Rangeland management and climate hazards in drylands: dust storms,desertification and the overgrazing debate

This paper examines the theory and supporting evidence for links between desertification, drought and dust storms with a particular focus on studies undertaken in and around the Gobi Desert. Overgrazing of rangeland by pastoralists has been the most commonly cited cause of desertification in global drylands for more than 30 years, but the evidence supporting this link is not always convincing. Nonetheless, overgrazing, desertification and dust storms are frequently connected, regardless. Drought is another well-known and important driver of vegetation cover change. Distinguishing between vegetation cover adversely affected by drought and that reduced by grazing is imperative for policy makers because identifying the incorrect driver of vegetation change risks the development of inappropriate policy.     

Fumarole monitoring with a handheld infrared camera: Volcán de Colima,Mexico, 2006–2007

This paper describes a methodology for the monitoring of fumarole temperatures at medium ranges (~ 6 km) using a handheld infrared camera (wavelength range: 8–13.5 µm). As a relationship between fumarole temperatures, gas flux and volcanic activity has been demonstrated by a number of studies, fumarole temperature data has a potential use as a monitoring tool. Volcán de Colima is an andesitic stratovolcano with a 300 m diameter summit crater formed by the destruction of the 2004 lava dome by a series of explosions in 2005. Between January 2006 and August 2007, sequences of thermal images were recorded from a viewpoint 6 km to the north during regular 24–48 hour monitoring excursions. The temperatures of fumaroles on the crater rim and the ground surface on the volcano's flanks were measured. A methodology was developed to remove data affected by clouds or volcanic water vapour based on rates of temperature change and scatter within the data. For the remaining data, it is demonstrated mathematically that at this range, typical variations in atmospheric transmissivity will affect the apparent temperatures by +/− 2 °C, while a 25% change in fumarole heat flux would change it by 5–10 °C. The mean night-time apparent temperature of the fumaroles was calculated for each excursion and showed an irregular decline over the 19 month period. Subtracting the radiant heat flux of flank rocks from those of the fumaroles removes seasonal variations and gives the clearest view of trends in the fumarole heat flux. A sharp drop in fumarole temperature during February 2007 coincided with the emergence of a lava dome in the crater. The declining fumarole temperature is interpreted to reflect decreasing gas flux from the crater in line with a change in eruptive regime from frequent, small, ash-rich explosions to slow effusion of lava.     

Combining USGS ShakeMaps and the OpenQuake-engine for damage and loss assessment

The evaluation of the potential impact of strong seismic events shortly after their occurrence is a critical step to organise emergency response and consequently minimise the adverse effects of earthquakes. The estimation of the impact from earthquakes considering the observed ground shaking from past events can be useful for the calibration of existing exposure and/or fragility and vulnerability models. This study describes a methodology to combine the publicly available information from the USGS ShakeMap system and the open-source software OpenQuake engine for the assessment of damage and losses. This approach is employed to estimate the number of structural collapses considering the 2012 Magnitude 5.9 Emilia-Romagna (Italy) earthquake and the aggregated economic loss because of the 2010 Magnitude 7.1 Darfield (New Zealand) event. Several techniques to calculate the ground shaking in the affected region considering the spatial and interperiod correlations in the intra-event ground motion residuals are investigated and their influence in the resulting damage or loss estimates are evaluated.     

Syn‐rift mass flow generated ‘tectonofacies’ and ‘tectonosequences’ of the Kingston Peak Formation,Death Valley,California, and their bearing on supposed Neoproterozoic panglacial climates

The Kingston Peak Formation of the Pahrump Group in the Death Valley region of the Basin and Range Province, USA, is the thick (over 3 km) mixed siliciclastic–carbonate fill of a long‐lived structurally‐complex Neoproterozoic rift basin and is recognized by some as a key ‘climatostratigraphic’ succession recording panglacial Snowball Earth events. A facies analysis of the Kingston Peak Formation shows it to be largely composed of ‘tectonofacies’ which are subaqueous mass flow deposits recording cannibalization of older Pahrump carbonate strata exposed by local faulting. Facies include siltstone, sandstone and conglomerate turbidites, carbonate megabreccias (olistoliths) and related breccias, and interbedded debrites. Secondary facies are thin carbonates and pillowed basalts. Four distinct associations of tectonofacies (‘base‐of‐scarp’; FA1, ‘mid‐slope’; FA2, ‘base‐of‐slope’; FA3, and a ‘carbonate margin’ association; FA4) reflect the initiation and progradation of deep water clastic wedges at the foot of fault scarps. ‘Tectonosequences’ record episodes of fault reactivation resulting in substantial increases in accommodation space and water depths, the collapse of fault scarps and consequent downslope mass flow events. Carbonates of FA4 record the cessation of tectonic activity and resulting sediment starvation ending the growth of clastic wedges. Tectonosequences are nested within regionally‐extensive tectono‐stratigraphic units of earlier workers that are hundreds to thousands of metres in thickness, recording the long‐term evolution of the rifted Laurentian continental margin during the protracted breakup of Rodinia. Debrite facies of the Kingston Peak Formation are classically described as ice‐contact glacial deposits recording globally‐correlative panglacials but they result from partial to complete subaqueous mixing of fault‐generated coarse‐grained debris and fine‐grained distal sediment on a slope conditioned by tectonic activity. The sedimentology (tectonofacies) and stratigraphy (tectonosequences) of the Kingston Peak Formation reflect a fundamental control on local sedimentation in the basin by faulting and likely earthquake activity, not by any global glacial climate.     

Trial by Fire: natural hazards,mixed-methods and cultural research

This paper considers the issues of research ‘relevance’ and ‘use’ to reflect upon a cultural geography research project on bushfire that did not begin with any specific aim of being useful to policy makers but which has garnered considerable and ongoing interest from a broad audience. It provides an example of how the integration of quantitative and qualitative research methods and data can enhance research into cultural aspects of natural hazards whilst simultaneously playing a key role in ensuring that the research results are of interest to a wide range of groups. Using a mixed-methods research approach was found to provide insight into complex factors that influence attitudes and actions towards bushfire amongst diverse landholders in rural–urban interface areas in south-east Australia. We argue that mixed-methods research is a powerful tool in building and enhancing a cultural geography that has policy relevance, retains analytical depth, and is acceptable to risk managers. The ability of cultural geography through mixed-methods research to illuminate how socio-cultural processes are central to environmental attitudes and preparedness behaviour has direct relevance to recent international discussions of how to manage the vulnerability of the growing number of people living in bushfire-prone rural–urban interface areas.     

Ottawa: the knowledge city and a labyrinth of obstacles

This research provides a comparative examination of Ottawa as an archetype of a knowledge city. Among Canada’s four largest cities, Ottawa is unique in terms of the characteristics of its labor force, the nature of its employment mix, and its infrastructure. Since the high-tech downturn of 2001, some of Ottawa’s options as a knowledge city seem to be contracting, despite some simultaneously encouraging signs (like recovering employment levels in the high-tech sector). This raises a question about Ottawa’s potential longevity as a knowledge center. The challenge is to understand the inventory of obstacles faced by the city, and address the sort of alchemy required to maintain and improve its competitiveness as a knowledge city.     

The characteristics of asymmetric pedestrian behavior: A preliminary study using passive smartphone location data

Understanding the movements of people is essential for the design and management of urban areas. This article presents a novel approach to understanding the asymmetry in route choice (i.e., the degree to which people choose different walking routes for their outbound and return journeys). The study utilizes a large volume of traces of individual routes, captured using a smartphone application. The routes are aggregated to a regular grid, and matrix statistics are developed to estimate the aggregate degree of route asymmetry for different types of route (shortest, longest, weekday, weekend, etc.). The results suggest that people change their route approximately 15% of the time. Although this varied little when observing trips made at the weekend or on a weekday, people taking journeys that deviated substantially from the shortest possible path were 6 percentage points less likely to change their routes than those taking journeys that were closest to the shortest path (14 and 20% asymmetry, respectively). The absolute length also impacted on the asymmetry of journeys, but not as substantially. This result is important because, for the first time, it reports a correlation between deviation from shortest route and aggregate pedestrian choice.     

Assessing ground cover at patch and hillslope scale in semi-arid woody vegetation and pasture using fused Quickbird data

The amount and distribution of vegetation and ground cover are important factors that influence resource transfer (e.g. runoff, sediment) in patterned semi-arid landscapes. Identifying and describing these features in detail is an essential part of measuring and understanding ecohydrological processes at hillslope scales that can then be applied at broader scales. The aim of this study was to develop a comprehensive methodology to map ground cover using high resolution Quickbird imagery in woody and non-woody (pasture) vegetation. The specific goals were to: (1) investigate the use of several techniques of image fusion, namely principal components analysis (PCA), Brovey transform, modified intensity-hue-saturation (MIHS) and wavelet transform to increase the spatial detail of multispectral Quickbird data; (2) evaluate the performance of the red and near-infra-red bands (NIR), the difference vegetation index (DVI), and the normalised difference vegetation index (NDVI) in estimating ground cover, and (3) map and assess spatial and temporal changes in ground cover at hillslope scale using the most appropriate method or combination of methods. Estimates of ground cover from the imagery were compared with a subset of observed ground cover estimates to determine map accuracy. The MIHS algorithm produced images that best preserved spectral and spatial integrity, while the red band fused with the panchromatic band produced the most accurate ground cover maps. The patch size of the ground cover beneath canopies was similar to canopy size, and percent ground cover (mainly litter) increased with canopy size. Ground cover was mapped with relative accuracies of 84% in the woody vegetation and 86% in the pasture. From 2008 to 2009, ground cover increased from 55% to 65% in the woody vegetation and from 40% to 45% in the pasture. These ground cover maps can be used to explore the spatial ecohydrological interactions between areas of different ground cover at hillslope scale with application to management at broader scales.