Quantification of source-level turbulence during LNG spills onto a water pond

The use of computational fluid dynamics (CFD) models to simulate LNG vapor dispersion scenarios has been growing steadily over the last few years, with applications to LNG spills on land as well as on water. Before a CFD model may be used to predict the vapor dispersion hazard distances for a hypothetical LNG spill scenario, it is necessary for the model to be validated with respect to relevant experimental data. As part of a joint-industry project aimed at validating the CFD methodology, the LNG vapor source term, including the turbulence level associated with the evaporation process vapors was quantified for one of the Falcon tests.This paper presents the method that was used to quantify the turbulent intensity of evaporating LNG, by analyzing the video images of one of the Falcon tests, which involved LNG spills onto a water pond. The measured rate of LNG pool growth and spreading and the quantified turbulence intensity that were obtained from the image analysis were used as the LNG vapor source term in the CFD model to simulate the Falcon-1 LNG spill test. Several CFD simulations were performed, using a vaporization flux of 0.127 kg/m² s, radial and outward spreading velocities of 1.53 and 0.55 m/s respectively, and a range of turbulence kinetic energy values between 2.9 and 28.8 m²/s². The resulting growth and spread of the vapor cloud within the impounded area and outside of it were found to match the observed behavior and the experimental measured data.The results of the analysis presented in this paper demonstrate that a detailed and accurate definition of the LNG vapor source term is critical in order for any vapor cloud dispersion simulation to provide useful and reliable results.     

Optimising the sampling effort in riparian surveys

Riparian condition is commonly measured as part of stream health monitoring programs as riparian vegetation provides an intricate linkage between the terrestrial and aquatic ecosystems. Field surveys of a riparian zone provide comprehensive riparian attribute data but can be considerably intensive and onerous on resources and workers. Our objective was to assess the impact of reducing the sampling effort on the variation in key riparian health indicators. Subsequently, we developed a non-parametric approach to calculate an information retained (IR) statistic for comparing several constrained systematic sampling schemes to the original survey. The IR statistic is used to select a scheme that reduces the time taken to undertake riparian surveys (and thus potentially the costs) whilst maximising the IR from the original survey. Approximate bootstrap confidence intervals were calculated to improve the inferential capability of the IR statistic. The approach is demonstrated using riparian vegetation indicators collected as part of an aquatic ecosystem health monitoring program in Queensland, Australia. Of the nine alternative sampling designs considered, the sampling design that reduced the sampling intensity per site by sixfold without significantly comprising the quality of the IR, results in halving the time taken to complete a riparian survey at a site. This approach could also be applied to reducing sampling effort involved in monitoring other ecosystem health indicators, where an intensive systematic sampling scheme was initially employed.     

Evaluation of surface water quality in aquatic bodies under the influence of uranium mining (MG, Brazil)

The quality of the water in a uranium-ore-mining area located in Caldas (Minas Gerais State, Brazil) and in a reservoir (Antas reservoir) that receives the neutralized acid solution leaching from the waste heaps generated by uranium mining was investigated. The samples were collected during four periods (October 2008, January, April and July 2009) from six sampling stations. Physical and chemical analyses were performed on the water samples, and the data obtained were compared with those of the Brazilian Environmental Standards and WHO standard. The water samples obtained from waste rock piles showed high uranium concentrations (5.62 mg L^?1), high manganese values (75 mg L^?1) and low average pH values (3.4). The evaluation of the water quality at the point considered the limit between the Ore Treatment Unit of the Brazilian Nuclear Industries and the environment (Consulta Creek) indicated contamination by fluoride, manganese, uranium and zinc. The Antas reservoir showed seasonal variations in water quality, with mean concentrations for fluoride (0.50 mg L^?1), sulfate (16 mg L^?1) and hardness (20 mg L^?1) which were low in January, evidencing the effect of rainwater flowing into the system. The concentrations for fluoride, sulfate and manganese were close or above to the limits established by current legislation at the point where the treated mining effluent was discharged and downstream from this point. This study demonstrated that the effluent discharged by the UTM affected the quality of the water in the Antas reservoir, and thus the treatments currently used for effluent need to be reviewed.     

European bee-eater (Merops apiaster) populations under arsenic and metal stress: evaluation of exposure at a mining site

Two populations of the European bee-eater were studied, one living at a reference site and the other at a metal mining site. The concentration of arsenic and 11 metals (Al, Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb, and Zn) was measured in feathers and regurgitated pellets collected at both sites. Cadmium, chromium, mercury, nickel, and lead were at least twofold higher in feathers of birds from the contaminated site than in the reference site, suggesting that this population was exposed to higher metal levels. Similarly, levels of aluminum, arsenic, cadmium, cobalt, chromium, iron, and lead were also at least twofold higher in pellets from the contaminated area. The obtained results suggested that the impacted population of Merops apiaster is at risk due to the exposure to some metals.     

Effects of Human Colonization on the Abundance and Diversity of Mammals in Eastern Brazilian Amazonia

Abstract: With its long history of colonization, eastern Amazonia has the highest population density in Brazilian Amazonia and represents the typical pattern of recent human occupation. Between 1991 and 1995, we surveyed the mammalian fauna at five sites, representing different degrees of human disturbance. We used line transects (1511 km surveyed) to describe differences in diversity and abundance at each site and to evaluate the effects of environmental factors. Twenty-two of the expected 44 species were recorded during surveys, but no more than 18 were recorded at any one site, and only 3 species were observed at all five sites. Despite a minimum transect length of 202 km, most species were recorded relatively infrequently at all sites, although overall sighting rates at different sites varied by more than 100%. Between-site differences were even more pronounced when we compared specific groups (e.g., arboreal, terrestrial, game, nongame), reflecting the differential effects of factors such as hunting, logging, and forest clearing. In general terms, species diversity, abundance, total biomass, and mean biomass all tended to decrease with increasing human disturbance. Two more specific patterns were also distinguished: decreasing abundance and biomass of game species with increasing hunting pressure and increasing abundance of nongame species with increasing forest disturbance. Intense hunting pressure alone may have deleterious short-term effects on abundance, but not necessarily on diversity, whereas prolonged hunting pressure, combined with forest clearing, results in marked distortions in the mammalian community. Overall, the study emphasizes the relative paucity of the mammalian fauna of eastern Amazonia, in terms of both species diversity and abundance, and its vulnerability to the ongoing process of human colonization in the region.     

Addressing statistical and operational challenges in designing large-scale stream condition surveys

Implementing a statistically valid and practical monitoring design for large-scale stream condition monitoring and assessment programs can be difficult due to factors including the likely existence of a diversity of ecosystem types such as ephemeral streams over the sampling domain; limited resources to undertake detailed monitoring surveys and address knowledge gaps; and operational constraints on effective sampling at monitoring sites. In statistical speak, these issues translate to defining appropriate target populations and sampling units; designing appropriate spatial and temporal sample site selection methods; selection and use of appropriate indicators; and setting effect sizes with limited ecological and statistical information about the indicators of interest. We identify the statistical and operational challenges in designing large-scale stream condition surveys and discuss general approaches for addressing them. The ultimate aim in drawing attention to these challenges is to ensure operational practicality in carrying out future monitoring programs and that the resulting inferences about stream condition are statistically valid and relevant.     

Prioritizing debt conversion opportunities for marine conservation

Incentivized debt conversion is a financing mechanism that can assist countries with a heavy debt burden to bolster their long-term domestic investment in nature conservation. The Nature Conservancy, an international conservation-based nongovernmental organization, is adapting debt conversions to support marine conservation efforts by small island developing states and coastal countries. Prioritizing debt conversion opportunities according to their potential return on investment can increase the impact and effectiveness of this finance mechanism. We developed guidance on how to do so with a decision-support approach that relies on a novel threat-based adaptation of cost-effectiveness analysis. We constructed scenarios by varying parameters of the approach, including enabling conditions, expected benefits, and threat classifications. Incorporating both abatable and unabatable threats affected priorities across planning scenarios. Similarly, differences in scenario construction resulted in unique solution sets for top priorities. We show how environmental organizations, private entities, and investment banks can adopt structured prioritization frameworks for making decisions about conservation finance investments, such as debt conversions. Our guidance can accommodate a suite of social, ecological, and economic considerations, making the approach broadly applicable to other conservation finance mechanisms or investment strategies that seek to establish a transparent process for return-on-investment decision-making.     

Women's experiences across disasters: a study of two towns in Texas,United States

Gender, although gaining attention, remains under-researched in disaster risk reduction protocols and response and recovery efforts. This study examines women's experiences of two disasters in small towns in the United States, utilising qualitative interviews with residents of Granbury and West, Texas, during the first year of disaster recovery. Granbury was struck by an EF-4 tornado on 15 May 2013, whereas an explosion occurred at a local fertiliser facility in West on 17 April 2013. The paper explores how women's experiences of inter-gender power dynamics in decision-making, the prioritisation of childcare, and women's participation in the community affect their post-disaster recovery. Previous research highlights different forms of human response and recovery vis-à-vis ‘natural’ and technological disasters, with less attention paid to gender differences. The results point to the persistent, and similar, effect of gender stratification on women's experiences across different types of disasters in the US and the continued importance of gender-sensitive disaster policies and programmes.     

Assessment of imposex and butyltin concentrations in Gemophos viverratus (Kiener, 1834), from São Vicente,Republic of Cabo Verde (Africa)

This work constitutes the first assessment of tributyltin (TBT) pollution levels in the Republic of Cabo Verde (Africa) and proposes the marine gastropod Gemophos viverratus (Kiener, 1834) as a new bioindicator of TBT pollution in the Macaronesia and west coast of Africa. Specimens were collected between August and October 2012 along a gradient of naval traffic in São Vicente Island. The results clearly indicate an increase of imposex levels (percentage of females affected with imposex, 0–100 %; vas deferens sequence index, 0–4.1; relative penis length index, 0–54.6 %) and female TBT contamination (from 5 to 37 ngSn g^?1 dry weight (dw)) from outside to inside the harbour of Porto Grande Bay and identify this area as the focus of TBT pollution in the island. The butyltin degradation index for G. viverratus tissues ranged between 1.3 and 2.2, which being above 1 suggests that a considerable part of TBT inputs to the bay may not be very recent. Sterile females were found inside the harbour with an incidence up to 21.4 %. Considering the existence of a planktonic veliger stage in the life cycle of G. viverratus, it is expected that recruitment of newborn individuals can be supplied from unaffected breeding females inside and outside the Porto Grande Bay, resulting in a reduced impact of TBT pollution on population abundance. G. viverratus is very promising to be used as a simple, inexpensive and efficient novel tool for TBT pollution biomonitoring in the Macaronesia and west coast of Africa, a region for which there is an astonishing lack of information concerning levels and ecological impacts of TBT pollution.