In order to extract a drainage network from a LANDSAT scene of mountainous terrain, it is necessary to use an illumination model to separate the reflectance information from the topographic information in the LANDSAT data. From the reflectance information, visible stream segments can be detected. From the topographic information, ridges and valleys can be located and assigned relative elevations by an elevation growing model. Based on these, a complete elevation model can be estimated by interpolating between ridges and valleys and this estimate can be improved by making it consistent with the topographic information. Also the LANDSAT imagery can be reconstructed to evaluate the illumination model. In order to label flow directions of visible stream segments, constraints at junctions based on orientations and lengths are defined and a consistent labeling technique is used. / Ph. D.

The goal of monitoring the water quality of shellfish beds is to provide protection against transmission of water-borne infectious diseases. The Coan River and the Little Wicomico River contain shellfish beds that are closed to harvest due to contamination with fecal bacteria. These two rivers are located in Northumberland County, Virginia, and empty into the lower Potomac River and the Chesapeake Bay. Bacterial source tracking (antibiotic resistance analysis of Eschericia coli) was used to determine the sources of fecal contamination that have caused shellfish harvest closures in these two rivers. A total of 1,248 Eschericia coli isolates were collected from known sources to build a regional library for the rivers. The Virginia Department of Shellfish Sanitation (DSS) and project cooperators collected known source samples from August 2001 to September 2002. The Average Rate of Correct Classification for the known source library was 71.9%, with a total of 930 isolates correctly classified. The categories (and rates of correct classification) were Birds (84.7%), Humans (74.8%), Livestock (72.4%), Pets (62.0%), and Wildlife (65.7%). The library was used to identify the sources of Eschericia coli isolated from DSS sampling stations along the Coan and Little Wicomico Rivers from August 2001 to September 2002. Some stations contained a substantial human signature, while wildlife and birds are also major contributors. The results will be used to decide the necessary changes that need to be addressed if the shellfish harvesting beds are to be reopened. / Master of Science

Typescript (photocopy). / Digitized by Kansas State University Libraries

Elderly recreational vehicle campers are attracted to the Lower Colorado River area during the winter season. Their numbers have grown in recent years and many are seeking alternatives to the usual practice of establishing residence in private trailer parks. As a result, various public land sites in the region are being subjected to concentrated winter use. Units in these camping areas represent users who are retired couples or individuals on fixed or limited incomes, living in "self-contained" campers, travel trailers or motor homes. Some of these visitors are utilizing designated campgrounds; others are squatting on the public domain where there are few, if any, sanitary or other facilities. The impact of elderly winter visitors on the public land resource of the Lower Colorado River basin area is varied. An understanding of environmental effects is important, but proposed solutions depend upon our ability to understand the people causing environmental deterioration. Answers have been sought to basic questions about winter visitor characteristics and behavior. The findings were applied toward the development of basic policy recommendations pertinent to appropriate public land management for the desert areas of the Southwest. Of theoretical interest was the evaluation of the relative importance of camping socialization experiences in explaining user behavior. Data were gathered from 580 visitor units during the winter of 1973-74 with a personal interview schedule. Important classes of variables included socio-economic characteristics, camping experience, and users' campground behavior and preferences. Interviews were conducted in seven sites representing various kinds of public and private camping facilities in the region. Discriminant function, correlational, multiple regression and bivariate analyses were utilized to render the collected data meaningful. The basic sub-groups in the sample were distinguished by significant differences in various socio-economic and experiential characteristics. The most important of these were income, education, age, value of mobile quarters, and pre-retirement adult camping experience. Length of stay in public land camping areas was not explained by differences in site characteristics. Differences in visitor characteristics accounted for 40-50% of variation in length of stay. Important predictor variables included income, age, average annual pre-retirement camping experience and the amount of previous recreational vehicle camping without utility and sewerage hookups. Support was evidenced for a basic theoretical orientation: that post-retirement behavior is, in part, a reflection of pre-retirement recreational socialization and leisure life style patterns and persistence. The results suggested certain implications for public land management. Recommendations include the desirability of moving elderly winter camper use to sites away from the Colorado River. High fees imposed along the river would discourage extended-stay winter use and restore a unique resource to the short-term water-oriented visitor. The establishment of a spectrum of "inland" camping sites with varying levels of facilities and fees would serve as a positive inducement to the older winter camper, and restore some order to what has been, in some areas, an uncontrolled camping environment. A public campground on Bureau of Land Management land in Why, Arizona, offers a possible solution to the problems posed by the limited resources available to most public land management agencies. There a parcel of public land has been leased by a non-profit community association and developed into a public campground with basic facilities for elderly winter visitors. Management expenses are met through the imposition of a modest graduated fee schedule which favors the extended-stay camper. In this case a squatting problem has been resolved through local initiative; the public land management agency, with its limited budget, has been spared the expense of development and that of direct management responsibility.

by Chan Kong Sang. / Thesis (M.Ph.)--Chinese University of Hong Kong, 1986 / Bibliography: leaves 107-110

This study used a geographic information system (GIS) and an empirical pollutant load model to estimate average annual pollutant loads contained in storm water charges from the City of Carrollton, Texas. The Geographic Resource Analyses Support System (GRASS) was used to create a number of spatial data layers as input variables to a model that estimates loads in Kilograms/Hectare/Year, and Kilogram/Basin/Year. Average annual pollutant loads for twelve pollutants were derived from average annual rainfall/runoff volumes, coupled with Local Dallas/Fort Worth Metroplex storm water Event Mean Concentrations.

An example of watershed disturbance activity undertaken to gain access to the oil sands is large scale mining in the Athabasca basin, Alberta, Canada. One of the remedial activities of this disturbance is the reclamation of the disturbed lands. In the process of reclamation, the overburden soil is placed back into the mined pits and reformed with soil covers (alternatively called reconstructed watersheds). In the design process of reclamation, a major concern is hydrological sustainability, which includes the soils ability to store enough moisture for the water requirements of vegetation growth and land-atmospheric moisture fluxes. Typically, the goal of the reclamation is to restore the disturbed watersheds, so that they mimic the natural watersheds in terms of the ecological sustainability. Therefore, a comparative evaluation of the hydrological sustainability of the reconstructed watersheds with natural watersheds is required.<p>The considered reconstructed watershed in this study (the flat top of the South Bison Hill, Fort McMurray, Alberta, which is about 6 years old) constitutes a thin layer of a peat-mineral mix (20 cm thick) overlying an 80 cm thick secondary (glacial till) layer on the shale formation, mimicking the natural soil horizons of undisturbed watersheds. As the reconstructed watershed is located in the boreal forest region, a mature boreal forest (Old Aspen site, about 88 years old) located in the Southern Study Area (SSA), BOREAS, Saskatchewan, Canada, is considered as a representative of natural watershed. The A-horizon with 25 cm of sandy loam texture, the B-horizon with 45 cm-thick sandy clay loam, and the C-horizon with 40 cm of a mixture of sandy clay loam and loam are considered in this study.<p>An existing System Dynamics Watershed (SDW) model (lumped and site-specific) is modified and adapted to model the hydrological processes of the reconstructed and natural watersheds, such as soil moisture, evapotranspiration, and runoff. The models are calibrated and validated on daily time scale using two years data (growing season) in each case. The hydrological processes are simulated reasonably well despite the high complexity involved in the processes of soil moisture dynamics and the evapotranspiration, for both study areas. Using the modified and calibrated models, long term simulations (48 years) are carried out on both the reconstructed and natural watersheds. Vegetation properties are switched between the reconstructed and natural watersheds and two scenarios are generated. Consequently, long term simulations are performed. With the help of a probabilistic approach, the daily soil moisture results are used to address the comparative soil moisture storage capability of the watersheds.<p>The results indicate that the selected reconstructed watershed is able to provide its designed store-and-release moisture of 160 mm (a requirement of the land capability classification for forest ecosystems in the oil sands) for the vegetation and meteorological moisture demands at a non-exceedance probability of 93%. The comparative study shows that the reconstructed watershed provides less moisture for evapotranspiration requirements than the natural watershed. The reconstructed watershed is able to provide less moisture than the natural watershed for both small and also mature vegetation scenarios. A possible reason for this may be that the reconstructed site is still in the process of restoration and that it may take a few more years to get closer to natural watersheds in terms of the hydrological sustainability. The study also demonstrates the utility of the system dynamics approach of modeling the case study under consideration. The future addition of a vegetation growth model to the hydrological model, and the development of a generic watershed modeling technique would be helpful in decision making and management practices of watershed reclamation.

An example of watershed disturbance activity undertaken to gain access to the oil sands is large scale mining in the Athabasca basin, Alberta, Canada. One of the remedial activities of this disturbance is the reclamation of the disturbed lands. In the process of reclamation, the overburden soil is placed back into the mined pits and reformed with soil covers (alternatively called reconstructed watersheds). In the design process of reclamation, a major concern is hydrological sustainability, which includes the soils ability to store enough moisture for the water requirements of vegetation growth and land-atmospheric moisture fluxes. Typically, the goal of the reclamation is to restore the disturbed watersheds, so that they mimic the natural watersheds in terms of the ecological sustainability. Therefore, a comparative evaluation of the hydrological sustainability of the reconstructed watersheds with natural watersheds is required.<p>The considered reconstructed watershed in this study (the flat top of the South Bison Hill, Fort McMurray, Alberta, which is about 6 years old) constitutes a thin layer of a peat-mineral mix (20 cm thick) overlying an 80 cm thick secondary (glacial till) layer on the shale formation, mimicking the natural soil horizons of undisturbed watersheds. As the reconstructed watershed is located in the boreal forest region, a mature boreal forest (Old Aspen site, about 88 years old) located in the Southern Study Area (SSA), BOREAS, Saskatchewan, Canada, is considered as a representative of natural watershed. The A-horizon with 25 cm of sandy loam texture, the B-horizon with 45 cm-thick sandy clay loam, and the C-horizon with 40 cm of a mixture of sandy clay loam and loam are considered in this study.<p>An existing System Dynamics Watershed (SDW) model (lumped and site-specific) is modified and adapted to model the hydrological processes of the reconstructed and natural watersheds, such as soil moisture, evapotranspiration, and runoff. The models are calibrated and validated on daily time scale using two years data (growing season) in each case. The hydrological processes are simulated reasonably well despite the high complexity involved in the processes of soil moisture dynamics and the evapotranspiration, for both study areas. Using the modified and calibrated models, long term simulations (48 years) are carried out on both the reconstructed and natural watersheds. Vegetation properties are switched between the reconstructed and natural watersheds and two scenarios are generated. Consequently, long term simulations are performed. With the help of a probabilistic approach, the daily soil moisture results are used to address the comparative soil moisture storage capability of the watersheds.<p>The results indicate that the selected reconstructed watershed is able to provide its designed store-and-release moisture of 160 mm (a requirement of the land capability classification for forest ecosystems in the oil sands) for the vegetation and meteorological moisture demands at a non-exceedance probability of 93%. The comparative study shows that the reconstructed watershed provides less moisture for evapotranspiration requirements than the natural watershed. The reconstructed watershed is able to provide less moisture than the natural watershed for both small and also mature vegetation scenarios. A possible reason for this may be that the reconstructed site is still in the process of restoration and that it may take a few more years to get closer to natural watersheds in terms of the hydrological sustainability. The study also demonstrates the utility of the system dynamics approach of modeling the case study under consideration. The future addition of a vegetation growth model to the hydrological model, and the development of a generic watershed modeling technique would be helpful in decision making and management practices of watershed reclamation.

Thesis (Ph. D.)--West Virginia University, 2009. / Title from document title page. Document formatted into pages; contains ix, 199 p. : ill. (some col.), col. maps. Includes abstract. Includes bibliographical references (p. 142-172).

Thesis(M.S.)--Auburn University, 2005. / Abstract. Vita. Includes bibliographic references.