The suburban stream syndrome : evaluating land use and stream impairments in the suburbs
Land use ; New York State ; Nitrate ; Seasonal variation ; Stream ; Suburbs ; United States of America ; Urban area ; Urban growth ; Water quality ; Watershed
To examine the effects of spatially expansive exurban development on stream water quality, the AA. examined water quality and impervious cover in 5 headwater streams draining directly into the Hudson River in Dutchess County, an area on the margin
of the New York City region. They used longitudinal sampling, with 4-6 sampling sites per stream, to detect whether NO3-N inputs were greater or less than in-stream potential for denitrification, and to detect changes in streams as watershed-scale land uses
This paper examines potholes on the streambed at the head of a gorge 200 m deep. Statistic analysis of geometric features of the stream potholes measured in the field, combined with relate field observations, reveals the origins, formation
Spatial and temporal patterns of stream channel incision in the loess region of the Missouri River
Base level ; Downcutting ; Fluvial erosion ; Fluvial processes ; Hydraulic works ; Iowa ; Loess ; Missouri ; Model ; Nebraska ; Spatial variation ; Stream ; United States of America ; Watershed
Stream channel incision is severe in the loess-dominated region of western Iowa and eastern Nebraska, with recent incision related to sediment capture by reservoirs on the Missouri River. This study confirms that the temporal pattern of incision
follows the rate law proposed by Graf (1977) with half-lives ranging from two to nine years and stream channels throughout the affected watersheds approaching a new dynamic equilibrium in one to three decades. The resulting spatial pattern of incision
on tributaries is demonstrated to follow a simple rule of base-level lowering at the outlet multiplied by a flow-length ratio. This rule is used to estimate depth of channel incision along all tributary streams of the Nebraska reach of the Missouri River
and confirms that Missouri River degradation, along with other local disturbances such as channelization, is an important cause of tributary stream incision in the study area. Using the flow-length ratio rule, a spatial model of stream channel incision
This work is aimed at the characterization of the morphology of braided streams, in order to assess whether the system reaches a steady state under constant flow conditions and, in that case, to determine how it can be described and on which
, related to total water discharge and stream power. The paper ends with a discussion on different width definitions and on the relationship between width and discharge, that distinctively characterize the braided pattern.
Sediment entrainment potential in modified alluvial streams : implications for re-mobilization of stored in-channel sediment
Carrying capacity ; Channel geometry ; Deforestation ; Fluvial erosion ; Grain size distribution ; Human impact ; Land use ; Sediment load ; Spatial variation ; Stream ; Tennessee ; United States of America
This study examines spatial patterns of sediment entrainment potential in 3 alluvial streams in the Lower Hatchie River Basin of western Tennessee with a history of channelization and significant land use change (historic deforestation). The purpose
is to determine if the streams have enough energy to transport the volumes of material they receive via bank failure processes. The results suggest that there is great potential for in-channel sediment storage features to be reworked and to serve as secondary
A conceptual model for the longitudinal distribution of wood in mountain streams
Carrying capacity ; Colorado ; Conceptual model ; Model ; Mountain ; Riparian vegetation ; Spatial distribution ; Stream ; United States of America ; Woody debris
In this study, the AA. evaluate longitudinal patterns of wood distribution in forested headwater streams of the Colorado Front Range, and potential channel-, valley- and watershed-scale controls on these patterns. Based on studies in other
environments, they hypothesize that wood load decreases downstream. Based on qualitative observations of wood in streams of the study area over many years, they hypothesize that wood is non-randomly distributed at channel lengths of tens to hundreds of meters
as a result of the presence of wood jams. They also hypothesize that the proportion of wood clustered into jams increases with drainage area as a result of downstream increases in relative capacity of a stream to transport wood introduced from the adjacent
riparian zone and valley bottom. Results support the first and second hypotheses, but are inconclusive with respect to the third hypothesis. The AA. use these results to propose a conceptual model illustrating downstream trends in wood within streams
Hungary ; Mountain ; Pollution ; Stream ; Torrent ; Water ; Water quality
Repeated chemical water quality measurements were carried out on the Apátkút and Lepence Streams, Visegrád Mountains, Hungary, between 1993 and 2008. The objective was to characterize the water-courses in space and to monitor temporal changes
. The prolonged monitoring shows a slow but steady deterioration of water quality for both streams. The unfavourable tendency can only be stopped by reducing pollution near the sources and on the catchment. - (AM)
Local scour estimation at check dams in torrential streams in south east Spain
Arid area ; Dam ; Erosion ; Flood ; Murcia ; Semi-arid area ; Spain ; Stream ; Torrent ; Watershed
the influence of dams in the studied channel reaches, according to physical factors such as bed grain size, outcrops of bedrock and bed slope. Two catchments are studies here, drained by Cárcavo and Torrecilla torrential streams belonging to the Segura Basin.
Changes in channel size and shape caused by a debris flow event along the length of a headwater stream (HWS) in the Ashio Mountains were captured with the aid of repeat high-definition surveys using terrestrial laser scanning (TLS) techniques
Wood distribution in neotropical forested headwater streams of La Selva, Costa Rica
Bank erosion ; Carrying capacity ; Costa Rica ; Discharge ; Model ; Multiple regression ; Spatial distribution ; Statistics ; Stream ; Tropical zone ; Woody debris
The aim of this study is to use data data on wood loads from headwater streams in La Selva Biological Station in north-eastern Costa Rica to examine potential differences in wood dynamics between temperate and tropical headwater streams
. The variables wood diameter/flow depth, stream power, the presence of backflooding, and channel width/depth are consistently selected as significant predictors by statistical models for wood load. The results along with the spatial distribution of wood
Assessing the effect of vegetation-related bank strength on channel morphology and stability in gravel-bed streams using numerical models
Bank erosion ; Braided channel ; British Columbia ; Canada ; Channel geometry ; Meander ; Model ; Numerical model ; Riparian vegetation ; Stream ; Threshold
Bank strength due to vegetation dominates the geometry of small stream channels, but has virtually no effect on the geometry of larger ones. A rational regime model is used to explore the scale effects: it parameterizes vegetation-related bank
strength using a dimensionless effective cohesion, Cr. The analyses show that the effect of vegetation on both downstream hydraulic geometry and the meandering-braiding threshold is strongest for the smallest streams in a watershed, but that the effect
Stream channel enlargment response to urban land cover in small coastal plain watersheds, North Carolina
Channel geometry ; Coastal plain ; Downcutting ; Fluvial erosion ; Grain size distribution ; Land use ; North Carolina ; Soil properties ; Stream ; United States of America ; Urbanization ; Watershed
The aim of the study was to characterize the effects of urban impervious area and associated stormwater runoff on the scaling of stream channel geometry and the associated grain size response with small Inner Coastal Plain watersheds in eastern
incision has frequently cut off streams from their floodplains, reducing floodplain sediment retention and water quality functions.
Longitudinal distributions of river flood power : the combined automated flood, elevation and stream power (CAFES) methodology
Digital elevation model ; Discharge ; England ; Geographical information system ; Methodology ; Sediment transport ; South-West England ; Stream ; Stream flow ; United Kingdom ; Watershed
The AA. present here a novel methodology CAFES (combined automated flood, elevation and stream power) to quantify downstream change in river flood power, based on integrating in a GIS framework Flood Estimation Handbook systems with the 5 m grid
Algorithm ; Bank erosion ; Erosion control ; Massachusetts ; Model ; Riparian vegetation ; Stream ; United States of America
This paper describes a method developed to use root-architecture data, obtained in previous studies, to create regressions showing changes in the number of roots crossing a shear plane within in a stream bank over time. In addition, variations
in root density with depth are studied so that root-reinforcement estimates obtained by RipRoot can be correctly applied to the layering within model runs of the bank stability and toe erosion model (BSTEM). It was found that stream-bank varied the most
Discharge ; Hydrobiology ; Model ; Precipitation ; Seasonal variation ; Stream ; Tennessee ; Turbidity ; United States of America ; Water quality ; Watershed
The AA. investigate how precipitation, discharge, sediment, and pathogens are related in the Little River. The goals are to : 1) determine the degree of correlation between precipitation, turbidity, stream discharge, and pathogen (total coliform
and E. coli) concentrations; 2) identify and describe seasonal patterns that may exist for both pathogens and turbidity; and 3) develop a simple statistical model that predicts pathogen concentration from rainfall, stream discharge, and turbidity
to flow depth, slope gradient and other hydraulic parameters such as shear stress, stream power and unit stream power. Multiple non-linear regression analyses indicate that detachment rates for all roads can be accurately predicted by power functions
of flow depth and slope gradient. According to the experimental results, stream power was suggested as an indicator to estimate soil detachment rate instead of shear stress in soil erosion models. However, considering the simplicity and availability, power
Braided channel ; Carrying capacity ; Channel geometry ; Comparative study ; Model ; Sediment transport ; Slope gradient ; Stream ; Stream flow
water equations. This comparison provides the first demonstration of the potential for deriving realistic predictions of in-channel flow depth, unit discharge, energy slope and unit stream power using simple flow routing schemes. It also highlights
the inadequacy of modelling unit stream power, shear stress or sediment transport capacity as a function of local bed slope, as has been common practice in a number of previous reduced-complexity models.