, etc.,
  • the table stareau_principale.canalisation is the parent of all the pipe tables: aep_canalisation, ass_canalisation, aep_canalisation_branchement, etc.,
  • all these tables also inherit the common fields of stareau_principale.champ_commun: network type, service status, INSEE code of the municipality, owner, operator, XY and Z precisions, dates, etc.

The data is stored in the child tables, e.g. a valve in stareau_aep.aep_vanne. A query on a parent table returns the objects of all its child tables: stareau_principale.noeud_reseau contains all the nodes of all the networks. The identifiers fid, id_noeud_reseau and id_canalisation are therefore unique across all the child tables.

Value lists#

Most fields contain a code from a value list, stored in the schema stareau_valeur (one table per list, with the fields code, valeur and description). For example, the field etat_ouverture of a valve uses the list aep_etat_ouverture: ouverte, fermee, partiel_ouverte, partiel_fermee.

Besides the values of the geostandard, every list contains the values non_renseigne, non_concerne, non_valide, non_determine and autre.

Network analysis#

Some tools use the extension pgRouting to find paths in the drinking water network:

  • the pipes between a node and the nearest target: water intake, treatment plant, reservoir,
  • the pipes between the water intakes and the treatment plants, or between the treatment plants and the reservoirs, to check the function of the pipes,
  • the valves to close to isolate a part of the network.

These tools use a routing graph computed from the AEP nodes and pipes, see Network analysis.

Glossary#

Concept French Definition
AEP Alimentation en eau potable Drinking water network
ASS Assainissement Sanitation network: wastewater, stormwater, combined sewer
Network node Nœud réseau Point object of the network linked to the pipes: valve, manhole, reservoir, etc.
Pipe Canalisation Line between an initial node and a terminal node
Service connection Branchement Part of the network between the main pipe and the user (schemas *_brcht)
Missing node Nœud manquant Start or end point of a pipe without any network node
Orphan node Nœud orphelin Network node which is not the initial or terminal node of any pipe
Duplicate node Nœud en doublon Orphan node located at the same place as another node
Water intake Captage Point where the raw water is taken from the resource
Treatment plant Traitement Drinking water treatment plant
Reservoir Réservoir Water tank or water tower
Valve Vanne Device used to open or close a pipe
Manhole Regard Access point to a sanitation pipe
PEI Point d'eau incendie Fire hydrant or fire water point (schema stareau_defense_incendie)
Vertex / Edge Node / pipe of the pgRouting graph, see Network analysis