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The inverse problem method can be applied to determine the properties of hydrological phenomena and estimate the parameters, which cannot be measured directly. This type of inverse focus can facilitate the implementation of the kinematic wave model (direct model-DM), to fill gaps for lateral inflow rate and runoff depth in watersheds. Thus, the goal of the study was the application of the inverse problem method (IP). The lateral inflow rate was generally obtained as a Fourier transform to represent any watersheds. The study was developed using a small catchment in the Amazon where intense rainfall events occur, producing runoff and sediments, which affect rural populations. Lateral inflow rate and runoff depth were derived using precipitation data and parameters estimated through the KINEROS2 (K2)/direct model (DM) model and the ensuing solution methods with MCMC (Markov chains Monte Carlo)/Fourier transform. The developed method was applied to four rainfall-runoff events, leading to a good fit between the observed and predicted data (Nash-Sutcliffe coefficients between 0.76 and 0.85 and RMSE values between 1.80 mm and 6.72 mm).

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Surface hydrologic modeling becomes a problem when insufficient spatial and temporal information is available. It is common to have useful modeling periods of less than 15 years. The purpose of this work is to develop a methodology that allows the selection of meteorological and hydrometric stations that are suitable for modeling when information is scarce in the area. Based on the scarcity of data, a series of statistical tests are proposed to eliminate stations according to a decision-making process. Although the number of stations decreases drastically, the information used is reliable and of adequate quality, ensuring less uncertainty in the surface simulation models. Individual basin modeling can be carried out considering the poor data. The transfer of parameters can be applied through the nesting of basins to have information distributed over an extensive area. Therefore, temporally and spatially extended modeling can be achieved with information that preserves statistical parameters over time. If data management and validation is performed, the modeled watersheds are well represented; if this is not done, only 26% to 50% of the runoff is represented.

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Rotavirus is considered a directly transmitted disease due to its high infectivity. Environmental pathways have, therefore, largely been ignored. Rotavirus, however, persists in water sources, and both its surface water concentrations and infection incidence vary with temperature. Here, we examine the potential for waterborne rotavirus transmission. We use a mechanistic model that incorporates both direct and waterborne transmission pathways, coupled with a hydrological model, and we simulate rotavirus transmission between two communities with interconnected water sources. To parameterize temperature dependency, we estimated temperature-dependent decay rates in water through a meta-analysis. Our meta-analysis suggests that rotavirus decay rates are positively associated with temperature (n = 39, P [Formula: see text] 0.001). This association is stronger at higher temperatures (over 20 °C), consistent with tropical climate conditions. Our model analysis demonstrates that water could disseminate rotavirus between the two communities for all modeled temperatures. While direct transmission was important for disease amplification within communities, waterborne transmission could also amplify transmission. In standing-water systems, the modeled increase in decay led to decreased disease, with every 1 °C increase in temperature leading to up to a 2.4% decrease in incidence. These effect sizes are consistent with prior meta-analyses, suggesting that environmental transmission through water sources may partially explain the observed associations between temperature and rotavirus incidence. Waterborne rotavirus transmission is likely most important in cooler seasons and in communities that use slow-moving or stagnant water sources. Even when indirect transmission through water cannot sustain outbreaks, it can seed outbreaks that are maintained by high direct transmission rates.

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Constructed wetlands systems demand preliminary and primary treatment to remove solids present in greywater (GW) to avoid or reduce clogging processes. The current paper aims to assess hydraulic and hydrological behavior in an improved constructed wetland system, which has a built-in anaerobic digestion chamber (AnC), GW is distributed to the evapotranspiration and treatment tank (CEvaT), combined with a subsurface horizontal flow constructed wetland (SSHF-CW). The results show that both the plants present in the units and the AnC improve hydraulic and volumetric efficiency, decrease short-circuiting and improve mixing conditions in the system. Moreover, the hydraulic conductivity measured on-site indicates that the presence of plants in the system and the flow distribution pattern provided by the AnC might reduce clogging in the SSHF-CW. It is observed that rainfall enables salt elimination, thus increasing evapotranspiration (ET), which promotes effluent reduction and enables the system to have zero discharge when reuse is unfeasible.

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Los modelos hidrometeorológicos, facilitan el control, monitoreo y planificación del recurso agua en cuencas hidrográficas, representando variables meteorológicas de forma distribuida. El objetivo del estudio, es proponer modelos hidrometeorológicos bidimensionales para cuantificar de forma precisa, las variables básicas que determinan la dinámica del recurso hídrico en la cuenca del río Atulapa, Esquipulas, departamento de Chiquimula, Guatemala. Se generaron y recopilaron datos hidrometeorológicos, con estaciones digitales instaladas y estaciones locales. Para el desarrollo de los modelos se elaboró una correlación entre altitud de las estaciones meteorológicas, como variable explicativa y registros climáticos como variable de respuesta. El modelo de escorrentía es una correlación entre alturas limnimétricas en la estación hidrométrica, como variable explicativa y el caudal óptimo de los aforos como variable de respuesta. La precipitación media de la cuenca obtenida con los modelos generados, es de 1,884 mm/año y la temperatura media de 18.92°C. El cambio de temperatura entre la parte baja y alta disminuye a razón de 1°C por cada 175 m.snm. El caudal medio anual es a razón de 0.5 m3 /seg en la estación hidrométrica del Puente. Los modelos hidrometeorológico generados en la cuenca del río Atulapa representaron la variabilidad climática en forma bidimensional, permitiendo un control y monitoreo del recurso hídrico en la cuenca, para la planificación del uso sostenible. La orografía en la cuenca, definió la estrecha relación con las variables meteorológicas precipitación y temperatura obteniendo modelos de regresión lineal precisos.

The hydrometeorological models facilitate the control and monitoring of the water resource in watersheds, representing meteorological variables in a distributed way, for the planning of the water resource. The objective of the study is to propose two-dimensional hydrometeorological models to accurately quantify the basic variables that determine the dynamics of water resources in the Atulapa River basin, Esquipulas, department of Chiquimula, Guatemala. Hydrometeorological data were generated and collected, with installed digital stations and local stations. For the development of the models, a correlation was made between the altitude of the meteorological stations, as an explanatory variable and climatic records as a response variable. The runoff model is a correlation between limnimetric heights in the hydrometric station, as an explanatory variable and the optimum flow of the gauging as a response variable. The average precipitation of the basin obtained with the generated models is 1,884 mm/ year and the average temperature is 18.92°C. The temperature change between the low and high part decreases at a rate of 1°C for every 175 masl. The average annual flow is at a rate of 0.5 m3 /sec at the Puente hydrometric station. The hydrometeorological models generated in the Atulapa River basin represented the climatic variability in two-dimensional form, allowing a control and monitoring of the water resource in the basin, for the planning of the sustainable use. The orography in the basin, defined the close relationship with meteorological variables precipitation and temperature obtaining accurate linear regression models.

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Three challenges compromise the utility of mathematical models of groundwater and other environmental systems: (1) a dizzying array of model analysis methods and metrics make it difficult to compare evaluations of model adequacy, sensitivity, and uncertainty; (2) the high computational demands of many popular model analysis methods (requiring 1000's, 10,000 s, or more model runs) make them difficult to apply to complex models; and (3) many models are plagued by unrealistic nonlinearities arising from the numerical model formulation and implementation. This study proposes a strategy to address these challenges through a careful combination of model analysis and implementation methods. In this strategy, computationally frugal model analysis methods (often requiring a few dozen parallelizable model runs) play a major role, and computationally demanding methods are used for problems where (relatively) inexpensive diagnostics suggest the frugal methods are unreliable. We also argue in favor of detecting and, where possible, eliminating unrealistic model nonlinearities-this increases the realism of the model itself and facilitates the application of frugal methods. Literature examples are used to demonstrate the use of frugal methods and associated diagnostics. We suggest that the strategy proposed in this paper would allow the environmental sciences community to achieve greater transparency and falsifiability of environmental models, and obtain greater scientific insight from ongoing and future modeling efforts.

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As a consequence of the limited resources of underdeveloped countries and the limited interest of the developed ones, the assessment of the chemical quality of entire water bodies around the world is a utopia in the near future. The methodology described here may serve as a first approach for the fast identification of water bodies that do not meet the good chemical status demanded by the European Water Framework Directive (WFD). It also allows estimating the natural background (or reference values of concentration) of the areas under study using a simple criterion. The starting point is the calculation the World-Wide Natural Background Levels (WWNBLs) and World-Wide Threshold Values (WWTVs), two indexes that depend on the concentration of seven elements present in sediments. These elements, As, Cd, Cr, Cu, Ni, Pb and Zn, have been selected taking into account the recommendations of the UNEP (United Nations Environment Programme) and USEPA (United States Environmental Protection Agency), that describe them as elements of concern with respect to environmental toxicity. The methodology has been exemplified in a case study that includes 134 sediment samples collected in 11 transitional water bodies from 7 different countries and 4 different continents. Six of the water bodies considered met the good chemical status demanded by the WFD. The rest of them exceeded the reference WWTVs, at least for one of the elements. The estuaries of the Nerbioi-Ibaizabal (Basque Country) and Cavado (Portugal), the sea inlet of Río San Pedro (Spain), the Sepetiba Bay (Brazil) and the Yucateco lagoon (Mexico) belong to that group.

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In order to evaluate the hydraulic performance of stormwater infiltration trenches, a study was undertaken to assess clogging and its distribution between the bottom and the sides. The method used was based on the calibration of the hydraulic resistance event by event according to Bouwer's model and applied to a demonstration trench in Belo-Horizonte monitored in the framework of the European Project Switch. The calibration was performed by minimizing the distance between measured and modeled infiltration flow rates and by using continuous measurements of rainfall, inflow, water temperature and depth in the trench. The study showed that the methodology and particularly Bouwer's model was able to produce satisfactory results. It revealed a significant clogging evolution within a year, with global resistance increasing by a factor of 9. A significant difference between the bottom and the sides was observed; the bottom being more rapidly prone to clogging. Sudden fluctuations of the hydraulic resistance of the bottom were found that could be explained by very high concentrations of total suspended solids from inflows (about 2,000 mg/L). Clogging of the sides evolves over the time but with a very low rate.

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Desenvolveu-se este experimento para avaliar as alterações hidrológicas físico-químicas no cultivo de tilápia-do-nilo (Oreochromis niloticus) em raceway, com diferentes taxas de trocas de água, para estimar o impacto do manejo na qualidade hídrica. Foram analisados quatro tratamentos com troca total de água em 30, 90, 120 e 150 minutos. Utilizaram-se 1.500 alevinos, revertidos para machos, alimentados três vezes ao dia com ração comercial extrusada 36% e 32% de proteína bruta. Avaliaram-se as seguintes variáveis físico-químicas da água: oxigênio dissolvido, temperatura, alcalinidade, pH, sólidos em suspensão, turbidez, condutividade elétrica, fósforo, nitrito e nitrato. Todos os tratamentos testados mantiveram as variáveis analisadas dentro dos padrões sugeridos à criação de peixes, possibilitando racionalizar o uso da água de cultivo.(AU)

This experiment was carried to evaluate the hydrological alterations in the production of Nile tilapia (Oreochromis niloticus) in raceway, with different rates of water exchanges, to estimate the impact of this system on water quality. Four treatments with total exchange of water at 30, 90, 120 and 150 minutes were analyzed. A total of 1,500 fingerlings were used. They were reverted for male, fed three times a day with commercial extruded ration 36% and 32% of crude protein. The following hydrological parameters were evaluated: dissolved oxygen, temperature, alkalinity, pH, solids in suspension, turbidity, electrical conductivity, phosphorus, nitrite and nitrate. All tested treatments maintained the hydrological variables within patterns suggested for fish raising, rationalizing the use of water for cultivation.(AU)

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Desenvolveu-se este experimento para avaliar as alterações hidrológicas físico-químicas no cultivo de tilápia-do-nilo (Oreochromis niloticus) em raceway, com diferentes taxas de trocas de água, para estimar o impacto do manejo na qualidade hídrica. Foram analisados quatro tratamentos com troca total de água em 30, 90, 120 e 150 minutos. Utilizaram-se 1.500 alevinos, revertidos para machos, alimentados três vezes ao dia com ração comercial extrusada 36% e 32% de proteína bruta. Avaliaram-se as seguintes variáveis físico-químicas da água: oxigênio dissolvido, temperatura, alcalinidade, pH, sólidos em suspensão, turbidez, condutividade elétrica, fósforo, nitrito e nitrato. Todos os tratamentos testados mantiveram as variáveis analisadas dentro dos padrões sugeridos à criação de peixes, possibilitando racionalizar o uso da água de cultivo.

This experiment was carried to evaluate the hydrological alterations in the production of Nile tilapia (Oreochromis niloticus) in raceway, with different rates of water exchanges, to estimate the impact of this system on water quality. Four treatments with total exchange of water at 30, 90, 120 and 150 minutes were analyzed. A total of 1,500 fingerlings were used. They were reverted for male, fed three times a day with commercial extruded ration 36% and 32% of crude protein. The following hydrological parameters were evaluated: dissolved oxygen, temperature, alkalinity, pH, solids in suspension, turbidity, electrical conductivity, phosphorus, nitrite and nitrate. All tested treatments maintained the hydrological variables within patterns suggested for fish raising, rationalizing the use of water for cultivation.

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