Protection of groundwater intended for human consumption: a proposed methodology for defining safeguard zones

Carbonate aquifers constitute a water reserve of essential importance for human supply. For this, it is necessary to establish suitable protection measures in order to achieve the good status of groundwater bodies intended for human supply according to the requirements of the Water Framework Directive. The objective of this paper is to present a methodology to define safeguard zones for the protection of carbonate groundwater bodies intended for human consumption. To do this, firstly the risk of groundwater contamination is evaluated through a combination of characterising pressures and the evaluation of the intrinsic vulnerability to contamination. Secondly, the existing water abstraction points are identified and their zones of contribution are delineated in order to establish priorities when defining protective measures in the region. Finally, the existing wellhead protection areas and those defined according to the proposed methodology must be integrated into the delineated safeguard zones. The results obtained in a carbonate groundwater body in southern Spain are consistent with the existing quality data and they show the percentage of land that must be protected to preserve the quality of water intended for human consumption, thus facilitating their future integration into adequate land use planning tools.     

Avoiding the Ghetto through hope and fear: an analysis of immanent technology using ideal types

With over one hundred million smart-phone users in the world, mobile, spatially-aware devices are radically altering how individuals move through and experience both physical and social environments. This article presents a theoretical and methodological framework for engaging the emerging geoweb as part of a longer tradition of research into society and technology. A close reading of Microsoft’s Pedestrian Route Production patent, dubbed the “avoid ghetto GPS”, is used to construct two ideal type futures—one hopeful and one frightening. One where spatial technology ensures efficiency, safety, and new forms of coordination, while the other algorithmically sorts society by race and class. Despite not yet and potentially never existing, the patent offers a viable means through which potential futures are made real in the present. Through comparative analysis of these futures, their underlying commonalities are drawn out, revealing the relationship between technology and the delimitation of human experience. This analysis avoids grand narratives and teleological arguments, while making it possible to draw forth the unthought acceptance within each ideal type for the future: the continuing shift of human life itself towards a teleological, always already-calculated standing-reserve. The work on technology of Martin Heidegger and Herbert Marcuse (re)situate the geoweb within long-standing theoretical work on technology and its role in society, modernity, and capitalism.     

Carbonate concretions—explained

Carbonate concretions are common features of sedimentary rocks of all geological ages. They are most obvious in sandstones and mudstones as ovoid bodies of rock that protrude from natural outcrops: clearly harder or better cemented than their host rocks. Many people are excited by finding fossils in the centre of mudstone‐hosted concretions ( Fig. 1 ) but spend little time wondering why the fossils are so well preserved. While the study of concretions has benefitted from the use of advanced analytical equipment, simple observations in the field can also help to answer many questions. For example, in cliff sections, original sedimentary beds and sedimentary structures can be traced right through concretions ( Fig. 2 ): so it can be deduced that the concretion clearly formed after these depositional structures were laid down. In this article we explain how and where concretions form and discuss the evidence, ranging from outcrop data to sophisticated laboratory analyses, which can be used to determine their origins. The roles of microbes, decaying carcasses, compaction and groundwaters are highlighted. Concretions not only preserve fossils but can also subdivide oil, gas and water reservoirs into separate compartments.

Figure 1 Open in figure viewer PowerPoint An early diagenetic carbonate concretion split in half to reveal an ammonite retaining its original aragonite shell, from the Maastrichtian of Antarctica. Image courtesy of Alistair Crame (British Antarctic Survey, NERC). Lens cap is 6 cm.     

A method of accelerating transport simulation when groundwater pumping is simulated

In solving groundwater transport problems with numerical models, the computation time (CPU processing time) of transport simulation is approximately inversely proportional to the transport time-step size. Therefore, large time-step sizes are favorable for achieving short computation time. However, transport time-step size must be sufficiently small to avoid numerical instability if an explicit scheme is used (and to guarantee enough model accuracy if an implicit scheme is used). For a transport model involving groundwater pumping, a small transport time-step size is often required due to the high groundwater velocities near the pumping well. Small grid spacing often specified near the pumping well also limits the time-step size. This paper presents a method to increase transport time-step size in a transport model when groundwater pumping is simulated. The key to this approach is to numerically decrease the groundwater seepage velocities in grid cells near the pumping well by increasing the effective porosity so that the transport time-step size can be increased without violating stability constraints. Numerical tests reveal that by using the proposed method, the computation time of transport simulation can be reduced significantly, while the transport simulation results change very little.     

Methods for point source analysis in high energy neutrino telescopes

Neutrino telescopes are moving steadily toward the goal of detecting astrophysical neutrinos from the most powerful galactic and extragalactic sources. Here we describe analysis methods to search for high energy point-like neutrino sources using detectors deep in the ice or sea. We simulate an ideal cubic kilometer detector based on real world performance of existing detectors such as AMANDA, IceCube, and ANTARES. An unbinned likelihood ratio method is applied, making use of the point spread function and energy distribution of simulated neutrino signal events to separate them from the background of atmospheric neutrinos produced by cosmic ray showers. The unbinned point source analyses are shown to perform better than binned searches and, depending on the source spectral index, the use of energy information is shown to improve discovery potential by almost a factor of two.     

Impact of lunar cycle and swell on the daily catch rate of western rock lobster (Panulirus cygnus) using time series modelling

The western rock lobster fishery is one of the most valuable single‐species fisheries in Australia, valued at AU$300 million per year. The impact of environmental factors such as lunar cycle and swell on the daily catch rate of the western rock lobster (Panulirus cynus) is of particular interest in the stock assessment and management of the fishery. The variation in daily catch rates was examined for two periods (migrating period November‐January, non‐migrating period February‐June), at different depths in three management zones for three categories of lobster (undersize, legal size, and setose). Regression and transfer function models for relationships between catch rates and environmental data were considered and compared. The lunar cycle has a significant impact on the daily catch rates with c. 30% lower catch rate during the full moon and c. 20% higher catches near the new moon. This impact occurs mainly during the non‐migrating period both in deep water (40–100 m) and shallow water (<40 m). The swell on the day before fishing was also shown to be significantly related to the catch rate with an increase of c. 10–15% for an increase in swell from light to moderate or moderate to high. These environmental factors can be used to standardise catch rates to provide an improved abundance index for stock assessment. Also, management closures are being considered for 3–5 days over the low catch rate, full moon period to reduce fishing costs and lower fishing effort.     

Astronomy at sea: Jim Wild's Cunard diary

When I saw an item on the RAS website seeking speakers for Cunard's Insights Lecture Programme, I was interested immediately. A chance to travel on some of the most famous ocean liners in the world and talk about my science to an enthusiastic audience? It seemed churlish not to apply!     

Seismic reliability of V‐braced frames: Influence of design methodologies

According to the most modern trend, performance‐based seismic design is aimed at the evaluation of the seismic structural reliability defined as the mean annual frequency (MAF) of exceeding a threshold level of damage, i.e. a limit state. The methodology for the evaluation of the MAF of exceeding a limit state is herein applied with reference to concentrically ‘V’‐braced steel frames designed according to different criteria. In particular, two design approaches are examined. The first approach corresponds to the provisions suggested by Eurocode 8 (prEN 1998—Eurocode 8: design of structures for earthquake resistance. Part 1: general rules, seismic actions and rules for buildings), while the second approach is based on a rigorous application of capacity design criteria aiming at the control of the failure mode (J. Earthquake Eng. 2008; 12 :1246–1266; J. Earthquake Eng. 2008; 12 :728–759). The aim of the presented work is to focus on the seismic reliability obtained through these design methodologies. The probabilistic performance evaluation is based on an appropriate combination of probabilistic seismic hazard analysis, probabilistic seismic demand analysis (PSDA) and probabilistic seismic capacity analysis. Regarding PSDA, nonlinear dynamic analyses have been carried out in order to obtain the parameters describing the probability distribution laws of demand, conditioned to given values of the earthquake intensity measure. Copyright © 2009 John Wiley & Sons, Ltd.