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Isochrones of travel time and distribution of flood storage from a tracer study on a small watershed
Author(s) -
Pilgrim David H.
Publication year - 1977
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/wr013i003p00587
Subject(s) - watershed , hydrograph , flood myth , hydrology (agriculture) , time of concentration , surface runoff , environmental science , streams , travel time , tracer , runoff model , geology , geotechnical engineering , geography , computer science , engineering , nuclear physics , biology , ecology , computer network , physics , archaeology , machine learning , transport engineering
In the practical application of many methods of flood hydrograph synthesis it is necessary to space isochrones of travel time over the watershed or to allocate the distribution of storage. The available evidence for guiding this procedure is reviewed, but most information applies to large stream systems and to flows lower than the flood discharges of interest. Times of travel data from tracing of flood runoff on a small watershed have been compared with the evidence from large streams. Average velocities were found to increase slightly in a downstream direction through the watershed, despite decreasing slope. This increase conforms with published hydraulic geometry relationships. Five geomorphological parameters have been tested as methods for spacing isochrones. Field inspection to determine mean depths, and possibly roughness, at bank‐full stages should lead to greatest accuracy, but simple parameters based on stream length also gave good results.