Eugene O'Neill Theater Center

Polybrominated diphenyl ethers (PBDEs) have been recognised as persistent organic pollutants (POPs) and are also among chemicals classified as endocrine-disrupting compounds (EDCs) which interfere with the endocrine system and disrupt the physiological function of hormones in animals and humans alike. This study determined the concentrations of six PBDE congeners (BDE 47, BDE 99, BDE 100, BDE 153, BDE 154 and BDE 183) in water and sediment samples from River Benue, in the Makurdi Metropolitan Area in North Central Nigeria using gas chromatograghmass spectrometer. These congeners are components of the penta-and octaBDE formulations that have been banned by the European Union. The samples were collected from the River, bimonthly, for one year across dry and wet seasons. All the congeners considered were found to be present in both water and sediment. The levels of 6 PBDEs in water ranged from 0.02 -0.11 ngL _1 during dry season and 0.10 -0.76 ngL _1 during wet season while the concentrations in sediment during dry and wet seasons ranged from 4.65 -26.74 ngg _1 and 4.40 -17.15 ngg _1 respectively. The percentage recoveries from solid phase and Soxhlet extractions ranged from 68 -111 % and 71 -109 % respectively. It was concluded that the presence of all the congeners in both water and sediment coupled with their established environmental persistence and bioaccumulation posed a pollution risk to the river which requires further monitoring and preventive measures to be taken.

In mountainous areas, cold air drainage from high to low elevations has pronounced effects on local temperature, which is a critical driver of many ecosystem processes, including carbon uptake and storage. Here, we leverage new approaches for interpreting ecosystem carbon flux observations in complex terrain to quantify the links between macro-climate condition, drainage flows, local microclimate, and ecosystem carbon cycling in a southern Appalachian valley. Data from multiple long-running climate stations and multiple eddy covariance flux towers are combined with simple models for ecosystem carbon fluxes. We show that cold air drainage into the valley suppresses local temperature by several degrees at night and for several hours before and after sunset, leading to reductions in growing season respiration on the order of ~8%. As a result, we estimate that drainage flows increase growing season and annual net carbon uptake in the valley by >10% and >15%, respectively, via effects on microclimate that are not be adequately represented in regional- and global-scale terrestrial ecosystem models. Analyses driven by chamber-based estimates of soil and plant respiration reveal cold air drainage effects on ecosystem respiration are dominated by reductions to the respiration of aboveground biomass. We further show that cold air drainage proceeds more readily when cloud cover and humidity are low, resulting in the greatest enhancements to net carbon uptake in the valley under clear, cloud-free (i.e., drought-like) conditions. This is a counterintuitive result that is neither observed nor predicted outside of the valley, where nocturnal temperature and respiration increase during dry periods. This result should motivate efforts to explore how topographic flows may buffer eco-physiological processes from macroscale climate change.

A methodology for incorporating site-specific landscape characteristics into vegetated stream buffer design has been developed. This methodology consists of calculations within a geographic information system format, and applies a sequential accumulation of the contribution of individual pixels of buffer width to overall performance. A demonstration of the application of the methodology to a watershed expecting development is presented here and implications for decision making are discussed. Information layers derived from landscape data layers and used in buffer-performance calculations are displayed. Specific calculations performed in the demonstration are buffer delineation, with implications related to the potential impact of variable versus fixed width buffers, to the impact of assumptions with respect to the type of sediment needing to be settled out, and to the need to mandate wider buffer widths adjacent to lower order streams. Sediment-trapping efficiency calculations can be used to set performance standards and assess the viability of certain criteria in terms of areas potentially available for buffers. The reduction in peak discharges of storm-water runoff (through some combination of infiltration and detention) is becoming a surrogate water-quality parameter for non-point-source pollution in recent total maximum daily load determinations. Infiltration-volume estimation can be used in assessing the feasibility of such a surrogate approach.

Background and Aims: Although cover crops are largely used in vineyards, limited information is available on the amount of water they use. The aim of this study was to quantify cover crop evapotranspiration (ETcc) in the inter-row of a Concord (Vitis labruscana Bailey) vineyard. In addition, the hypothesis that ETcc could be accurately estimated through a relationship with incident solar radiation and reference crop evapotranspiration was tested. Methods and Results: ETcc was measured using mini-lysimeters located across the inter-row of single curtain- and Geneva double curtain-trained vines. Over the course of the study, the ETcc ranged between 0.6 and 2.6 mm/day. ETcc was linearly correlated with a reference crop evapotranspiration adjusted for the solar radiation incident on the vineyard cover crop (r2 = 0.81) in both single curtain and Geneva double curtain. Conclusions: Our results indicate that ETcc under different vineyard canopies is mainly explained by the difference in solar radiation transmitted to the cover crop. Significance of the Study: This study provides new insights on the possibility to estimate ETcc in a vineyard. A more complete energy balance study is needed to test our hypothesis under different environmental conditions.

Abstract Areas of abandoned agricultural land in the Antelope Valley, western Mojave (high) desert of California have proven in our previous studies to be recalcitrant to conventional tillage and revegetation strategies designed to suppress wind erosion of soil and transport of sediment and fugitive dust. These areas represented a continuing source of drifting sand and of coarse and respirable suspended particulate matter. The traditional techniques failed because furrows collapsed and the water holding capacity of the overburden was too low to support seed germination and transplant survival. In this study a variety of wind barriers were evaluated for suppression of sediment transport. Airborne particles were measured with an array of coarse particle samplers at heights of 0.2, 1.0, and 2.0 m above the soil surface. Discrete artificial wind barriers, consisting of widely spaced roughness elements, were effective in suppressing fugitive emissions (>75% at 0.2 m). Wind fences established along the leeward edge of an area of blowing sand, perpendicular to the prevailing wind, significantly decreased fugitive emissions (>90% at 0.2 m). Control was greatest and precision of the measurements was highest under high wind conditions. These techniques provide rapid and effective suppression of fugitive emissions of soil‐derived particles under conditions that resist conventional tillage and revegetation techniques. A simple, indirect procedure for determining local wind velocity erosion thresholds requiring only sampling of wind run and suspended particulate mass compared favorably with direct measurement of saltation as a function of wind velocity.

Letter| February 01, 1983 Strong ground motion record of the 16 September 1978 Tabas, Iran, earthquake D. M. Hadley; D. M. Hadley Sierra Geophysics, Inc.15446 Bell-Red Road, Suite 400Redmond, Washington 98052 Search for other works by this author on: GSW Google Scholar H. G. Hawkins; H. G. Hawkins Southern California Edison2244 Walnut Grove AvenueRosemead, California 91770 Search for other works by this author on: GSW Google Scholar K. L. Benuska K. L. Benuska Kinemetrics222 Vista AvenuePasadena, California 91107 Search for other works by this author on: GSW Google Scholar Author and Article Information D. M. Hadley Sierra Geophysics, Inc.15446 Bell-Red Road, Suite 400Redmond, Washington 98052 H. G. Hawkins Southern California Edison2244 Walnut Grove AvenueRosemead, California 91770 K. L. Benuska Kinemetrics222 Vista AvenuePasadena, California 91107 Publisher: Seismological Society of America Received: 20 Jul 1982 First Online: 03 Mar 2017 Online Issn: 1943-3573 Print Issn: 0037-1106 Copyright © 1983, by the Seismological Society of America Bulletin of the Seismological Society of America (1983) 73 (1): 315–320. https://doi.org/10.1785/BSSA0730010315 Article history Received: 20 Jul 1982 First Online: 03 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation D. M. Hadley, H. G. Hawkins, K. L. Benuska; Strong ground motion record of the 16 September 1978 Tabas, Iran, earthquake. Bulletin of the Seismological Society of America 1983;; 73 (1): 315–320. doi: https://doi.org/10.1785/BSSA0730010315 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyBulletin of the Seismological Society of America Search Advanced Search This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.