Hydrology of hillslope‐wetland streams,Polar Bear Pass,Nunavut, Canada

Polar Bear Pass is a large High Arctic low‐gradient wetland (100 km²) bordered by low‐lying hills which are notched by a series of v‐shaped valleys. The spring and summer hydrology of two High Arctic hillslope‐wetland catchments, a first‐order stream, 0·2 km² Landing Strip Creek (LSC) and a larger second‐order basin, 4·2 km² Windy Creek (WC), is described here. A water balance framework was employed in 2008 to examine the movement of water from upland reaches into the low‐lying wetland. Snowcover was low in both basins (<50 mm in water equivalent units), but they both exhibited nival‐type regimes. After the main snowmelt season ended, runoff ceased in the smaller catchment (LSC), but not at the larger basin (WC) which continued to flow throughout the summer. Both basins responded to summer rains in different ways. At LSC, late‐summer continuous streamflow occurred only when rainfall satisfied the large soil moisture deficit in the upper bowl‐shaped zone of the basin. At WC, the presence of thinly thawed, ice‐rich polygonal terrain within the stream channel and in the upper reaches of the catchment likely limited infiltration in these near‐stream zones and enhanced runoff in response to both moderate and high rainfall. Subsequently, seasonal runoff ratios differed between the two sites (0·19 vs 0·68) as did the seasonal storage + residual (+16 vs ?50 mm). This suggests that the post‐snowmelt season runoff response to summer precipitation is very much modified by the unique basin characteristics (soil‐type, vegetation, ground ice) and their location within each stream order type. Copyright © 2010 John Wiley & Sons, Ltd.     

http://www.sciencedirect.com/science/article/pii/S1674987114000334

The Musgrave Province developed at the nexus of the North,West and South Australian cratons and its Mesoproterozoic evolution incorporates a 100 Ma period of ultra-high temperature(UHT) metamorphism from ca.1220 to ca.1120 Ma.This was accompanied by high-temperature A-type granitic magmatism over an 80 Ma period,sourced in part from mantle-derived components and emplaced as a series of pulsed events that also coincide with peaks in UHT metamorphism.The tectonic setting for this thermal event(the Musgrave Orogeny) is thought to have been intracontinental and the lithospheric architecture of the region is suggested to have had a major influence on the thermal evolution.We use a series of two dimensional,fully coupled thermo-mechanical-petrological numerical models to investigate the plausibility of initiating and prolonging UHT conditions under model setup conditions appropriate to the inferred tectonic setting and lithospheric architecture of the Musgrave Province.The results support the inferred tectonic framework for the Musgrave Orogeny,predicting periods of UHT metamorphism of up to 70 Ma,accompanied by thin crust and extensive magmatism derived from both crustal and mantle sources.The results also appear to be critically dependent upon the specific location of the Musgrave Province,constrained between thicker cratonic masses.     

Time evolution of complex networks: commuting systems in insular Italy

The aim of this paper is to study the dynamics of the commuting system of two insular regions of Italy, Sardinia and Sicily, inspected as complex networks. The authors refer to a 20-year time period and take into account three census data sets about the work and study-driven inter-municipal origin-destination movements of residential inhabitants in 1981, 1991 and 2001. Since it is likely that the number of municipalities (in this case, the vertices of the system) does not display sharp variations, the authors direct the study to the variation of the properties emerging through both a topological and a weighted network representation of commuting in the time periods indicated.     

NIMBY or how do the rural neighbours respond to genetically modified (GM) crops? An exploration of the structure of reactions by inhabitants in rural communities in The Netherlands to the commercial cultivation of GM crops in their community

The debate on genetic modification (GM) is persistent, polarized and mainly involves organized groups at the national level. With the European Union’s new policy of coexistence, commercial cultivation of GM crops is expected by the Dutch Ministry of Agriculture, Nature and Food Quality within the next few years, especially maize (BT) and potato (Phytophthera resistance and starch production). This makes the debate relevant for those directly confronted with this cultivation: the inhabitants of local rural communities. In The Netherlands, stakeholders formulated coexistence rules to prevent problems between conventional, organic and GM farmers that grow their crops in the same limited land area. Little is known, however, regarding the perceptions of the non-farming inhabitants of rural communities (“the neighbours”) in the debate. This paper presents the results of a focus group-based argumentative analysis of whether (and how) the GM issues play a decisive role among non-farming inhabitants of four rural communities in the Netherlands. We analysed the arguments in relation to a conceptual model that describes the potential rise and dynamics from a pre-Nimby ambivalence towards an outspoken Nimby position. We observed that the GM debate was given very little priority relative to other national issues on the political agenda and that more social cohesion correlates with fewer arguments in the national debate. It is argued that this mechanism keeps the Nimby ambivalence in an undetermined mode, which in turn diminishes the chances of radical rural-based protest against local GM cultivation of crops.     

Natural tracer profiles across argillaceous formations

Argillaceous formations generally act as aquitards because of their low hydraulic conductivities. This property, together with the large retention capacity of clays for cationic contaminants, has brought argillaceous formations into focus as potential host rocks for the geological disposal of radioactive and other waste. In several countries, programmes are under way to characterise the detailed transport properties of such formations at depth. In this context, the interpretation of profiles of natural tracers in pore waters across the formations can give valuable information about the large-scale and long-term transport behaviour of these formations. Here, tracer-profile data, obtained by various methods of pore-water extraction for nine sites in central Europe, are compiled. Data at each site comprise some or all of the conservative tracers: anions (Cl⁻, Br⁻), water isotopes (δ¹⁸O, δ²H) and noble gases (mainly He). Based on a careful evaluation of the palaeo-hydrogeological evolution at each site, model scenarios are derived for initial and boundary pore-water compositions and an attempt is made to numerically reproduce the observed tracer distributions in a consistent way for all tracers and sites, using transport parameters derived from laboratory or in situ tests. The comprehensive results from this project have been reported in Mazurek et al. (2009). Here the results for three sites are presented in detail, but the conclusions are based on model interpretations of the entire data set. In essentially all cases, the shapes of the profiles can be explained by diffusion acting as the dominant transport process over periods of several thousands to several millions of years and at the length scales of the profiles. Transport by advection has a negligible influence on the observed profiles at most sites, as can be shown by estimating the maximum advection velocities that still give acceptable fits of the model with the data. The advantages and disadvantages of different conservative tracers are also assessed. The anion Cl⁻ is well suited as a natural tracer in aquitards, because its concentration varies considerably in environmental waters. It can easily be measured, although the uncertainty regarding the fraction of the pore space that is accessible to anions in clays remains an issue. The stable water isotopes are also well suited, but they are more difficult to measure and their values generally exhibit a smaller relative range of variation. Chlorine isotopes (δ³⁷Cl) and He are more difficult to interpret because initial and boundary conditions cannot easily be constrained by independent evidence. It is also shown that the existence of perturbing events such as the activation of aquifers due to uplift and erosion, leading to relatively sharp changes of boundary conditions, can be considered as a pre-requisite to obtain well-interpretable tracer signatures. On the other hand, gradual changes of boundary conditions are more difficult to parameterise and so may preclude a clear interpretation.     

Carbonate sedimentation and hydrodynamic pattern on a modern temperate shelf: The strait of Bonifacio (western Mediterranean)

The sedimentary features of the inner-middle shelf of the strait of Bonifacio (western Mediterranean) were analyzed to evaluate the relationship between the production and transport of biogenic carbonate sediments and the basin morphology and hydrodynamics. A three-dimensional hydrodynamic modeling was performed in order to simulate the influence of waves and currents at seabed level. Superficial sediments were collected at depths ranging from 5 to 80 m and were analyzed for grain size, mineralogical composition and skeletal carbonate composition. Posidonia oceanica seagrass meadows border the coasts in a narrow strip on both sides of the strait down to a depth of 40 m. At greater depths, the seabed is characterized by the presence of plateaus and ridges which are controlled by outcropping bedrock morphology.     

Environmental justice implications of Maritime Spatial Planning in the European Union

This paper examines the implications of environmental justice in the regime for Maritime Spatial Planning (MSP) currently developing in the European Union (EU). An ‘ecosystem-based approach’ to marine management is enshrined in the new Integrated Maritime Policy and Marine Strategy Framework Directive and forms the basis of MSP. This concept is intended to encompass all aspects of an ecosystem, including the human element. Yet the modes of including meaningful public participation in the decision-making process for MSP remain undetermined. At the same time, the Aarhus Convention (on access to information, public participation in decision making and access to justice in environmental matters) empowers non-governmental organisations to hold EU Member States to account. Consequently the issue of transparency will gain increased importance, as will linkages between human and environmental rights. Such public interest-based activism on the part of NGOs has the potential to enforce the developing framework for stakeholder engagement within MSP, but it also has implications worth considering regarding the appropriate role of interest-based organisations in the international political arena.     

Seasonal temperature variations and energy demand

This paper presents an empirical study of the relationship between residential energy demand and temperature. Unlike previous studies in this field, the data sample has a global coverage and special emphasis is given to the heterogeneous response of different regions and to the contrasting effects on energy demand for cooling and heating purposes. To account for this we distinguish between different regions, seasons, and energy sources. Short- and long-run temperature demand elasticities are estimated. These features make the model results especially valuable in the analysis of climate change impacts as they provide an empirical basis for the study of the impact of climate change on energy demand. To illustrate the potential of the results as a basis for the study of climate change impacts, the estimates are used in a simple exercise that projects changes in energy demand due to temperatures increase in 2085.