Pathways,motivations and challenges: contemporary Tuvaluan migration to New Zealand

The global climate change literature suggests that at some point in the future it is possible that low-lying areas may be drowned due to rising sea levels, and a number of Pacific Ocean states could be particularly vulnerable. It is increasingly evident that the emerging scenario of environmental change has compounded more established push–pull factors leading to migration, and has provided a new imperative for migration decision-making. By interrogating the proposition that there is a clear distinction between the policy categories of ‘migrants’ and ‘refugees,’ we examine a hitherto un-defined group of Tuvaluan migrants whose movement is in response to environmental change and possible climate change effects. The paper examines Tuvaluan migration to New Zealand through various immigration schemes for permanent residency, with an emphasis on the International/Humanitarian stream.     

New Zealand geography: Sharpening the focus,raising the profile

Geography seems to be in good hands in New Zealand's schools and universities, but we cannot afford to be complacent. What are the key priorities for further strengthening geography in New Zealand in the years ahead? The New Zealand Geographical Society has to play a crucial role by helping to bring together geographers in the different sectors, as well as in promoting New Zealand geography internationally, and raising its profile in the media. Most of all, we need to demonstrate the vibrancy, significance and relevance of geography to the wider community.     

An analytical solution for rainfall infiltration into an unsaturated infinite slope and its application to slope stability analysis

Surficial slope failures in residual soils are common in tropical and subtropical regions as a result of rainfall infiltration. This study develops an analytical solution for simulating rainfall infiltration into an infinite unsaturated soil slope. The analytical solution is based on the general partial differential equation for water flow through unsaturated soils. It can accept soil–water characteristic curve and unsaturated permeability function of the exponential form into account. Numerical simulations are conducted to verify the assumptions of the analytical solution and demonstrate that the proposed analytical solution is acceptable for the coarse soils with low air entry values. The pore‐water pressure (pwp) distributions obtained from the analytical solution can be incorporated into a limit equilibrium method to do infinite slope stability analysis for a rain‐induced shallow slip. The analysis method takes into account the influence of the water content change on unit weight and hence on factor of safety. A series of analytical parametric analyses have been performed using the developed model. The analyses indicate that when the residual soil slope, consisting of a completely decomposed granite layer underlain by a less permeable layer, is subjected to a continuous heavy rainfall, the loss of negative pwp and the reduction in factor of safety were found to be most significant for the shallow soil layer and during the first 12 h. The antecedent and subsequent rainfall intensity, depth of a less permeable layer and slope angle all have a significant influence on the pwp response and hence the slope stability. Copyright © 2012 John Wiley & Sons, Ltd.     

Interactive Visualization to Advance Earthquake Simulation

The geological sciences are challenged to manage and interpret increasing volumes of data as observations and simulations increase in size and complexity. For example, simulations of earthquake-related processes typically generate complex, time-varying data sets in two or more dimensions. To facilitate interpretation and analysis of these data sets, evaluate the underlying models, and to drive future calculations, we have developed methods of interactive visualization with a special focus on using immersive virtual reality (VR) environments to interact with models of Earth’s surface and interior. Virtual mapping tools allow virtual “field studies” in inaccessible regions. Interactive tools allow us to manipulate shapes in order to construct models of geological features for geodynamic models, while feature extraction tools support quantitative measurement of structures that emerge from numerical simulation or field observations, thereby enabling us to improve our interpretation of the dynamical processes that drive earthquakes. VR has traditionally been used primarily as a presentation tool, albeit with active navigation through data. Reaping the full intellectual benefits of immersive VR as a tool for scientific analysis requires building on the method’s strengths, that is, using both 3D perception and interaction with observed or simulated data. This approach also takes advantage of the specialized skills of geological scientists who are trained to interpret, the often limited, geological and geophysical data available from field observations.     

Beyond peasant deforestation: environment and development in rural Jamaica

Jamaica is experiencing one of the highest rates of deforestation in the world, with severe environmental consequences attendant to the loss of its forests. It is also plagued by high levels of poverty, particularly in rural areas. As throughout much of the tropics, impoverished peasant farmers are blamed as the primary agents in Jamaica's forest colonisation. Employing a case study in the Blue Mountains, this paper explores the discord that exists between forest conservation and the development priorities of poor farmers, arguing that this unsustainable dichotomy can only be understood by acknowledging the political economy which constrains peasant agriculture.     

Who moves into, out of and within London?

Summary Eight variables from the 1991 Census 2% Sample of Anonymised Records are used to classify Greater London's population into ten socio-demographic groups. This provides the basis for examining differences between 'types of people' in the extent to which they changed address in the year before the Census and whether they moved into, out of or within London.     

Shear strength characterization of municipal solid waste at the Suzhou landfill, China

The current practice of slope stability analysis for a municipal solid waste (MSW) landfill usually overlooks the dependence of waste properties on the fill age or embedment depth. Changes in shear strength of MSW as a function of fill age were investigated by performing field and laboratory studies on the Suzhou landfill in China. The field study included sampling from five boreholes advanced to the bottom of the landfill, cone penetration tests and monitoring of pore fluid pressures. Twenty-six borehole samples representative of different fill ages (0 to 13 years) were used to perform drained triaxial compression tests. The field and laboratory study showed that the waste body in the landfill can be sub-divided into several strata corresponding to different ranges of fill age. Each of the waste strata has individual composition and shear strength characteristics. The triaxial test results showed that the MSW samples exhibited a strain-hardening and contractive behavior. As the fill age of the waste increased from 1.7 years to 11 years, the cohesion mobilized at a strain level of 10% was found to decrease from 23.3 kPa to 0 kPa, and the mobilized friction angle at the same strain level increasing from 9.9° to 26°. For a confinement stress level greater than 50 kPa, the shear strength of the recently-placed MSW seemed to be lower than that of the older MSW. This behavior was consistent with the cone penetration test results. The field measurement of pore pressures revealed a perched leachate mound above an intermediate cover of soils and a substantial leachate mound near the bottom of the landfill. The measurements of shear strength properties and pore pressures were utilized to assess the slope stability of the Suzhou landfill.     

The Romanian earthquake of August 30, 1986: A study based on GEOSCOPE very long-period and broadband data

The Romanian earthquake of August 30, 1986 is the second largest intermediate depth event in this area since the worldwide deployment of digital instrumentation, and the first one since the installation of GEOSCOPE network. It offers the unique opportunity to document this well-known but poorly understood zone of deep continental seismicity using high quality teleseismic data in different frequency bands. The source is well constrained both from very-long period surface wave data observed on GEOSCOPE stations and, independently, from body wave modelling at various worldwide stations. The depth obtained is approximately 140 kilometers, the seismic moment, 0.8 10²⁷ dyne-cm and the mechanism from both data sets is very similar to that of the previous 1940 and 1977 Vancrea events, indicating that these events, although having occurred at noticeably different depths, are expressions of the same tectonic process. However, from the detailed study of the source using broadband data, it can be inferred that the source presents much less complexity than the 1977 event.