Highways and roadways are the major source of stormwater runoff due to their prevalence and large non-permeable surface area. Best Management Practices (BMPs) such as bioswale provide effective on-site management and control of stormwater runoff from linear infrastructure such as highways. Many factors affect the performance of bioswales for stormwater volume reduction. The ratio of the installed BMP area to its service drainage area, characteristics of precipitation and the amount of sediment build-up over the surface of the BMP area are among the most important factors. Earlier studies have indicated that volume reductions in stormwater runoff from bioswale application range from 50% to 94%. However, the reported research lacks adequate information for a full understanding of how bioswales perform under various conditions. Consequently, additional systematic and in-depth research to better understand and the potential of bioswales as a method of controlling stormwater runoff is indicated. This research examined the effect of the following factors on bioswale performance: the ratio of the BMP area to the service drainage area, precipitation amounts and intensity, and sediment build-up. Hydraulic and hydrological processes were developed and analyzed through conceptual and physical models using appropriate governing equations including the Green-Ampt method. Field study of discrete rainfall events was conducted to collect information to calibrate and validate the numerical models. The field study tested various bioswale conditions with different levels of sediment accumulation. It also considered expected soil loss in the study area using the Universal Soil Loss Equation (USLE) method. In addition to field study, extensive simulations were conducted considering various contributing areas, rainfall depth and intensity, and sediment accumulation. These variables were manipulated to evaluate their effect on runoff volume reduction. Findings indicate that, for a given rainfall depth and duration, increasing the ratio of the BMP area to the service drainage area from 4% to16% results in increased bioswale efficiency ranging from 84% to 99%. The results revealed that input flowrate to the bioswale ranged from 0.04 to 4.7 in./min. depending on the rainfall intensity and soil type in the area. The runoff reduction performance of a newly constructed bioswale ranged from 44% for the highest input flowrate to 99% for the lowest input flowrate rainfall events. On the low end of rainfall volume/intensity, a 4% increase in the BMP area ratio results in a 34% improvement in efficiency (50% to 84%). On the high end of rainfall volume/intensity, a 16% increase in the area ratio results in only a 5% increase in efficiency (94% to 99%). Results also show that sediment accumulation has a substantial negative effect on infiltration rate. The observed efficiency of a bioswale in runoff reduction ranged from 13% to 100%. According to the USLE, the expected amount of soil loss occurring in the right-of-way area of a highway is approximately 1 ton/acre annually. The research revealed that for a given rainfall depth, duration, and area ratio; increasing the amount of sediment accumulation from 0 lbs./sq. ft. (equivalent to a newly constructed bioswale) to 2.7 lbs./sq. ft. (equivalent to a 10-year old bioswale) results in a 52% reduction in the runoff effectiveness of the bioswale sub-catchment from 98% to 46%. Finally, the physical model and associated governing equations were analyzed to describe the process of each studied factor. These results can be used for further study where the sediment accumulation rates differ from those modeled in this research.

O objetivo deste trabalho foi de avaliar economicamente uma unidade de produção de alevinos de espécies reofílicas do estado de Rondônia e desta forma estruturar a análise de custos, econômica e gerencial do empreendimento. O empreendimento avaliado possui 54 ha de área total e 6,5 ha de lâmina d’água disponíveis para a alevinagem. Na safra 2010/2011 o empreendimento produziu os seguintes produtos: alevinos de tambaqui (Colossoma macropomum) nos tamanhos de 3g, 5g, 10g, 15g, 20g e 30g; alevinos de piavuçu (Leporinus macrocephalus); e alevinos de curimba (Prochilodus lineatus). O empreendimento ainda comprou e revendeu alevinos de pirarucu (Arapaima gigas) e alevinos de Jundiara (♀ Pseudoplathystoma fasciatum X ♂ Leiarius marmoratus). A fim de avaliar como a produção de alevinos consumiu os recursos disponíveis do empreendimento, realizou-se o mapeamento do fluxo de produção do empreendimento e de sua estrutura que custos . Foram calculados os seguintes indicadores de custo e rentabilidade: custo operacional efetivo e total, custo total de produção, receita liquida e lucro, além dos indicadores de fluxo de caixa usuais e seus alternativos integrados, ponto de nivelamento e margem de contribuição total. Através do mapeamento do fluxo de produção verificou-se que o plantel de reprodutores apresenta resultados reprodutivos satisfatórios, porém o empreendimento apresenta falhas no manejo de arraçoamento de reprodutores e alevinos e não realiza o controle dos estoques de alevinos e dos parâmetros de qualidade de água nos viveiros. Entre os produtos efetivamente produzidos no empreendimento, os que apresentaram os menores custos médios e as melhores rentabilidades estão os alevinos de tambaqui de 3g, 5g e os alevinos de piavuçu. A análise custos e econômica mostrou que empreendimento apresenta uma baixa lucratividade a médio prazo em relação ao capital investido e economicamente inviável a longo prazo, devido a sua onerosa estrutura de produção. Diante destes resultados fica evidente que as tomadas de decisão para determinação de valores de investimento e preço de venda dos produtos são realizadas sem todas as informações necessárias para o adequado planejamento do empreendimento, o que mostra a importância do contínuo controle dos processos e avaliação econômica deste tipo de empreendimento. / The objective of this study was to evaluate a unit cost of production of fingerlings of reophilic species in the state of Rondônia, Brazil, and thereby structure the cost analysis, and the economic management of the enterprise. The enterprise has 54 ha and 6.5 ha of water is available for the nursery. In the season 2010/2011 the enterprise produced the following products: fingerlings of tambaqui (Colossoma macropomum) in 3g, 5g, 10g, 15g, 20g and 30g weights; piavuçu fingerlings (Leporinus macrocephalus) and curimba fingerlings (Prochilodus lineatus). The venture has bought and resold pirarucu fingerlings (Arapaima gigas) and jundiara fingerlings (♀ Pseudoplathystoma fasciatum X ♂ Leiarius marmoratus). In order to evaluate how the production of fingerlings consumed the resources of the enterprise, was conducted the flow map of production of the enterprise and its cost structure. Was calculated the following indicators of cost and profitability, and total operational cost, total cost of production, net income and earnings, and indicators of cash flow and its usual alternative integrated point of leveling and total contribution margin. By mapping the production flow it was found that the bloodstock breeding presents satisfactory results, but the venture fails in the management and feeding of fingerlings and does not perform the control of fingerlings stocks and the parameters of water quality. Among the products actually produced in the enterprise, who had the lowest average costs and better returns are 3 g and 5 g tambaqui fingerlings, and piavuçu fingerlings. The analysis showed that costs and economic analysis has low profitability in the medium term in relation to capital invested and economically unviable in the long term, due to its costly production structure. Given these results it is evident that the decision making process for determining values of investment and the selling price of the products are made without all the information necessary for proper planning of the enterprise, which shows the importance of continuous control process and economic evaluation of this type of business venture.

O objetivo deste trabalho foi de avaliar economicamente uma unidade de produção de alevinos de espécies reofílicas do estado de Rondônia e desta forma estruturar a análise de custos, econômica e gerencial do empreendimento. O empreendimento avaliado possui 54 ha de área total e 6,5 ha de lâmina d’água disponíveis para a alevinagem. Na safra 2010/2011 o empreendimento produziu os seguintes produtos: alevinos de tambaqui (Colossoma macropomum) nos tamanhos de 3g, 5g, 10g, 15g, 20g e 30g; alevinos de piavuçu (Leporinus macrocephalus); e alevinos de curimba (Prochilodus lineatus). O empreendimento ainda comprou e revendeu alevinos de pirarucu (Arapaima gigas) e alevinos de Jundiara (♀ Pseudoplathystoma fasciatum X ♂ Leiarius marmoratus). A fim de avaliar como a produção de alevinos consumiu os recursos disponíveis do empreendimento, realizou-se o mapeamento do fluxo de produção do empreendimento e de sua estrutura que custos . Foram calculados os seguintes indicadores de custo e rentabilidade: custo operacional efetivo e total, custo total de produção, receita liquida e lucro, além dos indicadores de fluxo de caixa usuais e seus alternativos integrados, ponto de nivelamento e margem de contribuição total. Através do mapeamento do fluxo de produção verificou-se que o plantel de reprodutores apresenta resultados reprodutivos satisfatórios, porém o empreendimento apresenta falhas no manejo de arraçoamento de reprodutores e alevinos e não realiza o controle dos estoques de alevinos e dos parâmetros de qualidade de água nos viveiros. Entre os produtos efetivamente produzidos no empreendimento, os que apresentaram os menores custos médios e as melhores rentabilidades estão os alevinos de tambaqui de 3g, 5g e os alevinos de piavuçu. A análise custos e econômica mostrou que empreendimento apresenta uma baixa lucratividade a médio prazo em relação ao capital investido e economicamente inviável a longo prazo, devido a sua onerosa estrutura de produção. Diante destes resultados fica evidente que as tomadas de decisão para determinação de valores de investimento e preço de venda dos produtos são realizadas sem todas as informações necessárias para o adequado planejamento do empreendimento, o que mostra a importância do contínuo controle dos processos e avaliação econômica deste tipo de empreendimento. / The objective of this study was to evaluate a unit cost of production of fingerlings of reophilic species in the state of Rondônia, Brazil, and thereby structure the cost analysis, and the economic management of the enterprise. The enterprise has 54 ha and 6.5 ha of water is available for the nursery. In the season 2010/2011 the enterprise produced the following products: fingerlings of tambaqui (Colossoma macropomum) in 3g, 5g, 10g, 15g, 20g and 30g weights; piavuçu fingerlings (Leporinus macrocephalus) and curimba fingerlings (Prochilodus lineatus). The venture has bought and resold pirarucu fingerlings (Arapaima gigas) and jundiara fingerlings (♀ Pseudoplathystoma fasciatum X ♂ Leiarius marmoratus). In order to evaluate how the production of fingerlings consumed the resources of the enterprise, was conducted the flow map of production of the enterprise and its cost structure. Was calculated the following indicators of cost and profitability, and total operational cost, total cost of production, net income and earnings, and indicators of cash flow and its usual alternative integrated point of leveling and total contribution margin. By mapping the production flow it was found that the bloodstock breeding presents satisfactory results, but the venture fails in the management and feeding of fingerlings and does not perform the control of fingerlings stocks and the parameters of water quality. Among the products actually produced in the enterprise, who had the lowest average costs and better returns are 3 g and 5 g tambaqui fingerlings, and piavuçu fingerlings. The analysis showed that costs and economic analysis has low profitability in the medium term in relation to capital invested and economically unviable in the long term, due to its costly production structure. Given these results it is evident that the decision making process for determining values of investment and the selling price of the products are made without all the information necessary for proper planning of the enterprise, which shows the importance of continuous control process and economic evaluation of this type of business venture.

Preventing impairment of waterbodies requires control, reduction and interception of contaminant losses at the field and subwatershed level. Three specific research objectives were accomplished in this study: 1) compare the HSPF-predicted flow, sediment, total nitrogen (TN) and total phosphorus (TP) loads resulting from simulation of spatially distributed site-specific and county-level disaggregated land use data at subwatershed and watershed levels, 2) evaluate the effects of site-specific and county-level disaggregated BMP data on modeled BMP responses in HSPF-predicted flow, sediment, TN and TP loads at the watershed level, and 3) analyze the long-term effects of the two spatial BMP datasets on achieving the Chesapeake Bay Total Maximum Daily Load (TMDL) goals for sediment, TN and TP. Site-specific data are derived from the local watershed inventory while disaggregated data are based on county-level aggregated data that are distributed to portions of river segments that intersect each county. The study site was the Upper Opequon Watershed in northern Virginia. Results for each research objective are as follows: (1) HSPF-predicted flow, sediment, TN and TP were higher using disaggregated land use data in subwatersheds at monthly and annual time-steps. (2) Predicted load reductions were higher with site-specific BMP data than with disaggregated data for the study watershed. (3) Current levels of cost-shared BMP implementation in the Upper Opequon Watershed using either site-specific or county-level disaggregated BMP datasets do not meet the Chesapeake Bay TMDL goals. Increasing BMP implementation level to 100% of the available land also failed to meet TMDL target goals. Generally, use of disaggregated land use data does not accurately represent the existing watershed conditions. Further, for the study watershed, use of disaggregated county-level BMP data poorly represented actual watershed conditions, which resulted in higher pollutant yields and higher levels of BMPs needed to meet water quality goals. The study suggests that site-specific land use and BMP data must be used during TMDL implementation planning to maintain credibility with local stakeholders and improve the accuracy of the developed implementation plans. / Ph. D.

The agriculture community is faced with new challenges to increase food production on a limited amount of suitable land to keep up with the growing population. Fertilizers and intensive cropping are needed to meet food demand, but these practices contribute to environmental degradation due to nutrients and sediment leaving fields and entering waterbodies. Non-point source (NPS) pollution from agriculture has been scrutinized for significantly contributing to eutrophication and hypoxic dead zones. To reduce the harmful impacts of NPS pollution from agriculture, producers and land users have implemented in-field and edge-of-field Best Management Practices (BMP). Water and Sediment Control Basins (WASCoBs) are an example of an in-field BMP that has helped reduce erosion and sediment loading of receiving waters. Cover crops are another in-field BMP that have been used to mitigate erosion and nutrient leaching. The impacts of WASCoBs paired with cover crops on water quality, specifically nutrient loading, is lacking in the current literature and was the focus of this research. Our study site was located in Menard County near Atterberry, IL. The farm had relatively steep topography (5-18% slopes) and suffered from severe gully erosion. In 2018, the Natural Resource Conservation Service (NRCS) partnered with the landowner and installed a series of WASCoBs to address the erosion issues. Along with the NRCS and landowner, we worked with the Illinois Farm Bureau (IFB) to investigate the impacts of WASCoBs and cover crops on nutrient and sediment runoff, hydrology, and crop yields.Four sub-watersheds were included in the study: 1) a 1.5-hectare basin treated with a WASCoB; 2) a 1.4-hectare basin treated with a WASCoB and a cover crop; 3) a 0.2-hectare gully drained watershed treated with a cover crop; and 4) a control, 3.8-hectare gully-drained watershed. ISCO automated water samplers collected runoff from storm events in a time-weighted composite sampling regime. The measured water quality parameters were total suspended solids (TSS), ammonium-nitrogen (ammonium-N), nitrate-nitrogen (nitrate-N), dissolved reactive phosphorus (DRP), and total phosphorus (TP). The WASCoB treatment reduced TSS by 98.5-99.8%, TP by 83.8-97.4%, ammonium-N by 42.3-82.9%, and nitrate-N by 32.0-59.6%, respectively. Cover crop impacts on the water quality parameters were not detected, due to poor gemination of the annual rye cover crop. The water quality improvement WASCoBs are a potential tool for farmers and land managers to reduce loading of nutrients and sediment to receiving waters.

The fate and distribution of copper-based crop protectants, applied to tomato fields to protect against disease, were investigated in a greenhouse-scale simulation of farming conditions in a coastal environment. Following rainfall, 99% of the applied copper was found to remain on the fields sorbed to the soil and plants; most of the soil-bound copper was found sorbed to the top 2.5 centimeters of soil. Of the copper leaving the agricultural fields, 82% was found in the runoff with the majority, 74%, sorbed to the suspended solids. The remaining copper, 18%, leached through the soil and entered the groundwater with 10% in the dissolved phase and 8% sorbed to suspended solids. Although only one-percent of the copper was found to leave the field, this was sufficient to cause high copper concentrations (average 2102 ± 433 mg/L total copper and 189 ± 139 mg/L dissolved copper) in the runoff. Copper concentrations in groundwater samples were also high (average 312 ± 198 mg/L total copper and 216 ± 99 mg/L dissolved copper). Sedimentation, a best management practice for reducing copper loadings, was found to reduce the total copper concentrations in runoff by 90% to a concentration of 245 ± 127 mg/L; however, dissolved copper concentrations remained stable, averaging 139 ± 55 mg/L. Total copper concentrations were significantly reduced by the effective removal of suspended solids with sorbed copper. This research was supported by a grant from the Virginia Department of Agriculture and Consumer Services. Funding was also provided by Sea Grant. / Master of Science

Increasing awareness of hypoxia in coastal marine regions across the globe has led to creation of nutrient reduction strategies to protect water resources and organisms living in affected waters. In the Mississippi River Basin, the Governor’s Action Plan has called for a 45% load reduction of both, total nitrogen (N) and total phosphorus (P), to reduce the Gulf of Mexico hypoxic zone to a manageable size. Objectives of this dissertation aimed to determine nutrient reduction efficiencies of low-grade weirs, and to evaluate abundance and composition of microbial communities involved in key processes of denitrification following low-grade weir implementation in the Mississippi Delta. Results of this dissertation evidenced the efficiencies of low-grade weirs to reduce nutrient runoff to downstream waters as a viable BMP. Average median load reductions in N, P, and sediment of -5%, 23%, and 29%, respectively, were determined in ditches with low-grade weirs. Results highlighted more efficient reductions in P and sediment, and greater variability in N reductions during storm events, prompting management considerations toward BMP successes and limitations. Valuable insight towards seasonal nutrient fluxes in agricultural runoff due to spring fertilizer applications, increased rainfall patterns in the winter and spring, and drying-wetting cycles, was also evidenced by the data collected. It was determined that utilizing a three-scale sampling regime was most effective for capturing patterns of microbial community abundance and composition in ditches with low-grade weirs. Preliminary evidence towards weir proximity influencing microbial community abundance, and relationships between microbes and soil carbon and N was also found. Utilizing the three-scale sampling regime, microbial communities in multiple drainage ditches, with and without weirs, were investigated. Outcomes showed that weirs increased soil moisture, which subsequently increased functional gene abundance of 16S rRNA and nirS. Furthermore, weir implementation and associated constructions were not found to directly influence microbial community diversity, abundance, or chemical parameters. Results from this dissertation support the potential benefits of weirs to create suitable environments to physically reduce P and sediment loads and for denitrifying microbes to remediate N from agricultural runoff.

No description available.

No description available.

Forests of the Southeastern United States produce approximately 12% of all the world's wood products and represent 40% of all U.S. timberland, thus emphasizing the importance of Southeast in support of the United States' role as the world's largest timber producer. Producing such quantities of timber requires a substantial areas of forest harvest operations, which have the potential to disturb soils, facilitate erosion and potentially reduce water quality. Harvest sites routinely contain operational features such as skid trails, harvest areas, haul roads, decks/landings and stream crossings, all of which have the potential to influence erosion and sediment deposition in streams. Forestry best management practices (BMPs) were created to minimize the effects of harvesting operations on sedimentation and are implemented at varying levels throughout the Southeastern U.S. We quantified the area of these features on 111 recent harvest sites throughout 11 Southeastern states and three physiographic groupings (Mountains, Piedmont, Coastal Plain). No significant differences were found between the groupings with regard to the percent of area occupied by each operational feature. Decks, haul roads, skid trails, and stream crossings comprised an average of 1.43%, 3.21%, 7.03%, and 0.19% of the harvest operations. Roads, decks, skid trails, and structures were combined into an access feature category. These combined access features occupied 13.0% of harvests in the Mountains, 10.2% in the Piedmont, and 10.4% in the Coastal Plain (10.4%). A companion study was developed to trap sediment delivered to the stream and quantify the sediment delivery ratios (SDRs) on a subset of harvests sites in order to determine the average amount of eroded material that could reach a stream from each specific operational feature following a harvest. Across all groupings, stream crossings had the highest average SDR (34.32%), while skid trails had the second highest SDR (21.04%). Substantial site variability resulted in large SDR differences with few meaningful significant differences, but stream crossings, skid trails, and haul roads had sufficiently high sediment delivery ratios across all groupings to warrant additional BMP focus on these areas. / Master of Science / The Southeastern United States is a major producer of forests and forest products, comprising about 40% of US timberland and 12% of global wood products. Support of this industry requires that over 4 million acres of forests are harvested annually across the southeastern U.S. and improper or under usage of forestry best management practices could result in soil erosion and subsequent transport to streams as sediment. Previous research indicates that different operational and access features found on logging sites have different erosion rates yet little data exists which document the percentages of erosion that is delivered as sediment to streams. Skid trails (trails that forestry equipment use within a harvesting operation) compromised the largest access feature average percent area (second to harvest area), followed by haul roads, then decks (area where equipment is kept and logs are processed and loaded), and finally stream crossings with the smallest average area. Stream crossings, skid trails and haul roads consistently had the highest average sediment delivery ratios for all groupings combined. However, substantial site variability resulted in large sediment delivery ratio differences with few meaningful significant differences.