Volume 15, 2015
Historical sources and meandering river systems in urban sites: the case of Manchester, UK
Rodolfo Alves da Luz,
Department of Geography, University of São Paulo, Brazil.
Nigel Lawson,
School of Environment, Education and Development,
University of Manchester.
Ian Douglas,
School of Environment, Education and Development,
University of Manchester.
Cleide Rodrigues,
Department of Geography, University of São Paulo, Brazil.
Abstract
Past geomorphological changes to meandering rivers due to urbanization derived from historical sources are used to explore three scales of channel adjustment in Greater Manchester. Human activity has often extended the first terrace narrowing the flood plain and raising flood heights, requiring later construction of flood walls and flood detention basins. Urban development near waterways often occurs over buried former meanders that potentially pose hazards during and after construction. The active post-glacial meandering channel of the Mersey Basin are not all totally controlled, marked changes in the Mersey River channel have occurred in the reach downstream of Ashton on Mersey. A comparison of the roles of pre-urban geomorphology and anthropogenic changes in Greater Manchester with those in São Paulo Brazil revealed the value of the analysis of past conditions for river management and urban construction in both older and newly industrialising cities across the continents.
Sefton Coast’s vulnerability to coastal flooding using DEM data
Irene Delgado-Fernandez, Matthew McBride, Rachel Platt and Mark Cameron,
Geography Department, Edge Hill University
Abstract
A preliminary analysis of the vulnerability of the Sefton coast to coastal flooding was carried out using a high-resolution DEM and census data from 2011. Results indicate that up to 12,500 people live within areas below the significant dune erosion level. Low-lying areas are clustered in two main locations, the South Formby / Hightown and Southport. High dunes from 15 to 35 m high are common in the central part of the Sefton Coast, including Formby Point and Ainsdale. This highlights the significance of the Sefton dune field system as a potential defence mechanism against coastal erosion and flooding, and the need to consider management schemes that would allow the dunes to adapt to sea level rise and climate change.
Analysis of ‘hummocky moraine’ using Structure-from-Motion photogrammetry
Simon J. Cook1, Toby N. Tonkin2, Nicholas G. Midgley2 and Anya Wicikowski2,
1School of Science and the Environment, Manchester Metropolitan University.
2School of Animal, Rural and Environmental Sciences, Nottingham Trent University.
Abstract
This study presents results of a high-resolution topographic survey of the proglacial area of Austre Lovénbreen, Svalbard. Structure-from-Motion (SfM) was used to generate a digital elevation model (DEM) of the proglacial zone from aerial imagery. This DEM is used to explore the topography of a zone of hummocky moraine within the glacier ‘s Neoglacial limit. The origin of hummocky moraine has proven controversial, but detailed morphological studies can contribute to a better understanding of how these features form, and the extent to which they may be preserved in the palaeo-glaciological record, including within northwest Britain. In cross-profile, hummocky moraine is characterised by a sequence of asymmetrical ridges, with longer, low angle up-glacier faces, and shorter, steeper down-glacier faces. This profile is interpreted to represent a sequence of ridges stacked-up against a bedrock riegel and reverse bedslope. Whilst the origin of these features is uncertain, the enhanced compression associated with glacier flow against a bedrock riegel, possibly during a glacier surge, may have been sufficient to have generated debris-rich englacial thrusts that subsequently melted-out to form the observed hummocky moraine. The significance of this research highlights ongoing studies aimed at understanding the origin and palaeo-glaciological significance of hummocky moraine in northwest Britain.