Interdisciplinary research: framing and reframing

Framing encompasses the processes of identifying and bounding the area of research and based on our own experiences as academics we have found significant differences in the ways that researchers establish and frame a disciplinary, compared to an interdisciplinary, research project. In this paper we have attempted to contribute to the development of the conceptual framework underpinning interdisciplinary research through analysis of interviews with a number of academics already working in an interdisciplinary manner. Successful projects are able to identify and support the processes that allow the communication and negotiation that is necessary, not just for the initial framing of a research funding proposal but to be able to maintain negotiation. Self awareness and continual reflexivity and a willingness to be questioned by others are essential to this process.     

Census and typology of braided rivers in the French Alps

Following the implementation of the European Water Framework Directive (WFD) and the need to reach a “good ecological status” for rivers, key-questions are being raised about braided rivers. Before any environmental policy can be drawn up, these rivers need to be located, long term changes must be evaluated, and the regional diversity of such systems must be understood, as their inner complexity has not yet been well studied. Therefore, the aim of this work is to carry out a census of the braided channels of the French Alps and to establish a typology based on basic geomorphic indicators. A minimum estimate of the cumulative length of braided rivers prior to major infrastructure construction amounted to 1214 km. Around 53% of these rivers have disappeared during the last two centuries in relation to embankment or channelization, but a loss of 17% is still unexplained. The range in catchment size, mean slope and active channel width has been determined for the Western Alpine braided channels as well as the range in changes due to narrowing, widening and shifting. Seven types of braided rivers have been distinguished based on geographical settings (climate conditions and geology) and differences in terms of adjustment to human pressure on peak flow and sediment delivery. The percentage area of islands in the active channel and the relative length of banks also show a regional difference. Maximum and minimum thresholds of braided activity have been established taking into account the active channel width and the catchment area. The position of the studied reaches between these two thresholds are discussed in relation to position of rivers known in the literature, considering both long-term trends and short-term fluctuations in channel width.     

Reconnaissance report and preliminary ground motion simulation of the 12 May 2008 Wenchuan earthquake

The M _w = 8.0 Wenchuan earthquake of May 12, 2008, caused destruction over a wide area. The earthquake cost more than 69,000 lives and the damage is reported to have left more than 5 million people homeless. It is estimated that 5.36 million buildings were destroyed and 21 million buildings were damaged in Sichuan and the nearby provinces. Economic losses due to the event are estimated to be 124 billion USD. From a field reconnaissance trip conducted in October 2008, it is evident that the combination of several factors, including mountainous landscape, strong ground shaking, extensive landslides and rock-falls, has exacerbated the human and economic consequences of this earthquake. Extensive damage occurred over a wide area due to the shear size of the earthquake rupture combined with poor quality building construction. In order to investigate the ground shaking during the earthquake, we have conducted a strong ground motion simulation study, applying a hybrid broadband frequency technique. The preliminary results show large spatial variation in the ground shaking, with the strongest ground motions along the fault plane. The simulation results have been calibrated against the recorded ground motion from several near-field stations in the area, and acceleration values of the order of 1 g are obtained, similar to what was recorded during the event. Comparison with the damage distribution observed in the field confirms that the effect of fault rupture complexity on the resulting ground motion distribution also controls to a large extent the damage distribution. The applied simulation technique provides a promising platform for predictive studies.     

Getting Canadians prepared for natural disasters: a multi-method analysis of risk perception,behaviors, and the social environment

As part of our broader research agenda on the psychology of risk communication and of risk management, we use a socio-ecological approach, inspired by Bronfenbrenner (Am Psychol 32:513–531, 1977. https://doi.org/10.1037/0003-066x.32.7.513), to better understand how Canadians perceive and prepare for risks originating from natural disasters. In this article, we present three empirical mixed-method studies as layers of analysis—a national survey, a social-spatial multi-level analysis, and a series of qualitative interviews—to bring a better understanding of how to engage Canadians in disaster preparedness and risk management. From our data, we examined how individuals perceived and understood natural disaster risks in Canada and how these fit in their social and life contexts. Given the increasingly diverse Canadian population, we used a cultural lens to contrast immigrants to Canadian-born individuals. After introducing the conceptual background and presenting our empirical studies, we conclude with a discussion on the implications for risk communication and management for natural disasters. Our findings suggest that Canadians could benefit from culturally targeted disaster risk reduction strategies that engage individuals–communities–government at all levels and are more attuned to the realities and specificities of life stressors.

     

The Effect of Bottle Fill Rate and Pour Technique on the Recovery of Volatile Organics

This field study was conducted to examine whether the method or the flow rate (fill rate) used to fill a sample vial affects recovery of volatile organics (VOCs). To our knowledge, there have not been any systematic studies that have examined this issue. For this field study, three fill rates (50 mL/min, 250 mL/min, and ~1 L/min) and three filling methods (top‐pour, side‐pour, and bottom‐fill) were used to fill sample vials. We found that the bottom‐fill method, with the tubing submerged in the sample as it fills, yielded the greatest recovery (i.e., highest concentrations) of VOCs. Little improvement was observed by pouring down the side of a vial vs. simply pouring straight down from the top. We also found that filling the vials at the fastest fill rate (~1 L/min) yielded higher recovery than the slowest fill rate (50 mL/min) using all three filling methods. These results are counter to prevailing guidance and conventional wisdom that slower filling is preferable to faster filling and that pouring down the side of a sample vial is the best practice for VOC sampling. However, because we were unable to randomize the order the samples were collected with respect to fill rate, we recommend a follow‐on study be conducted that will allow us to confirm our findings and better determine which fill rates minimize losses of VOCs     

Lipid biomarkers and bacterial lipase activities as indicators of organic matter and bacterial dynamics in contrasted regimes at the DYFAMED site, NW Mediterranean

This study investigated the relationships between dissolved organic matter (DOM) composition and bacterial dynamics on short time scale during spring mesotrophic (March 2003) and summer oligotrophic (June 2003) regimes, in a 0–500 m depth water column with almost no advection, at the DYFAMED site, NW Mediterranean. DOM was characterized by analyzing dissolved organic carbon (DOC), colored dissolved organic matter (CDOM) and lipid class biotracers. Bacterial dynamic was assessed through the measurement of in situ bacterial lipase activity, abundance, production and bacterial community structure. We made the assumption that by coupling the ambient concentration of hydrolysable acyl-lipids with the measurement of their in situ bacterial hydrolysis rates (i.e. the free fatty acids release rate) would provide new insights about bacterial response to change in environmental conditions. The seasonal transition from spring to summer was accompanied by a significant accumulation of excess DOC (+5 μM) (ANOVA, p<0.05, n=8) in the upper layer (0–50 m). In this layer, the free fatty acids release rate to the bacterial carbon demand (BCD) ratio increased from 0.6±0.3 in March to 1.3±1.0 in June (ANOVA, p<0.05, n=8) showing that more uncoupling between the hydrolysis of the acyl-lipids and the BCD occurred during the evolution of the season, and that free fatty acids contributed to the excess DOC. The increase of lipolysis index and CDOM absorbance (from 0.24±0.17 to 0.39±0.13 and from 0.076±0.039 to 0.144±0.068; ANOVA, p<0.05, n=8, respectively), and the higher contribution of triglycerides, wax esters and phospholipids (from <5% to 12–31%) to the lipid pool reflected the change in the DOM quality. In addition to a strong increase of bacterial lipase activity per cell (51.4±29.4–418.3±290.6 Ag C cell⁻¹ h⁻¹), a significant percentage of ribotypes (39%) was different between spring and summer in the deep chlorophyll maximum (DCM) layer in particular, suggesting a shift in the bacterial community structure due to the different trophic conditions. At both seasons, in the chlorophyll layers, diel variations of DOM and bacterial parameters reflected a better bioavailability and/or DOM utilization by bacteria at night (the ratio of free fatty acids release rate to bacterial carbon demand decreased), most likely related to the zooplankton trophic behaviour. In mesotrophic conditions, such day/night pattern was driving changes in the bacterial community structure. In more oligotrophic period, diel variations in bacterial community structure were depth dependent in relation to the strong summer stratification.     

Axial and transverse deep-water sediment supply to syn-rift fault terraces: Insights from the West Xylokastro Fault Block,Gulf of Corinth,Greece

Deep-water syn-rift systems develop in partially- or transiently-linked depocentres to form complicated depositional architectures, which are characterised by short transport distances, coarse grain sizes and a wide range of sedimentary processes. Exhumed systems that can help to constrain the tectono-stratigraphic evolution of such systems are rare or complicated by inversion tectonics. Here, we document a mid-Pleistocene deep-water syn-rift system fed by Gilbert-type fan deltas in the hangingwall of a rift margin fault bounding the West Xylokastro Horst block, on the southern margin of the Gulf of Corinth, Greece. Structural and stratigraphic mapping combined with digital outcrop models permit observations along this syn-rift depositional system from hinterland source to deep-water sink. The West Xylokastro Fault hangingwall is filled by two distinct sediment systems; an axial system fed by coarse-grained sediment gravity flows derived from fault-tip Gilbert-type fan deltas and a lateral system dominated by mass transport deposits fed from an evolving fault-scarp apron. Abrupt changes in stratigraphic architecture across the axial system are interpreted to record changes in relative base level, sediment supply and tectonics. Locally, depositional topography and intra-basinal structures controlled sediment dispersal patterns, from bed-scale infilling of local rugose topography above mass transport complexes, to basin-scale confinement from the fault scarp apron. These acted to generate a temporally and spatially variable, heterogeneous stratigraphic architecture throughout the basin-fill. The transition of the locus of sedimentation from a rift margin to a fault terrace through the syn-sedimentary growth of a basinward fault produced regressive surfaces updip, which manifest themselves as channels in the deep-water realm and acted to prograde the system. We present a new conceptual model that recognises coeval axial and transverse systems based on the stratigraphic architecture around the West Xylokastro fault block that emphasizes the lateral and vertical heterogeneity of rift basin-fills with multiple entry points.     

Impact of climate change on Pacific Northwest hydropower

The Pacific Northwest (PNW) hydropower resource, central to the region’s electricity supply, is vulnerable to the impacts of climate change. The Northwest Power and Conservation Council (NWPCC), an interstate compact agency, has conducted long term planning for the PNW electricity supply for its 2005 Power Plan. In formulating its power portfolio recommendation, the NWPCC explored uncertainty in variables that affect the availability and cost of electricity over the next 20 years. The NWPCC conducted an initial assessment of potential impacts of climate change on the hydropower system, but these results are not incorporated in the risk model upon which the 2005 Plan recommendations are based. To assist in bringing climate information into the planning process, we present an assessment of uncertainty in future PNW hydropower generation potential based on a comprehensive set of climate models and greenhouse gas emissions pathways. We find that the prognosis for PNW hydropower supply under climate change is worse than anticipated by the NWPCC’s assessment. Differences between the predictions of individual climate models are found to contribute more to overall uncertainty than do divergent emissions pathways. Uncertainty in predictions of precipitation change appears to be more important with respect to impact on PNW hydropower than uncertainty in predictions of temperature change. We also find that a simple regression model captures nearly all of the response of a sequence of complex numerical models to large scale changes in climate. This result offers the possibility of streamlining both top-down impact assessment and bottom-up adaptation planning for PNW water and energy resources.