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Characterization of the urban runoff from the city of Saskatoon to the South Saskatchewan riverMcLeod, Shaun M. 31 January 2007 (has links)
A major upgrade to the wastewater treatment plant in Saskatoon, Canada significantly improved the final effluent quality. Consequently, the relative impact of the citys urban runoff on the receiving stream, the South Saskatchewan River, has increased. Moreover, at the inception of the study, pending amendments to provincial legislation governing urban runoff were such that urban runoff would no longer be automatically exempt from regulation. In response to this impending change, which has since been made, Saskatchewan Environment initiated a study to examine the water quality of the urban runoff in Saskatoon, because little had been done to date involving the water quality of urban runoff in Saskatchewan.<p>The field program was conducted in 2001 and 2002 to collect representative urban runoff water quality and flow rate data from four different land uses: newer residential, older residential, commercial, and industrial. Three characterizations of the water quality were developed on the basis of the data collected: Site Mean Concentration (SMC), multiple variable regression models, and the unit load. The SMC results indicate that the average water quality parameter concentrations in Saskatoon are greater than those from NURP, the updated U.S. nationwide urban runoff database, and from Vancouver, Canada, but are similar to those from Wisconsin. The regression analyses indicate that the rainfall depth is the most frequently significant parameter in the prediction of event loads. The unit load analyses indicate that the commercial catchment produces the most pollutant load per unit area. Comparison of the methods indicates that the SMC can be used to estimate longer term urban runoff loads, in lieu of the more complex regression method.<p>Heavy metals, pesticides, and fecal coliforms were detected in the urban runoff at concentrations that exceed guideline values. Further investigation is recommended.<p>In comparison to the loads discharged by local point sources, urban runoff contributes larger total suspended solids (TSS) and total Kjeldahl nitrogen (TKN) loads to the South Saskatchewan River. The load of COD to the river is comparable to that of the Saskatoon Wastewater Treatment Plant (WWTP). The total phosphorus load contributed by urban runoff is slightly smaller than that of the WWTP. Considering the relative load of TSS from urban runoff to the WWTP and the potential for other, more toxic pollutants to adsorb to the TSS, sediment controls should be implemented at all levels of development. Further examination of urban runoff with specific emphasis on spring and winter runoff is recommended.
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Relações entre precipitação, escoamento e sedimentos suspensos na bacia do Rio das Antas, Goiás / Relationships between rainfall, runoff and suspended sediments in the Antas River watershed, GoiásDidonet, Thais Teodoro dos Santos Cordeiro 06 September 2017 (has links)
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Previous issue date: 2017-09-06 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Sediments transported by surface runoff and by rivers are essential components in the
comprehension of changes in a river basin and the quality of aquatic systems. The high variability
of rainfall events, the SSC and the relation between them produce complex behavioral dynamics
difficult to interpret but the study of these aspects is a useful and frequently used tool in the
quantification of impacts due to erosive and hydrossedimentological processes. The main objective
of this study was to characterize and quantify the hydrological, sedimentological and granulometric
characteristics of the urban watercourse of the Rio das Antas basin, located in Anápolis, Goiás,
wich faces various erosion processes. Continuous monitoring of precipitation, flow rates, sediment
concentrations and turbidity was performed using pluviographs, linigraphs, an automatic sampler
and a laser granulometer during most of a rainy season, where samples were collected and 14
events were analyzed. Descriptive statistical analyzes, identification of hysteresis patterns, Event
Mean Concentration, “first flush” phenomenon effects and grain size distribution and their
relationships with precipitations and flow rates were performed. The peak concentration of total
sediments reached 3,380 mg L -1 , and approximately 83% were suspended sediments. No “first
flush" has been recorded in any event. The highest mean concentration observed for suspended
sediments was 1,714.6 mg/m3 and the mean of the events was 1,001.3 mg/m3, values considered to
be high when compared to river basin flows, where the highest was 15.49 m 3 s -1 . The maximum
flow rates were determinant in the total sediment, however, the same flow range carried very
different amounts of suspended sediments during the floods. This behavior suggests that the
variation also depends on precipitation characteristics and sediment sources. In the hysteresis
analyzes, it can be verified that these sources are located farther from the monitoring point, but are
also the river itself, since the most frequent hysteresis loop was "Figure Eight" followed by the"Counter Clock-wise” type. There were complex hysteretic loops characterized by multiple peaks
of flow and sediments. The size of particles carried by the flow varies throughout the rainy season.
The suspended sediment particles had dimensions between 0.0019 mm and 0.990 mm being
characterized as sandy silt material. The small and medium particles were more frequent in final
events and larger particles occurred in the middle of the period. Finner particles were more present
during the rise of the hydrograph and in the recession phase the amount of particles with
dimensions between 0.2 mm e 0.6 mm increased in some events. Particles larger than 0.6 mm were
not related to precipitation. It was also observed that the amount of dissolved solids decreases with
increasing particle size and may indicate that larger particles have less capacity to absorb/adsorb
other pollutants. It is observed that the suspended sediments vary between the events and within
the same event and depends on the hydrological behavior, the characteristics of the water body and
the type of monitoring. / Os sedimentos transportados pelo escoamento superficial e pelos rios são componentes essenciais
no entendimento das mudanças ocorridas em uma bacia hidrográfica e da qualidade de sistemas
aquáticos. A alta variabilidade dos eventos chuvosos, da CSS e da relação entre eles produzem
dinâmicas comportamentais complexas de difícil interpretação. Porém o estudo destes aspectos é
uma ferramenta útil e frequentemente usada na quantificação dos impactos decorrentes de
processos erosivos e hidrossedimentológicos. Este estudo teve por objetivo caracterizar e analisar
quanti-qualitativamente as características hidrológicas, sedimentológicas e granulométricas dotrecho urbano da bacia do Rio das Antas, localizado no município de Anápolis, Goiás, o qual
enfrenta vários processos erosivos. Um monitoramento contínuo das precipitações, vazões,
concentrações de sedimentos e turbidez foi realizado utilizando pluvíografos, linígrafos, um
amostrador automático e um granulômetro a laser durante o período chuvoso, onde foram coletadas
amostras e analisados 14 eventos. Análises estatísticas descritivas, identificação dos padrões de
histerese, Concentração Média do Evento, efeitos de “first flush” e a distribuição granulométrica e
suas relações com as precipitações e vazões foram realizados. O pico de concentração de
sedimentos totais foi de 3.380 mg L -1 , sendo que, aproximadamente, 83% eram sedimentos
suspensos. Não foi registrado o fenômeno “first flush” em nenhum evento. A maior Concentração
Média do Evento observada para os sedimentos suspensos foi de 1.714,6 mg/m3 e a média dos
eventos foi de 1.001,3 mg/m3, valores considerados altos quando comparados as vazões de base do
rio, onde o maior pico registrado foi 15,49 m3 s -1 . As vazões máximas foram determinantes no total
de sedimentos, no entanto, uma mesma faixa de vazão transportou quantidades bem diferentes de
sedimentos suspensos durante as cheias. Este comportamento sugere que sua variação também
depende das características das precipitações e das fontes geradoras de sedimentos. Nas análises de
histerese, pode-se verificar que estas fontes estão presentes no próprio rio, mas também em locais
mais distantes do ponto de monitoramento, pois o laço de histerese mais frequente foi “Figura
Oito” seguido do tipo “Anti-horário”. Houveram laços histeréticos complexos caracterizados por
picos múltiplos de vazão e sedimentos. O tamanho das partículas transportadas pelo escoamento
varia em todo o período chuvoso. As partículas de sedimentos suspensos tinham dimensões entre
0,0019 mm e 0,990 mm sendo caracterizadas como material silte arenoso. As partículas pequenas e
médias foram mais frequentes nos eventos finais do período chuvoso e as partículas maiores
ocorreram no meio do período. Partículas mais finas estavam mais presentes durante a ascensão do
hidrograma e, na fase de recessão, a quantidade de partículas com dimensões entre 0,2 mm e 0,6
mm aumentava em alguns eventos. As partículas maiores que 0,6 mm não apresentaram relação
com a precipitação. Foi observado ainda que a quantidade de sólidos dissolvidos diminui com o
aumento do tamanho da partícula, podendo indicar que partículas maiores tem menor capacidade
de absorver/adsorver outros poluentes. Observa-se que os sedimentos suspensos variam entre os
eventos e dentro do mesmo evento e depende do comportamento hidrológico, das características do
corpo hídrico e do tipo de monitoramento.
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Performance Analysis of an Urban Stormwater Best Management Practice RetrofitSimko, Andrew Jack 22 September 2014 (has links)
Historically, the primary objective of traditional stormwater best management practices (BMPs) was to attenuate peak runoff discharges from urban areas. There has been growing demand to construct BMPs that improve stormwater runoff quality to reduce pollutant loading into downstream water bodies. A BMP located in Herndon, Virginia was retrofitted in 2009. Previously a dry detention pond, the new BMP design contains permanent wet pools as well as elements of Low Impact Development practices. A performance analysis was conducted on the retrofit to determine if the BMP was removing pollutants from stormwater runoff. Two mass-based methods were utilized for the performance analysis: the Summation of Loads Method and Effluent Probability Method. The Kaplan-Meier method and Robust Regression on ordered statistics (ROS) were used to make it possible to include censored datasets in the analysis. Analysis with the SOL method showed removal of suspended sediment, nitrogen, iron, and copper. Export of dissolved solids, phosphorus, organic carbon, and manganese was observed. The results of the Effluent Probability Method showed statistically significant reductions of sediment, iron, and copper across the entire range of monitored storm event sizes (p-value≤0.05). There was no statistical difference between the influent and effluent loads of nitrogen. Negative performance of dissolved solids, phosphorus, organic carbon, and manganese were observed for the entire range of monitored storm event sizes. The results of both methods indicated that the BMP retrofit is effectively removing sediment but failing to achieve significant nutrient reductions. This may be due to the creation of anoxic conditions from the oxygen demand of the micropool sediments and microbial degradation of vegetation within the BMP. Removal of the sediment bed and harvesting of the vegetation would likely improve the performance of the BMP. / Master of Science
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Modelagem da carga de poluição difusa em escala de bacia com valores de concentração média por evento a partir de dados de uma rede de monitoramento local / Modeling the diffuse pollution load at basin scale with event mean concentration values based on data from a local monitoring networkMartins, Renata Genova 06 April 2017 (has links)
As águas superficiais vêm sofrendo impactos em diversas cidades e o escoamento superficial tem sido uma das causas primárias de degradação dos recursos hídricos devido à poluição difusa, além das fontes pontuais, como efluentes domésticos e industriais. A Concentração Média do Evento (CME) tem sido muito utilizada para caracterizar a poluição difusa gerada no escoamento superficial durante o evento de precipitação, além de ser empregada como parâmetro de entrada na estimativa de carga de origem difusa por meio de modelos hidrológicos. Este estudo se dedicou especialmente à avaliação de como a CME influencia a estimativa de cargas difusas quando parâmetro de entrada para modelos hidrológicos. Para isso, além de atividades de campo visando à confecção de modelos de previsão da CME com base em dados reais de uma bacia hidrográfica urbana (Mineirinho, São Carlos, SP) em resposta a eventos chuvosos, buscou-se ajustar, à realidade brasileira, um modelo consagrado para estimativa de cargas difusas e aplicado principalmente em países com clima temperado. Os resultados desta pesquisa mostraram que, em geral, os valores de CME observados são de 2 a 12 vezes maiores que os encontrados na literatura internacional. Em comparação com estudos nacionais, observou-se uma variação nos dados encontrados dependendo das características da bacia hidrográfica monitorada. Além disso, ao adequar o modelo hidrológico L-THIA às características locais, verificou-se um aumento na estimativa da carga de origem difusa quando se utilizavam dados locais. Por fim, com base nas análises realizadas neste estudo, foi possível verificar que os valores de CME que melhor representam as características da bacia hidrográfica do Mineirinho são: nitrogênio total Kjeldahl 6,19 mg.L-1, fósforo total 1,00 mg.L-1, sólidos suspensos totais 870 mg.L-1, chumbo 0,78 mg.L-1, cobre 0,09 mg.L-1 e zinco 0,34 mg.L-1. Reforça-se, portanto, a necessidade de estudos locais para análise da poluição difusa para o planejamento de ações de mitigação de poluição difusa no Brasil. / Surface water has been impacted in several cities and surface runoff has been one of the primary causes of degradation of this resource due to nonpoint source pollution besides the point sources, like domestic effluents and industries. The Event Mean Concentration (EMC) has been widely used to characterize the diffuse pollution generated in the surface runoff during the precipitation event, and it is still used as input parameter in hydrological models that seek to estimate diffuse load. This study focused particularly on the evaluation of how the EMC influences the estimation of diffuse loads as input parameter for hydrological models. To that end, in addition to field activities for the preparation of EMC forecast models based on real data from a river basin in response to rainy events, we attempted to adjust to the Brazilian reality a well-established model for estimating diffuse loads and mainly applied in countries with temperate climate. The results of this research showed that, overall, the EMC observed values are from 2 to 12 times higher than those found in the international literature. Compared with national studies, a variation was observed in the data found depending on the characteristics of the monitored watershed. In addition, when adapting the L-THIA hydrological model to local characteristics, there was an increase in the diffuse source load estimate when using local data. Finally, based on the analyzes carried out in this study, it was possible to verify that the EMC values which best represent the characteristics of the Mineirinho river basin are: Total Kjeldahl Nitrogen 6.19 mg.L-1, Total Phosphorous 1.00 mg.L-1, Total Suspended Solids 870 mg.L-1, Lead 0.78 mg.L-1, Copper 0.09 mg.L-1 and Zinc 0.34 mg.L-1. Therefore, it is necessary to carry out local studies to analyze diffuse pollution in order to create a more solid basis for the planning of mitigation actions to control diffuse pollution in Brazil.
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Avaliação de cargas poluidoras e contaminantes emergentes na bacia hidrográfica Vacacaí - Vacacaí Mirim / Evaluation of emerging pollutants and contaminants loads in the Vacacai – Vacacai Mirim watershedPivetta, Glaucia Ghesti 19 January 2017 (has links)
The point and nonpoint source pollution released in rivers are the main responsible for the deterioration of the surface water quality. This study aimed to evaluate the water quality of the Vacacai – Vacacai Mirim watershed, in sub-basins located in the city of Santa Maria – RS. In the Vacacai Mirim River, the quality of the water and surface runoff were evaluated through the monitoring of five precipitation events in Joao Goulart sub-basin. The surface runoff negatively influenced the water quality of this water body. The EMC for the analysed parameters, as well as for the transported pollutants masses varied considerably among events. The average EMC for the BOD variable (51.3 mg∙L-1) stands out. The limit established for this variable for class 2 of CONAMA Resolution 357/2005 is only 5 mg∙L-1. Furthermore, the variability of the nonpoint source pollution in Vacacai Mirim River was evaluated in five sub-basins: João Goulart, Rancho do Amaral, Alto da Colina, Menino Deus II, and Menino Deus IV through cluster and principal components analysis using data from current and previous monitoring performed in this watershed. The five sub-basins were grouped according to the water quality and predominant land use and occupation. The BOD variable was essential in the water quality characterization of all sub-basins, and for the majority of them the total coliforms, E. coli, total solids, nitrogen and phosphorus variables were also essentials. In the Vacacai and Vacacai Mirim Rivers the presence of pharmaceutical and hormonal residues was studied in two urban sub-basins with large percentage of impermeable area. In Cancela-Tamandai sub-basin, the hormone etisterone and ibuprofen and paracetamol drugs were detected. The equivalent of 30 tablets of ibuprofen and 15 of paracetamol were released in this water body, on average per day. In the João Goulart sub-basin only the drugs ibuprofen and paracetamol were detected, hence the equivalent daily average load released in this water body is 52 tablets of ibuprofen and 14.5 of paracetamol. The hormones 17β-estradiol, estriol, estrone and megestrol acetate were not detected in the studied watersheds. Therefore, there is the necessity of investments to ensure the improvement of the sewage networks and treatment of domestic effluents, as well as the solid waste collection services. Together these sources contribute to the poor water quality confirmed in this study. / As fontes de poluição pontuais e difusas lançadas nos rios são as principais responsáveis pela degradação da qualidade da água superficial. Este estudo teve como objetivo avaliar a qualidade da água da bacia hidrográfica Vacacaí – Vacacaí Mirim, em sub-bacias localizadas no município de Santa Maria, RS. No rio Vacacaí Mirim, foi avaliada a qualidade da água e do escoamento superficial através do monitoramento de cinco eventos de precipitação na sub-bacia denominada João Goulart. O escoamento superficial impactou negativamente a qualidade da água desse corpo hídrico. As concentrações médias dos parâmetros analisados variaram consideravelmente entre os eventos, assim como as massas poluentes transportadas no curso hídrico. Destaca-se a concentração média do evento para a variável DBO, que foi 51,3 mg∙L-1, sendo que o limite estabelecido para a classe 2 da Resolução CONAMA 357/2005 é de apenas 5 mg∙L-1. Ainda no rio Vacacaí Mirim, foi avaliada a variabilidade da poluição difusa em cinco sub-bacias: João Goulart, Rancho do Amaral, Alto da Colina, Menino Deus II e Menino Deus IV por meio das análises estatísticas de agrupamento e componentes principais utilizando dados de monitoramento atual e realizados anteriormente nesta bacia. As cinco sub-bacias foram agrupadas conforme a qualidade da água e o uso e ocupação do solo predominante. A variável DBO foi importante na caracterização da qualidade da água de todas as sub-bacias, e para a maioria delas, as variáveis CT, E.coli, ST, nitrogênio e fósforo também foram importantes, pois são variáveis que descrevem a qualidade da água com elevada significância. Nos rios Vacacaí e Vacacaí Mirim foi investigada a presença de resíduos farmacêuticos e hormonais em duas sub-bacias urbanas e com grande porcentagem de área impermeável. Na sub-bacia Cancela-Tamandaí foram detectados o hormônio etisterona e os fármacos ibuprofeno e paracetamol. A partir das concentrações analisadas, estima-se que foi lançado nesse corpo hídrico, em média por dia, o equivalente a 30 comprimidos de ibuprofeno e 15 de paracetamol. Na sub-bacia João Goulart foram detectados apenas os fármacos ibuprofeno e paracetamol, sendo lançada a carga média diária equivalente a 52 comprimidos de ibuprofeno e 14,5 comprimidos de paracetamol nesse curso hídrico. Os hormônios 17 β-estradiol, estriol, estrona e acetato de megestrol nunca foram detectados nas bacias estudadas. Diante do exposto, verifica-se a necessidade de investimentos na melhoria de redes de coletas e tratamentos de efluentes domésticos, assim como os serviços de coleta de resíduos sólidos. Juntamente, essas fontes contribuem para má qualidade da água verificada nesse estudo.
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Modelagem da carga de poluição difusa em escala de bacia com valores de concentração média por evento a partir de dados de uma rede de monitoramento local / Modeling the diffuse pollution load at basin scale with event mean concentration values based on data from a local monitoring networkRenata Genova Martins 06 April 2017 (has links)
As águas superficiais vêm sofrendo impactos em diversas cidades e o escoamento superficial tem sido uma das causas primárias de degradação dos recursos hídricos devido à poluição difusa, além das fontes pontuais, como efluentes domésticos e industriais. A Concentração Média do Evento (CME) tem sido muito utilizada para caracterizar a poluição difusa gerada no escoamento superficial durante o evento de precipitação, além de ser empregada como parâmetro de entrada na estimativa de carga de origem difusa por meio de modelos hidrológicos. Este estudo se dedicou especialmente à avaliação de como a CME influencia a estimativa de cargas difusas quando parâmetro de entrada para modelos hidrológicos. Para isso, além de atividades de campo visando à confecção de modelos de previsão da CME com base em dados reais de uma bacia hidrográfica urbana (Mineirinho, São Carlos, SP) em resposta a eventos chuvosos, buscou-se ajustar, à realidade brasileira, um modelo consagrado para estimativa de cargas difusas e aplicado principalmente em países com clima temperado. Os resultados desta pesquisa mostraram que, em geral, os valores de CME observados são de 2 a 12 vezes maiores que os encontrados na literatura internacional. Em comparação com estudos nacionais, observou-se uma variação nos dados encontrados dependendo das características da bacia hidrográfica monitorada. Além disso, ao adequar o modelo hidrológico L-THIA às características locais, verificou-se um aumento na estimativa da carga de origem difusa quando se utilizavam dados locais. Por fim, com base nas análises realizadas neste estudo, foi possível verificar que os valores de CME que melhor representam as características da bacia hidrográfica do Mineirinho são: nitrogênio total Kjeldahl 6,19 mg.L-1, fósforo total 1,00 mg.L-1, sólidos suspensos totais 870 mg.L-1, chumbo 0,78 mg.L-1, cobre 0,09 mg.L-1 e zinco 0,34 mg.L-1. Reforça-se, portanto, a necessidade de estudos locais para análise da poluição difusa para o planejamento de ações de mitigação de poluição difusa no Brasil. / Surface water has been impacted in several cities and surface runoff has been one of the primary causes of degradation of this resource due to nonpoint source pollution besides the point sources, like domestic effluents and industries. The Event Mean Concentration (EMC) has been widely used to characterize the diffuse pollution generated in the surface runoff during the precipitation event, and it is still used as input parameter in hydrological models that seek to estimate diffuse load. This study focused particularly on the evaluation of how the EMC influences the estimation of diffuse loads as input parameter for hydrological models. To that end, in addition to field activities for the preparation of EMC forecast models based on real data from a river basin in response to rainy events, we attempted to adjust to the Brazilian reality a well-established model for estimating diffuse loads and mainly applied in countries with temperate climate. The results of this research showed that, overall, the EMC observed values are from 2 to 12 times higher than those found in the international literature. Compared with national studies, a variation was observed in the data found depending on the characteristics of the monitored watershed. In addition, when adapting the L-THIA hydrological model to local characteristics, there was an increase in the diffuse source load estimate when using local data. Finally, based on the analyzes carried out in this study, it was possible to verify that the EMC values which best represent the characteristics of the Mineirinho river basin are: Total Kjeldahl Nitrogen 6.19 mg.L-1, Total Phosphorous 1.00 mg.L-1, Total Suspended Solids 870 mg.L-1, Lead 0.78 mg.L-1, Copper 0.09 mg.L-1 and Zinc 0.34 mg.L-1. Therefore, it is necessary to carry out local studies to analyze diffuse pollution in order to create a more solid basis for the planning of mitigation actions to control diffuse pollution in Brazil.
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Modelling of nonpoint source pollution in the Kuils River Catchment, Western Cape - South AfricaAyuk, James Ayuk January 2008 (has links)
>Magister Scientiae - MSc
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Modelling of nonpoint source pollution in the Kuils River catchment, Western Cape - South AfricaAyuk, James Ayuk January 2008 (has links)
>Magister Scientiae - MSc / The Kuils River Catchment is an urban river catchment that forms part of the larger Kuils-Eerste River system draining the eastern half of the Cape Metropolitan Authority area and Stellenbosch Municipality. Rapid urbanisation has resulted in the encroachment of residential and industrial areas into the river system through channelization and sewage disposal. This research project intends to assess the quality of surface runoff in the Kuils River catchment and determining non-point source pollutant loading rates in the catchment using GIS-based modelling. The study results show how modelled potential sources of surface runoff and NPS pollutants using desktop GIS analysis tools in a sequential process that involved different levels of software applications could explain the characteristics of the catchment. With the help
of the Expected Mean Concentration (EMC) values associated with surface runoff from land use/covers, NPS pollutant loads were assessed downstream towards the Kuils River Catchment outlet using the Nonpoint Source Pollution and Erosion Comparison Tool (N-SPECT) based in ArcGIS. The outputs from this model consist of predicted annual pollutant loading (mg/mvyear) for each Kuils-Eerste River that
occurs in the catchment. The results have shown clearly the spatial distribution of sources of particular pollutants in the catchment. Further or advanced processing knowhow with this model might provide far reaching insights into the problem and it is however recommended that these results produced using N-SPECT be compared to those of other hydrologic models using the same inputs.
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