I am currently working on an assignment where I need to model flood risk areas. Firstly I was asked to identify potential flood risk zones based on the following criteria:
identify areas that I would consider to have steep slopes. I think I have completed this task. I used the Slope tool here.
Identify a 20 year flood zone and base this on an estimated distance from rivers. Then repeat the task for a 100 year flood return. A guide value would be not to go beyond 2 kilometers for the 100 year and less for the 20 year. I have no idea how to even start this. I have googled different things have come up with extensions that can be used but we never went over any such extensions in the college practicals.