From: Roger Bettess To: Subject: Rivers-List: Problems for 21st Century Date: 30 June 2000 15:56 Dear Erik Mosselman, Yes, I agree with your comments that the item on regime theory was poorly wordrd. Perhaps it would have been better to say: 6) Provide a physically-based theory to predict the size and shape of stable alluvial channels. In the orginal formulation the word 'regime' was just used as a quick shorthand as it is cretaes in people's minds a picture of what the theory should be predicting. Can I pursue further a point that you raise. You suggest that for specified inputs the equilibrium vales are not unique but can take a range. Can I ask through the mechanism of rivers-list whether this is a widely held view? My concept is that if one had a number of identical flumes and set identiavl conditions in them then the resulting equilibrium channels would all be identical, to within the accuracy that one can impose the conditions and take the measurements. You seem to suggest that some of the channels would be different. What do other people think? Regards Roger Bettess "Faxes and emails are used by HR Wallingford as a convenience for confidential, and often legally privileged, business communications both within the firm and with Clients. Disclosure to parties other than addressees through for example forwarding, copying, printing, distribution etc requires HR Wallingford's specific consent. HR Wallingford is not liable for unauthorised disclosures nor for subsequent actions or omissions in reliance upon them. If you have received this message in error please notify us immediately and destroy all copies of it."