Quantification of channel bed morphology in gravel-bed rivers using airborne multispectral imagery and aerial photography

Winterbottom, S. J.; Gilvear, David

doi:10.1002/(sici)1099-1646(199711/12)13:6<489::aid-rrr471>3.0.co;2-x

Cited by 171 publications

(173 citation statements)

References 7 publications

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“…Water depths were measured every 2 hours using a new noninvasive image-based dye density technique. The principle behind the technique is similar to one developed by Winterbottom and Gilvear [1997] using airborne multispectral imagery in natural rivers. We ran a 2 ppm (parts per million) solution of rhodamine dye through the flume and obtained vertical images with a digital camera.…”

Section: Methodsmentioning

confidence: 99%

Riparian vegetation controls on braided stream dynamics

Gran¹,

Paola²

2001

Water Resources Research

348

314

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Abstract. Riparian vegetation can significantly influence the morphology of a river, affecting channel geometry and flow dynamics. To examine the effects of riparian vegetation on gravel bed braided streams, we conducted a series of physical experiments at the St. Anthony Falls Laboratory with varying densities of bar and bank vegetation. Water discharge, sediment discharge, and grain size were held constant between runs. For each run, we allowed a braided system to develop, then seeded the flume with alfalfa (Medicago sativa), allowed the seeds to grow, and then continued the run. We collected data on water depth, surface velocity, and bed elevation throughout each run using imagebased techniques designed to collect data over a large spatial area with minimal disturbance to the flow. Our results show that the influence of vegetation on overall river patterns varied systematically with the spatial density of plant stems. Vegetation reduced the number of active channels and increased bank stability, leading to lower lateral migration rates, narrower and deeper channels, and increased channel relief. These effects increased with vegetation density. Vegetation influenced flow dynamics, increasing the variance of flow direction in vegetated runs and increasing scour depths through strong downwelling where the flow collided with relatively resistant banks. This oblique bank collision also provides a new mechanism for producing secondary flows. We found it to be more important than the classical curvature-driven mechanism in vegetated runs.

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Section: Methodsmentioning

confidence: 99%

Riparian vegetation controls on braided stream dynamics

Gran¹,

Paola²

2001

Water Resources Research

348

314

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“…That means that variations in valley width have not been driven 229 by modern bank and valley-wall erosion processes, but are from ancient processes of valley 230 aerial photographs Gurnell, 1997;Winterbottom and Gilvear;254 Winterbottom, 2000). Winterbottom and Gilvear (1997) showed that aerial photos can be used 255 to accurately quantify channel bed elevation, and Winterbottom (2000) found GIS an effective 256 and accurate tool in quantifying medium-and short-term channel changes on a wandering 257 gravel-bed river from survey maps and aerial photos. 258 259…”

Section: Persistence Of Riffle-pool Sequences 161mentioning

confidence: 99%

Valley width variation influences riffle–pool location and persistence on a rapidly incising gravel-bed river

2010

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“…[5] Airborne multispectral remote sensing techniques have already been successfully applied to large-scale geomorphological work in fluvial environments [Winterbottom and Gilvear, 1997;Wright et al, 2000;Zhang, 2000;Legleiter et al, 2002]. These authors demonstrated that it is possible to classify morphological units in fluvial environments such as pools, riffles, and rapids from multispectral imagery with resolutions ranging from 0.25 to 3 m. Furthermore, an empirical method of automated grain size measurement using a combination of centimeter-resolution airborne digital color imagery and close range millimeter resolution imagery has been proposed by Verdú et al [2003].…”

Section: Introductionmentioning

confidence: 99%

Catchment‐scale mapping of surface grain size in gravel bed rivers using airborne digital imagery

Carbonneau

Lane

Bergeron

2004

Water Resources Research

180

255

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[1] This study develops and assesses two methods for estimating median surface grain sizes using digital image processing from centimeter-resolution airborne imagery. Digital images with ground resolutions of 3 cm and 10 cm were combined with field calibration measurements to establish predictive relationships for grain size as a function of both local image texture and local image semivariance. Independently acquired grain size data were then used to assess the algorithm performance. Results showed that for the 3 cm imagery both local image semivariance and texture are highly sensitive to median grain size, with semivariance being a better predictor than image texture. However, in the case of 10 cm imagery, sensitivity of image semivariance and texture to grain size was poor, and this scale of imagery was found to be unsuitable for grain size estimation. This study therefore demonstrates that local image properties in very high resolution digital imagery allow for automated grain size measurement using image processing and remote sensing methods.

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Quantification of channel bed morphology in gravel-bed rivers using airborne multispectral imagery and aerial photography

Cited by 171 publications

References 7 publications

Riparian vegetation controls on braided stream dynamics

Riparian vegetation controls on braided stream dynamics

Valley width variation influences riffle–pool location and persistence on a rapidly incising gravel-bed river

Catchment‐scale mapping of surface grain size in gravel bed rivers using airborne digital imagery

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