Suresh Muthukrishnan

Trail User Demographics, Physical Activity Behaviors, and Perceptions of a Newly Constructed Greenway Trail

To better understand and promote physical activity on a newly constructed trail, the present study examined the demographic characteristics and physical activity behaviors of trail users; the demographic characteristics of trail users compared to the demographic profile Greenville County, South Carolina residents; trail users’ purpose for using the trail; the distance trail users traveled to access the trail from their homes; channels through which trail users learned about the trail; and trail characteristics liked by trail users. Using a valid and reliable intercept survey, 1,148 trail users were interviewed. Trail users were mostly white (93.1%), male (59.1%) adults (84.2%) who reported using the trail for exercise (91%). Significant associations were identified between trail user demographic characteristics and how trail users learned about the trail and trail characteristics liked by trail users. The findings may contribute to the development of targeted health promotion efforts to promote physical activity on this and similar trails.

Chapter 24 Relations among land cover, vegetation index, and nitrate concentrations in streams of the Enoree River Basin, piedmont region of South Carolina, USA

Abstract Globally, high nitrate concentrations and fluxes in rivers are correlated with human population density and can lead to eutrophication of estuaries and coastal oceans. Although elevated nitrate concentrations often are associated with agricultural land cover, urban land cover also can contribute substantially to elevated nitrate concentrations in streams and rivers. In the piedmont region of the southeastern United States, urban areas typically are located in the headwater areas of watersheds. Because headwaters account for the majority of stream channel length in a watershed, the effect of urbanization on the biogeochemical cycling of nitrogen is magnified. We examined the relations between stream nitrate concentrations, land cover, and vegetation density in watersheds of nineteen tributaries of the Enoree River in northwestern South Carolina, USA. Based on data from 134 sample localities, stream nitrate concentrations generally increased with increasing urban land cover and decreased with increasing forest cover and vegetation density (normalized density vegetation index). Although watersheds with the highest percent urban land cover typically had the highest nitrate concentrations, nitrate concentrations were most variable spatially in drainage basins with 5 to 20% urban land cover. The relations between land cover, vegetation density, and nitrate concentrations are complicated by variation in the intensity of urbanization and spatial location of urban and forested land within the drainage basin of each sample locality. Artificial ponds in urban areas appear to play an important role in lowering stream nitrate concentrations and contribute to the spatial variability of nitrate concentrations.

Relationships between Dry Deposition of Ions and Urban Land Cover in the South Carolina Piedmont

Atmospheric deposition can be an important source of ions to terrestrial and aquatic ecosystems. Previous studies have indicated that dry deposition of ions in and near large cities is greater than in nearby rural areas. However, few studies have compared dry deposition in and near smaller cities. We measured dry deposition of ions at various distances from Greenville, a smaller city in the piedmont of northwestern South Carolina. Dry deposition was estimated by exposure of artificial surfaces (glass Petri plates and paper filters) to the atmosphere at 13 locations during June–July 2008. Petri plates were expected to collect dust particles primarily, whereas filters were expected to collect both dust and gases. Fluxes measured by filters were significantly greater than those measured by Petri plates for nitrate and ammonium, suggesting that dry deposition of nitrogen in gases exceeded dry deposition in dust. Dry deposition of ammonium and nitrate declined significantly with distance from Greenville, and rates were significantly higher at urban than at rural locations. Also, dry deposition rates of ammonium correlated positively with road densities and traffic volumes around sampling locations, suggesting that automobiles were important sources of ammonia gas. Relationships between ammonium deposition and urban land cover and roads were stronger than for nitrate deposition, perhaps reflecting the influence of automobiles using catalytic converters. Base cation concentrations in dry deposition typically were below detection, precluding flux calculations. Overall, our results provide evidence that smaller cities influence atmospheric deposition of nitrogen, though perhaps not as strongly as larger cities.