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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Evaluation of a Combination Approach to Pedagogy in a Soil Science Laboratory Classroom and an Environmental Site Assessment Sample

Gervais, Emily Linda 01 July 2015 (has links) (PDF)
Chapter 1 of this study explores research that has shown that the use of technology in the classroom can be beneficial to student learning. Additionally, a need for Environmental Site Assessment (ESA) instruction in university level core environmental science classrooms has been demonstrated. This study includes an investigation of the potential benefits of using a combination of pedagogies: web-based teaching tools and ESA instruction in a laboratory classroom. The research design included two class formats, one that employed web-based tools (PowerPoint and video) and ESA instruction, and one that did not, with four class sections. All classes were taught by the same instructor and teaching assistant. Weekly quizzes, labs, a final exam, informal interviews and a student survey were used to measure effectiveness of the teaching tools. Significant improvement was exhibited on application questions featured on the final exam with the experimental group scoring higher on 6 of the 15 questions. Additionally, students' preparation and enthusiasm was improved among the experimental groups. Student ratings and performance for the two different formats were similar. Success in the class may depend on the students' preparation and personal desire to succeed. In conclusion, these results suggest that a combination of pedagogies that employs web-based tools and ESA instruction in the laboratory classroom may improve student's preparation for class activities and acquisition of career skills, as well as their enjoyment and enthusiasm to participate in class activities. Chapter 2 represents a sample of the required application activity from the soil science class. It includes the background, test results, procedures, conclusions and recommendations for an Environmental Site Assessment (ESA). ESA instruction is arguably an important addition to soil science curriculum and as such is demonstrated here as an example of the skills displayed and information applied by students who are instructed in writing ESAs.
2

Assessing Phosphorus Sources with a GIS-Based Phosphorus Risk Index in a Mixed-Use, Montane Watershed

Johns, Josiah A. 01 June 2017 (has links)
Elevated phosphorus (P) loading of freshwater lakes and reservoirs often results in poor water quality and negative ecological effects. Critical source areas (CSA) of P in the watershed can be difficult to identify and control. A useful concept for identification of a CSA is the P risk index (P Index) that evaluates the P risk associated with distinct source and transport pathways. The objectives of this study were to create a GIS model that adapts the Minnesota (MN) P Index for use at the watershed scale in a mixed-use, mountain environment, and to evaluate its effectiveness relative to field-based assessment. A GIS-based model of the MN P Index, adapted for montane environments and relying primarily on publicly available geospatial data, was created and applied in the Wallsburg watershed, located in the mountains of Central Utah. One necessary data input, P found in plant residue of common Utah ecosystems, was found lacking after literature review. We experimentally determined a range of observed values from multiple ecosystems to adapt and validate the GIS model. The GIS P Index was evaluated against the results of 58 field scale applications of the MN P Index conducted throughout the watershed. The field-scale analysis resulted in about 14% of the sites sampled being identified as high or very high risk for P transport to surface water. Spatially, these high risk areas were determined to be a geographic cluster of fields near the lower middle agricultural section of the watershed. The GIS model visually and spatially identified the same cluster of fields as high risk areas. Various soil test P scenarios were explored and compared to the known 58 site values. Soil test phosphorus had little effect on the GIS model's ability to accurately predict P risk in this watershed suggesting that high volume soil sampling is not always necessary to identify CSAs of P. Variable hypothetical livestock density scenarios were also simulated. The GIS model proved sensitive to variable P inputs and highlighted the necessity of accurate applied P source data. On average the model under-predicted the known field-site values by a risk score of 1.3, which suggests reasonable success in P assessment based on the categorical risk scores of the MN P Index and some potential for improvement. The GIS model has great potential to give land managers the ability to quickly locate potential CSAs and prioritizing remediation efforts to sites with greatest risk.
3

Assessing Phosphorus Sources with Synoptic Sampling in the Surface Waters of a Mixed-Use, Montane Watershed

Pearce, Austin Willis 01 May 2017 (has links)
Few elements in surface waters are monitored as closely as phosphorus (P) due to its role in the eutrophication and degradation of surface waters. Limiting P mobilization from source areas is, therefore, a central goal of water quality protection plans. But the work of locating sources in mixed-use watersheds is challenged by the spatial and temporal variability of critical source areas (CSAs) of P. Synoptic sampling is a proven method for capturing the spatial variation of water quality parameters in surface waters, though it's not often used to track temporal dynamics across the same study area. Phosphorus fractionation is an analytical method that divides the total P (TP) in water into fractions, which for this study included total dissolved P (TDP), particulate P (PP), dissolved reactive P (DRP), and dissolved organic P (DOP). The objective of this study was to demonstrate the utility of combining temporally repeated synoptic sampling with simple P fractionation as a unique strategy for locating and characterizing CSAs of P. Seven synoptic sampling campaigns were conducted over a two-year period (March 2015 – July 2016) in a rural, montane watershed in north central Utah, USA. In each campaign, we sampled 18 sites across three tributaries (Main Creek, Spring Creek, and Little Hobble Creek) during three distinct, annual hydrologic periods (rising flow, peak flow, and baseflow). Temporal repetition clearly identified the rising flow period as the period with greatest P loading in the watershed. Combining repeated synoptic sampling and P fractionation successfully identified CSAs of P and most probable transfer pathways. Specifically, stream segments along lower Spring Creek and Main Creek were associated with the greatest increases of PP loads during periods of rising flow and peak flow. In the same time periods, the greatest DOP loads stemmed from forested areas as well as areas in the lower watershed associated with winter grazing of cattle. The watershed exhibited a significant background concentration of DRP from groundwater-driven subsurface sources in the lower half of the watershed that persisted year-round. These assessments can be used to develop management practices that limit various P loads from these respective critical source areas. The characterization of CSAs could not have been made using only a traditional synoptic sampling approach. This study demonstrated that the combination of repeated synoptic sampling and P fractionation can be an effective technique for locating and characterizing critical P source areas in order to guide best management practices that improve surface water quality.

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