Forested watersheds in the Southeastern U.S. provide high quality water vital to ecosystem integrity and downstream aquatic resources. Excessive sediment from human activities in forested watersheds is of concern to responsible land managers. Prescribed fire is a common treatment applied to Southeastern Piedmont forests and is becoming increasingly important under the threat of higher fuel loads, and higher intensity storm events from changing land uses and climate. Several studies have been conducted to evaluate the impacts of fire on sedimentation processes with conflicting conclusions. Measuring the amount of runoff and erosion from fire-induced forested watersheds is difficult due to the high variability inherent in these systems. Erosion simulation models assist in relieving the time and resources consumed measuring these effects. The process-based Water Erosion Prediction Project (GeoWEPP) is widely used in the Western U.S. to predict erosion resulting from forest fires, but has yet to be tested in Southeastern Piedmont settings. The objective of this study was to evaluate the effectiveness of the GeoWEPP model in predicting sediment amounts from low-, moderate- and high-intensity forest fires on pine stands of the Sumter National Forest in the piedmont region of South Carolina. GeoWEPP simulation results were compared to observed sediment production from two ongoing prescribed burn studies in the Enoree and Long Cane Ranger Districts. Erosion measurements were conducted using 48 silt fences placed on hillslopes within 22 x 22 m plots. The measurements were collected biennially following low- and high-intensity prescribed burnings of the forested plots. The annual observed erosion amounts averaged 0.014 and 0.022-kg/m (width) for the Enoree and Long Cane sites respectively. Modeling results from the simulations of the same sites averaged 1.94-kg/m width of fence and 0.55-kg/m (width) annually. The model largely over predicted the amounts of erosion at these low levels. However, the average observed erosion amounts and average GeoWEPP predictions of 0.01 t/ac/yr were well below the tolerable soil loss value (T-value) of 0.41 t/ac/yr during the unburned, low-, and high-intensity forest fire conditions of the treatments. Predicted erosion exceeded this value only for high-intensity fires followed by high-intensity storm events (>20-yr return periods). These results suggest that low-intensity fires may not elevate sediment loading above tolerable rates; however, higher-severity fires can cause soil erosion and sediment loading at levels of concern in water quality degradation. Land topography, fire intensity and soil surface texture type are key variables to predicting soil erosion and runoff. We conclude that this model may be a useful tool to land managers for evaluating and predicting the effects of fire on erosion following forest fires. This study is the first to evaluate the effectiveness of the GeoWEPP model in predicting runoff and sedimentation in Southeastern piedmont watersheds. From this initial testing, recommendations were made to improve the model for applications in the Southeast.

We investigated techniques to discriminate long leaf pine (Pinus palustris) and loblolly pine (Pinus taeda) in 126 band HyMap imagery with a 4 meter spatial resolution. Field assessment provided stand composition information, and crowns of known species were selected in the imagery to represent species types for model construction. A Quadratic Discriminant Analysis used with a likelihood ratio test was able to identify southern yellow pine with a producerâs accuracy of 98% and a userâs accuracy of 96%. The same test identified loblolly pine with a producerâs accuracy of 80% and a userâs accuracy of 49%. Longleaf pine identification had a producerâs accuracy of 60% and a userâs accuracy of 76%. Price of image acquisition, the relatively low accuracy of discrimination between longleaf and loblolly pine crowns, and inherent bias in the approach make this particular method unreliable as an option for targeting potential sites for RCW habitat restoration.

Culverts and bridges are necessary in order to cross waterways during road construction. However, these structures have detrimental affects on the hydrology and ecology of the streams they cross. The objective of this study was to investigate how these bridges and culverts alter stream hydrology and geomorphology by determining the effects on the upstream and downstream reaches of a road crossing on the cross sectional area, the hyporheic depth, on riffle habitat, and substrate types. Three types of culverts (arch, box, and pipe) and small bridges were evaluated. All four types of stream crossings were determined to increase the cross sectional area downstream of the structure. Crossing structures also affected hyporheic zone depths by decreasing average depths downstream of the structure. Finally, most mussels seemed to occur in substrates that were dominated by relatively large particles (gravel and cobble) that were less movable by sheer stress during higher flows. Each of the problems discovered with these structures is a result of the channel restriction and the increased flow velocity and turbulence scour that it creates. These detrimental conditions can be mitigated by providing for floodplain access for higher flows. It is recommended that culverts be designed for low flows and high flows. Oversizing culverts, compared to current design criteria will allow floodplain access and build bankfull benches in the extra openings to restrict low flows to a few openings. The use of bridges that span across the valley limiting fill and allowing floodplain access may even be more beneficial. When valley fill is necessary, then side culverts in the floodplain may alleviate degradation and allow more natural floodplain hydrology.

Conservation and human rights are currently threatened by direct and indirect effects of border enforcement practices on the Arizona-Sonora border. Increased border enforcement in urban areas has pushed migrants into remote conservation areas, threatening both the vulnerable borderland ecosystems and the human migrants passing through them. This study examines responses to human and environmental impacts of border policies in the case study region of Altar Valley in southern Arizona, where migrant traffic has increased greatly as a result of the expanded border enforcement near urban centers. We use ethnographic methods to explore and understand the actions of land-management and humanitarian aid groups attempting to address the socio-ecological crises wrought by increased border enforcement, in order to look for ways to reduce the crises through a better understanding of the context. Community partners include the Buenos Aires National Wildlife Refuge, the Coronado National Forest, and the No More Deaths humanitarian aid group, all located within 25 miles of the Arizona-Sonora border. The results of this study, carried out largely during the summer of 2008, describe how the actions of land-management and humanitarian groups eventually conflicted and resulted in littering citations for the humanitarian aid volunteers who left water for migrants along trails on the wildlife refuge. The conflict was branded as an issue of conservation versus human rights. I argue that the conflict between land-management personnel and humanitarian aid volunteers arose not just from differing conservation and humanitarian goals, but from their different conceptions of problems associated with border activity and different ideas of the borderlands as a place.

Polycyclic aromatic hydrocarbon (PAH) bioavailability does not correlate directly with total PAH sediment concentration because PAHs strongly sorb to organic matter. Many current toxicological models assume that PAHs present in the dissolved phase reflect actual PAH bioavailability to organisms. Plants can release significant amounts of plant organic matter (POM) to soils and sediments; however, the mechanisms by which POM may affect PAH bioavailability in sediments are unclear. The rhizosphere may increase PAH bioavailability by destabilizing soil organic matter (SOM) and enhancing PAH desorption, or the rhizosphere may alter SOM composition and provide new carbon matrices to sorb/sequester PAHs and reduce PAH desorption. Desorption studies were conducted to determine if vegetation decreased or increased the rate and mass amounts of desorbable PAHs. Replicate desorption studies were conducted using vegetated and non-vegetated bulk sediment and HF/HCl humin fractions; sediments were collected from a coastal refinery distillate waste pit (RP) and refinery-impacted sediments from a freshwater canal (IH). Desorption isotherms for four PAHs were determined by two methods, aqueous and TenaxTM bead extractions. PAHs were quantified by gas chromatography/mass spectrometry selected ion monitoring (GC/MS SIM). Results showed differences in PAH desorption based on the amount of time vegetation had been present in sediments. Vegetated sediments with 30+ years of vegetative growth (RP) desorbed more PAHs than non-vegetated sediments by TenaxTM extraction in both bulk and humin sediment fractions. Recently vegetated, IH freshwater sediments desorbed fewer PAHs than non-vegetated IH sediments by aqueous and TenaxTM extractions in bulk and humin sediment fractions. These findings suggest that initial exposure of sediment to vegetation slows PAH desorption and that extensive exposure to vegetation enhances PAH desorption from both labile and refractory SOM.

<P>ESSIC, JEFFERSON FORREST. Applications of Geographic InformationSystems for Growth Management Planning and Water Quality Protection inthe Coastal Region of North Carolina. (Under the direction of Hugh A. Devine.)<P>Research efforts conducted in coastal areas of North Carolina andother regions have documented numerous examples of negative impacts toestuarine water quality as a result of unplanned and unmanaged development.However, new construction is continuing at a rapid pace in these areas,forcing local planners to make complex decisions regarding land uses andprotection of cultural and natural resources.<P>A Geographic Information System (GIS) is a computer-driven toolthat has proven valuable in assisting with this decision making process.GIS technology provides the means to efficiently collect, store, and retrievevast amounts of spatial data. Then, this information may be visually displayedin a manner that supports better understanding and analysis of the physicalenvironment and the potential impacts of growth.<P>There have been many instances during the past decade in whichGIS has been used to meet the educational and informational needs of citizensand local officials who want to ensure a strong economy and healthy environmentis planned for the future of their community. Most of these projects haveoriginated at the state level, either through the North Carolina CooperativeExtension Service, or other agencies.<P>A number of zoning options and growth management planning measureshave recently been recommended that coastal government officials shouldconsider for promoting stewardship and protecting important natural resourceswhile continuing to maintain economic vitality. This paper focuses on theapplication of GIS for analyzing and implementing many of those strategieswith emphasis on local responsibility.<P>In particular, the natural suitability of cluster development forCurrituck County, North Carolina, is examined with GIS. Attention to growthmanagement planning in this coastal county is critical since the populationis projected to increase over 73 percent from 1990 to 2020. GIS data layersfrom the North Carolina Center for Geographic Information and Analysis,as well as digitized Federal Emergency Management Agency Flood InsuranceRate Maps, are used to determine the extent of Primary Conservation Areasin the county. In addition, Secondary Conservation Areas are identified

<p>In recent years, mapping software utilizing scanned?or ?softcopy??aerial photographs has become widely available. Using scanned photos of Valley Forge (PA) National Historical Park, I explored some of the latest tools for image processing and computer-based vegetation mapping. My primary objective was to compare different approaches for their efficiency and accuracy. In keeping with the USGS-NPS Vegetation Mapping Program protocol, I classified the park?s vegetation according to The Nature Conservancy?s National Vegetation Classification System (NVCS).<p>Initially, I scanned forty-nine 1:6000 color-infrared air photos of the area at 600 dpi using an Epson desktop scanner. I orthorectified the images by two different methods. First, I did so on a single-image basis using ERDAS Imagine. In this approach, United States Geological Survey (USGS) Digital Ortho Quarter Quadrangles (DOQQ) and a 10-meter Digital Elevation Model (DEM) served as references for between seven and twelve ground control points per photo. After achieving a root mean square error (RMSE) of less than 1 meter for an image, I resampled it into an orthophoto. I then repeated the process using Imagine Orthobase. Via aerial triangulation, Orthobase generated an RMSE solution for the entire block of images, which I resampled into orthophotos using a batch process. <p> Positional accuracies were remarkably similar for image mosaics I created from the single-image as well as the Orthobase orthophotos. For both mosaics, planimetric x-coordinate accuracy met the U.S. National Map Accuracy Standard for Class 1 maps, while planimetric y-coordinate accuracy met the Class 2 standard. However, the Orthobase method is faster?reducing process time by 50%?and requires 20% (or less) of the ground control points necessary for the single-image method.<p>I delineated the park?s vegetation to the formation level of the NVCS. Using ESRI ArcMap, I digitized polygons of homogeneous areas observed from the orthophotos. This on-screen mapping approach was largely monoscopic, though I verified some areas using a scanning stereoscope and the original hard-copy photos. The minimum mapping unit (MMU) was 0.5 acres (ac), smaller than that recommended by the USGS-NPS protocol. Based on field data, thematic accuracy for this map met the National Map Accuracy Standard of 80%. Misestimation of the hydrologic period of certain polygons resulted in some classification errors, as did confusion between evergreen and deciduous vegetation. <p>In addition to orthophotos, Orthobase creates a stereo block viewable in ERDAS Stereo Analyst, a digital stereoscopic software package. Using Crystal Eyes? eyewear and a high-refresh-rate monitor, a user can observe imagery full screen, three-dimensionally. Features delineated on the images are stored in ESRI shapefile format. I created a preliminary vegetation map at the alliance level of the NVCS with this software. Thematic accuracy of this map will be known when assessment is completed this summer. Notably, the classification scheme has required revision to accommodate the anthropogenically altered landscape of Valley Forge. <p>Nevertheless, it is clear that Stereo Analyst offers advantages for vegetation and other types of mapping. Stereoscopic view and sharp zoom-in capabilities make photo interpretation straightforward. Because features are delineated directly into a GIS, Stereo Analyst cuts process time by 70% and avoids two steps that can introduce errors in conventional mapping methods (i.e., transfer to map base and digitizing). Perhaps most importantly, joint use of Orthobase and Stereo Analyst allows simultaneous orthophoto creation and GIS data collection; in contrast, the ArcMap approach requires finished orthophotos before features can be delineated. Ultimately, though, both monoscopic and stereoscopic methods have roles in vegetation mapping projects. The level of detail required for the project should determine which technique is most appropriate. <P>

<p>Conflict between the public interests in non-timber amenities of forests and the private rights of forest owners has focused attention on voluntary conservation agreements as a policy tool. In North Carolina, the Natural Heritage Program identifies ecologically significant sites and provides two mechanisms for landholders to participate in conservation of those sites. Evaluation of the program from a spatial perspective focused on the mountain province of North Carolina, using a geographic information system (GIS) to characterize the conservation outcome of the program (i.e., what has been conserved) and the determinants of participation in the program (i.e., who has conserved). To characterize the participation decision, literature was reviewed on voluntary forest stewardship and conservation programs and spatial analysis of land-use. The effect of neighborhood characteristics (e.g., near-by protected areas) and distance (e.g., from highways and cities) was considered, as well as characteristics of the landowner and of the site. The conservation outcome of the program was evaluated in terms of protection of ecologically significant sites, considering both Heritage Program rankings and land cover.<P>

<p>ABSTRACTHARRELL, MELANI HIX. Development of a digital protocol for vegetation mapping. (Under the direction of Dr. Hugh Devine)Softcopy photogrammetry has proven useful to reduce mapping time with aerial photography and aids in producing a digital product that is easily transferable over other electronic media. This study brings together computer stereo viewing with scanned aerial photos in a GIS to produce a fully digital protocol for mapping vegetation to the formation level. Erdas Imagine was used to generate digital images from aerial photos, Erdas Orthobase was applied to orthorectify the images through a joint triangulation solution for 42 photos, and Erdas StereoAnalyst provided on screen stereo viewing for vegetation delineation. Vegetation polygons were then classified using the National Vegetation Classification System formations in ArcView 3.2, and a thematic accuracy assessment was carried out on the vegetation map using the USGS-NPS standards. A positional accuracy assessment was conducted on the photo mosaic produced from the orthorectified images. Thematic accuracy was 77.55% initially, and the revised map had an 88.70% thematic accuracy. Positionally, the photo mosaic had Class 1 positional accuracy along the X-coordinate with 0.603 meters RMSE and had Class 2 accuracy along the Y-coordinate with 2.415 meters RMSE. A protocol using entirely digital methods was produced with the software cited that meets the formation level USGS-NPS vegetation mapping standards. <P>

The dynamics of propelling a pig through a natural gas pipeline, using the gas being transported, are analyzed. The gas flow is assumed to be isothermal, quasi-steady, and one-dimensional. The pig is modeled as a cylinder. For the cases considered, the pig may either obstruct the pipe and allow no gas to flow past it, or may permit gas to flow through a concentric hole in the pig, through an annulus formed by the pig and the inside of the pipe, or through both. The governing equations which describe the motion of the pig and the flow of gas in the pipe are developed. These equations form a system of nonlinear differential equations which must be solved numerically. Time derivatives are replaced by backward differences, and at each time step a system of nonlinear algebraic equations is solved. A FORTRAN program is included which solves for the important gas flow parameters and the position, velocity, and acceleration of the pig as it moves through the line. ii iii Such a quantitative analysis provides a basis for pig design which could be applied to regulate pig velocities or to increase gas flow rates while the pig is in the line.