Evaluation of the QUIC-URB fast response urban wind model for a cubical building array and wide building street canyon

This paper describes the QUIC-URB fast response urban wind modeling tool and evaluates it against wind tunnel data for a 7 × 11 cubical building array and wide building street canyon. QUIC-URB is based on the Röckle diagnostic wind modeling strategy that rapidly produces spatially resolved wind fields in urban areas and can be used to drive urban dispersion models. Röckle-type models do not solve transport equations for momentum or energy; rather, they rely heavily on empirical parameterizations and mass conservation. In the model-experiment comparisons, we test two empirical building flow parameterizations within the QUIC-URB model: our implementation of the standard Röckle (SR) algorithms and a set of modified Röckle (MR) algorithms. The MR model attempts to build on the strengths of the SR model and introduces additional physically based, but simple parameterizations that significantly improve the results in most regions of the flow for both test cases. The MR model produces vortices in front of buildings, on rooftops and within street canyons that have velocities that compare much more favorably to the experimental results. We expect that these improvements in the wind field will result in improved dispersion calculations in built environments.     

Natural and anthropogenic geochemical signatures of floodplain and deltaic sedimentary strata, Sacramento-San Joaquin Delta, California, USA

The geochemical history of an upper deltaic plain pending tidal wetland restoration was reconstructed to assess remobilization of redox-sensitive constituents in sediment, identify depositional processes promoting geochemical retention, and determine the extent of contamination with Hg, As, Pb, Cu, and Zn. Three 12-14-m sediment cores were analyzed for bulk sediment geochemistry using ICP-AES. Rather than showing similar stratigraphic and geochemical down-core trends, cores had a unique record indicative of strong spatial gradients in deposition processes. Each strata type (e.g. basal clay, sand channel, distal floodplain, and agriculturally impacted surficial horizon) had a unique geochemical "fingerprint". The agriculturally impacted surficial layer showed high [Hg], [As], and [Pb]. The significance is that a restored upper delta will have a complex geomorphology defying conventional criteria of "success" in a restoration framework. Also, there is a significant risk of generating toxic, bio-available CH3Hg+ that would be hazardous to fish.     

Patterns and inventories of radioactive contamination of island sites of the Yenisey River, Russia

The distribution of radioactive contamination at three island sites downstream from the Krasnoyarsk Mining and Chemical Combine (KMCC) was studied with the objectives of mapping contamination levels, interpreting radionuclide distributions through consideration of alluvial processes and determining radionuclide inventories. Contamination was measured using in situ gamma spectrometry and landforms characterised using topographic surveying methods. Maximum (137)Cs contamination densities (700 kBq m(-2)) were found on low- and middle-level floodplains and low-lying interconnecting areas of Beriozovy Island (16 km from the KMCC). On Mikhin Island (180 km from the KMCC) maximum total (60)Co, (152)Eu and (154)Eu activity concentrations (30-40 kBq m(-2)) occur in low-lying areas inundated during flooding. Maximum (137)Cs and total (60)Co, (152)Eu and (154)Eu contamination densities on Cheriomukhov Island (250 km from the KMCC) were 390 and 50 kBq m(-2), respectively. Estimated (137)Cs inventories were 145, 148 and 16GBq for Beriozovy, Mikhin and Cheriomukhov Islands, respectively.     

Detection and Classification of Motor Vehicle Noise in a Forested Landscape

Noise emanating from human activity has become a common addition to natural soundscapes and has the potential to harm wildlife and erode human enjoyment of nature. In particular, motor vehicles traveling along roads and trails produce high levels of both chronic and intermittent noise, eliciting varied responses from a wide range of animal species. Anthropogenic noise is especially conspicuous in natural areas where ambient background sound levels are low. In this article, we present an acoustic method to detect and analyze motor vehicle noise. Our approach uses inexpensive consumer products to record sound, sound analysis software to automatically detect sound events within continuous recordings and measure their acoustic properties, and statistical classification methods to categorize sound events. We describe an application of this approach to detect motor vehicle noise on paved, gravel, and natural-surface roads, and off-road vehicle trails in 36 sites distributed throughout a national forest in the Sierra Nevada, CA, USA. These low-cost, unobtrusive methods can be used by scientists and managers to detect anthropogenic noise events for many potential applications, including ecological research, transportation and recreation planning, and natural resource management.     

Revegetation of high zinc and lead tailings with municipal biosolids and lime: greenhouse study

Acidic (pH 4.1) and high Cd, Pb, and Zn mine tailings (mean +/- SD: 17 +/- 0.4, 3800 +/- 100, and 3500 +/- 100 mg kg(-1), respectively) from an alluvial tailings deposit in Leadville, Colorado were amended with municipal biosolids (BS) (224 Mg ha(-1)) and different types of lime (calcium carbonate equivalent of 224 Mg ha(-1) CaCO3) in a greenhouse column study to test the ability of the amendments to neutralize surface and subsoil acidity and restore plant growth. The types of lime included coarse, agricultural, and fine-textured lime (CL, AL, and FL), sugar beet lime (SBL), and lime kiln dust (LK). The FL was also added alone. All treatments increased bulk pH in the amended horizon in comparison to the control, with the most significant increases observed in the FL, SBL+BS, and LK+BS treatments (7.33, 7.34, and 7.63, respectively). All treatments, excluding the FL, increased the pH in the horizon directly below the amended layer, with the most significant increases observed in the SBL+BS and LK+BS treatments (6.01 and 5.41, respectively). Significant decreases in 0.01 M Ca(NO3)2-extractable Zn and Cd were observed in the subsoil for all treatments that included BS, with the largest decrease in the SBL+BS treatment (344 and 3.9 versus 4 and 0.1 mg kg(-1) Zn and Cd, respectively). Plant growth of annual rye (Lolium multiflorum L.) was vigorous in all treatments that included BS with plant Zn, Cd, and Pb concentrations reduced over the control.     

Risk assessment of unsuitable winter conditions for manure and nutrient application across Ontario

Practical guidelines addressing the timing of manure and nutrient application must consider the concerns of the farm operators while ensuring the protection of the environment. An approach was developed and analyzed through case studies to determine the first recommended day in the spring, and the last in the fall, for manure and nutrient application based on probability analysis. Since most manure and nutrient application guidelines recommend avoiding adverse conditions, the three criteria established to perform a risk assessment were: (i) a frost depth greater than 0.05 m; (ii) a snow accumulation of greater than 0.05 m; and (iii) a soil volumetric water content greater than or equal to that of the plastic limit for the soil. Climatic data and typical soil information for seven locations in Ontario were used to model volumetric soil water contents, frost depths, and snow accumulation from the simultaneous heat and water (SHAW) model for a 48-yr period (1954-2001). Applying the three criteria to the modeled output, the average range between the least limiting probability (0.1, or one in ten year occurrence) and the greatest limiting probability (0.001, or one in one thousand year occurrence) analyzed among the locations was 16 d in the spring as compared to 29 d in the fall. Although geographical location affected the predicted spring start and fall end recommended manure and nutrient application dates, local climate and soil hydraulic properties also played an important part in the determination of these days. Overall the prediction method developed performed reasonably well and provided insight into the environmental factors influencing manure and nutrient application timing.     

Gasoline prices and traffic crashes in alabama, 1999-2009

Objective: The price of gasoline has been found to be negatively associated with traffic crashes in a limited number of studies. However, most of the studies have focused either on fatal crashes only or on all crashes but measured over a very short time period. In this study, we examine gasoline price effects on all traffic crashes by demographic groups in the state of Alabama from 1999 to 2009. Methods: Using negative binomial regression techniques to examine monthly data from 1999 to 2009 in the state of Alabama, we estimate the effects of changes in gasoline price on changes in automobile crashes. We also examine how these effects differ by age group (16-20, 21-25, 26-30, 31-64, and 65+), gender (male and female), and race/ethnicity (non-Hispanic white, non-Hispanic black, and Hispanic). Results: The results show that gasoline prices have both short-term and long-term effects on reducing total traffic crashes and crashes of each age, gender, and race/ethnicity group (except Hispanic due to data limitations). The short-term and long-term effects are not statistically different for each individual demographic group. Gasoline prices have a stronger effect in reducing crashes involving drivers aged 16 to 20 than crashes involving drivers aged 31 to 64 and 65+ in the short term; the effects, however, are not statistically different across other demographic groups. Conclusions: Although gasoline price increases are not favored, our findings show that gasoline price increases (or decreases) are associated with reductions (or increases) in the incidence of traffic crashes. If gasoline prices had remained at the 1999 level of $1.41 from 1999 to 2009, applying the estimated elasticities would result in a predicted increase in total crashes of 169,492 (or 11.3%) from the actual number of crashes. If decision makers wish to reduce traffic crashes, increasing gasoline taxes is a possible option-however, doing so would increase travel costs and lead to equity concerns. These findings may help to shape transportation safety planning and policy making.     

Ecotoxicological responses to chalcopyrite exposure in a proxy for deep-sea hydrothermal vent shrimp: implications for seafloor massive sulphide mining

Deep-sea mineral prospecting has raised concerns regarding potential ecotoxicological impacts of deep-sea mineral extraction. Although metal mineral phases are predicted to exhibit low bioavailability, few data explore the relative toxicity of mineral phases and dissolved constituent metals. Acute 96?h chalcopyrite (CuFeS₂) (<250?µm grain size) exposures using the shallow-water ecophysiological model organism Palaemon varians as an ecotoxicological proxy for deep-sea hydrothermal vent shrimp revealed no effect in both lethal and sublethal assays up to 2.888?g?L^?1, suggesting that chalcopyrite is not bioavailable. Deep-sea species, therefore, appear at greater ecotoxicological risk from dissolved metals during seafloor massive sulphide (SMS) mining. Consequently, an approach combining modelling the release, and spatial and temporal dilution of dissolved metals during SMS mining, with data on sublethal effects of dissolved metals on shallow-water proxies, may best constrain the potential ecotoxicological impacts of SMS mining, and deliver ecotoxicological threshold concentrations for active SMS extraction.