Isochrones of travel time and distribution of flood storage from a tracer study on a small watershed

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.

[1]  L. B. Leopold,et al.  The hydraulic geometry of stream channels and some physiographic implications , 1953 .

[2]  D. H. Pilgrim.  Radioactive tracing of storm runoff on a small catchment: II. Discussion of results , 1966 .

[3]  L. Brush.  Drainage basins, channels, and flow characteristics of selected streams in central Pennsylvania , 1961 .

[4]  C. O. Clark.  Storage and the Unit Hydrograph , 1945 .

[5]  W. Langbein.  Geometry of River Channels , 1964 .

[6]  C. W. Carlston.  Downstream variations in the hydraulic geometry of streams; special emphasis on mean velocity , 1969 .

[7]  D. H. Pilgrim.  Travel Times and Nonlinearity of Flood Runoff From Tracer Measurements on a Small Watershed , 1976 .

[8]  F. Henderson.  Open channel flow , 1966 .

[9]  M. Wolman.  The natural channel of Brandywine Creek, Pennsylvania , 1955 .

[10]  Jerry E. Mueller.  Re-evaluation of the Relationship of Master Streams and Drainage Basins , 1972 .

[11]  L. B. Leopold.  Downstream change of velocity in rivers , 1953 .

[12]  V. T. Chow.  Open-channel hydraulics , 1959 .

[13]  D. H. Pilgrim.  Radioactive tracing of storm runoff on a small catchment: I. Experimental technique , 1966 .

[14]  J. Brice.  Erosion and deposition in the loess-mantled Great Plains, Medicine Creek drainage basin, Nebraska , 1966 .

[15]  Luna Bergere Leopold,et al.  The concept of entropy in landscape evolution , 1962 .

[16]  Chih Ted Yang,et al.  Hydraulic Geometry of 12 Selected Stream Systems of the United States , 1970 .

[17]  L. B. Leopold,et al.  Ephemeral streams; hydraulic factors and their relation to the drainage net , 1956 .

[18]  T. Dunne,et al.  A salt tracing method for measuring channel velocities in small mountain streams , 1970 .

[19]  M. A. Kohler,et al.  Hydrology for engineers , 1958 .