R. Duck - Academia.edu (original) (raw)

Papers by R. Duck

Fluvial Sedimentology VI, 1999

... The tidal range is between 4 and 6 m (macrotidal) with a tidal reach of 50 km. Two multipier ... more ... The tidal range is between 4 and 6 m (macrotidal) with a tidal reach of 50 km. Two multipier bridges, the Tay Railway Bridge and the Tay Road Bridge, cause obstructions to the free flow of the tidal waters and geographically define the field study area (Fig. ...

Physical processes in the coastal zone: …, 1998

... 232 Silke Wewet: er and Robert Duck Goedheer GJ and Misdorp R, 1985, Spatial variability and ... more ... 232 Silke Wewet: er and Robert Duck Goedheer GJ and Misdorp R, 1985, Spatial variability and variations in bedload transport direction in a ... pp 95-110 McQuillin R and Ardus DF, 1977, Exploring the geology of shelf seas, Graham &amp; Trotman (London) Morang A and McMaster ...

$Research paper thumbnail of A Hammer Seismic Refraction Survey of a Scottish Lacustrine Delta to Estimate Sediment Yield$

International Journal of Remote Sensing

Nutrients and Eutrophication in Estuaries and Coastal Waters, 2002

The Ria de Aveiro estuary-coastal lagoon system of northern Portugal is estimated to currently re... more The Ria de Aveiro estuary-coastal lagoon system of northern Portugal is estimated to currently receive mean annual influxes of total nitrogen (N) and total phosphorus (P) of c. 6118 t y −1 and 779 t y −1 , respectively, from its influent rivers. In low summer flows the mean N and P fluxes decrease to c. 10% of the annual average. The sewage contribution to the inland-derived N load on an annual basis is c. 5% but, during the summer low flow conditions, the sewage component increases to c. 65% of the total river loading. The sewage contribution to the inland-derived P load on an annual basis is c. 11% but, during the dry season, it is 1.2 times larger than the river-derived flux. The construction of a regional sewer system linked to a submarine outfall, due for completion in 2005, is expected to lead to a reduction in nutrient fluxes from inland to the lagoon of c. 15% for N and c. 26% for P relative to the present values. While this system will reduce the nutrient loading in the upper reaches of the lagoon, an increase in nutrients derived from the ocean is anticipated, due to the proximity of the outfall to the inlet.

Scottish Journal of Geology, 2001

... Page 4. as TABL E 1. Analytical data for calcareous concretions in the ECF, Gallowflat Sample... more ... Page 4. as TABL E 1. Analytical data for calcareous concretions in the ECF, Gallowflat SampleECFG-1 ECFG-2 ECFG-3 ECFG-4 ECFG-5 ECFG-6 ECFG-7 ECFG-8 Standards SRM3159 SRM3164 Reported values SRM3159 SRM3164 (238TJ/232 Th )l 7.11 ±0.1 2 13.8 ± 0.22 ...

Scottish Journal of Geology, 2006

Progress in Physical Geography, 2005

... The standard survey (Fox et al., 1998) covers a 500 m length of river corridor, 100 m wide. .... more ... The standard survey (Fox et al., 1998) covers a 500 m length of river corridor, 100 m wide. ... Other applications arise in the identification of environmental opportunities for riverine species (Brewin et al., 1998; Naura and Robinson, 1998), and the development of national Physical ...

Journal of the Geological Society, 2000

Journal of Sea Research, 2009

A decrease in the areas covered by seagrasses within the Ria de Aveiro, Portugal, has been observ... more A decrease in the areas covered by seagrasses within the Ria de Aveiro, Portugal, has been observed over the past five decades, resulting in a corresponding increase of the areas of uncovered sediment supporting the growth of sparse macroalgae populations only. Presently, several macroalgae (Ulva spp., Gracilaria sp.) and one seagrass species (Nanozostera noltii (Hornem.) Toml. &amp; Posl.) comprise the

Journal of Hydrology, 1995

To obtain remotely sensed synoptic measurements of surface water temperatures, use has been made ... more To obtain remotely sensed synoptic measurements of surface water temperatures, use has been made of a Heimann Radiometer (Model KT79). This instrument, sensitive to thermal infrared radiation in the 8–14 μm wavelength range of the electromagnetic spectrum is fitted with a telephoto lens and gives a restricted field of view at the water surface, enabling temperature estimation to ±0.2°C. For example, over a period of 1 h it was possible, from suitably selected vantage points, to record 475 point measurements of temperature over the entire surface of a reservoir some 1 km2 in area (Embalse de Rioseco, northern Spain). Repeated sets of observations permitted the recognition of upwelling and sinking water masses. The technique enabled the detection of influx of cold water from springs along a geological fault zone in the Embalse de Tanes. Additionally, the inception and the temporal and spatial evolution of an influent plunging plume was monitored using this equipment. Although thermal radiometry is restricted to the measurement of surface water temperatures, its speed of data acquisition over a wide area should enhance appreciation of the thermal behaviour of lakes and provide an important complement to existing techniques.

Journal of Coastal Conservation, 2012

ABSTRACT The Intergovernmental Panel on Climate Change (IPCC) considers eustatic sea level rise t... more ABSTRACT The Intergovernmental Panel on Climate Change (IPCC) considers eustatic sea level rise to be a major impact driven by climate change. Relative sea level change, whether positive or negative, will affect industries, communities and ecology along the world’s coastlines and estuaries. Estimates of global eustatic sea level rise between 1961 and 2003 are 1.8 ± 0.5 mm a−1, reflecting results from validated global tide gauge records. Over the last two decades, several studies have used automatic tide gauge records with at least 80 years of data to generate global prediction models. The IPCC recognises that global change is not uniform, therefore local policy for flood management and coastal protection should rely on local change models that incorporate glacio-isostatic adjustment (GIA) and apply accurate data correction techniques. Some of the longest tidal records are held within the Northern Hemisphere, e.g. Cascais, Amsterdam, Aberdeen, Sheerness and Newlyn. The UK provides several important case studies highlighting changes in relative sea level between the north and the south, primarily due to variations in GIA rates of land uplift and subsidence. Tide gauge records are held by a variety of governmental, non-governmental and private organisations. However, each source may typically compile data in different ways, relying on diverse equipment and recording techniques, often with variations in frequency, length, quality and corrections applied. Even within a single organisation there may be differences in dataset quality. This paper examines some of the key sources of error when working with historical tidal datasets in local geographic areas and aims to identify the limitations of locally derived data thereby assisting in the determination of relative sea level trends that are of widespread value to infrastructure and policy makers.

International Journal of Remote Sensing, 1999

... 1992, McManus et al. ... it is evident that any attempt increase eƒ uent discharges as a resu... more ... 1992, McManus et al. ... it is evident that any attempt increase eƒ uent discharges as a result of development of the village would need to recognise that the discharges would not become fully mixed through the entire water mass passing the harbour, but would be con®ned to the ...

Hydrology and Earth System Sciences, 2002

The morphological and climatic conditions of the Atlantic coast of northern Portugal result in a ... more The morphological and climatic conditions of the Atlantic coast of northern Portugal result in a prevailing upwelling circulation over the continental shelf. A submarine outfall releases wastewater into the ocean c. 3 km directly offshore (at ~16 m water depth) from S. Jacinto, 5 km to the north of the inlet to the estuarine coastal lagoon system of the Ria

Hydrology and Earth System Sciences, 2004

ABSTRACT The Ria de Aveiro is an estuary–coastal lagoon system connected to the Atlantic Ocean by... more ABSTRACT The Ria de Aveiro is an estuary–coastal lagoon system connected to the Atlantic Ocean by a channel with a cross-sectional area that, for more than a century, has increased steadily, partly because of dredging over the last 50 years. Local ocean tides, with amplitudes of up to 3 m, are today transmitted to the lagoon by the single, engineered inlet channel and propagate to the end of the lagoon channels as a damped progressive wave. The increase in tidal amplitude with time has affected the lagoon ecosystem and the water has become more saline. Seagrass beds are important indicators of ecosystem change; until 1980, much of the lagoon bed was covered by seagrasses ( Zostera, Ruppia, Potamogeton ), which were collected in large quantities for use in agriculture. After 1960, the harvesting declined and the seagrass beds became covered in sediment, so that the area of seagrasses decreased substantially despite the decline in the quantity collected. The change in the pattern of seagrass populations can be related to changes in the physical forcing associated with increased tidal wave penetration. This has, in turn, induced transport and redistribution of coarser, sandy sediment and increased re-suspension and turbidity in the water column. However, the initiating cause for this ecosystem change was dredging, which, since the 1950s, has been used increasingly to widen and deepen the channels of the system.

Bulletin of the International Association of Engineering Geology, 1993

A collaborative programme enables coastal problems in the Cantabrian rfas of NW Spain to be compa... more A collaborative programme enables coastal problems in the Cantabrian rfas of NW Spain to be compared with those of the firths of the Scottish east coast. Engineers and scientists have studied the problems of the two coastal areas and commenced joint research into problems of coastal stability, with a view to improving protection techniques currently used in the two regions.

Netherlands Journal of Aquatic Ecology, 1995

Two small estuaries, the Eden Estuary of eastern Scotland and the Ria de Foz of north west Spain,... more Two small estuaries, the Eden Estuary of eastern Scotland and the Ria de Foz of north west Spain, are compared. The former was glaciated during the Pleistocene, the latter was not. These water bodies are macrotidal, of similar size, entrance morphology and advanced state of sedimentary infill. There are, however, major differences in their sedimentary dynamics partly as a result of anthropogenic interference. A training wall partially confines the main channel of the Ria de Foz, whereas the Eden Estuary lacks comparable structures. Prior to the extension of the Foz wall, the rate of migration of a spit at the mouth of the ria was up to one order of magnitude greater than that of a similar spit in the Eden Estuary. Following completion of the wall, the rate of spit erosion in the Ria de Foz increased to two orders of magnitude greater than that of natural processes in the Eden. A beach nourishment scheme at Foz, relocating sediment deposited within the Ria, has succeeded in stabilising the spit and substantially reducing erosion. Relative stability of land and sea may have existed over the last 5,000 years at Foz but not at the mouth of the Eden, where isostatic uplift has exceeded sea level rise. The requisite stability for complete sedimentary infill at Foz may not exist owing to the predicted worldwide rise of sea level due to global warming. The rise of sea and land levels around the Eden Estuary are now believed to be counterbalanced, providing the necessary geological conditions for complete sedimentary infill.

Aquatic Conservation: Marine and Freshwater Ecosystems, 2005

... to any type of anthropogenic hydrological impact such as impoundments, abstractions or flowau... more ... to any type of anthropogenic hydrological impact such as impoundments, abstractions or flowaugmentation. ... to generate synthetic series of daily mean flows, supplemented by flow alteration data ... alteration and supporting mapping, which will be of value to river basin managers. ...

A user manual …, 2000

... HYDROLOGICAL REGIME ASSESSMENT METHOD By Andrew Black, Olivia Bragg, Rob Duck, Allan Jones, J... more ... HYDROLOGICAL REGIME ASSESSMENT METHOD By Andrew Black, Olivia Bragg, Rob Duck, Allan Jones, John Rowan and Alan Werritty July 2000 SNIFFER report SR (00) 01/2F Page 2. METHODS OF ASSESSING ANTHROPOGENIC ...