Tidal estuary width convergence : theory and form in North Australian estuaries
Australia ; Coastal geomorphology ; Estuary ; Geographical information system ; LANDSAT ; Northern Territory ; Remote sensing ; Tidal creek
In order to better understand the relations between tidal estuary shape and geomorphic processes, the width profiles of 79 tidal channels from within 30 estuaries in northern Australia have been extracted from LANDSAT 5 imagery using GIS. Statistics
describing the shape and width convergence of individual channels and entire estuaries (which can contain several channels) are analysed along with proxies for the tidal range and fluvial inputs of the estuaries in question. No clear relation between
the estuarine width convergence length and tidal range could be discerned within the Northern Australian estuaries.
Marsh loss in the Nanticoke estuary dates from the 1920 s. Since 1938 overall rate of loss has averaged 49.6 ha annually, with rates increasing down estuary. Most losses have occurred in submerged upland marshes| tidal freshwater marshes are stable
. Interior ponding has been the primary mechanism of loss. Rising water levels are postulated to be the underlying force behind marsh losses in this estuary.
The estimation of estuary dimensions using a simplified form model and the exogenous controls
Estuary ; Geomorphology ; Hydrodynamics ; Model ; Sedimentology ; Tide ; United Kingdom ; Wave
An idealized representation of the three-dimensional (3D) form of an estuary has been proposed and is here applied to a wide range of UK estuaries to explore its ability to predict the gross properties of a range of different estuary types. When
for determining the estuary dimensions and how they are likely to change over time. This in turn provokes a broader definition of an estuary than those commonly cited.
Most of these microtidal estuaries have acquired their present morphology during the Holocene marine transgression. A variety of geomorphological forms are identified that result from variation in antecedent topography, fluvial sediment supply
and marine sediment supply. 5 distinctive estuary types are identified on the basis of contemporary morphodynammics. These are categorised into 3 types of normally open estuary, and 2 types of normally closed estuary, which are separated from the sea for long
periods by a continuous supratidal barrier. The contemporary morphodynamics and sedimentary environments of each estuary type are discussed.
and changed run-off characteristics. The relationship between the estuaries and the estuary mouth forms the basis of the interpretation presented. Disruption of the tidal regime has led to substantial hydrodynamic and morphological changes, triggering complex
Morphological changes of estuarine channels and tidal flats depend on erosion, sediment transport and deposition. This thesis focuses on a smaller part of this system : the settling of mud flocs in an estuary. The research is based on measurements
of the size and settling velocity of mud flocs in the Dollard estuary on different time and spatial scales. It is concluded that turbulent shear and residence times play an essential role in flocculation dynamics. Furthermore it is showed that biological
Dissolved arsenic species in the Schelde Estuary and watershed, Belgium
Inputs of industrial and domestic effluents create a region of anoxic conditions in the water column of the upper estuary. Arsenic concentrations and speciation in the watershed shows that the ratio of As (III) to As (V) is elevated in the anoxic
part of the estuary and those tributaries that are depleted in oxygen. The combination of a near-constant anthropogenic arsenic emission and seasonally fluctuating water discharge creates a variable arsenic concentration in the river end member
. This variability can explain the non-linearity in the arsenic-salinity relationship in the estuary, where a pronounced arsenic maximum is seen in a region without local arsenic sources.
Morphology and sediment dynamics of the ephemeral Mfolozi estuary, KwaZulu-Natal, South Africa
Arid area ; Earth surface processes ; Estuary ; Humid environment ; KwaZulu-Natal ; Sediment transport ; South Africa
The Mfolozi estuary is a shallow, micro-tidal estuary with average depths of less than 1.5 m during mean flow conditions. The short term observed transitional changes between estuarine and logoonal conditions are ourlined in relation to long term
The application of Yangtze Estuary Tidal Wetlands Geographic Information System
China ; Environmental management ; Estuary ; Geographical information system ; Heavy metals ; Humid environment ; Modelling ; Pollution ; Shanghai ; Spatial distribution
Yangtze Estuary Tidal Wetlands Geographic Information System (YETWGIS) is a comprehensive software system for environmental management and decision of Yangtze estuary tidal wetlands. This paper firstly outlines the system structure, key techniques
Late Holocene δ13C and pollen records of paleosalinity from tidal marshes in the San Francisco Bay estuary, California
California ; Carbon ; Estuary ; Holocene ; Isotope analysis ; Palaeo-environment ; Palynology ; Pollen diagram ; San Francisco ; Sedimentology ; Tidal marsh ; United States of America
Records of stable carbon isotopes (δ13C) are presented from cores collected from 4 San Francisco Bay marshes and used as a proxy for changes in estuary salinity. The 4 marshes included in this study are located along a natural salinity gradients
that exists in the San Francisco Bay, and records of vegetation change at all 4 sites can be used to infer changes in overall estuary paleosalinity. The δ13C values complement pollen data from the same marsh sites producing a paleoclimate record for the late
Geomorphological effects of catastrophic flooding on a small subtropical estuary
This paper focusses on the Mgeni Estuary and records and interprets the impact of the flood on estuarine channel morphology and bottom sediment distribution. The effects on the adjacent littoral and nearshore zones are briefly considered.
Aeolian features ; Classification ; Coastal environment ; Delaware ; Dune ; Estuary ; Human impact ; New Jersey ; Sand ; Topography ; United States of America
are derived from field surveys conducted in two relatively large ria-type estuaries (Raritan Bay and Delaware Bay) on the northeastern coast of the United States. A generic classification is presented for typical dune forms, identifying their dimensions
Upland and coastal sediment sources in a Chesapeake Bay estuary
Bay ; Chesapeake ; Coastal environment ; Coastal erosion ; Environment management ; Estuary ; Fluvial processes ; Human impact ; Maryland ; Palynology ; Resource management ; Sedimentation ; Sedimentology ; Stream ; United States
New data from the South River, Maryland and reexamination of existing literature suggest that coastal erosion may be the dominant process driving sediment inputs along the lenght of many tributary estuaries of the Chesapeake. This paper addresses