Fluvial geomorphology

This is the Fluvial Geomorphology Report produced by the National Rivers Authority (NRA) in 1994. The purpose of this paper is to briefly outline the relevance of fluvial geomorphology and the substantial benefits which could accrue from applying it nationally across the NRA. It compliments information given in a previous paper dated 27 October 1993 which was presented to a national FRCN meeting on 9 March 1994

Fluvial Geomorphology and Bank Stabilization: White River at Stotts Creek Confluence

Fluvial geomorphology is the study of how rivers and streams move or change their cross section and adjacent land form over time under the influence of water flow. This presentation focuses on the fluvial geomorphology of the White River in the vicinity of the Stotts Creek confluence and proposed actions to protect I-69 (currently SR 37) from lateral migration of the river and subsequent erosion and scour

Modern empirical and modelling study approaches in fluvial geomorphology to elucidate sub-bend-scale meander dynamics

Major developments in theory and modelling techniques have taken place within the past couple of decades in the field of the fluvial geomorphology. In this review, we examine the state-of-the-art empirical and modelling approaches and discuss their potential benefits and shortcomings in deepening understanding of the sub-bend-scale fluvial geomorphology of meander bends. Meandering rivers represent very complex 3D flow and sedimentary processes. We focus on high-resolution techniques which have improved the spatial and temporal resolution of the data and thereby enabled investigation of processes, which have been thus far beyond the capacity of the measurement techniques. This review covers the measurement techniques applied in the field and in laboratory circumstances as well as the close-range remote sensing techniques and computational approaches. We discuss the key research questions in fluvial geomorphology of meander bends and demonstrate how the contemporary approaches have been and could be applied to solve these questions.</jats:p

Highways in the river environment, hydraulic and environmental design considerations: training and design manual

CER 73-74EVR-SK-KM-DBS-MAS49.September, 1974.Includes bibliographical references.1. Introduction -- 2. Open channel flow -- 3. Fundamentals of alluvial channel flow -- 4. Fluvial geomorphology -- 5. River mechanics -- 6. River stabilization, bank protection and scour -- 7. Needs and sources for data -- 8. Hydraulic and environmental considerations of highway river crossing and encroachments1. Introduction -- 2. Open channel flow -- 3. Fundamentals of alluvial channel flow -- 4. Fluvial geomorphology -- 5. River mechanics -- 6. River stabilization, bank protection and scour -- 7. Needs and sources for data -- 8. Hydraulic and environmental considerations of highway river crossing and encroachment

Local Applications of Fluvial Geomorphology

This study proposed a method for developing regional curves based solely on hydraulic modeling. Regional curves relate bankfull channel geometry and discharge to drainage area and are typically used to design channel reaches in natural stream systems at locations where stream modifications are required. Such modifications may result from the following projects - highway improvement, bank stabilization, flood control, etc. There are simply situations where modifications must be made to reaches of natural streams in order to accommodate improved drainage structures or to address flooding, scour or erosion problems. Tributaries of the Marais des Cygne River in Johnson County, KS were used for this study. The watershed for the region studied is predominantly rural and, thus, has many natural reaches. Moreover, detailed terrain data was available for the portion of the Marais des Cygne River considered in this study – with 1-ft contour interval data along the stream corridors. HEC-RAS modeling was used at eight sites or stream reaches within the area studied. Each of the eight stream reaches were judged to be natural based of aerial photography. A HEC-RAS model was developed for each site at a riffle location. Each model used the downstream normal depth boundary condition and contained from 4 to 9 cross sections developed using HEC GeoRAS. The bankfull elevation was estimated for every cross section based on the elevation where the flow appeared from the cross section plot to spill out into one or both of the overbanks. Trial and error was used for each model to determine the discharge (bankfull flow) that produced the minimum sum of squares of the differences between the computed water surface elevation and the assumed bankfull elevation for all modeled cross sections. The bankfull flow channel geometry parameters were then determined for each cross section and average values were related to drainage basin area via regional curves. The drainage basin areas used were from the recent Johnson County flood study of the Marais des Cygne River

Fluvial Geomorphology and River Management

This Special Issue deals with the role of fluvial geomorphology in landscape evolution and the impact of human activities on fluvial systems, which require river restoration and management [...

RELATING FLUVIAL GEOMORPHOLOGY TO MACROINVERTEBRATE DISTRIBUTION

Modern rivers undergo constant stress from disturbances such as bank stabilization, channelization, dams, and water expenditures. As these anthropogenic activities persist, efficient methods of characterizing rivers remain essential. Macroinvertebrates are an important feature in evaluating fluvial health, because they are often the first to react to contaminants. These toxins can be transferred through macroinvertebrates to other trophic levels. The purpose of this research was to use a geospatial model to differentiate instream macroinvertebrate habitats, and determine if the model is a viable method for stream evaluation. Through the use of ArcGIS and digital elevation models, the geomorphology of the Qu’Appelle River, Saskatchewan was assessed. Four geomorphological characteristics of the river were isolated (sinuosity, slope, fractal dimension, stream width) and clustered through a Principle Component Analysis, yielding sets of river reaches with similar geomorphological characteristics, called typologies. These typologies were mapped to form a geospatial model of the river, and grouped into geomorphological response units (GRUs). Macroinvertebrate data were aligned to the model, revealing relationships between macroinvertebrate taxa and fluvial geomorphology. A Kruskal-Wallis analysis and post hoc pairwise multiple comparisons pinpointed significant relationships between several genera and typologies. Furthermore, certain GRUs contained more sensitive macroinvertebrate families and healthier levels of diversity than other GRUs. Typologies were better suited to relate geomorphology to macroinvertebrate taxa, because they represented a more direct relationship to localised geomorphological characteristics than GRUs