Thesis (M.S.)--Oregon State University, 2005. / Printout. Includes bibliographical references (leaves 51-55). Also available on the World Wide Web.

Thesis (M.S.)--Oregon State University, 2007. / Printout. Includes bibliographical references (leaves 102-110). Also available on the World Wide Web.

Thesis (Ph. D.)--Ohio State University, 2007. / Title from first page of PDF file. Includes bibliographical references (p. 134-146).

This report presents a study of the various mechanisms that may cause erosion of streambanks and the corresponding mitigation techniques used to combat them. The determination of each may depend upon a number of considerations. The source of the information comes from a variety of reports and papers, which are referenced in the text. Of all the mitigation techniques available to prevent streambank erosion, fabrics will generally offer the most cost effective method. Fabrics have had a good service record since their inception approximately 20 years ago. Further, as the technology continues to advance, it seems likely that fabric applications in this area will only increase. However, there are some concerns that need to be addressed. These include, assessment of geotextile performance in long term use under the different forces it will be subjected to, clogging potential of fabrics for various soil distributions, and the type of fabrics, woven or nonwoven, used in these applications. These factors should become more clearly defined as long term case study data becomes available. / M. Eng.

The goal of the Aquatic Indicators of Land Condition (AILC) project is to develop analytical tools that integrate land condition information with stream condition for improved watershed management within the United States Bureau of Land Management (BLM). Based on the goal of the AILC, two objectives for this study were: to determine the effect of four GIS-derived distance measurements on potential relationships between common BLM landscape stressors (mining and grazing) and changes in benthic macroinvertebrate community structure; and to assess the effectiveness of individual questions on a commonly-used Bureau-wide qualitative stream assessment protocol, the proper functioning condition (PFC) assessment. The four GIS distance measurements assessed for biotic relevance included: straight-line distance, slope distance, flow length, and travel time. No significant relationships were found between the measured distance to stressor and macroinvertebrate community structure. However, the hydrological relevance of flow length and travel time are logically superior to straight-line and slope distance and should be researched further. Several individual questions in the PFC assessment had statistically significant relationships with the final reach ratings and with field-measured characteristics. Two of the checklist questions were significantly related to the number of cow droppings. This may indicate a useful and efficient measure of stream degradation due to grazing. The handling and use of the PFC assessment within the BLM needs further documentation and examination for scientific viability, and the addition of quantitative measurements to the PFC in determining restoration potential would be desirable. / Master of Science

A seasonal groundwater model was developed to simulate fluxes and head distributions with periodic boundary conditions within the San Pedro Riparian National Conservation Area (SPRNCA) in southeastern Arizona. This model incorporated a seasonal approach for the period 1940-1995. Two years were used to simulate streamflow, 1990 and 1995. The model, as currently calibrated, does not accurately reproduce observed baseflow conditions in the San Pedro River and simulates an exaggerated effect of retiring irrigation within the SPRNCA. The model simulated increased baseflows while the observed baseflows declined at the USGS Charleston stream gage, though increases in baseflow contributions between Hereford Bridge and Lewis Springs have been reported. The original (Corell, et al., 1996) model and the seasonal transient model suffer from over- estimation of discharge from the floodplain aquifer to the San Pedro river, as well as errors in the seasonal transient model's simulation of riparian ET, and seasonal variations in stream conductance. These problems precluded the seasonal transient model from replicating the observed baseflows in the San Pedro river at the Charleston bridge, however, the results of the simulation are thought to be qualitatively indicative of changes in the flow system resulting from the retirement of irrigated agriculture in the San Pedro Riparian National Conservation Area. Possible sources for this problem include replacement of irrigation stresses by the expansion of cones of depression more distant from the river, overestimation of mountain front recharge, poor baseflow estimates and evapotransipration calculations from the stream gages at Charleston and Palominas, and the effects of a recently discovered silt -clay body that may dampen the speed of the rivers response to changes in stress. Additional efforts to re- calibrate the model, taking these areas into account, should provide better simulated baseflow values of the observed data.

Agriculture is key to New Zealand�s economy with land-use conversions in response to market forces occurring regularly. Recently, high-intensity dairy farming has replaced low-density livestock farming, often degrading surrounding waterways. Of particular concern is that dairy cattle can be a source of the parasite Giardia, which in humans is a common cause of gastrointestinal infection. Thus, this thesis evaluated whether dairy farm conversions posed significant consequences for public health. First I examined the prevalence of Giardia in calves in a rapidly intensifying dairying region of New Zealand. A total of 1190 faecal samples were collected from calves one to seven weeks old during two spring calving seasons and screened by direct immunofluorescent microscopy. Giardia cysts were detected in 31% of samples. To evaluate the potential risk that this environmental source of Giardia posed to the human population, molecular genotyping was used to compare forty Giardia strains isolated from calves with thirty isolates from humans collected in the same region and period. Sequencing the β-giardin gene, Giardia duodenalis assemblages A and B were identified from both hosts, with genotype comparisons revealing substantial overlap of identical genotypes for both assemblages, implying zoonotic transmission. Environmental agencies routinely promote the planting of streamside edges to decrease nonpoint pollution from dairy farms entering waterways. However, current methods for tracking pathogens across farmland and into waterways via surface runoff are limited and typically have been developed using artificially created landscapes. Furthermore, no studies have investigated how Giardia moves across the landscape in farm surface runoff. I developed a field-based tracking method specific for Giardia and used this technique to compare the ability of recently planted vegetation strips with bare soil strips cleared of vegetation at decreasing pathogen concentrations; a typical scenario when planting barriers to reduce waterway contamination. A spike containing a bromide tracer and inactivated Giardia cysts was applied in drip-irrigated surface runoff, with one-minute samples collected from the bottom of the plot. A significant treatment effect was identified for Giardia, with 26% fewer detected in runoff from the planted strip, highlighting the immediate benefit of vegetation planting in removing pathogens. Next I evaluated the effects of four riparian treatments on Giardia runoff: exotic pasture grass and weeds growing in the absence of cattle grazing due to fencing, in comparison to monocultural plantings of three New Zealand native grassland species. Runoff experiments were performed after planting, both prior to and following the main summer growing season. Bromide recovery was high from all four treatments (54 - 99%), with no significant treatment effects. By comparison, Giardia recovery was low (1 - 13%). Prior to summer, two native species reduced Giardia in runoff more than the pasture grass/weed treatment which was almost vegetation-free at this time. After summer, Giardia recoveries were uniformly lower in all treatments. These results demonstrate that after one growing season, fencing waterways produces riparian buffers, via the growth of exotic pasture plants released from grazing, that decrease pathogen concentrations in surface runoff to concentrations indistinguishable from native plantings. Given infectious organisms are known to be in the environment, it is important to assess the risk these pose to human populations. Findings from this research can be used to improve currently available risk-assessment models for Giardia transmission from infected dairy animals via water to humans.

Agriculture is key to New Zealand�s economy with land-use conversions in response to market forces occurring regularly. Recently, high-intensity dairy farming has replaced low-density livestock farming, often degrading surrounding waterways. Of particular concern is that dairy cattle can be a source of the parasite Giardia, which in humans is a common cause of gastrointestinal infection. Thus, this thesis evaluated whether dairy farm conversions posed significant consequences for public health. First I examined the prevalence of Giardia in calves in a rapidly intensifying dairying region of New Zealand. A total of 1190 faecal samples were collected from calves one to seven weeks old during two spring calving seasons and screened by direct immunofluorescent microscopy. Giardia cysts were detected in 31% of samples. To evaluate the potential risk that this environmental source of Giardia posed to the human population, molecular genotyping was used to compare forty Giardia strains isolated from calves with thirty isolates from humans collected in the same region and period. Sequencing the β-giardin gene, Giardia duodenalis assemblages A and B were identified from both hosts, with genotype comparisons revealing substantial overlap of identical genotypes for both assemblages, implying zoonotic transmission. Environmental agencies routinely promote the planting of streamside edges to decrease nonpoint pollution from dairy farms entering waterways. However, current methods for tracking pathogens across farmland and into waterways via surface runoff are limited and typically have been developed using artificially created landscapes. Furthermore, no studies have investigated how Giardia moves across the landscape in farm surface runoff. I developed a field-based tracking method specific for Giardia and used this technique to compare the ability of recently planted vegetation strips with bare soil strips cleared of vegetation at decreasing pathogen concentrations; a typical scenario when planting barriers to reduce waterway contamination. A spike containing a bromide tracer and inactivated Giardia cysts was applied in drip-irrigated surface runoff, with one-minute samples collected from the bottom of the plot. A significant treatment effect was identified for Giardia, with 26% fewer detected in runoff from the planted strip, highlighting the immediate benefit of vegetation planting in removing pathogens. Next I evaluated the effects of four riparian treatments on Giardia runoff: exotic pasture grass and weeds growing in the absence of cattle grazing due to fencing, in comparison to monocultural plantings of three New Zealand native grassland species. Runoff experiments were performed after planting, both prior to and following the main summer growing season. Bromide recovery was high from all four treatments (54 - 99%), with no significant treatment effects. By comparison, Giardia recovery was low (1 - 13%). Prior to summer, two native species reduced Giardia in runoff more than the pasture grass/weed treatment which was almost vegetation-free at this time. After summer, Giardia recoveries were uniformly lower in all treatments. These results demonstrate that after one growing season, fencing waterways produces riparian buffers, via the growth of exotic pasture plants released from grazing, that decrease pathogen concentrations in surface runoff to concentrations indistinguishable from native plantings. Given infectious organisms are known to be in the environment, it is important to assess the risk these pose to human populations. Findings from this research can be used to improve currently available risk-assessment models for Giardia transmission from infected dairy animals via water to humans.

Thesis (Ph.D.)--University of Melbourne, Dept. of Civil and Environmental Engineering, 2006. / Typescript. Includes bibliographical references (leaves [1]-[10])

Current riparian management objectives in the Pacific Northwest promote both retention of existing conifers and conversion of hardwood-dominated areas to conifers. Although understanding of relationships between riparian vegetation and salmonid prey availability is growing, temporal variation in these relationships is poorly understood. Seasonal fluxes in availability of aquatic and terrestrial invertebrate prey for coastal cutthroat trout (Oncorhynchus clarki clarki) were investigated by estimating invertebrate biomass from aquatic (benthos and drift) and allochthonous (terrestrial) sources in three watersheds in the Oregon Coast Range. To investigate the influence of vegetation type on food sources, samples were collected in each watershed from stream sections dominated by deciduous, conifer, and mixed vegetation. During each sample period, diet was assessed by examining gut contents of captured trout. Stream discharge appeared to be an influential factor regulating seasonal fluxes of aquatic invertebrate biomass in the benthos and drift. Total allochthonous invertebrate biomass at deciduous and mixed vegetation sites (64 and 61 mg·m⁻²·day⁻¹, respectively) was almost 30% higher than at coniferous sites (45 mg·m⁻²·day⁻¹). Although aquatic insects dominated the total gut contents during this study, prey from terrestrial origin was more common during summer and fall. These results suggest that systematic removal of deciduous vegetation in riparian zones to promote conifers may have unintended consequences on the food resources of coastal cutthroat trout and the productivity of aquatic food webs in the Pacific Northwest. / Graduation date: 2004