APPENDIX A: LITERATURE REVIEW OF SEDIMENT TRAPS 

 AND SAMPLING DEVICES 



Introduction 



1. This appendix presents a review of riverine and coastal apparatus 

 for measuring sediment transport. The chapter is organized with an introduc- 

 tion and general discussion, description of various types of riverine suspend- 

 ed and bed-load traps, and description of coastal suspended, bed-load, and 

 total load measuring techniques. Riverine devices are discussed first because 

 their development preceded the development of coastal apparatus, and the flow 

 environment is simpler than that of the coastal zone. 



2. The first field measurements of entrained sediment were conducted in 

 rivers and streams (Subcommittee on Sedimentation 1963). Sedimentation and 

 erosion in the riverine environment created navigational and structural 

 problems for the ancient civilizations of China, Mesopotamia, and Egypt. 

 However, the earliest documented study was performed in 1808-1809 and concern- 

 ed measurements of suspended sediment on the Rhone River , France . Suspended 

 sediment is defined as sediment which is supported by the surrounding fluid 

 during its entire motion. Sediment is kept in suspension by a turbulent - 

 velocity component of the flow, and its concentration varies through time both 

 vertically and horizontally. Unfortunately, measurement techniques and 

 apparatus employed in the earliest studies were not recorded. The first docu- 

 mented technique for measuring suspended sediment, dating from the 1800 's, 

 made use of ordinary pails to sample the concentration of sediment near the 

 surface. The sample was assumed to represent the mean of the vertical sus- 

 pended sediment at that point (Inter -Agency Committee on Water Resources 

 1940b).* 



3. A bed-load sampler was first developed in 1898 and used in the 

 Nicaragua Canal (Inter-Agency Committee on Water Resources 1940a). Bed load 

 is defined as that part of the solids load of the stream which is supported by 

 the bed, rolling, skipping, or sliding along the bottom, and moving in con- 



* References cited in the Appendix can be found in the list of references 

 at the end of the main text. 



Al 



