Sediment Movement in Bear River, Utah
Abstract (Summary)In the northern part of Cache Valley, Utah, accelerated erosion in recent decades has cut deep gullies of impressive size into the flat, irrigated bench land along the Bear River. Millions of tons of fine sediment have been washed into the river and great amounts have been deposited in the river bed. The resulting flooding and high water-table have caused much damage to the land near the river. In addition to summarizing much of what has already been written concerning the problem, this thesis traces the development of the present day conditions and gives a detailed description of the Bear River in Cache Valley. The possible effects of the fluctuating river discharge (caused by the operation of upstream power plants) upon the sedimentation of the stream and the resulting flooding is discussed. The effect of the backwater of a downstream reservoir upon the deposits in the river bed is also described and some general conclusions concerning the future condition of the river are made. Some of the methods which might be used to control the erosion in the gullies are suggested and measures for the rehabilitation of the damaged lands by proper river management are set forth. In recent years much progress has been made, principally by means of flume studies, in developing a theory by which the amount of bed-material transported by a stream can be predicted. Comparsion of the calculated transport rates with field measurements of the bed-load is of great value in testing the usefulness and accuracy of the theory. Field measurements of the bed-load are especially needed in streams such as the Bear River which have a flat slope and small bed-material grain size. Previous measurement in similar rivers have show that the present theory gives unsatisfactory answers in some cases. The ready accessibility of the Bear River and the wealth of hydrologic and hydraulic information available for the stream make it ideal for such investigations. The instrumentation and technique of bed-load sampling as used on the Bear River is described herein. A method is developed by which bed-load measurements are utilized to test the findings of flume experiments and to indicate the modifications of the present theory which may be necessary in its application to streams similar in character to the Bear River.
School:Utah State University
School Location:USA - Utah
Source Type:Master's Thesis
Date of Publication:06/01/1953