<< Click to Display Table of Contents >> Navigation: waterRIDE FLOOD > SETUP > Flood Forecasting > Setting Up A Flood Forecast System > Create Rating Curves |
Rating curves form an important part of many flood forecasting systems. There are two parts to creating ratings curves:
•Extracting hydrographs (flow vs time) from the time-varying water surfaces
The tools are accessed on the Setup Panel, using the Rating Curves tool in the Flood Forecasting section.
This tool will extract flow hydrographs from multiple time-varying water surfaces. The cross sections along which to extract the hydrographs flow are defined as polylines in a GIS layer. A field in the GIS layer defines the ID for each cross section.
When the tool is run, the hydrographs will be saved in separate CSV files with the following nomenclature:
XSectID-WaterSurfaceFileName.CSV
Once hydrographs have been extracted, a rating curve can be manually created using this tool.
1) Load all relevant waterRIDE hydrograph files (*.csv), or TUFLOW PO Line Export Files (*.csv) for a location.
2) Enter drawing mode to draw the rating curve to match the raw data. Left clicking on the chart when in this model will add a point to the rating curve. The cursor will change to a cross.
3) Enter zoom/pan mode to zoom in on the raw data. Left click at the top left of your desired zoom window and drag down and right to draw the zoom window. Right click and drag to pan the chart. Left click and drag to the upper left to reset back to the full chart extent.
4) Enter edit rating curve mode. Left click on a rating curve point and drag to its new position, or simply left click anywhere on the chart to move the nearest node to that point. The cursor will change to a hand.
5) Save the current rating curve to a waterRIDE™ rating curve file (*.csv)
waterRIDE rating curves follow a simple CSV file format. An example is provided below:
TITLE,Sample Rating Curve for reference only, not used by system
GAUGE,Cab_Test for reference only, not used by system
Q,WL header line for rating data
0,500 start of rating curve data
17.45,524.42
33.18,524.7
57.57,524.96
...