Ouachita River Reach Dimension Exercise

Exercise Objective

Exercise Process

1. Obtain a high resolution image of the picture shown on this page by right clicking on the image with your mouse to Save Target As … on your computer.
2. View the high resolution image 06_53_01a.jpg in ImageJ and determine cross sectional FGM properties. Recall that in determination of bankfull height, one side of the channel may have a more clear indicator of the transition from active channel to floodplain. In the field, several cross sections are visited to gather multiple estimates of bankfull, to assist in discerning outliers and trends. Once you have identified the bankfull point, your measurements can proceed.
3. Measure the following. To make these measurements, you may need to refer to earlier instruction in FGM Module Section 3.
   • Maximum Bankfull Depth or d_mbkf
   • Bankfull Width or W_bkf
   • Bankfull Area or A_bkf
   • Flood Prone Area Width or W_fpa
4. Please save your measurements for future application in this exercise.
5. Compute the following: To make these calculations, you may need to refer to earlier instruction in FGM Module Section 3.
   • Entrenchment Ratio.
   • Width to Depth Ratio.