Objective Identification of Pools and Riffles

O’Neill, Máire; Abrahams, Athol D.

doi:10.1029/wr020i007p00921

Cited by 105 publications

(54 citation statements)

References 14 publications

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“…Few studies, however, have compared the faunas of different stream habitats, and those that have (e.g., Armitage 1976;Scullion et al 1982;Logan & Brooker 1983) are concerned mainly with riffles and pools. These two habitats differ markedly in current velocity, depth, and substratum (O'Neill & Abrahams 1984), and therefore it is not surprising that their faunas often differ in abundance and kind. Differences between the faunas of riffles and runs, however, may not be as marked.…”

Section: Introductionmentioning

confidence: 99%

Comparison of the macroinvertebrate faunas of runs and riffles in three New Zealand streams

Pridmore

Roper

1985

New Zealand Journal of Marine and Freshwater Research

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The macroinvertebrate faunas of runs and riffles in three North Island streams were studied during February 1984. In all three streams, both habitats supported similar numbers of taxa and all species found in runs were also present in riffles. No more than two taxa in any one stream were exclusive to riffles, and of these, only the trichopteran Costachorema xanthoptera was exclusive to that habitat whenever it was found. In two of the streams (Rangitukia and Waitakaruru), the mean total densities of macroinvertebrates supported by runs and riffles were not significantly different. However, in Kiripaka Stream, higher total densities were found in riffles than in runs. Most of the taxa (63-68%) in each stream had similar densities in runs and riffles, but some (20-30%) were more abundant in riffles and a few (6-12%) were more abundant in runs. Of the nine major taxonomic groups recorded, only Ephemeroptera had consistently higher relative abundances in riffles than runs, whereas Gastropoda and Amphipoda had consistently higher relative abundances in runs. The distribution and abundance of macroinvertebrates are discussed in relation to environmental and biotic factors. The relevance of the data to invertebrate sampling programmes is also discussed.

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Section: Introductionmentioning

confidence: 99%

Comparison of the macroinvertebrate faunas of runs and riffles in three New Zealand streams

Pridmore

Roper

1985

New Zealand Journal of Marine and Freshwater Research

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“…Les hydrogéomorphologues considèrent les faciès, et notamment les alternances de radiers et de mouilles, comme les unités fondamentales des rivières (O'NEIL et ABRAHAMS, 1984 ;NEWBURY et GABOURY, 1993). Ils leur attribuent une fonction physique de dissipation optimale de l'énergie.…”

Section: Introductionunclassified

Description Standardisée Des Principaux Faciès D’écoulement Observables en Rivière : Clé De Détermination Qualitative Et Mesures Physiques.

Malavoi

Souchon²

2002

Bull. Fr. Pêche Piscic.

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RÉSUMÉLa détermination visuelle des faciès des cours d'eau lors d'une visite de terrain est toujours délicate. Elle peut donner lieu à des appellations et des interprétations différentes de la part de plusieurs observateurs. Afin de mieux standardiser ce type d'observation, nous proposons une clé de détermination empirique basée sur une expérience d'expert. Cette clé est applicable en l'état pour les cours d'eau de taille moyenne à grande (jusqu'à plus de 100 m de large) mais peut demander des adaptations pour les très petits cours d'eau (largeur inférieure à 2 m).Les variables discriminantes de premier niveau conseillées sont la hauteur d'eau (supérieure ou inférieure à 60 cm) et la vitesse d'écoulement (supérieure ou inférieure à 30 cm/s). Elles sont facilement observables lors d'un étiage moyen. D'autres critères complémentaires sont également discutés comme la forme du profil en travers. Des conseils opératoires sont prodigués.Lorsque l'on veut établir un lien entre la nature des faciès et la biologie, il est prudent de tenir compte également de l'hydrologie et donc de la dynamique temporelle des variables physiques d'habitat. Les mesures quantitatives simples proposées permettent de renseigner les équations de géométrie hydraulique qui établissent les relations entre la largeur mouillée, la hauteur d'eau, la vitesse et le débit, grandeurs plus pertinentes pour établir un lien avec la biologie. Mots-clés : faciès morphodynamiques, géométrie hydraulique, mésohabitat.Bull. Fr. Pêche Piscic. (2002) ABSTRACTThe direct visual appreciation of geomorphic unit (GU) in running waters is always delicate. Some misinterpretation is frequent among different observers. To standardized the GU description, we proposed a decision key, based on expert' experience. The first discriminative variables are the water depth (limit at D = 60 cm) and water velocity (limit at V = 30 cm/s). They are easily observable at an average interannual low flow. Else complementary criteria are also argued, particularly the transversal water profile. Any operating advices are also given.In order to link GU and biology, it is advisable to take into account the hydrology as a dynamic physical control factor of the aquatic system. Quantitative measurements are usefull to work with the hydraulic geometry equations. These equations linked width, depth, velocity with discharge. All of them are more pertinent variables to rely physics and biology.

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“…In the regions with slow flow, a pool with an above average depth can be expected, and the fastest flows are observed at steps and shallow reaches. Thus, several studies were conducted to determine bed morphology from the water surface slope or longitudinal profile of talweg [29].…”

Section: Applicability Of Uas Data In Fluvial Geomorphologymentioning

confidence: 99%

Multitemporal Monitoring of the Morphodynamics of a Mid-Mountain Stream Using UAS Photogrammetry

Miřijovský

Langhammer

2015

Remote Sensing

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This paper explores the potential of Unmanned Aerial Systems (UASs) for the analysis of variations in the fluvial dynamics of a mid-mountain stream. The UAS photogrammetry was employed to acquire a multitemporal set of high-precision digital terrain models (DTMs) and orthoimages, thereby enabling the reconstruction of variations in riverbed and quantitative analysis of volumetric changes. A hexacopter UAS platform was used for the repeated acquisition of data for the photogrammetric analysis of a stretch of mid-mountain streams with elevated fluvial dynamics. Photogrammetric reconstruction enabled the development of accurate DTMs and orthoimages with spatial resolutions of 2 cm per pixel. These were identified and used to quantitatively assess the segments of channels with active lateral erosion. The UAS-derived data facilitated an analysis of the shifts of stream banks and the calculation of the areal extent of changes and volumetric extent of bank erosion. Comparison of UAS-derived point clouds with aerial LiDAR scanning data demonstrated the high spatial accuracy and precision of the UAS data. The accuracy and high operability of the imaging provide spatial data of a new qualitative level and the potential for the detailed analysis of experimental areas where spatial information is of limited availability. OPEN ACCESSRemote Sens. 2015, 7 8587

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Objective Identification of Pools and Riffles

Cited by 105 publications

References 14 publications

Comparison of the macroinvertebrate faunas of runs and riffles in three New Zealand streams

Comparison of the macroinvertebrate faunas of runs and riffles in three New Zealand streams

Description Standardisée Des Principaux Faciès D’écoulement Observables en Rivière : Clé De Détermination Qualitative Et Mesures Physiques.

Multitemporal Monitoring of the Morphodynamics of a Mid-Mountain Stream Using UAS Photogrammetry

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