--- title: "1D Urban Networks | Tutorials" slug: "1d-urban-networks" description: "Read the introduction to 1D urban networks: selection mode, labels, editing and more. " updated: 2022-08-21T10:58:29Z published: 2022-08-21T10:58:29Z canonical: "help.floodmodeller.com/1d-urban-networks" stale: true --- > ## Documentation Index > Fetch the complete documentation index at: https://help.floodmodeller.com/llms.txt > Use this file to discover all available pages before exploring further. # 1D Urban Networks A 1D simulation always requires a **network** to represent the 1D components. When modelling a pipe drainage system, a 1D urban network describes the system itself. The urban network file also contains details about the simulation associated to the network. Unlike 1D river modelling, you do not create new urban simulations independently of networks - you can run the simulation associated to the urban network, or create a new urban network for a new simulation. Flood Modeller provides functionality to [load](/v1/docs/how-to-load-a-1d-urban-network) and [save](/v1/docs/how-to-save-a-1d-urban-network) existing urban networks, or [create new](/v1/docs/how-to-save-a-1d-urban-network) networks. To work on a loaded urban network, ensure you have **Selection Mode** set to **1D Urban**. Viewing the network on the **Map** view may be easier if **Labels** are added. If adding new components to the network, you will also find it helpful to edit your **Model Defaults**. #### How to set the Selection Mode **Selection Mode** is displayed at all times at the bottom of the map view. When building and editing 1D urban networks, you must be in **1D Urban** selection mode. Right-click anywhere on the **Map view** to access a menu allowing you to adjust the selection mode. ![](https://cdn.document360.io/5074bc26-a9ef-4bf4-b1de-a5c6ce628aca/Images/Documentation/SelectionMode.png) Selection mode can also be turned on and off using the toggle provided on the **1D Urban Build tab**. ![](https://cdn.document360.io/5074bc26-a9ef-4bf4-b1de-a5c6ce628aca/Images/Documentation/SelectionMode2.png) --- #### How to add labels to the map On the **Home tab**, check-boxes allow you to add **labels** and **icons** to the map view. If your urban network a geo-referenced, a basemap can also be added from here. ![](https://cdn.document360.io/5074bc26-a9ef-4bf4-b1de-a5c6ce628aca/Images/Documentation/addlabels.png) The **1D Urban Build tab** also provides general urban network functionality, including the check-boxes allow you to add **labels** and **icons** to the map view. ![](https://cdn.document360.io/5074bc26-a9ef-4bf4-b1de-a5c6ce628aca/Images/Documentation/addlabels2.png) --- #### How to edit Model Defaults The urban Model Defaults window is accessed from the **1D Urban Networks** section of the **Project** panel. Click the network name to highlight it, then **right-click** and select **Model Defaults** from the menu. ![](https://cdn.document360.io/5074bc26-a9ef-4bf4-b1de-a5c6ce628aca/Images/Documentation/opendefaults.png) The window contains three tabs all containing default settings that will be applied as you build your urban network, and to the associated simulation. All of these can be left at their pre-set values, although you may find your urban modelling easier to adjust these to suit your project. ![](https://cdn.document360.io/5074bc26-a9ef-4bf4-b1de-a5c6ce628aca/Images/Documentation/idlabels.png) The **ID Labels** tab specifies a prefix and incremental number to be provided as the name/label of new nodes and links added to your urban network. These labels can also be edited further within individual nodes/links once created. ![](https://cdn.document360.io/5074bc26-a9ef-4bf4-b1de-a5c6ce628aca/Images/Documentation/subdef.png) The **Subcatchment** tab specifies defaults to be applied to new subcatchments. The **Area** can be left at 0 and new Subcatchments will have the area automatially calculated from the shape drawn on the map. There are also several **Additional Subcatchment parameters** that can be specified here. The **Infiltration Model** can be selected from a drop-down. Note that if you adjust this model, a pop-up will ask if you want to apply the adjustment to any existing Subcatchments. The same infiltration model must be applied to all Subcatchments, and is specified in the Model Settings. It is recommended to select your infiltration model before adding any Subcatchments. ![](https://cdn.document360.io/5074bc26-a9ef-4bf4-b1de-a5c6ce628aca/Images/Documentation/nodedef.png) The **Nodes/Links** tab specifies the remaining defaults to be applied to the urban network. Default values for **Node parameters** can be defined. The **Link length** will apply to Conduit links, alongside Pump, Orifice, Weir and Outlet links. This value can be left at 0 and new links will have the length automatially calculated from the line drawn on the map. A default geometry and roughness can also be provided as **Additional link parameters**. The **Units** to be used are chosen here. We recommend these are selected prior to building your urban network. The **Offset convention** can be adjusted from depth to elevation if required. Conduit links can have an offset specified at the inflow and outflow ends. This setting indicates whether these offset values are depths (distance from the invert level of the inflow/outflow node) or elevations. **Routing Settings** are also provided here. Dynamic Wave is the most sophisticated routing method available. More on the routing methods can be found in the [Urban Simulations](/v1/docs/1d-urban-simulations) section. In Dynamic Wave routing, the Force Main equation may apply to calculate friction losses if your Conduits become pressurised. **Related topics:** Technical details on the [Urban Model Defaults](/v1/docs/urban-network-panel). --- ## More on 1D urban modelling Features of the underlying system such as manholes, connections between pipes, and outfalls, are represented using [Urban Junction and Outfall Nodes](/v1/docs/urban-junction-and-outfall-nodes). These specify divides in flow, and details of water leaving the system. Flow between nodes is defined by [Urban Conduit Links](/v1/docs/urban-conduits). These provide details of the pipes themselves, such as the geometry, dimensions and roughness. Your network may also consist of other [Urban Structures and Features](/v1/docs/urban-structures-and-features). This may include units for storage, pumps to allow water to be lifted to higher elevations, or devices used to regulate flows within the system, such as weirs. [Urban Inflow](/v1/docs/1d-urban-flow) will also be required to specify water entering the network. This can be defined directly, or a combination of Rain Gage and Subcatchment nodes can be utilised. To set up [Urban Simulations](/v1/docs/1d-urban-simulations), details of timing and run-type must be provided alongside other simulation options. Climatology inputs can also be specified. Urban simulations can be run individually, or in batches. If you encounter issues with urban modelling, exploring the [Urban Diagnostics](/v1/docs/1d-urban-diagnostics) will help identify problems and resolve warnings and errors. Multiple options are provided for viewing [Urban Results](/v1/docs/urban-results), including plots with animation functionality to show water level changing over time. Each chart can be fully formatted to customise as needed, alongside providing various methods for exporting the data for post-processing or use in reports. You may also be interested in linking your 1D urban network to a 1D river network or to 2D components. Details of this can be found in the [Integrated Modelling](/v1/docs/integrated-modelling-overview) section of this manual.