The answer to this question was posted last week, however, due to NPTEL website technical problem, I am reposting the reply now.
"Dear Sagar, Thank you for asking this interesting question. If you are asking the difference in terms of exact definitions, well, then there is no difference. It is the approach with which we discuss the concepts in hydraulics that decides whether it is at basic or advanced level. In under-graduate curriculum, the course open channel hydraulics begins with brief discussions on critical flow, uniform flow, GVF, and/or RVF and their governing equations are expressed without much emphasis on the fundamental conservation principles. The same concepts are discussed in the advanced level here as well with emphasis on the principles governing
the features. We have extensively used the Reynolds Transport Theorem to discuss the conservation principles in open channel flows and derive their subsequent mathematical expressions with proper physics involved."
Dr. Suresh A Kartha Date: