Bank Erosion Hazard Index Exercise
Exercise Objective
To estimate Rosgen Bank Erosion Hazard Index (BEHI) based on given Stream characteristics.
Exercise Process
 Use the BEHI rating sheets to follow the exercise.
 Read the following river assessment for the E4 channel, inventoried for your consideration:
 Bank height to Bankfull height ratio value is 1.6
 Root depth to bank height ratio value is 0.3
 Root density value is 79%
 Bank angle value is 61 degrees
 Surface protection value is 54%.
 Further, the E4 has a cobble bank material with less than 25% gravel and sand to consider
 Find the values for each condition in the BEHI table. Note the range given allows for variability.
 Determine the approximate index number for each value, located below the value number. Again, note the range of numbers given.
 Sum the total numeric index score. You may interpolate index numbers within the range, or select a set or an average value.
 Record each numeric value and sum the values for each of the 5 Stream bank categories (bank height to surface protection).
 Use the provided table to convert the BEHI Total Score into a Hazard or Risk Ranking.
Image modified courtesy of Rosgen
