A test for geographers: the geography of educational achievement in Toronto and Hamilton, 1997

The recent introduction of standardised achievement tests in several provinces has created an opportunity for Canadian geographers to contribute to public and theoretical debates. Geographers are well‐equipped to comprehend and analyse the effects that neighbourhoods have upon pupil achievement. Independent of family background and school funding, such effects may be stronger in education than in other fields, such as voting behaviour and health research, but they have been ignored in recent public debates. They should be considered if informed judgements are to be made about whether specific teachers, schools, and boards are doing an adequate job. Analysis of the Ontario Grade 3 test results for 1997 in public schools in the City of Toronto and in Hamilton‐Wentworth indicate that social class had a greater effect on pupil achievement than language background. Differences in the determinants of achievement between these two urban centres may be attributable to local variations in occupational structure and residential patterns. L'introduction récente en éducation des tests de compêtences standardisés, dans plusieurs provinces, offre aux géographes canadiens l'occasion de contribuer aux débats publics et théoriques. Les géographes sont bien placés pour comprendre et analyser les effets de quartier sur le rendement scolaire des élèves. Indépendamment du milieu socioculturel et du financement scolaire, ces effets ont peut être plus d'impact en éducation que dans les domaines tels que le comportement électoral et la recherche dans le milieu de la santé, cependant, ils demeurent à l'écart des débats publics. Ces éléments doivent être considérés si l'on prétend juger en connaissance de cause l'efficacité et le rendement des écoles, le corps enseignant et les conseils scolaires. L'analyse des résultats d'examens de l'Ontario en 1997, pour les élèves des écoles publiques de la troisième année des villes de Toronto et Hamilton‐Wentworth, démontre que la réussite scolaire est plus liée au niveau socio‐économique qu'à l'origine linguistique. La divergence des facteurs de réussites des deux centres urbains est peut‐être attribuable aux variations des structures d'occupation locales et résidentielles.     

Local indicators for categorical data: impacts of scaling decisions

When the geographic distribution of landscape pattern varies, global indices fail to capture the spatial nonstationarity within the dataset. Methods that measure landscape pattern at a spatially local scale are advantageous, as an index is computed at each point in the dataset. The geographic distribution of local indices is used to discover spatial trends. Local indicators for categorical data (LICD) can be used to statistically quantify local spatial patterns in binary geographic datasets. LICD, like other spatially local methods, are impacted by decisions relating to the spatial scale of the data, such as the data grain (p), and analysis parameters such as the size of the local neighbourhood (m). The goal of this article is to demonstrate how the choice of the m and p parameters impacts LICD analysis. We also briefly discuss the impacts spatial extent can have on analysis; specifically the local composition measure. An example using 2006 forest cover data for a region in British Columbia, Canada where mountain pine beetle mitigation and salvage harvesting has occurred is used to show the impacts of changing m and p. Selection of local window size (m = 3,5,7) impacts the prevalence and interpretation of significant results. Increasing data grain (p) had varying effects on significant LICD results. When implementing LICD the choice of m and p impacts results. Exploring multiple combinations of m and p will provide insight into selection of ideal parameters for analysis.     

Do counterterrorism and counterinsurgency go together?

One of the underlying assumptions of the contemporary debate over Afghanistan is that counterterrorism objectives can be achieved through counterinsurgency methods. The recent decision by President Barack Obama to deploy 30,000 extra troops to Afghanistan is premised on the idea that to disrupt Al Qaeda and prevent it from forming training camps in Afghanistan it will be necessary to first reverse the momentum of the Taleban insurgency. This approach—which places the US and UK on the offensive to disrupt terrorist plots before they arrive on their shores—assumes that the threats from Al Qaeda and the Taleban are intertwined and thus the strategy of response must seamlessly comprise elements of counterterrorism and counterinsurgency. In fact, counterterrorism and counterinsurgency are very different—often contradictory—models of warfare, each with its own associated assumptions regarding the role of force, the importance of winning support among the local population, and the necessity of building strong and representative government. Rather than being mutually reinforcing, they may impose tradeoffs on each other, as counterterrorism activities may blunt the effectiveness of counterinsurgency approaches and vice versa. The last four years in Afghanistan provide evidence that when employed in the same theatre counterterrorism and counterinsurgency strategies can offset one another. To be in a position to begin the withdrawal of US troops before July 2011, the Obama administration will need to find a way to manage the tradeoffs between its counterterrorism and counterinsurgency strategies in Afghanistan.     

Response of Alum Rock springs to the October 30, 2007 Alum Rock earthquake and implications for the origin of increased discharge after earthquakes

The origins of increased stream flow and spring discharge following earthquakes have been the subject of controversy, in large part because there are many models to explain observations and few measurements suitable for distinguishing between hypotheses. On October 30, 2007 a magnitude 5.5 earthquake occurred near the Alum Rock springs, California, USA. Within a day we documented a several‐fold increase in discharge. Over the following year, we have monitored a gradual return towards pre‐earthquake properties, but for the largest springs there appears to be a permanent increase in discharge. The Alum Rock springs discharge waters that are a mixture between modern (shallow) meteoric water and old (deep) connate waters expelled by regional transpression. After the earthquake, there was a small and temporary decrease in the fraction of connate water in the largest springs. Accompanying this geochemical change was a small (1–2°C) temperature decrease. Combined with the rapid response, this implies that the increased discharge has a shallow origin. Increased discharge at these springs occurs both for earthquakes that cause static volumetric expansion and for those that cause contraction, supporting models in which dynamic strains are responsible for the subsurface changes that cause flow to increase. We make a quantitative comparison between the observed changes and model predictions for three types of models: (i) a permanent increase in permeability; (ii) an increase in permeability followed by a gradual decrease to its pre‐earthquake value; and (iii) an increase of hydraulic head in the groundwater system discharging at the springs. We show that models in which the permeability of the fracture system feeding the springs increases after the earthquake are in general consistent with the changes in discharge. The postseismic decrease in discharge could either reflect the groundwater system adjusting to the new, higher permeability or a gradual return of permeability to pre‐earthquake values; the available data do not allow us to distinguish between these two scenarios. However, the response of these springs to another earthquake will provide critical constraints on the changes that occur in the subsurface and should permit a test of all three types of models.     

Spring temperatures in the Sagehen Basin, Sierra Nevada, CA: implications for heat flow and groundwater circulation

Heat flow in the Sierra Nevada, CA, is low despite its young geologic age. We investigate the possibility that advective heat transport by groundwater flow leads to an underestimate of heat flow in the Sierras based purely on borehole measurements. Using temperature and discharge measurements at springs in Sagehen Basin, we find that groundwater removes the equivalent of approximately 20–40 mW m⁻² of geothermal heat from the basin. This is comparable with other heat flow measurements in the region and indicates that, in this basin, at least, groundwater does transport a significant amount of geothermal heat within the basin. Additionally, we use estimates of the mean residence time of water discharged at the springs along with hourly temperature records in springs to provide constraints on groundwater flow depths within the basin. An analytical model based on these constraints indicates that the heat removed by groundwater may represent 20% to >90% of the total heat flow in the basin. Without better constraints on the regional hydrogeology and the depth of circulation, we cannot determine whether the heat discharged at the springs represents a change in the mode of heat transfer, i.e. from conduction to advection at shallow depths (<100 m) or whether this is a component of heat transfer that should be added to measured conductive values. If the latter is true, and Sagehen Basin is representative of the Sierras, basal heat flow in the Sierra Nevada may be higher than previously thought.     

Comfort blanket or weapon of war: what is Trident for?

A hangover from the Cold War, Britain's nuclear capability has acquired a totemic quality and, in some unexplained way, is expected to shield us from unspecified dangers. There has been no serious attempt at cost—benefit analysis and such as there is ignores opportunity costs: policies or procurement foregone. The most important are political and the more significant—the things Britain could do or achieve if it did not have a nuclear capability—relate to our role in the world and, more specifically, to the NPT. This is a national issue which does not depend on international negotiations or agreement. In drawing conclusions, the article therefore ignores the larger question of whether the global elimination of nuclear weapons is both desirable and feasible. This international issue is addressed in a separate final section.     

Global Change and Southern Africa

The developing nations of southern Africa have previously been identified as vulnerable to the vagaries of global change, particularly in terms of future climate change. This paper explores recent climate change scenarios for the region in terms of some representative sectors of the environment‐society interface, namely biodiversity, agriculture and related land uses, water resources and health issues. It is concluded that the impacts of predicted climate changes over the next century are likely to be very marked indeed. Biome distribution, agriculture, rangelands and water resources are highlighted as being negatively impacted in ways that will increase the vulnerability of the great majority of the region's population to natural hazards. The potential impact of these changes on the prolific biodiversity of southern Africa is clear. Holistic policy responses, incorporating both environmental and human development concerns, are required in the near future if a crisis is to be averted.     

Empire by denial: the strange case of the United States

The issue of empire has once again become a major political question in American foreign policy discourse. But whereas in the 1960s the discussion was one that mainly concerned the radical left, over the past few years the debate has largely been conducted within neo-conservative circles. The discussion is one that should be taken seriously-in part because of its intrinsically interesting character and in part because of what it tells us about the Bush grand strategy. In the end, though, the issue of whether or not there is-or is not- an American empire, is perhaps of less importance than the fact that most Americans deny that such an empire exists. This has consequences both for the conduct of American foreign policy and for its successful execution.