For a fantastic exploration of the issues of river discharge or flooding, spend an hour or so working through the wonderful VIRTUAL RIVER courtesy of the US Geology Labs On-Line. This is great, and you get a certificate to prove that you've been through it to show the teacher. Do the River Discharge exercise first to get the hang of the main terms, and then move on to River Flooding. Some great animations: timing the suspended load with the stopwatch has to be one of the highlights. Keep persevering to get to the end, and marvel at the little applications which make it just like the real thing, but without the wellies.
This was particularly useful during the foot and mouth outbreak which prevented us from planned fieldwork at the River Noe in Edale last year. There's nothing better than going to a well-developed meander and actually seeing that what it says in the textbook actually happens. We used to go to Castle Acre in Norfolk, where the River Nar winds along a meadow past some old watercress beds, past the old castle, and on towards the Priory. That was in the days when a sixth form group could still fit in a minibus.
Recommended (by an expert virtual hydrologist, according to my certificate)
The place to start exploring should be the ENVIRONMENT AGENCY. They have a lot of excellent material on their website, plus they will send out booklets. I received a very useful one on 'Understanding Riverbank Erosion'. I also receive a monthly newsletter which gives information on recent work that the EA has been involved in.
We used to use a pack produced by the old Geography 14-18 project called 'Water and River' by R.T Hare and published by Macmillan Education. Anyone else remember that ? One of the things that has endured is the section on the Lynmouth Flood, although I still use several other items. I also used the RAINDROP GAME: this used a sheet and 6 sided die to follow a raindrop through the various possibilities that were open to it.