When using EFDC_Explorer and CVLGrid it is often useful to have a background map of the region displayed behind the model. This How-To guide describes the approach to develop these background maps. To create the background map in EE or CVLGrid the following tools are required:
The software allows us to generate images and coordinates of determined area.
Generally, an image will be determined by two coordinates:
Example: generating geo-reference map for Okeechobee city of Florida, United States.
Step 1: Determine Magnetic Declination
Figure 1 Options feature in Tool menu of Google Earth.
Figure 2 Setup Google Earth Options.
Figure 3 Add a temporary placemark on Lake Okeechobee.
Figure 4 USGS web calculator interface.
Figure 5 Entering the coordinates of the placemark to USGS web calculator.
Figure 6 Declination of the placemark.
Figure 7 Entering declination of the placemark into Heading field.
Step 2: Determine Upper Left (UL) and Lower Right (LR) Coordinates
UL | LR |
Easting 467419.45 m E Northing 3009561.68 m N | Easting 563219.52 m E Northing 2951517.39 m N |
Figure 8 Setup UTM option on Google Earth.
Figure 9 Define UL co-ordinates.
Figure 10 Define LR co-ordinates.
Step 3: Save image for UL-LR Area
Figure 11 UL and LR image saving.
Figure 12 Choosing Premium resolution.
Figure 13 Geo-Referencing tool in CVLGrid.
Figure 14 Load bitmap file.
Figure 15 Declare UL co-ordinates.
Figure 16 Declare LR co-ordinates.
Figure 17 Save geo-reference file.
Figure 18 Naming and storing geo-reference file.
Figure 19 Geo-reference file loaded by CVLGrid.