🌐 Surface Area Take-Off
🌍 Overview
The Area Take-Off (ATO) option facilitates the auto-calculation of runoff surface areas and the contributing areas of subcatchments using GIS data.
📚 For a deeper dive into the theory, refer to the Area Take-Off Technical Note.
📋 Prerequisites for ATO
- Checked out model with included subcatchment areas 🔄
- Impermeable Area Survey (IAS) drawing 🗺️
- A coded, digitised map of the catchment's impermeable area for IAS 📍
🛠️ Incorporating IAS into Model
- 📌 Go to Model menu > Select
SubcatchmentArea take off
. - 🖥️ This action prompts the Area Take Off Dialog.
- 📤 Import the digitised GIS IAS data by:
- Browsing for a GIS file 📁
- Selecting a Layer in the GeoPlan View 🌏
- Choosing polygons imported from GIS based on Category Field 🔄
🚀 Using the Area Take-Off Function
- Click on the icon or opt for
Grid windowsNew subcatchments window
from the Window menu. - Open the Subcatchment Grid Window of the Subcatchments Grid 🔲.
- Highlight the entire
Contributing Areas
column, then right-click on any selected cell. - Set the flag to #G (geo) via the
FDlags
option 🚩. - For updating specific subcatchments, follow these steps:
- Select all subcatchments for the update 🔄.
- Navigate to the
Grid menu
> SelectGroup network selections at top of grid
. - In the Subcatchment Grid View, choose
Contributing Areas
column and pick the areas for the chosen subcatchments. - Alter the flag for the picked cells to #G (geo).
- Access
SubcatchmentArea take off
from the Model menu 📌. - Indicate the source for the Impermeable Area Survey data, which could be:
- A GIS file 📁
- A layer in the GeoPlan Window 🌏
- Previously imported polygons from the GIS file.
- Opt for other settings as required. If you used the alternative method in step 5, tick the
Update Selected Subcatchments Only
box 📦. - Press OK to wrap up the process ✅.
- For any issues during the Area Take Off procedure, always review the log file 📜.