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The overall goal of this study was to develop a comprehensive tool for assessing the effectiveness of selected BMPs on both hydrology and water quality and to demonstrate the applicability of the system by considering 1) temporally and spatially changing land use management practice in an agricultural watershed and 2) interaction between surface and ground water over the entire system. A user interface and Dynamic Agricultural Non-point Source Assessment Tool (DANSAT) were developed to achieve this goal. DANSAT is the only distributed-parameter, physically-base, continuous-simulation, and multi-soil layer model for simulating impacts of agricultural BMPs on hydrology and water qulality in small agricultural watersheds. DANSAT was applied to QNB plot (18m à 27m) and two agricultural watersheds in Virginia, including Owl Run watershed (1140 ha) and QN2 in the Nomini Creek watershed (216 ha), to evaluate the model components and its performance in predicting runoff, sediment yield, and pesticide load. DANSAT performed well in predicting total runoff and temporal variations in surface runoff for both field-scale and watershed-scale applications. Total percent errors between the measured and predicted results were less than 10% except for one case (39.8% within a subwatershed of Owl Run watershed), while the daily Nash-Sutcliffe model efficiencies were greater than 0.5 in all applications. Predicted total sediment yields were within ±35% of observed values in all applications. However, the performance of DANSAT in predicting temporal trend and spatial distribution of sediment loads was acceptable only within Owl Run watershed, where high correlations between flow rates and sediment loads exist. The predicted total pesticide loads were within ±100% of observed values. DANSAT failed to simulate the temporal occurrence of pesticide loads with a 0.42 daily Nash-Sutcliffe efficiency value. The Dual-Simulation (DS) was developed within the linked ground water approach to resolve problems encountered due to the existence of different temporal scales between DANSAT and the existing ground water models such as MODFLOW and MT3D. The linked approach performed better in predicting the seasonal trend of total runoff compared to the integrated approach by showing an increase in monthly Nash-Sutcliffe efficiency value from 0.53 to 0.60. Surface and subsurface output variables were sensitive to the changes in spatially distributed soil parameters such as total porosity and field capacity. A maximum grid size of 100 m was recommended to be appropriate for representing spatial distribution of topographic, land use, and soil characteristics based on accuracy analysis during the GIS manipulation processes. Larger time-step based on predefined acceptable maximum grid size, decreased the computational time dramatically. Overall sensitivity to different grid sizes and time-steps was smallest for hydrology components followed by sediment and pesticide components. Dynamic crop rotation was considered by DANSAT, and the model successfully simulated the impacts of temporal and spatial changes in crop rotations on hydrology and water quality for both surface and subsurface areas. DANSAT could prove to be a useful tool for non-point source pollution managers to assess the relative effectiveness of temporally and spatially changing BMPs on both surface and ground water quantity and quality. / Ph. D.

A decision support system for preventive integrated pest management (IPM) and nonpoint source (NPS) pollution control was designed, implemented and evaluated. The objective of the system was to generate plans at the farm level to satisfy economic and production goals while limiting risks of insect pest outbreaks, nitrate and pesticide leaching and runoff, and soil erosion. The system is composed of a constraint satisfaction planner (CROPS-LT), a modified version of CROPS (Stone, 1995), a farm-level resource management system (FLAME), an NPS module, which includes a weather generator, CLIGEN (Nicks et al. 1995), and an NPS distributed-parameter model, ANSWERS (Bouraoui, 1994), databases, a database engine and utility programs. The performance of the system was analyzed and performance enhancing features were added to increase the planner's ability to find near-optimal plans within a limited planning time. Using heuristics to sort potential crop rotations based on profit generally improved the planner's performance, as did removal of fields that were not suitable for growing target crops. Not surprisingly, the planner was best able to find plans for crops that can be grown in a variety of rotational systems. Throughout, the ability to apply environmental constraints selectively to individual fields greatly improved the planner's ability to find acceptable plans. Preventive IPM (PIPM) heuristics to control corn rootworms CRW (<I>Diabrotica virgifera virgifera</I> and <I>D. barberi</I>) were added to the planner. The model was represented and solved as a constraint satisfaction problem. Results indicated that plans obtained using PIPM heuristics had less risk of CRW damage, reduced chemical control costs, higher profit and reduced soil erosion as compared to a control plan. Linking the planner to the NPS model in a feedback control loop improved the planner's ability to reduce soil losses while preserving economic and production goals. / Ph. D.

Efforts to control surface runoff and erosion from forest roads at stream crossings are critical for the protection of aquatic ecosystems in forests. In this research, annual and event-based sediment delivery rates were estimated for reopened legacy roads at forest stream crossings in the Virginia Piedmont physiographic region, USA. Sediment delivery rates were compared among stream crossing approaches with diverse intensities of best management practice (BMP) implementations for surface cover and water control. Model predictions from the Water Erosion Prediction Project (WEPP) were compared to field observations of surface runoff and sediment delivery to evaluate model performance. Annual sediment delivery rates from reopened (bare) legacy road approaches to stream crossings were 7.5 times higher than those of completely graveled approaches. Sediment delivery rates ranged from 34 to 287 Mg ha⁻¹ year⁻¹ for the bare approaches and from 10 to 16 Mg ha⁻¹ year⁻¹ for the graveled approaches. Event-based surface runoff and associated total suspended solids (TSS) concentrations were compared among a succession of gravel surfacing treatments that represented increasing intensities of BMP implementations on reopened approaches. The three treatments were No Gravel (10-19% cover), Low Gravel (34-60% cover), and High Gravel (50-99% cover). Median TSS concentration of surface runoff for the No Gravel treatment (2.84 g L⁻¹) was greater than Low Gravel (1.10 g L⁻¹) and High Gravel (0.82 g L⁻¹) by factors of 2.6 and 3.5, respectively. WEPP predictions of event-based sediment yield show clear differences among the different road surface treatments, but prediction intervals were wide, reflecting substantial prediction uncertainty. These findings show that reopened legacy roads and associated stream crossing approaches can deliver significant quantities of sediment if roads are not adequately closed or maintained and that corrective best management practices (BMPs), such as gravel and appropriate spacing of water control structures, can reduce sediment delivery to streams. Watershed management decisions that hinge upon WEPP predictions of sediment yield from forest roads must necessarily take into account a wide range of potential erosion rates for specific management scenarios. / Ph. D.

For over 30 years, federal and state governments have been engaged in a collective effort to improve the water quality and living resources in the Chesapeake Bay (CB), focusing particularly on reducing delivered nitrogen and phosphorus loads. However, achievement of water quality objectives remains elusive. In Virginia, agriculture represents the single largest source of nutrient loads to the Chesapeake Bay. Despite aggressive regulatory efforts in other nutrient source sectors, state authorities rely on educational programs and voluntary financial assistance programs to induce landowners to adopt best management practices (BMPs) that reduce agricultural nutrient loads. This study explores two economic aspects of efforts to reduce agricultural nonpoint source (NPS) pollution in the Virginia portion of the CB watershed. Firstly, current and possible future transactions costs associated with specific aspects of agricultural NPS participation in water quality trading (WQT) programs are examined in Chapter 1. A case study approach is used to consider the possible cost consequences of expanding the use of NPS credits from agricultural 'working lands' BMPs in Virginia. Findings indicate that overall transactions costs for nutrient trades involving agricultural NPS in Virginia are currently relatively low, due to the type of activities being credited: simple land conversions. Based on best available evidence, the administrative transactions costs of creating credits on agricultural 'working lands' using management and structural BMPs will be 2 to 5 times more costly on a per project basis than for credits generated from land conversions. Compliance monitoring protocols were found to be a significant driver of costs for credits generated from working agricultural lands. These results suggest an important cost/risk tradeoff between verification cost and compliance certainty for program designers to consider. The second study (Chapter 2) considers the economic cost of meeting pollution reduction targets for the Virginia portion of the CB Watershed. Existing cost models are based on simplifying behavioral assumptions about public transactions costs, conservation adoption rates, and implementation costs of agricultural BMPs. This study builds on the existing literature and uses the estimates of transactions costs from Chapter 1 together with information on producer BMP adoption rates to examine the implications of including transactions costs and differential BMP costs and adoption rates when estimating the minimum costs of achieving specified nutrient reduction goals in Virginia. The paper uses a cost-minimizing mathematical programming approach and models a number of different cost scenarios. Results indicate that inclusion of transactions costs substantially affects estimates of total costs of meeting nutrient reduction goals; on average total costs increased by 44 percent, but ranged between 19 and 81 percent depending on the scenario analyzed. Analysis of the modelled scenarios shows that those BMPs that account for the most implementation costs do not necessarily account for the most transactions costs (and vice versa). This suggests that transactions costs should be acknowledged to vary with the type of practices being implemented, rather than being approximated as either a fixed amount or a fixed proportion of implementation costs. In addition, the analysis highlights the disproportionate costs associated with achieving nutrient reductions via high-cost adopters, and suggests there may be a role for education or extension to assist landholders to lower opportunity costs of participating in conservation. / Master of Science

Master of Landscape Architecture / Department of Landscape Architecture/Regional and Community Planning / Lee R. Skabelund / Stormwater management is typically approached from different perspectives by practicing professionals. As such, stormwater planning/design is not always completed as a multi-disciplinary coalition of experts using holistic and synergistic methods. For a number of years, engineers and design professionals, particularly landscape architects, have been employing various strategies and techniques to address on-site stormwater management in terms of water quality and quantity. There is increasing awareness that in order to create solutions that are effective over both the short and long-term a landscape architect’s approach needs to account for the health, safety and welfare perspectives carried by engineers, the unique aspects of particular project sites, their surroundings and bio-regional context, as well as the perceptions of clients, other key stakeholders, and the broader public. This research investigates the various criteria integral to developing an analytic framework for ecologically-appropriate stormwater planning/design (Sustainable Stormwater Evaluation and Site Assessment or SSWESA). SSWESA is proposed as a type of decision-tree for site analysis of sustainable systems pertaining to stormwater. Using the SSWESA process is expected to help researchers and professionals make better planning and design decisions as they select and implement appropriate best management practices (BMPs) for a given site and context. My intent in developing SSWESA is to help designers assess existing and potential stormwater functions at the site scale in order to promote sustainable planning and design based upon the important principle: “First, do no harm”. It is also my intent to promote further research related to sustainability by providing references and sources from experts in the various fields related to ecologically-based stormwater management. A review of the literature related to ecological factors relevant to low impact stormwater management assisted in the development and refinement of the criteria for stormwater assessment and evaluation. In this report, the SSWESA framework is tested on a public school property in Manhattan, Kansas to demonstrate how the framework is applied and to understand the questions and issues that arise from its use.

published_or_final_version / Environmental Management / Master / Master of Science in Environmental Management

Com a consolidação do saneamento em algumas bacias urbanas, um novo desafio surge: o da recuperação dos corpos dágua. O que a principio parece ser uma consequência do processo, na realidade se mostra uma tarefa muito mais complexa e que envolve diversos fatores, tornando o processo de recuperação lento e dispendioso. Muito se diz a respeito da despoluição dos corpos dágua através da eliminação da carga pontual, mas o que se observa na prática é que, mesmo diante do controle das cargas pontuais, os corpos dágua continuam poluídos devido às cargas difusas. A preocupação com a poluição por carga difusa já é um assunto muito estudado em locais onde a poluição por cargas pontuais já possui um controle efetivo, mas este assunto ainda é um grande desafio em países como o Brasil, onde o controle da carga pontual ainda não constitui uma realidade palpável. Atualmente, na região metropolitana de São Paulo, há diversos programas atuando na despoluição de corpos dágua através do controle de cargas pontuais, dentre eles o programa Córrego Limpo se destaca por agir na otimização de sistemas de esgotamento sanitário, e apesar dos bons resultados obtidos, como o programa se baseia no controle de cargas pontuais, estas bacias não se encontram completamente despoluídas. Considerando o caso brasileiro, o programa é pioneiro no que se refere à adoção de medidas que integram a população no processo de recuperação, pois implanta em algumas de suas bacias um programa de governança colaborativa, que, através da mobilização da população, promove a integração desta com o corpo dágua. Diante deste panorama, o presente estudo, tem como intuito, através da análise de córregos de interesse do programa Córrego Limpo, contribuir para a melhor compreensão dos desafios envolvidos no processo de recuperação de corpos dágua urbanos através do controle de cargas pontuais e difusas. No estudo empregou-se o método da Unidade de carga para quantificação da geração de cargas difusas nas bacias e identificação do seu potencial poluidor, resultando na criação de um índice de qualidade da superfície da bacia; Avaliou-se também a qualidade ambiental destes corpos dágua através de indicadores físicos, químicos e biológicos, o que revelou a importância do uso conjunto destes indicadores, já que obteve-se resultados distintos para cada um destes indicadores; com base nos resultados obtidos nestes estudos foi possível avaliar o quão complexo é o processo de recuperação de corpos dágua em áreas urbanas. / With the consolidation of sanitation in some urban watersheds, a new challenge arises: the recovery of bodies of water. What at first appears to be a consequence of the process, in fact it shows to be a much more complex task and involves several facts, making the recovery process slow and costly. Much is said about the remediation of water bodies by removing point charge, but what we notice in practice is that even after controlling of point charge, they remain polluted because nonpoint pollution. The concern with nonpoint pollution is much studied in places where pollution by point charge already has an effective control, but this issue is still a challenge in countries like Brazil, where the control point charge does not constitutes a tangible reality. Currently, the São Paulo metropolitan area there are several programs working on recovering of water bodies through the control of point charge, including the Córrego Limpo that acts optimizing sewage systems, and is notorious the improvement in the quality of water bodies covered its actions. However, as the program based on controlling of point charge, the streams are not completely unpolluted. Considering the Brazilian case, the program is a pioneer when it comes to the adoption of measures that integrate the population in the recovering process. It deploys in some watersheds a program of collaborative governance that, through the people mobilization, promotes the body of water, resulting in reduction of the potential pollution in the watersheds and rendering more effective the process. The present study has the intention, through the analysis of streams of interest to the program Córrego Limpo, contribute to a better understanding of the challenges involved in the recovery process of urban water bodies through the control of the point and nonpoint pollution. In the study was used the method of unit load to quantify the generation of diffuse loads in basins and identification of their pollution potential, resulting in the creation of an index of quality of the surface of the basin, also evaluated the environmental quality of these bodies of water through physical, chemical and biological indicators, which revealed the importance of the combined use of these indicators, since we obtained different results for each of these indicators, the results of this study showed how complex is the recovery process of water bodies in urban areas.

Em caráter experimental, a tese examina o desempenho de sistemas de biorretenção na mitigação da poluição difusa ocasionada pelas águas de chuva. A avaliação dessa tecnologia ambiental urbana partiu da construção de um modelo de manejo dos escoamentos pluviais, utilizando uma matriz orgânica composta por vegetação, solo e agregados para retenção e tratamento inicial localizados. O protótipo, em escala 1:1, implementado na Cidade Universitária Armando Salles de Oliveira (CUASO-USP), São Paulo, SP, é composto por dois canteiros isolados entre si, que recebem as vazões através da sarjeta na via adjacente. Com preenchimentos iguais, os canteiros receberam coberturas vegetais distintas: gramado (G), com uma única espécie de gramínia, e jardim (J), com forrações, herbáceas e arbustos diversos, predominantemente nativos. O experimento foi monitorado por um ano, entre março de 2012 e março de 2013, quando foram coletados os dados referentes ao seu funcionamento e eficiência em sete eventos chuvosos paulistanos. A compilação dessas informações permitiu a análise comparativa da qualidade da água dos escoamentos antes e depois da passagem pelos canteiros. Com recursos da FUNDEP, FCTH e LabVERDE, a pesquisa interdepartamental e interdisciplinar, desenvolvida numa cooperação entre a FAU-USP e a Escola Politécnica-USP, busca oferecer respostas às hipóteses com que trabalha a Arquitetura da Paisagem ao propor soluções naturalizadas de manejo dos escoamentos pluviais em complementação às técnicas convencionais atualmente empregadas nas cidades brasileiras, tomando a cidade de São Paulo como cenário. Como efeito do processo histórico de canalização do seu patrimônio hídrico, ocupação das áreas de várzea e impermeabilização, a população paulistana e da RMSP tem sofrido com enchentes que se agravam com o crescimento urbano e com a intensificação das chuvas. As soluções imediatistas para essa situação crítica seguem a práxis das obras convencionais de engenharia, que segregam a drenagem urbana dos processos ecológicos e hidrológicos e não contribuem para melhoria da qualidade ambiental dos escoamentos antes de destiná-los aos corpos hídricos superficiais, o que agrava o quadro generalizado de poluição dos rios e córregos urbanos. Os resultados do experimento prático atestam o desempenho da biorretenção na mitigação da poluição difusa, com reduções médias das cargas poluidoras acumuladas de 89,94% para o gramado e 95,49% para o jardim, que foi comprovadamente mais eficiente. Aliados ao estudo de tipologias paisagísticas já utilizadas com sucesso em outras cidades do mundo, esses resultados poderão corroborar o processo de transição na infraestrutura de São Paulo, respaldando tecnicamente e cientificamente as soluções investigadas de manejo das águas de chuva através da biorretenção no tratamento dos espaços abertos e na conformação de uma Infraestrutura Verde na cidade. / This thesis experimentally assesses the performance of bioretention systems in mitigating nonpoint-source pollution caused by runoff. A 1:1 scale experiment of a stormwater management facility was built in USP Campus based in São Paulo, SP. This prototype has been evaluated for one year, since March 2012, over its technical efficiency to improve water quality by analyzing runoff samples collected in its inlet and outlet. Combining landscape architecture and hydraulic engineering knowledge, this experiment consists of two independent vegetated plots connected to the gutter through a concrete channel, which drives the runoff into the facility from the avenue next to it. Each plot has its own spillway, where samples were collected for laboratory analysis under 22 water quality parameters and thus compared to gutter runoff. Regarding construction techniques, it was decided to apply simplified solutions without unnecessary expenses, but that ensured feasibility, solidity and isolation to the plots from the ground on all faces. As for filling the model, it was chosen to use the same material for both facilities, laid out from bottom to surface: 60cm of broken rocks, 15cm of gravel, coconut geotextile fabric, 5cm of coarse sand and, finally, 45 to 75cm of planting substrate with side slopes and covered with mulch. Regarding vegetation cover, two sets of plants have been used in the bioretention cells as a research strategy to compare the efficiency among different models in stormwater management, considering other issues in addition to improving the environmental quality of water, such as maintenance, adaptation and development of species and visual interest. Thus, the experiment plots were filled with the same substrate but with different vegetable toppings, according to the following configuration: mixed garden (M) - ground covers with predominance of native shrubs and herbaceous vegetation, and lawn (L) - covered only with emerald grass carpet (Zoysia japonica), which has been extensively used for lawns all over the country. This experimental model has provided scientific answers that attest the effectiveness of techniques using vegetated surfaces to retain and treat stormwater. Its results have attested the performance of bioretention for diffuse pollution mitigation, with average reductions of accumulated pollutant loads of 89.94% in the lawn (L) and 95.49% in the mixed garden (M), which wasproven to be more efficient. This research developed by USP Faculty of Architecture and Urbanism in partnership with Polythecnic School, does not aim to threat conventional methods of urban drainage in local cities, but to join them in the efforts of reaching solutions and technical knowledge that are suitable for urban ecosystems and harmless to environment and landscape.