The focus of this paper is to examine the response of the Ntamogba Stream, a very small stream in the heart of Port Harcourt to the increasing urbanization of its watershed and to use findings thereof as guide for similar watershed management
. This study highlights that all natural flood receptacles have been destroyed by land speculators and because the catchment's characteristics determine sediment and nutrient inputs to the streams, it was observed that upland disturbance has affected
Analysis of bedload transport characteristics of Idaho streams and rivers
Carrying capacity ; Grain size distribution ; Idaho ; Model ; Mountain ; Sediment load ; Sediment transport ; Stream ; United States of America
Data collected for 33 sites on 31 mountain streams and rivers in Central Idaho have enabled the analysis of sediment transport characteristics in streams and rivers with different geological, topographic, morphological, hydrological, hydraulic
, and sedimentological characteristics. The particle size distributions of bedload and bed material, watershed and in-stream characteristics, sediment transport patterns and bedload transport rates are considered in this paper. The obtained results and conclusions
Measures of physical heterogeneity in appraisal of geomorphic river condition for urban streams : Twin streams catchment, Auckland, New Zealand
Aquatic ecosystem ; Auckland ; Environmental degradation ; Habitat ; Impact ; New Zealand ; North Island ; Sediment transport ; Stream ; Urban environment ; Urbanization ; Watershed
Analysis was carried out at 27 sites in the Twin Streams catchment in West Auckland. The method successfully recorded the extent of degradation of physical structure following European settlement of the catchment. With the exception of one
subcatchment, streams were found to be largely intact in the headwaters. Geomorphic conditions is more degraded in downstream areas. Fine-grained sediment has smothered stream courses in the lower half of the catchment, covering bed material and creating
The Steensby Inlet ice stream in the context of the deglaciation of northern Baffin Island, eastern Arctic Canada
This paper deals with the glacial history of northern Baffin Island. Its main focus is the glacial bedforms and debris dispersal attributed to the Steensby Inlet flow event, which is interpreted as an ice stream. Antecedent conditions
are illustrated based on recent mapping. The evolution of the ice cover, including its thickness, flow patterns, moraine construction, debris dispersal and inferred ice streams, is presented. The Steensby Inlet flow event and inferred ice stream are then discussed
. Finally, the paper details the devolution of the ice stream into streams of decreasing size and discusses associated corridors of evacuation and lateral sliding scarps.
Formation mechanisms for ice-stream lateral shear margin moraines
The AA. review the characteristics of lateral shear margin moraines and present 2 quantitative models for their formation : 1) differential erosion rates related to lateral variations in the stream velocity and 2) lateral incursion from inter-stream
ridges after the thinner stream retreats, where the shear margin moraine is consequently just a terminal moraine of the inter-stream ridge. The conditions that permit shear margin moraines to form are quite constrained. This is consistent
Channel flow competence and sediment transport in upland streams in southeast Australia
Australia ; Carrying capacity ; Flood ; Grain size distribution ; New South Wales ; River regime ; Sediment load ; Sediment transport ; Stream ; Stream flow
Bedload transport data from planebed and step-pool reach types are used to determine grain size transport thresholds for selected upland streams in southeast Australia. Morphological differences between the reach types allow the effects
of frictional losses from bedforms, microtopography and bed packing to be incorporated into dimensionless critical shear stress value. Local sediment transport data are also included in a regime model and applied to mountain streams, to investigate whether
Spatial-temporal differences in in-stream flow requirement based on GIS : a case study of Yan'an region, northern Shaanxi
China ; Flood ; Geographical information system ; Sediment transport ; Semi-arid area ; Shaanxi ; Stream ; Stream flow ; Water resources
for measuring in-stream flow requirement has been put forward supported by experiential models and GIS spatial analysis. Additionally, the changes of in-stream flow requirement for environment and economic development have been addressed from spatial-temporal
The aim of this paper is to analyse the calibration of the piezoelectric bedload impact sensor (PBIS) system with the detailed sediment observations carried out in 1994 and 1995 in the Pitzbach mountain stream in Austria. They discuss these results
Modeling fluvial response to in-stream woody vegetation : implications for stream corridor restoration
Bank erosion ; Braided channel ; Channel geometry ; Erosion control ; Experimental catchment ; Mississippi ; Numerical model ; Reforestation ; Riparian vegetation ; Stream ; United States of America ; Vegetation
) to compare these experimental results with a recently developed numerical model capable of simulating flow, sediment transport and bed morphology in meandering streams with riparian and in-stream vegetation. This was accomplished by constructing a distorted
Froude-scale physical model for a designated prototype, Abiaca Creek in northern Mississippi, USA. It is envisioned that such numerical models could become the primary tool for designing future stream restoration programs involving vegetation
Palaeo-ice-stream onsets : examples from the north-eastern Laurentide Ice Sheet
The AA. report on observations of glacial landscapes at the head of geomorphologically interpreted palaeo-ice streams, i.e. palaeo-ice-stream onsets. Their work is based on the results of systematic palaeoglaciological mapping of the portion
. conclude that conditions for the preservation of the onset zones are more likely to be met in the case of relatively small ice streams because these are more rapidly deglaciated.
Superimposition of ribbed moraines on a palaeo-ice-stream bed : implications for ice stream dynamics and shutdown
In this paper, detailed observations of an intriguing subglacial landform assemblage of ribbed moraines superimposed on glacial lineations on the Dubawnt Lake Ice Stream bed (north-west Canadian Shield) are presented, including their morphometry
Wood storage in three mountain streams of the Southern Andes and its hydro-morphological effects
Andes ; Argentina ; Channel geometry ; Chile ; Forest ; Mountain ; Sediment budget ; South America ; Stream ; Stream flow ; Watershed
to the sub-Antarctic Tierra del Fuego (Argentina). Amount, characteristics and dimensions of large wood were recorded, as well as their effects on stream morphology, hydraulics and sediment storage. Results show that major differences in LW abundance exist
Based on data from around 200 alluvial rivers in several countries, a systematic comparison of flow shear stress and stream power has been made between sand- and gravel-bed rivers. The formation of channel pattern can be regarded as the outcome
River recovery in an urban catchment : Twin streams catchment, Auckland, New Zealand
Agricultural land use ; Auckland ; Deforestation ; Human impact ; Human occupation ; Impact ; Longitudinal section ; New Zealand ; North Island ; Stream ; Urban environment ; Urbanization ; Watershed
throughout the catchment. Differing forms and rates of geomorphic adjustment are characterized for 5 different types of stream. The relative geomorphic resilience of this urbanizing catchment is considered to reflect the geologic imprint upon this landscape
Le Gulf Stream est un acteur de la Meridional Overturning Circulation induite par la plongée des eaux de surface en mer du Groenland, qui fait que le transport océanique de chaleur vers les hautes latitudes est particulièrement élevé dans
Geological constraints on Antarctic palaeo-ice-stream retreat
Submarine landforms preserved in bathymetric troughs on the Antarctic continental shelf show that the style of ice stream retreat across the shelf following the last glacial maximum varied between different troughs. Three styles of retreat
are inferred from the geological evidence : rapid, episodic and slow. They indicate that Antarctic palaeo-ice-streams did not respond uniformly to external forcing at the end of the last glacial cycle. Rather, their diachronous retreat reflects the dominance
Bank permeability in an Australian ephemeral dry-land stream : variation with stage resulting from mud deposition and sediment clogging
Arid area ; Australia ; Bank erosion ; Flood ; Infiltration ; New South Wales ; Permeability ; Stream
This paper presents the results of 69 field determinations of bank infiltrability made on Fowlers Creek, an ephemeral dryland stream located in arid western New South Wales. Fowlers Creek carries high concentrations of suspended sediments, which
Carrying capacity ; Channel geometry ; Discharge ; Flood ; Gujarat ; India ; Interannual variability ; Madhya Pradesh ; Monsoon ; River bed ; Stream
, this paper has 3 aims : 1) to estimate the daily specific stream power and total energy expenditure throughout the monsoon season over a period of 51 years (1949-1999); 2) to quantify the power and share of extraordinary floods in the annual energy
expenditure; 3) to compare the estimates of effective stream power with work thresholds. The channel morphology appears to be adjusted to catastrophic floods that occur at an interval of more than a century.
Carrying capacity ; Comparative study ; Methodology ; Mountain ; Rocky Mountains ; Sediment load ; Sediment transport ; Stream ; United States of America
Gravel bedload transport rates were measured at 8 study sites in coarse-bedded Rocky Mountain streams using 4-6 bedload traps deployed across the stream width and a 76 by 76 mm opening Helley Smith sampler. Differences in sampler opening size