Geomorphic Assessment of Channel Systems
If it is desired to complete particle size analysis of sand-sized sediment in the field, a
field sieve stack and electronic scale can be used, although the sieve stack will not fit into the
fieldpack and must be carried separately.
Probe Rod. As well as sampling sediments, it is often useful to investigate the
thickness of sedimentary units and of loose sediment stored in the bed and in bars, by using
a probe rod. A probe rod is also useful to examine the depth and extent of any tension cracks
and piping cavities in the banks.
A variety of rods could be used for this purpose, but in the field tests carried out in
developing the reconnaissance sheets presented here a jointed, stainless steel gun-cleaning rod
was found to be ideal. This rod is strong enough to penetrate most alluvial sediments,
including densely packed sands, but can be taken apart to store neatly inside the fieldpack.
Gravelometer. The gravelometer is used to measure particle size in the Wolman
pebble-count or grid-by-number method of sampling armor layers and other alluvial gravels
that are too course to be handled by bulk sampling. It is a light, thin sheet of aluminum alloy
with square holes machined in it that follow the Wentworth Scale and range between 2 and
180 millimeters in size.
Geological Hammer and Rock Identification Charts. The geological hammer is
useful for examination and sampling of rocks and other lithified materials encountered during
stream reconnaissance. A pack of rock identification charts, available from most supplier of
equipment for petroleum geology, can be very useful in assisting non-specialists in making
rudimentary observations concerning geological controls and influences on channel form and
Miniature Cassette/Voice Recorder. A miniature cassette or voice recorder is
extremely useful for taking notes to supplement the written and photographic records of a
reconnaissance trip. The recorder can be used to preserve thoughts or ideas triggered by field
observations and may be used during inclement weather and in other situations where writing
or taking video would be impossible. Field notes may also be dictated immediately after
completing a survey or when traveling between sites, to be typed up later.
35mm Still Camera. A compact, automatic 35mm camera is suitable for field
reconnaissance. A water proof or, at least weather proof camera should be used. Ideally one
equipped with a zoom lense should be chosen for versatility in photographing both wide,
panoramic views of the river and floodplain, and detailed shots of bank and sedimentary
features that are difficult to access closely.
Slide film is usually preferred over print film because slides are more compact to store
and are useful for illustrating and presentations concerning the project. Either prints or slides
can easily be scanned into a computer for electronic enhancement and storage, but if
computer-based storage is to be used, investment in one of the new, relatively inexpensive,