Sn. Lane et al., DEVELOPMENTS IN MONITORING AND MODELING SMALL-SCALE RIVER BED TOPOGRAPHY, Earth surface processes and landforms, 19(4), 1994, pp. 349-368
Recent research in fluvial geomorphology has emphasized the spatially
distributed feedbacks amongst river channel topography, flow hydraulic
s and sediment transport. Although understanding of the behaviour of d
ynamic river channels has been increased markedly through detailed wit
hin-channel process studies, less attention has been given to the accu
rate monitoring and terrain modelling of river channel form using thre
e-dimensional measurements. However, such information is useful in two
distinct senses. Firstly, it is one of the necessary boundary conditi
ons for a physically based, deterministic modelling approach in which
three-dimensional topography and river discharge drive within-channel
flow hydraulics and ultimately spatial patterns of erosion and deposit
ion and therefore channel change. Secondly, research has shown that an
alternative means of estimating the medium-term bedload transport rat
e can be based upon monitoring spatial patterns of erosion and deposit
ion within the river channel. This paper presents a detailed assessmen
t of the distributed monitoring and terrain modelling of river bed top
ography using a technique that combines rigorous analytical photogramm
etry with rapid ground survey. The availability of increasingly sophis
ticated terrain modelling packages developed for civil engineering app
lication allows the representation of topographic information as a lan
dform surface. Intercomparison of landform surfaces allows visualizati
on and quantification of spatial patterns of erosion and deposition. A
detailed assessment is undertaken of the quality of the morphological
information acquired. This allow some general comments to be made con
cerning the use of more traditional methods to monitor and represent s
mall-scale river channel morphology.