Dissolved organic carbon (DOC) is composed of a diverse array of compounds, predominantly humic substances, and is a near ubiquitous component of natural groundwater, notwithstanding climatic extremes such as arid and hyper-arid settings. Despite being a frequently measured parameter of groundwater quality, the complexity of DOC composition and reaction behaviour means that links between concentration and human health risk are difficult to quantify and few examples are reported in the literature. Measured concentrations from natural/unpolluted groundwater are typically below 4 mg C/l, whilst concentrations above these levels generally indicate anthropogenic influences and/or contamination issues and can potentially compromise water safety. Treatment processes are effective at reducing DOC concentrations, but refractory humic substance reaction with chlorine during the disinfection process produces suspected carcinogenic disinfectant by-products (DBPs). However, despite engineered artificial recharge systems being commonly used to remove DOC from recycled treated wastewaters, little research has been conducted on the presence of DBPs in potable groundwater systems. In recent years, the capacity to measure the influence of organic matter on colloidal contaminants and its influence on the mobility of pathogenic microorganisms has aided understanding of transport processes in aquifers. Additionally, advances in polymerase chain reaction techniques used for the detection, identification, and quantification of waterborne pathogens, provide a method to confidently investigate the behaviour of DOC and its effect on contaminant transfer in aquifers. This paper provides a summary of DOC occurrence in groundwater bodies and associated issues capable of indirectly affecting human health.

La Verticilosis del olivo (VO) causada por el hongo de suelo y colonizador vascular Verticillium dahliae Kleb., es la enfermedad más grave de este cultivo desde las perspectivas fitopatológica y económica. En el contexto actual de una creciente superficie de olivar en regadío unido al conocimiento de que el riego afecta a la VO y a la posible presencia de V. dahliae en el agua de riego en Andalucía, no solo es importante saber qué estrategia de riego (con agua no infestada) puede contribuir a paliar la VO sino también conocer el estado fitosanitario respecto a V. dahliae del agua de riego para desinfestarla en el caso de estar contaminada. Separar los efectos del agua sobre el desarrollo de la VO de los efectos del aporte reiterado de inóculo a través del agua de riego ayudaría a comprender mejor porqué el riego influye en la VO y a poder integrar ambas medidas de manejo cuando las circunstancias lo requieran. El primer objetivo de este trabajo consistió en evaluar el efecto del riego sobre V. dahliae en el suelo y sobre la VO, ya que para un manejo integrado eficaz de la VO es importante establecer si los tratamientos de riego (usando agua libre de V. dahliae) que minimizan la enfermedad, también reducen el inóculo más y menos persistente del patógeno en el suelo. Para ello, se dispuso un ensayo con la combinación susceptible cultivar de olivo Picual-aislado defoliante (altamente virulento) de V. dahliae bajo condiciones de ambiente natural, donde los plantones crecieron en macetas de grandes dimensiones y se regaron para dos rangos de contenidos de agua en el suelo (RCA; alto y bajo) a tres frecuencias de riego superficial por goteo. En el suelo infestado e independientemente de la temperatura y del RCA, los eventos diarios de riego condujeron a mayores reducciones en la incidencia (39.2%) e índice de intensidad de la enfermedad (43.9%) en los plantones que otras frecuencias de riego, así como de micropropágulos (MpD), o propágulos del hongo menos persistentes (88.0%) en el suelo. A su vez, el RCA alto ocasionó menores niveles de esclerocios o estructuras más persistentes (70.8-84.9%) en el suelo pero un mayor porcentaje de plantones infectados (18.0%) que el RCA bajo, con independencia de la frecuencia de riego. El riego diario a RCA bajo mitigó el desarrollo de la VO y redujo la incidencia de infección, manteniendo el suelo a los niveles más bajos de MpD y resultando en la menor cantidad de esclerocios en el suelo tras dos años y medio. Bajo las condiciones anteriormente descritas (los mismos tratamientos de riego), el siguiente objetivo fue comparar las respuestas morfológicas y fisiológicas en plantones de olivo crecidos en suelo infestado y no infestado por V. dahliae sometidos a tratamientos de riego por goteo que causan reacciones diferenciales a la VO, y determinar cuáles de estas respuestas ayudan a explicar los efectos del riego sobre la enfermedad. De manera general, las respuestas comparadas fueron afectadas por el RCA, la frecuencia de riego y V. dahliae como factores simples. El hongo redujo los parámetros morfológicos y fisiológicos. El riego a RCA alto resultó en una relación de peso seco raíz/planta completa más baja que el RCA bajo, lo que pudo favorecer las infecciones radiculares y la colonización vascular a RCA alto. Además, el riego diario pudo prevenir el incremento en síntomas característico de otras frecuencias de riego por ocasionar los mayores incrementos de crecimiento en longitud y biomasa de la parte aérea del plantón junto con los valores más altos de potencial hídrico, mejorados por una reducción menor de la conductancia estomática. El último objetivo consistió en evaluar la eficacia de la desinfestación química del agua para reducir las conidias de V. dahliae. Tres desinfestantes se testaron por su eficacia frente a infestaciones por conidias previas (eficacia supresiva) y subsiguientes (eficacia preventiva) al tratamiento químico en función de la concentración del desinfestante y la virulencia diferencial de los aislados de V. dahliae sobre olivo. Las concentraciones recomendadas para OX-VIRIN® y OXAGUA AL 25®, basados principalmente en agentes oxidantes y no oxidantes, respectivamente, mostraron mayor eficacia supresiva y preventiva que las recomendadas para el producto a base de hipoclorito de sodio. Los ensayos de simulación de la desinfestación del agua embalsada infestada con conidias realizados en ambiente natural en primavera, demostraron que OX-VIRIN® aplicado cada 28 días al agua a una concentración recomendada por el fabricante fue 100% eficaz después de 56 días. En el contexto actual del olivar en regadío, los resultados obtenidos suponen un avance significativo con relación al manejo del riego para el control integrado de la VO. Se ha demostrado que determinadas estrategias de riego reducen el desarrollo de VO, la infección de los plantones, los propágulos menos persistentes de V. dahliae en el suelo y a medio plazo también los esclerocios; las mismas estrategias de riego en presencia del hongo en el suelo son las que disminuyen menos el uso eficiente del agua y el potencial hídrico entre otros. Existen desinfestantes que aplicados directamente al agua reducen considerablemente a V. dahliae pudiendo disminuir el incremento del hongo en el suelo. | Verticillium wilt of olive (VWO), caused by the vascular-colonizing, soilborne fungus Verticillium dahliae Kleb., is the most serious disease affecting this crop, in terms of the potential phytopathological and economic consequences. The current context of an ever-expanding area dedicated to irrigated olive groves, together with the knowledge that irrigation affects VWO and the possible presence of V. dahliae in irrigation water in Andalusia, makes it important to not only determine which irrigation strategy (with non-infested water) may help mitigate VWO, but also to know the phytosanitary status of irrigation water in terms of V. dahliae infestation, so that it can be disinfected if it is contaminated. Separating the effects of water on the development of VWO from the effects of repeated inoculum supply through irrigation water would help to better understand why irrigation has an effect on VWO, and thus to be able to integrate both management measures when circumstances require it. The first objective of this study was to evaluate the effect of irrigation on V. dahliae in soil and on VWO since, to ensure efficient integrated management of VWO, it is important to establish whether irrigation treatments (with V. dahliaefree water) that mitigate the disease, also reduce the levels of more and less persistent propagules of the pathogen in the soil. To that end, a trial was carried out with the Picual olive cultivar and a highly virulent V. dahliae defoliating isolate. The susceptible combination was placed under natural environmental conditions, where plants were grown in large pots and were irrigated to two ranges of soil water content (RWC; high and low) at three surface drip-irrigation frequencies. In the infested soil, regardless of temperature and RWC, daily irrigation events led to greater reductions in disease incidence (39.2%) and disease intensity index (43.9%) than in plants under other irrigation frequencies, as well as to greater reductions in micropropagules (MpD), or less persistent fungus propagules, in the soil (88.0%). On the other hand, high RWC caused lower levels of sclerotia, or more persistent structures, in the soil (70.8-84.9%), but a higher percentage of infected plants (18.0%) than low RWC, regardless of the frequency of irrigation. Daily irrigation to low RWC helped halt the development of VWO and reduced the incidence of infection, keeping the soil at the lowest levels of MpD and resulting in the least amount of sclerotia in the soil after two and a half years. Under the conditions described above (the same irrigation treatments), the next objective was to compare the morphological and physiological responses in olive plants grown on V. dahliae-infested and non-infested soil, subjected to drip irrigation treatments that cause differential reactions in terms of VWO. The aim was to determine which of these responses help explain the effects of irrigation on the disease. In general, the comparative responses were affected by RWC, irrigation frequency and V. dahliae, as simple factors. The fungus showed reduced morphological and physiological parameters. High RWC irrigation resulted in a lower root weight ratio than with low RWC, meaning that high RWC could favour root infections and vascular colonization. In addition, daily irrigation could prevent the increase in symptoms characteristic of other irrigation frequencies, as a result of the greater growth increases in length and biomass of the aerial part of the plants associated with this irrigation frequency, together with highest water potential values, improved by lower stomatal conductance reduction. The last objective was to evaluate the efficacy of chemical water disinfestation in reducing V. dahliae conidia. Three disinfestants were tested for their efficacy against previous (suppressive efficacy) and subsequent (preventive efficacy) conidia infestations, as a function of the concentration of the disinfestant and the differential virulence of V. dahliae isolates to olive trees. The recommended concentrations for OX-VIRIN® and OX-AGUA AL 25®, which are based primarily on oxidizing and non-oxidizing agents, respectively, showed greater suppressive and preventive efficacy than those recommended for the product based on sodium hypochlorite. Simulated disinfestation assays of stored and conidia-infested water performed under natural environmental conditions in spring demonstrated that OX-VIRIN® applied every 28 days to water at a concentration recommended by the manufacturer was 100% effective after 56 days. In the current context of expanding irrigated olive groves, the results obtained represent a significant advance in relation to irrigation management for the integrated control of VWO. It has been demonstrated that certain irrigation strategies reduce the development of VWO, the infection of the plants, the amount of less persistent propagules of V. dahliae in the soil and, in the medium term, also the sclerotia. In the presence of the fungus in the soil, those same irrigation strategies are the ones that least diminish the efficient water use and the water potential, among others. Disinfestants have also been identified which, when directly applied to the irrigation water, result in considerable reductions in V. dahliae and can help limit the increase of the fungus in the soil.

Las instituciones gubernamentales deben promover el uso eficiente de los recursos, buscando así la prevención y la mitigación de los impactos ambientales negativos generados por su consumo al interior de la entidad. Por lo tanto, el presente Plan pretende articular los actuales programas existentes dentro del PIGA de ahorro y uso eficiente de agua y energía bajo una misma estructura metodológica, estableciendo el estado actual de los servicios públicos dentro de la entidad, generando a partir de ello acciones y estrategias que permitan el logro de los objetivos de ahorro y uso eficiente, en pro del bienestar laboral de los funcionarios, contribuyendo a la efectividad económica y socioambiental. | Government institutions must promote the efficient use of resources, seeking to prevent and mitigate the negative environmental impacts generated by their consumption within the entity. Therefore, this Plan aims to articulate the existing programs within the PIGA for saving and efficient use of water and energy under the same methodological structure, establishing the current state of public services within the entity, generating from this actions and strategies that allow the achievement of the objectives of saving and efficient use, in favor of the labor welfare of the employees, contributing to the economic and socio-environmental effectiveness.

Resumo Este estudo avaliou a viabilidade do aproveitamento da água das chuvas no Tanque de Provas, utilizado em ensaios de modelos reduzidos de embarcações da Faculdade de Tecnologia de Jahu - Fatec Jahu, SP. O trabalho considerou os dados pluviométricos locais, a área de cobertura para captação e a demanda de água. Foi estimada a necessidade de água no processo de limpeza por filtragem, lavagem e evaporação do Tanque de Provas. O dimensionamento do reservatório foi calculado conforme as metodologias descritas na NBR 15527, que determina os requisitos para o aproveitamento de coberturas em áreas urbanas para fins não potáveis. O volume do reservatório selecionado como a melhor alternativa após as análises comparativas considerou as restrições locais e o risco de não atendimento, permitiu o máximo aproveitamento da água pluvial e resultou na maior redução possível da demanda de água potável do sistema de abastecimento público. | Abstract This paper explores the possibility of harvesting rainwater in a Testing Tank used to test scale models of boats and ships in Jahu College of Technology, São Paulo State. We considered local rainfall data, the coverage area for catchment and the demand for water. Water demand was estimated for cleaning, filtering and evaporation processes in the Testing Tank. The dimensions of the reservoir were calculated according to the methodologies described in the NBR 15527, which prescribes the requirements for the use of roofs in urban areas for the catchment of rainwater for non-potable purposes. The volume of the reservoir selected enabled the best use of rainwater and resulted in a better reduction of water demand on the public supply system. It was chosen as the best alternative after comparative analysis considering the local restrictions and the risk of non-compliance.

Drinking water monitoring plans are important to characterize both treated and untreated water used for drinking purposes. Access to drinking water increased in recent years as a response to the Millennium Development Goals set for 2015. The new Sustainable Development Goals aim to ensure universal access to safe drinking water by 2030. Within the framework of these global goals, it is crucial to monitor local drinking water systems. In this paper, treated and untreated water from different sources currently consumed in a specific town in Salta, northern Argentina, was thoroughly assessed. Monitoring extended along several seasons and included the physical, chemical and microbiological variables recommended by the Argentine Food Code. On the one hand, treated water mostly complies with these standards, with some non-compliances detected during the rainy season. Untreated water, on the other hand, never meets microbiological standards and is unfit for human consumption. Monitoring seems essential to detect anomalies and help guarantee a constant provision of safe drinking water. New treatment plants are urgently needed to expand the water grid to the entire population.

Ingeniero Químico | Pregrado

"Un tren convencional de tratamiento de agua potable tiene: 1) Coagulación, 2) Floculación, 3) Sedimentación, 4) Filtración, 5) Desinfección. Se tiene entonces una alta probabilidad de formación de subproductos de desinfección (SPDs) en situaciones donde el afluente tenga altas trazas de materia orgánica natural (MON) que posteriormente pueda reaccionar con desinfectantes como Cl2, cloraminas, O3, entre otros. Es claro que el intento por controlar los SPDs no puede poner en peligro la desinfección, ya que los riesgos en una desinfección deficiente son mucho mayores que los de consumo de SPDs. (Organización Mundial de la Salud, 2006) Es ahí donde los procesos de adsorción, ampliamente utilizados en contextos de importancia tecnológica, biológica y ambiental, entran a perfeccionar la calidad del efluente obtenido disminuyendo el riesgo de ingesta de SPDs. El carbón activado granular (GAC), material utilizado por excelencia, tiene la capacidad de retener contaminantes como pesticidas, herbicidas, detergentes, hidrocarburos aromáticos policíclicos (HAP)..." -- Tomado del Formato de Documento de Grado | "A conventional train for drinking water treatment has: 1) Coagulation, 2) Flocculation, 3) Sedimentation, 4) Filtration, 5) Disinfection. There is then a high probability of formation of disinfection byproducts (SPDs) in situations where the affluent has high traces of natural organic matter (MON) that can later react with disinfectants such as Cl2, chloramines, O3, among others. It is clear that the attempt to control the SPDs can not endanger the disinfection, since the risks in a deficient disinfection are much greater than those of SPD consumption. (World Health Organization, 2006) This is where adsorption processes, widely used in contexts of technological, biological and environmental importance, begin to improve the quality of the effluent obtained by reducing the risk of intake of SPDs. Granular activated carbon (GAC), the material used for excellence, has the capacity to retain contaminants such as pesticides, herbicides, detergents, polycyclic aromatic hydrocarbons (PAH)..." -- Tomado del Formato de Documento de Grado | Ingeniero Ambiental | Pregrado

Os lagostins de água doce são crustáceos encontrados em várias regiões do mundo, com a ocorrência das famílias Astacidae e Cambaridae no hemisfério norte e Parastacidae no hemisfério sul. Os parastacídeos estão distribuídos em quase todos continentes, com a exceção da Antártida e o continente africano. Na América do Sul são conhecidas 16 espécies, pertencentes a três gêneros: Virilastacus Hobbs 1991, Samastacus Riek 1971 e Parastacus Huxley 1879, que podem ocupar ambientes permanentes e temporários. Embora existam informações sobre riqueza de espécies, distribuição e biologia, os dados são insuficientes. Assim, o primeiro capítulo traz a atualização dos dados sobre a distribuição e o reconhecimento de registros de espécies simpatria e sintopia para as espécies sulamericanas. A caracterização dos habitats ocupados pelos lagostins foi também realizada, mas somente para as espécies da porção Atlântica do continente. Os dados de ocorrência foram compilados das coleções zoológicas (CZ), da literatura publicada e das amostragens na região sul do Brasil (Rio Grande do Sul - RS e Santa Catarina - SC). No total, foram obtidos 51 novos registros de ocorrência para América do Sul; incluindo a presença de Parastacus fluviatilis Ribeiro & Buckup, 2016 no lugar mais alto do RS e a captura de P. saffordi Faxon, 1898 quase quatro décadas após a revisão taxonômica do gênero Parastacus. A ocorrência de espécies em simpatria e sintopia foi confirmada, destacando o registro inédito de quatro espécies em um buffer < 5 km no Chile. Os dados obtidos neste estudo representam um avanço sobre o conhecimento da distribuição e a ocupação do habitat, podendo ser usados para melhorar a precisão da avaliação dos riscos de extinção, por exemplo. As ameaças à sobrevivência dos lagostins de água doce na América do Sul são numerosas e estão relacionadas aos impactos diretos na estrutura do hábitat, como poluição, canalização de cursos d’água e drenagem de áreas úmidas. Entretanto, uma potencial e silenciosa ameaça não tem sido considerada, que são as mudanças climáticas ao longo da distribuição das espécies. O segundo capítulo utilizou o conhecimento atual da ocorrência das espécies para projetar os efeitos das mudanças climáticas sobre a distribuição delas. As principais alterações estimadas foram expansão ou redução do tamanho da área geográfica em dois cenários: atual e 2070. Os dados de ocorrência contabilizaram 216 locais de presença que foram reunidos em quatro grupos: aquáticos, semiaquáticos, semiterrestres Atlântico e semiterrestres Pacífico. O desempenho dos modelos foi avaliado de bom a ótimo e a adequabilidade das áreas no cenário atual foi < 100.000 km² para todos os grupos. A temperatura foi a variável que mais contribuiu para a construção dos modelos (presente e futuro). Potencialmente, esta variável foi responsável pela expansão da área de distribuição das espécies em 2070. Assim, os lagostins apresentaram uma tendência à ocupação de regiões mais altas e menos impactadas pelas ações humanas. Portanto, sugerimos que a atenção seja voltada à conservação das espécies dos grupos semiterrestres da porção Atlântico e do Pacífico. As áreas ocupadas pelas espécies apresentaram alta complexidade ambiental e diferentes níveis de fragmentação. Além disso, as zonas úmidas tendem a desaparecer mais rápido, devido às interferências do clima na dinâmica dos ecossistemas de água doce. Diante das potenciais modificações do hábitat das espécies e a perda recente de áreas dentro da distribuição dos lagostins, a caracterização genética das populações traz uma nova abordagem sobre a fauna e a conservação dos organismos. Dessa forma, o terceiro capítulo investiga a diversidade genética intraespecífica de Parastacus brasiliensis (von Martens 1869) no sul do Brasil. A reconstrução filogenética foi utilizada para identificar a diversidade críptica a partir de marcadores mitocondriais e nucleares. As análises indicaram a existência de cinco unidades evolutivas e somente uma pode ser considerada como Parastacus brasiliensis sensu stricto. A distância genética entre P. brasiliensis sensu stricto e as demais linhagens “A”, “B” e “C” aumenta com distância geográfica, sugerindo que o isolamento por distância pode ser um importante fator de diversificação e eventualmente especiação para os lagostins escavadores. Além disso, uma das quatro linhagens corresponde à subespécie Parastacus brasiliensis promatensis Fontoura & Conter 2008, que foi elevada para o nível de espécie. De acordo com esta pesquisa, P. brasiliensis ocorre principalmente na Bacia do Lago Guaíba. As populações estudadas no Guaíba I e Guaíba II apresentaram conectividade e fluxo gênico limitado, provavelmente devido à fragmentação do habitat. Com base nos dados de distribuição e genética, o estado de conservação de P. brasiliensis foi estabelecido como Quase Ameaçada - “Near Threatened”, conforme a IUCN. Estes resultados nos encorajam a propor uma área de preservação para a população isolada do Guaíba II e enfatiza a importância de preservar estes distintos “pools” para a manutenção da diversidade genética desta espécie. O conhecimento limitado sobre os lagostins de água doce e os efeitos das ações antrópicas sobre as populações, reforçam a importância da continuidade de investigações desse cunho. Outras abordagens podem ser conduzidas a partir dos dados gerados nesta tese como ponto de partida, utilizando os lagostins como uma ferramenta de análise da paisagem, mudanças climáticas e urbanização. | Freshwater crayfishes are crustaceans found in several regions of the world, with the occurrence of the Astacidae and Cambaridae families in the northern hemisphere and Parastacidae in the southern hemisphere. Parastacids are distributed on almost all continents except Antartida and the African continent. In South America 16 species belonging to three genera are known: Virilastacus Hobbs 1991, Samastacus Riek 1971 e Parastacus Huxley 1879, which could occupy permanent and temporary environments. Although there is information on species richness, distribution and biology, the data are insufficient. Thus, the first chapter brings an update on the distribution of crayfishes in South America and the recognition of sympatry and sintopy records. The characterization of the occupied habitat by crayfishes was also carried out, but only for the species that occur in Atlantic portion. Occurrence data were compiled from the records of zoological collections (ZC), literature and samplings performed in southern Brazil (states of Rio Grande do Sul - RS and Santa Catarina – SC). In total, 51 new occurrence records were obtained; including the presence of Parastacus fluviatilis Ribeiro & Buckup, 2016 at the highest place on RS and the capture of P. saffordi Faxon, 1898 almost four decades after the last taxonomic revision of Parastacus. Species occurring in sympatry and sintopy were confirmed, highlighting unpublished record of four species within a buffer < 5 km in Chile. Therefore, the data obtained in this study represent an advance on the knowledge of distribution and habitat occupation, which could be used to improve the precision of extinction risk assessments, for example. The threats to the survival of freshwater crayfish from South America are numerous and closely related to impacts in habitat structure, such as pollution, watercourse canalization and wetland drainage. Nevertheless, a potential and silent threat has not been considered: the climate changes along the species’ distribution. The second chapter used the current knowledge on species occurrence to project the effects of climate changes on distribution. The main alterations estimated were the expansion or reduction in the size of geographical ranges in two scenarios: present and 2070. Occurrence data accounted 216 presence sites that were gathered in four groups: aquatic, semi-aquatic, Atlantic semi-terrestrial and Pacific semi-terrestrial. The model performance was evaluated from good to optimal and suitable areas in the present scenario were < 100, 000 km² for all groups. Temperature was the variable that most contributed for the building of models (present and future). It was potentially, responsible for the expansion of the species’ distribution area in 2070. Thus, crayfishes show a tendency to occupy higher regions that are less disturbed by human actions. Therefore, we suggest that immediate attention must be paid to the conservation of the Atlantic and Pacific semi-terrestrial groups. Areas occupied by these species presented high environmental complexity and different levels of fragmentation. In addition, wetlands tend to disappear faster due to climate influences on the dynamic of freshwater ecosystems. In the face of potential modifications to the species’ habitats and the recent loss of areas within the current crayfish distribution, the genetic characterization of populations brings a new approach to the study of fauna and the conservation of organisms. Thus, the third chapter investigates the intraspecific genetic diversity of Parastacus brasiliensis (von Martens 1869) in South America. Phylogenetic reconstructions based on mitochondrial and nuclear markers were used to identify cryptic diversity. Analyses indicated the existence of five evolutionary significant units and only one can be considered as P. brasiliensis sensu stricto. Genetic distances among P. brasiliensis sensu stricto and the remaining lineages “A”, “B” and “C” increase with geographical distances, suggesting isolation by distance as an important driver of diversification and eventual speciation in these burrowing crayfishes. In addition, one of the other four units corresponds to the subspecies Parastacus brasiliensis promatensis Fontoura & Conter 2008, which is here elevated to species level. According to this study, P. brasiliensis occurs mainly in the Guaíba Lake basin. The studied populations Guaíba I and II show limited connectivity and gene flow, probably due to habitat fragmentation. Based on genetic and distribution data, the conservation status of P. brasiliensis as Near Threatened (NT) has been confirmed, according to IUCN. These findings lead us to encourage the establishment of a preservation area for the isolated Guaíba II population and to highlight the importance of preserving these distinct gene pools in order to maintain species genetic diversity. The restricted knowledge on freshwater crayfishes and the effects of anthropic actions on populations reinforces the importance of these investigations. Other approaches could be conducted with the data generated in this thesis as a starting point, using crayfish distribution as a tool for landscape, climate change and urbanization analysis.

La presente tesis realiza una contribución metodológica al problema de la gestión integral de procesos de regulación de presión en redes de distribución de agua urbana mediante válvulas reductoras de presión. En este estudio se contemplan dos etapas de este tipo de proyectos: diseño de las maniobras de regulación y evaluación de su impacto. Las finalidades para las que se puede implantar un plan de este tipo son diversas. Esta tesis se ha focalizado en dos de las más relevantes: reducción de caudal fugado y mejora del servicio sobre usuarios. El caudal fugado tiene una relación directa con la presión de la red. A mayor presión en la red mayor será el caudal perdido a través de pequeños orificios o roturas. Por lo tanto, la reducción de la presión beneficia la disminución de estas pérdidas. Contrariamente, una reducción de presión excesiva, puede influir negativamente en la calidad del nivel de servicio a usuarios. Un criterio establecido de forma generalizada por parte de las empresas operadoras para ofrecer un buen nivel de servicio es definir un valor de presión de referencia de servicio como límite inferior para definir el rango de presión en todos los nodos de la red. Este conflicto entre reducir la presión para evitar fugas pero no demasiado para no afectar a los usuarios, hace que en ocasiones sea complejo definir las maniobras de regulación más eficientes. Tras una detallada revisión de la bibliografía, se ha observado que los trabajos en este ámbito utilizan, en general, métodos y criterios ‘ad-hoc’ basados en la experiencia del profesional encargado del diseño del plan de gestión de presiones. Existen enfoques más académicos para aspectos concretos, como por ejemplo, la definición de una consigna de regulación a través del planteamiento de problemas de optimización. No obstante, la mayoría de estudios encontrados, si bien aportan gran valor, están enfocados en un aspecto específico, careciendo de capacidad de generalización. La metodología para el diseño de planes de gestión de presiones propuesto en esta tesis se ejecuta en dos pasos. Primero, la selección de la técnica de regulación más conveniente atendiendo a las características de la zona regulada, a los patrones de consumo y a condicionantes económicos. Segundo, la definición de la consigna de regulación óptima en función de los objetivos perseguidos y las restricciones impuestas en cada caso. En relación a los métodos para evaluar el impacto que tienen dichas maniobras sobre los objetivos perseguidos – disminución de caudal fugado y mejora del servicio a usuarios – existen múltiples enfoques. Por un lado, se pueden utilizar modelos numéricos con la ventaja de que ofrecen valores de forma distribuida en todos los nodos y líneas, aunque con la desventaja de falta de representatividad de los escenarios hidráulicos que suceden en tiempo real. Por otro lado, existen métodos agregados como la utilización del balance hidráulico y el concepto de Caudal Mínimo Nocturno, más generalizables y utilizando datos obtenidos de dispositivos monitorización, con mayor capacidad de tratamiento en tiempo real. Su mayor inconveniente es que su utilización conlleva la introducción de una serie de hipótesis simplificativas, con la incertidumbre asociada en los resultados obtenidos. Como segundo gran aporte de esta tesis, se proponen una serie de métodos y criterios originales para analizar el impacto de la gestión de presiones. Especialmente relevantes son los sub-métodos propuestos para mejorar diferentes fases de la estimación de fugas a través del concepto caudal mínimo. Los métodos propuestos se aplican sobre varios casos de estudio comparando los resultados con técnicas más convencionales y evaluando su potencial a la hora de mejorar la precisión en las estimaciones. Los múltiples aspectos tratados, son recogidos finalmente en forma de herramienta que pueda asistir a los gestores de este tipo de infraestructuras y a investigadores en la toma de decisión de estas dos fases – diseño y evaluación del impacto – ofreciendo un entorno versátil, multi-criterio y adaptable a los datos disponibles en cada caso de estudio. This thesis presents a methodological contribution to address the problem about how to manage pressure regulation processes in urban water distribution systems through pressure reducing valves. Two stages of these projects are studied: design of regulation operations and assessment of its impact. Several purposes can be searched with this type of operations. This thesis has focused on two of the most relevant: reduction of leakage flow and customer service improvement. The leakage flow has a direct relationship with the pressure of the network. The higher the pressure in the network the greater the flow lost through small holes or breaks. Therefore, pressure reduction benefits the decrease of water losses. Conversely, an excessive pressure reduction may adversely affect the quality of service level to users. A widespread criterion implemented by water utilities to comply this target is to offer pressure at all nodes above a predefined value which ensure a good service. This conflict between reducing the pressure to avoid leakage but not too much to not affect users, makes it sometimes difficult to define the most efficient regulation operation rules. After a detailed review of the literature, it was observed that most of the existing studies or projects in this field use 'ad-hoc' methods and criteria based on the experience of the professional in charge of the design of the pressure management plan. Certain academic approaches are more focused on specific aspects, for example, the definition of a regulation slogan through the approach of optimization problems. However, most of the studies found, while providing great value, are focused on a specific aspect, lacking a capacity for generalization. The methodology for the design of pressure management plans proposed in this thesis is executed in two steps. First, the most appropriate regulation technique is selected: considering three features: characteristics of the regulated area, consumption patterns and economic constraints. Secondly, the optimal regulation pressure-curve is defined according to the objectives pursued and the constraints imposed in each case. Related to the existing methods to assess the impact of such operation rules - reducing leakages and improving user level of service - there are multiple approaches. On the one hand, it is possible to use numerical models with the advantage that they offer values in a distributed way in all the nodes and lines. Its main disadvantage is that they can provide results which do not represent real time conditions. On the other hand, there are aggregated methods such as the use of water balance and the concept of Minimum Night Flow, more which can be used more globally and using data obtained from monitoring devices, with greater capacity for real-time evaluation. Its main drawback is that its use involves the introduction of a series of simplifying assumptions, with the associated uncertainty in the results obtained. As a second major contribution of this thesis, a series of original methods and criteria are proposed to analyze the impact of pressure management. Especially relevant are the sub-methods proposed to improve different phases of leakage estimation through the minimum flow concept. The proposed methods are applied to several case studies by comparing the results with more traditional techniques and evaluating their potential to improve the accuracy of the calculation. All this aspects have been finally collected in the form of a tool which can assist the managers of these type of infrastructures and researchers in the decision making of these two phases - design and impact assessment - offering a versatile, multi-criteria and adaptable environment to the data available in each case study.

Proporciona aspectos específicos que deben considerarse para el desarrollo y evaluación de modelos conceptuales del flujo de agua subterránea. Adicionalmente, señala que el modelo conceptual, como una representación descriptiva del sistema de agua subterránea, incorpora la descripción e interpretación de las condiciones geológicas e hidrológicas incluyendo las fronteras, conceptualización del flujo, los componentes del balance de agua y las propiedades hidráulicas del acuífero. Por otro lado, indica que en el marco de evaluación de los recursos hídricos, la Autoridad Nacional del Agua (ANA), a través de la Dirección de Conservación y Planeamiento de Recursos Hídricos, estima las reservas explotables, caracteriza hidráulicamente a los acuíferos, desarrolla prospección geofísica, sistematiza información; así como aplica modelos de flujo en acuíferos de la costa peruana; además, dicha Dirección, en los estudios de impacto ambiental, evalúa un componente importante de hidrogeología que incluye el modelamiento.