GIS derived synthetic rating curves and HAND model to support on-the-fly flood mapping

Natural Hazards - Acknowledging the devastating consequences of past earthquakes, current research efforts focus on the development of tools for assessing and controlling the risk and losses...     

Doing community geography

Community Geography offers researchers, community groups, and students opportunities to engage in action oriented applied geographical research. Creating and sustaining these research programs can be challenging, programs can involve many partners from both academic and the community, have different goals and purposes, and utilize a variety of methods to perform research. In this paper we offer a framework of three primary overarching principles for implementing CG projects; (1) Who, (2) Why, and (3) How. (1) “Who” describes who is involved in CG, including researchers, community partners, academic institutions, (2) “Why” describes the justifications and benefits of taking this approach. (3) “How” explains how CG borrows methodologies from many disciplines within geography and beyond. Our examples are not exhaustive; rather, they serve as starting points to inspire researchers interested in CG.

     

Long-term shoreline retreat rates on Whidbey Island,Washington, USA

Long-term retreat rates of Puget Sound's unconsolidated sediment shorelines have been difficult to quantify, and little systematic research has been completed to constrain retreat in this area. We put forward a new application of cosmogenic ¹⁰Be exposure dating to assess long-term shoreline retreat on Whidbey Island, WA by dating lag boulders exposed on the shore platform as the shoreline erodes. Production of ¹⁰Be in shoreline boulders is modulated by both tidal submergence and topographic shielding from the retreating bluff. By modeling the combined effect of these variables on ¹⁰Be production, the timing of exposure can be determined and used to calculate long-term (10³–10⁴ yr) bluff retreat rates. In rare cases, retreat rates are underestimated due to inherited ¹⁰Be. Within the study area, average retreat rates ranged between 0 and 8 cm yr^? 1. Our results demonstrate the utility of cosmogenic nuclides for determining long-term shoreline retreat rates in areas with thick sediment cover, where large numbers of samples can be collected, and where the pre-depositional history of the boulders is uncomplicated.     

Provision,transport and deposition of debris in urban waterways

The transport of woody debris from urban surfaces,through local urban waterways,to constriction and blockage risk locations is not well understood.Flume trials have identified debris and watercourse dimensions as influential factors on debris movement,and large woody debris movement has been traced in the natural rural environment using time series photography,active transponders,and field surveys.Using novel passive transponder technology,small woody debris has been traced through an urban case study watercourse to establish key influential factors on urban debris transport.Through incorporating urban debris transport detail into the source and deposition process,a complete picture of urban debris transport can be created,supporting effective culvert and trash screen design,watercourse maintenance and blockage risk assessment.This case study highlights that factors beyond watercourse depth and velocity are influential in debris movement within an urban watercourse.Debris dimension and source location upstream are shown to significantly affect the potential for debris to reach a downstream constriction,illustrating a possible distance limitation in nuisance flow debris blockage risk.     

Separating climatic and possible human impacts in the early Holocene: biotic response around the time of the 8200 cal. yr BP event

The early Holocene is characterised by rapid climate change events, which in the North Atlantic region are often associated with changes in thermohaline circulation. Superimposed on this in northwest Europe is localised evidence for human impact on the landscape, although separating climatic and anthropogenic mechanisms for environmental change is often difficult. Biotic and sedimentological evidence from a lacustrine sequence from the Inner Hebrides, Scotland, shows a considerable reduction in inferred local woodland centred upon 8250 cal. yr BP. These data correlate precisely with a distinctive rise in the charcoal:pollen ratio and hence suggest a possible Mesolithic human impact upon the vegetation around this time. A quantitative temperature reconstruction from chironomid analyses from the same sequence, supported by sedimentological data, indicates that the fall in arboreal pollen taxa occurred as climate warmed significantly during the early Holocene. This warming was followed by a significant cold event, with mean July temperatures reduced by 2°C, that lasted for at least 320 years ca. 7790–7470 cal. yr BP. Woodland recovered during this phase suggesting that the vegetation during the 8250 cal. yr BP interval was likely to have been responding to human activity, and not climate, and hence it is possible at specific sites to separate the influence of these key drivers of environmental change. Copyright © 2006 John Wiley & Sons, Ltd.     

At home and abroad with cine enthusiasts: Regional amateur filmmaking and visualizing the Mediterranean, ca. 1928–1962.

After the appearance of a portable Kodak cine camera in 1923, home moving making grew steadily in popularity in the years leading up to and following World War II. Cine enthusiasts, particularly in the pre-war period, tended to be male, white and middle class, although exceptions exist, and they tended to travel with their cameras much as earlier generations had documented their experiences in written and artistic form. Despite their amateur status, they were often very professional in their approach to cinematography and they produced material for a range of domestic and public audiences on varied topics and in different genres. Specialist publications and the rapid growth of local amateur film societies fostered the rise of an active non-professional film movement; the result is a highly distinctive although neglected component of film history. With reference to materials held at the North West Film Archives in Manchester, England, this discussion considers the rise of non-professional filmmaking at the regional level during the decades before and after the second world war. Making and showing home movies is placed within various socio-cultural contexts. The imagery discloses much about visual practice, including filmmakers' perceptions and their relationships with different kinds of subject matter. The making of holiday footage, in Mediterranean settings, and its subsequent screening in domestic or public places, connects with broader issues of visualization, social practice and leisure-related consumption. This revised version was published online in August 2006 with corrections to the Cover Date.     

A new type of isotopic anomaly in shergottite sulfides

The isotopic composition and abundance of sulfur in extraterrestrial materials are of interest for constraining models of both planetary and solar system evolution. A previous study that included phase‐specific extraction of sulfur from 27 shergottites found the sulfur isotopic composition of the Martian mantle to be similar to that of terrestrial mid‐ocean ridge basalts, the Moon, and nonmagmatic iron meteorites. However, the presence of positive Δ³³S anomalies in igneous sulfides from several shergottites, indicating incorporation of atmospherically processed sulfur into the subsurface, complicated this interpretation. The current study expands upon the previous work through analyses of 20 additional shergottites, enabling tighter constraints on the isotopic composition of juvenile Martian sulfur. The updated composition (δ³⁴S = ?0.24 ± 0.05‰, Δ³³S = 0.0015 ± 0.0016‰, and Δ³⁶S = 0.039 ± 0.054‰, 2 s.e.m.), representing the weighted mean for all shergottites within the combined population of 47 without significant Δ³³S anomalies, strengthens our earlier result. The presence of sulfur isotopic anomalies in igneous sulfides of some meteorites suggests that their parent magmas may have assimilated crustal material. We observed small negative Δ³³S anomalies in sulfides from two meteorites, NWA 7635 and NWA 11300. Although negative Δ³³S anomalies have been observed in nakhlites and ALH 84001, previous anomalies in shergottites have all shown positive values of Δ³³S. Because NWA 7635 has formation age of 2.4 Ga and is much more ancient than shergottites analyzed previously, this finding expands our perspective on the continuity of Martian atmospheric sulfur photochemistry over geologic time.