.. _connect-wastewater-network-elements: Connect Wastewater Network Elements =============================================== This represents a guide on how to connect wastewater network elements in TWW. General ------------ * TWW has a tool to connect wastewater network elements .. figure:: images/connect_wastewater_network_elements_button.jpg How to connect reaches to nodes or reaches to reaches ----------------------------------------------------- * It does not matter, which layer is selected * The **vw_tww_reach** layer has to be in edit mode * Click the **Connect wastewater network elements** button * If you move the mouse over a reach, that can be connected, it is marked (orange color): you can click * Move the mouse to the network element, to which the first object will be connected (again: selectable objects get marked) and click again .. figure:: images/connecting_1.jpg .. note:: the topology-layers are turned on in the screenshot to show the effect of the connection. * A window appears, where you can choose, which connection will be defined. If you connect a reach, the window looks like this: .. figure:: images/connecting_2.jpg .. note:: there is no options 'Reach Point From' in this example, because in a connection from reach to reach, it is not allowed to connect a From-reach point to another reach. * If everything is ok, you will see a message in a blue bar on top of the map-window .. figure:: images/connecting_3.jpg * To show the new connection, save your edits, click on the TWW-SQL-Button (refresh network topology) and refresh the screen. Now you can see the new connection in the topology-layers .. figure:: images/connecting_4.jpg Video Tutorial (not adapted for TWW) -------------- * See `this video tutorial (QGIS version 2): `_ How to delete a connection -------------------------- There is no special tool in the moment to delete a connection between network elements. * Select the **vw_tww_reach** layer and set it to edit mode * Click on the **Identify Features** button and select the reach to modify by double clicking * Delete the value in the **rp_..._fk_wastewater_networkelement** field to delete the connection .. figure:: images/connecting_delete_connection.jpg .. note:: Be aware of the 'VSA Erfassungsgrundsätze': A reach point from (rp_from_fk_wastewater_networkelement) should never be connected to another reach. For example, when you have a reach discharging directly into another one without a structure between the two, the upstream reach should be connected to the downstream reach (rp_from_fk_wastewater_networkelement = downstream reach). But inversely, the downstream reach shouldn't be connected to the upstream one. This rule is for swwf-channels (secondary network). In pwwf-network, there must be always a node between two reaches.