EFFECTS OF GRAVEL REMOVAL ON RIVER HYDROLOGY AND HYDRAULICS 



L. A. Rundquist 



INTRODUCTION 



The purpose of the hydrology and hydraulics study was to evaluate 

 the effects of floodplain gravel removal on the river configuration, hy- 

 draulics, sedimentation, ice characteristics, and hydrology at the 25 study 

 sites. The locations of these sites are shown in Figure I. The characteris- 

 tics describing the physical aspects of the site and the gravel removal 

 methods are listed in Table I. General descriptions of the sites are pro- 

 vided in DESCRIPTION OF STUDY RIVERS. 



Previous studies of gravel removal from river floodplains are limited 

 in number. A preliminary report for this project (Woodward-Clyde Consultants 

 1976a) reviewed literature on gravel removal up to that time. Significant 

 results of that review are included and expanded upon in this section. Other 

 pertinent literature identified since 1976 are included in this section. 



A few general statements (from Woodward-Clyde Consultants 1976a) con- 

 cerning the behavior of rivers are given in the following paragraphs to 

 provide a basis for the information presented in subsequent sections. 



A river continually changes its position and shape as a consequence of 

 hydraulic forces acting on its bed and banks. These changes reflect the 

 dynamic condition of the natural environment; they may be slow, gradual 

 processes or sudden morphological changes resulting from an extreme flood 

 event. A river system always strives toward a state of equilibrium in order 

 to convey the water and sediment delivered to it. 



67 



