Geomorphic Assessment of Channel Systems
digital cameras will prove cost-effective since the time and costs of processing and scanning
are eliminated.
Stereo photographs are especially valuable in that they yield considerably more
information than single photographs and can be used to determine morphological changes
between successive visits to a site. They can be generated by taking two photographs of the
same scene from points separated by a distance of about 2% of the distance to the primary
object in the scene. The availability of computer software for analysis of digital-stereo
photographs makes this the appropriate technology for the 1990s.
8mm Video Camera. A light, compact video camera such as a `palmcorder' or
`viewcam' is extremely useful in conducting stream reconnaissance because it captures both
a moving, visual record of the stream and a verbal commentary. Video can be stored on tape
for future reference or is easily transferred to a computer system as part of a multi-media
archive.
Maps and Reference Materials. Maps of suitable scales to cover the study area are
essential tools in stream reconnaissance, both for route finding and identification of landscape
features. In remote areas with few reference points in the field, a hand-held GPS will prove
useful.
Aerial photographs are also valuable to gain an overview of the channel and its
surroundings. Historical as well as contemporary maps and aerial photographs should be
obtained if possible because comparison of present and past features adds a valuable time-
dimension to the reconnaissance survey.
A geological map yields valuable information on landscape-forming materials and
possible geological controls on the fluvial system. Relevant geological maps should at least
be consulted prior to setting out on a survey, even if they cannot be taken to the field.
Miscellaneous Equipment and Supplies. There is a wide range of auxiliary
equipment that can be useful on a stream reconnaissance trip, and the selection of
miscellaneous items to be included in the fieldpack is largely a matter of individual choice.
Based on experience from trips in the UK, USA and SE Asia, items that have proved useful
include a clipboard, umbrella, cagoul or waterproof suit, thigh waders, calculator, magnifying
glass, and brush knife or woodsman's axe.
Safety Equipment. Safety must be of paramount importance and fieldworkers must
assess all potential hazards associated with reconnaissance of a given stream before setting
out. Steps must then be taken to avoid hazards where possible and to take all reasonable
precautions to minimize the risks where hazards cannot be avoided entirely.
With regard to safety, as a bare minimum, the fieldpack must include a first aid kit,
with the contents sufficient to satisfy the relevant safety legislation. Additionally, it would be
prudent to include a canteen of drinking water, torch (flashlight), safety matches, sun block
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