Re: Does temperature of stream water affects stream velocity?

Well, temperature definitely changes the density of water, but my answer greatly depends on how much water you’re working with and how greatly the temperature varies. For exact measurements of closed systems and their flow rates, try the link below. They might have some software that could be of help- and by all means, try to get the department to pay for it!

Aside from the changes in density, there’s always: the evaporative rate of the surface (also dependant on ambient humidity/dewpoint/wind), the transpiration rate (water flow into and through plants along the shore), and surface disturbance (if there’s a waterfall, or the wind is making waves on the surface, not only will there be evaporation, but the stream flow and increased surface area will affect the temperature- the opposite of what you’re looking for!).

I cannot recall having used a model that relates density or temeperature to flow with the exception of temperatures within a few degrees of 0C and freeze/thaw rates. In Singapore, you have the rare opportunity to observe streams in a relatively stable environment. I consider you very lucky (wow, can I take a vacation?) I’m not sure that the daily temperature change will do any more to the density-related flow rate than increase or decrease your flows by a few hudredths of a percent of your hourly rate.

Best of luck, and be sure to share with the rest of us when you get published!

http://www.scisoftware.com/products/feflow_details/feflow_details.html