The Suburbanization of Food Insecurity: An Analysis of Projected Trends in the Atlanta Metropolitan Area

Although general patterns of food insecurity in the United States are known, few studies have attempted to estimate small area food security or account for ongoing socioeconomic changes. Here we address these issues by producing small area estimates of food insecurity in the Atlanta metropolitan area using two methodologies: fixed effects modeling and demographic metabolism. In both cases, we use county-level data from the Current Population Survey to determine the association between food insecurity and demographic predictors. These associations are then applied to tract-level data from the 2009 to 2013 American Community Survey and projected data for 2020 to create small area estimates of food insecurity. We find broad consensus between our two methods. For both time periods, food insecurity is highest in southern sections of the city of Atlanta and its neighboring suburbs. Projections to 2020, however, show that food insecurity rates are projected to increase in outer-ring suburbs east and west of the city while decreasing in the urban core. These results highlight the need to further adapt antihunger efforts for often sprawling suburban communities, where poverty rates are increasing but spatial mismatch combined with poor transit access might hinder access to food assistance.     

Calibration of Shallow Borehole Drilling Sites Using the Electrical Resistivity Imaging Technique in the Granitoids of Central Region,Ghana

The electrical resistivity imaging (ERI) technique has been used to calibrate existing successful and dry borehole drilling locations in the Cape Coast Granitoid Complex of the Central Region of Ghana. The area has a low groundwater potential and most of the communities do not have access to potable water. Surface water is generally expensive to treat and is therefore not considered as a good water supply option in such rural and dispersed communities where incomes are low. Supply of water to communities from existing boreholes is inadequate. Therefore, there was the need to construct more boreholes to increase access to potable water to meet coverage targets. Results show that the ERI technique is capable of detecting shallow bowl-shaped conductive zones up to 75 m represented by low resistivity values mainly due to weathered granitoids and/or fractures within the granitoids. Resistivity values typically less than 500 Ω-m obtained between depths of 10–50 m on model resistivity sections accounted for about 80% of successful productive boreholes. Resistivity values in the range 500–1,500 Ω-m represented marginally successful borehole locations which could be suitable for hand-pump installation and values greater than 1,500 Ω-m were confirmation for dry borehole locations.     

A hierarchical approach measures the aerial extent and concentration levels of PAH-contaminated shoreline sediments at historic industrial sites in Prince William Sound, Alaska

A field study was conducted in 2003 to estimate the areal distribution and concentrations of polycyclic aromatic hydrocarbons (PAH) in intertidal sediments at sites of past human and industrial activity (HA sites) in Prince William Sound (PWS), Alaska, the site of the 1989 Exxon Valdez oil spill. More than 50 HA sites, primarily in western PWS, were identified through analysis of historic records and prior field studies, and nine sites were selected for detailed surveys. The areal assessment process consisted of seven steps: (1) identify site from historic records and field surveys; (2) locate visual evidence of surface oil/tar at a site; (3) prepare a site map and lay out a sampling grid over the entire site with 10-m grid spacing; (4) excavate pits to 50 cm depth on the grid; (5) perform a field colorimetric test to estimate total PAH (TPAH) in sediments from the wall of each pit and record the results in the ranges <1 ppm; 1-10 ppm; >10 ppm TPAH; (6) expand grid size if necessary if elevated PAH levels are detected colorimetrically; (7) select 20 samples from each site for same-day shipboard PAH analysis by immunoassay (SDI RaPID PAH) and, based on these results, select sediment samples from each site for full PAH analysis in the laboratory to identify PAH sources. A total of 416 pits were dug at the nine sites. Nine acres of sediments with TPAH >2500 ppb dry wt. were mapped at the nine sites. TPAH concentrations obtained by immunochemical analysis of 181 samples from the nine sites ranged from 20 to 1,320,000 ppb (wet wt.). The contaminants are mixtures of petroleum products (2-3 ring PAH) and combustion products (4-6 ring PAH) unrelated to the 1989 Exxon Valdez oil spill. Mussels and clams collected at these sites have elevated levels of PAH that are compositionally similar to the PAH in the sediments. These findings indicate that at least a portion of the sediment PAH is bioavailable. The PAH sources at these historic industrial sites are chronic. They include relict fuel oil tanks and works located above and within the intertidal zone, with contamination at some locations extending into nearshore sub-tidal sediments. This study shows how a hierarchical approach can be used to quickly and successfully map, quantify, and subsequently, identify sources of PAH in shoreline sediments.     

Assessment of gold mineralisation in Osu–Amuta–Itagunmodi areas,Southwestern Nigeria

Tight conglomerate reservoirs have complex pore structure and strong heterogeneity which could bring great difficulties in the identification of oil and wa     

Sheet flow in a salt-marsh basin,North Inlet,South Carolina

The magnitude of sheet flow in a small South Carolina salt marsh was evaluated by comparing the storage curve for the basin based on topographic data with that based on current measurements in the main channel. The results indicate that on spring tides more than 50% of the volume of water that enters the basin enters as sheet flow over the grassy flats of the marsh. The current data also suggest that the actual storage curve may be a hysteresis loop with separate flood and ebb segments.     

SEDIMENT DAMAGES AND RECENT TRENDS IN THE UNITED STATES

lINTRODUCTIONWeoftenhavethepercepti0nthatsedimentisthebr0wnishoryell0wishcoloringinrunoffwater,thatlooksunpleasant,buteventually"g0esaway,"downstream,unseen.Butsedimentisn0tonlyaestheticallyunpleasant,itisalsoacarrierofpotentialchemicalc0ntaminants,fillsupwaterb0dies,andcausesphysicaldamaget0farmland,wildlife,andwatertreatmentsystemsandpowergenefat0rs.ThepurposeofthispaPeristoprovidean0verallperspectiveonthemagnitudeandtrendsofsedimelltasap0llutritintheUnitedStates.2CURRENTKNOWLEDG…