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Parameterization of stream channel geometry in the distributed modeling of catchment dynamics
Author(s) -
Orlandini Stefano,
Rosso Renzo
Publication year - 1998
Publication title -
water resources research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.863
H-Index - 217
eISSN - 1944-7973
pISSN - 0043-1397
DOI - 10.1029/98wr00257
Subject(s) - routing (electronic design automation) , hydrograph , channel (broadcasting) , geometry , hydrology (agriculture) , drainage basin , surface runoff , geology , geography , mathematics , geotechnical engineering , computer science , computer network , ecology , cartography , biology
A simple and efficient procedure for incorporating the effects of stream channel geometry in the distributed modeling of catchment dynamics is developed. At‐a‐station and downstream fluvial relationships are combined and the obtained laws of variability in space and time for water‐surface width and wetted perimeter are incorporated into a diffusion wave routing model based on the Muskingum‐Cunge method with variable parameters. The parameterization obtained is applied to the approximately 840‐km 2 Sieve catchment (Central Italian Apennines) to test the possibility of estimating channel geometry parameters from cross‐section surveys and to assess the impact of dynamic variations in the channel geometry on catchment dynamics. The use of the estimated channel geometry in surface runoff routing produces a significant improvement in the flood hydrograph description at the catchment outlet with respect to less detailed network parameterizations. In addition, the results obtained from a “downstream” analysis of the velocity field indicate that the stream characteristics related to the locally varying cross‐section shape may have a strong control on flow velocities, and thus they should be monitored and synthesized for a comprehensive description of the distributed catchment dynamics.