Import loads from shapefile containing polygons with land use type and total population

  Product(s): WaterGEMS, SewerGEMS, CivilStorm, StormCAD, PondPack, SewerCAD, HAMMER, WaterCAD
  Version(s): 08.11.XX.XX
  Area: Data Input/Model Creation


How can I import loads with Loadbuilder if I have a shapefile containing polygons with land use type and total population?

Problem ID#: 58481


First, you would need to create a new field in the shapefile for population density, which you can calculate based on the area and total population of each polygon. Then, you'll need to create a service area layer for your nodes, using a method such as the Thiessen Polygon generator tool in WaterCAD/WaterGEMS(Tools>Thiessen Polygon). Next, open Loadbuilder and choose Load Estimation by Population, under Population/land use data.

Click the ellipsis (...) button next to "Service Area layer", and select your polygon shapefile that contains the service areas for each node. If you used the Thiessen Polygon generator tool, select the shapefile generated by this tool. For the "Node ID" field, select the field in the service area shapefile that contains the IDs that match the nodes in your model. Click the ellipsis button next to "population layer" and select the shapefile that you have, containing the land use type and population. For the "population density type field", select the field containing the land use type. For the "population density field", select the field in the shapefile that contains the population density.

In the table at the bottom, enter your load density for each land use type. If you need to change the units, right click on the column header for "Load density" and choose "units and formatting". Loadbuilder will then find the total load for each polygon based on the density, then distribute that load to the nodes based on how much of the area overlaps the node's associated service area.

See Also

Distributing loads based on areas of different Population type

Why doesn't my load use type field show up in the "population density type" field