For more than two centuries, Beaufort West has been an essential stopover for people traversing an arid and sparsely populated region. Throughout its existence, the town has been plagued by water problems, whether they be drought, flash floods, or sanitary in origin. Many factors contributed to Beaufort West’s sanitary woes. Situated in the semi-arid central Great Karoo with an average rainfall of a mere 250mm, Beaufort West’s unique geographical positioning renders it climatologically vulnerable and because its water supply is heavily reliant on rainfall, regular droughts are inevitable. Groundwater extracted from boreholes has played an increasingly important role in the development of Beaufort West. Since the 1850s, it has been reliant on a very rudimentary potable water reticulation system of open street furrows, and a sewage system comprising cesspools and pail removals. Until the first half of the twentieth century many of the residents were self-sustaining and on their properties they kept farm animals such as pigs, sheep, goats, fowl and cows as food and horses as draught animals. These conditions created almost unsurmountable sanitation problems. The council minutes and sanitation reports of the Beaufort West Municipality frequently note the prevalence of two diseases – typhoid and diphtheria. This article investigates the root causes, manifestation, and health impact of these diseases on the community of Beaufort West. It traces the municipal initiatives to combat their occurrence, and the efforts made to improve the town’s general sanitary conditions. This case study of Beaufort West corroborates a hypothesis that modern-day outbreaks of water-borne diseases and sanitation in South Africa have a long historical antecedent.

Oor twee eeue heen, was Beaufort-Wes 'n noodsaaklike rushalte vir reisigers wat deur 'n droë en ylbevolkte omgewing gereis het. Sedert sy stigting is die dorp deurlopend geteister deur waterprobleme, hetsy droogte, vloedwater of besoedeling. Baie faktore het tot die dorp se gesondheidsprobleme bygedra. As gevolg van sy unieke geografiese ligging is die dorp klimatologies baie kwesbaar. Beaufort-Wes is in die sentrale Groot Karoo se semi-woestyn geleë, met 'n gemiddelde jaarlikse reënval van slegs 250 mm. Watervoorsiening aan die dorp is grotendeels van reënval afhanklik en gereelde droogtes is onvermydelik. Grondwater, wat deur middel van boorgate onttrek word, het deur die jare heen 'n toenemend belangrike rol in die ontwikkeling van Beaufort-Wes gespeel. 'n Baie rudimentäre waterverspreidingstelsel, wat oorspronklik uit oop straatleivore bestaan het, asook 'n rioolstelsel, bestaande uit nagemmer verwydering en putlatrines, is ontwikkel. Baie dorpenaars was selfonderhoudende inwoners wat plaasdiere soos varke, skape, bokke, hoenders en koeie as voedselbronne op hul eiendomme aangehou het. Hierdie situasie het byna onoorkomelike gesondheidsprobleme opgelewer. Twee waterdraende siektes -ingewandskoors en witseerkeel - het vir baie jare met reëlmaat opgeduik in die notules en gesondheidsverslae van Beaufort-Wes se munisipaliteit. Die studie ondersoek die oorsake, manifestering en gesondheidsimpak van hierdie siektes op die gemeenskap van Beaufort-Wes, asook die munisipale inisiatiewe wat aangewend is om die voorkoms daarvan te bestry en pogings om die dorp se algemene gesondheidstoestand te verbeter. Die gevallestudie van Beaufort-Wes bevestig die hipotese dat moderne uitbrekings van waterdraende siektes en sanitasie in Suid-Afrika 'n lang historiese aanloop het.

Chakama is an area of 46 small villages in Kilifi County, Kenya. Climate change has led to more frequent and longer periods of drought in this semi-arid region as well as locust invasions. This has led to a lack of water, with many rivers drying up and poor water quality as a result of pollution of the remaining river water. The lack of water and locust invasion have led to a failure of the crops and loss of livestock. Many pastoralists and farmers have lost their livelihood. Wild animals from local nature reserves have also come into conflict with the community over water scarcity. Many families have migrated in search of water and income. The health effects are seen in the rising number of people suffering from malnutrition and gastroenteritis as well as in terms of mental health problems. Primary health care services are not always available, and the quality of such services is poor. Facilities and healthcare workers also struggle to be resilient in the face of the same environmental challenges. Local nongovernment organisations are attempting to assist through health and social services, community engagement and multisectoral action.

Abstract Nano fertilizers offer benefits in nutrition management through their strong potential to increase nutrient use efficiency. Traditional fertilizers are not only costly for the producer but may be harmful to humans and the environment. Furthermore, nano fertilizers may also be used for enhancing abiotic stress tolerance. This study was performed on the evaluation of nano chelated nitrogen and urea fertilizers on the physiological characteristics of wheat under drought stress conditions. Experiments were carried out in two locations in Fars province, Iran. The experimental design was performed as a split-split plot in RCBD design. The first factor included irrigation treatments (normal and withholding irrigation at the flowering stage), sub factor was nitrogen treatment (0, 37, 74 and 110 k g.ha-1) in the form of Urea fertilizer, and sub-sub factor was nitrogen (0, 14, 27 and 41 kg.ha-1) in the form of nano chelated nitrogen fertilizer. Studied traits were RWC, Ion Leakage, Protein, Phosphorus and Potassium content, Remobilization and photosynthesis rate. According to the analysis of variances, stress, nitrogen (urea) and nano chelated nitrogen had significant effects on all studied traits. Mean comparisons showed that drought stress led to 13% reduction in RWC, 21% Ion Leakage, 26% Protein, 13% Phosphorus and 26% Potassium content, 22% Remobilization and 69% photosynthesis rate compared to normal irrigation. In conclusion Application of 41 kg.ha-1 nano chelated nitrogen fertilizer in comparison with urea led to increase 4% in Rwc, 3% Ion leakage, 52% protein, 26% phosphor, 6% potassium, 6% Remobilization and 21% photosynthesis rate compared to control, respectively.

RESUMO Objetivo A umidade e a temperatura são fundamentais para o equilíbrio no ciclo da vida dos seres vivos e, consequentemente, para manter o bem-estar da população humana e diminuir a prevalência de doenças infecciosas. Visando mitigar o impacto das alterações climáticas, principalmente no período em que a umidade não é a ideal, é preciso adotar algumas medidas assistencialistas. O presente estudo visa elucidar qual seria a opção mais indicada para melhorar a qualidade de vida do ser humano e esclarecer qual melhor recurso (umidificador de ar, balde com água ou toalha molhada) é eficaz para melhorar a umidade do ar em épocas de seca e baixa umidade. Métodos Estudo experimental realizado com higrômetros INKBIRD que permitiram a análise da variação da umidade do ar ao longo do dia. Foram estabelecidas três formas de tratamento: umidificador, toalha molhada e balde com água. Em cada quarto, foram colocados dois higrômetros equidistantes do ocupante do quarto e seu respectivo tratamento, que variava entre 1m e 2m de distância da cabeceira da cama dentro de cada cômodo. Além disso, dois ambientes foram utilizados como controle, sendo um externo e outro fechado interno, totalizando cinco cômodos para o estudo. Os cômodos foram monitorados entre o final do mês de julho até final do mês de agosto de 2019 em Goiânia (GO). Resultados Apesar de as medidas assistencialistas serem utilizadas para melhora significativa da umidade do ar em épocas de extrema seca, há uma diferença significativa entre elas. O umidificador e a toalha molhada possuíram 7,50% e 5,71% a mais de umidade em relação à área externa (controle externo), respectivamente, sendo considerados mais eficientes. Já o balde de água não se diferenciou significativamente (p>0,05), não havendo variação. Conclusão O umidificador e a toalha foram os tratamentos considerados mais eficientes, com efeito significativo da distância sobre a umidade. Portanto, 1m de distância é mais eficiente no aumento e/ou na manutenção da umidade do ar, induzindo melhorias na saúde da população.

ABSTRACT Objective Humidity and temperature are fundamental for the balance in the life cycle of living beings and, consequently, for maintaining the well-being of the human population and reducing the prevalence of infectious diseases. Thus, in order to mitigate the impact of climate change, especially in the period when humidity is not the ideal, it is necessary to adopt some assistance measures. The present experimental study aims to elucidate what would be the recommended option to improve the quality of life of the human being and to clarify which resources (air humidifier, bucket of water or wet towel) will be effective to improve the humidity of the air in times of drought and low moisture. Methods The experimental study was carried out with INKBIRD hygrometers allowing the analysis of the variation of air humidity throughout the day. Three forms of treatment were established: humidifier, wet towel and bucket of water. In each room, two hygrometers were placed equidistant from the occupant of the room and their respective treatment that varied between 1m and 2m away from the headboard indoor each room. In addition, two environments were used as controls, one being an external environment and the other an internal closed environment, totaling five rooms for the study. The rooms were monitored between the end of July and the end of August 2019 in Goiania (GO). Results Although assistance measures are used to significantly improve air pollution in times of extreme drought, there was a significant difference between them. The humidifier and a wet towel had 7.50% and 5.71% more humidity in the external relation (external control), respectively, more efficient. The volume of water, however, did not show significant difference (p>0.05) and, therefore, there was no variation. Conclusion The humidifier and the towel are treatments considered more efficient, and that there was a significant effect of distance on humidity. Therefore, 1m of distance is more efficient in increasing and/or maintaining air humidity, inducing improvements in the populations’ health.

ABSTRACT Background: Anthropogenic climate change is a phenomenon that is becoming increasingly important in many areas such as economics and politics, but it also has great scientific relevance due to the important effects it has on people's health, the relationship between climate change and Health has caused an increase in the production of scientific knowledge about this topic and therefore the objective of this article was to provide an updated review of the open access scientific evidence, in the last five years, related to the effects of anthropogenic climate change in Public Health. Methods: A systematic review was conducted, in Spanish and English, in four non-subscription databases; using online thesaurus terms, the inclusion and exclusion criteria, an evaluation with the STROBE checklist were applied. Results: Finally, 18 publications were analyzed. These showed: the relationship between extreme events, such as heat and cold waves, with the increase in mortality from various causes, especially from heart attacks; the alteration of the rainy and drought periods as a determinant of various infectious diseases; air pollution from emissions derived from the use of fossil fuels with the reduction of 2.9 years in world life expectancy. In addition, other authors reported predictions from climate alterations in health risks; and perceptions of the population, and decision-makers about the impacts of climate change on Public Health. Conclusion: The studies, regardless of the region or country, showing the relationships and impacts, local and global, of climatic variations on the health of populations.

RESUMEN Fundamentos: El cambio climático antropogénico es un fenómeno que adquiere cada vez más importancia en muchos ámbitos como la economía y la política, pero además tiene gran relevancia científica debido a los importantes efectos que tiene en la salud de las personas. La relación del cambio climático con la salud ha provocado un aumento de la producción de conocimiento científico acerca de este tema y por ello el objetivo de este artículo fue proporcionar una revisión actualizada de la evidencia científica de acceso abierto, en los últimos cinco años, relacionada con los efectos del cambio climático antropogénico en la Salud Pública. Métodos: Se realizó una revisión sistemática de la literatura, en español e inglés, en cuatro bases de datos sin subscripción, a partir de términos de tesauros en línea; se aplicaron criterios de inclusión y exclusión, y una evaluación con la estrategia STROBE. Resultados: Se analizaron finalmente 18 publicaciones evidenciando la relación entre los eventos extremos, como olas de calor y frío, con el aumento de la mortalidad por diversas causas, especialmente por infartos; la alteración de los periodos de lluvias y sequía como un determinante de diversas enfermedades infecciosas; la contaminación del aire por las emisiones derivadas del uso de combustibles fósiles con la reducción de 2,9 años de la expectativa de vida mundial. Además, otros autores reportaron predicciones a partir de alteraciones del clima en riesgos a la salud; y las percepciones de la población y de los responsables de políticas públicas sobre los impactos del cambio climático en la salud. Conclusiones: Los estudios, sin importar la región o país, se conectan entre sí, mostrando las relaciones e impactos, locales y globales, de las variaciones climáticas sobre la salud de las poblaciones.

ABSTRACT Background: Anthropogenic climate change is a phenomenon that is becoming increasingly important in many areas such as economics and politics, but it also has great scientific relevance due to the important effects it has on people's health, the relationship between climate change and Health has caused an increase in the production of scientific knowledge about this topic and therefore the objective of this article was to provide an updated review of the open access scientific evidence, in the last five years, related to the effects of anthropogenic climate change in Public Health. Methods: A systematic review was conducted, in Spanish and English, in four non-subscription databases; using online thesaurus terms, the inclusion and exclusion criteria, an evaluation with the STROBE checklist were applied. Results: Finally, 18 publications were analyzed. These showed: the relationship between extreme events, such as heat and cold waves, with the increase in mortality from various causes, especially from heart attacks; the alteration of the rainy and drought periods as a determinant of various infectious diseases; air pollution from emissions derived from the use of fossil fuels with the reduction of 2.9 years in world life expectancy. In addition, other authors reported predictions from climate alterations in health risks; and perceptions of the population, and decision-makers about the impacts of climate change on Public Health. Conclusion: The studies, regardless of the region or country, showing the relationships and impacts, local and global, of climatic variations on the health of populations.

RESUMEN Fundamentos: El cambio climático antropogénico es un fenómeno que adquiere cada vez más importancia en muchos ámbitos como la economía y la política, pero además tiene gran relevancia científica debido a los importantes efectos que tiene en la salud de las personas. La relación del cambio climático con la salud ha provocado un aumento de la producción de conocimiento científico acerca de este tema y por ello el objetivo de este artículo fue proporcionar una revisión actualizada de la evidencia científica de acceso abierto, en los últimos cinco años, relacionada con los efectos del cambio climático antropogénico en la Salud Pública. Métodos: Se realizó una revisión sistemática de la literatura, en español e inglés, en cuatro bases de datos sin subscripción, a partir de términos de tesauros en línea; se aplicaron criterios de inclusión y exclusión, y una evaluación con la estrategia STROBE. Resultados: Se analizaron finalmente 18 publicaciones evidenciando la relación entre los eventos extremos, como olas de calor y frío, con el aumento de la mortalidad por diversas causas, especialmente por infartos; la alteración de los periodos de lluvias y sequía como un determinante de diversas enfermedades infecciosas; la contaminación del aire por las emisiones derivadas del uso de combustibles fósiles con la reducción de 2,9 años de la expectativa de vida mundial. Además, otros autores reportaron predicciones a partir de alteraciones del clima en riesgos a la salud; y las percepciones de la población y de los responsables de políticas públicas sobre los impactos del cambio climático en la salud. Conclusiones: Los estudios, sin importar la región o país, se conectan entre sí, mostrando las relaciones e impactos, locales y globales, de las variaciones climáticas sobre la salud de las poblaciones.

Resumo Este trabalho pretende avaliar o comportamento da EOA (espessura ótica dos aerossóis) sobre regiões da América do Sul (Cone Sul, Amazônia legal, do Nordeste do Brasil e Sul do Brasil), com característica climáticas diversas, analisando seu comportamento médio para o período dos anos de 2005 a 2019. Os dados são coletados pelo sensor OMI (Ozone monitoring Instrument) da NASA (National Aeronautics and Space Administration) a bordo do satélite Aura com resolução espacial de 1° x 1° e resolução temporal diária. Dos dados utilizados foram feitas médias e percentis, foi observado que existe um comportamento sazonal nos locais analisados, com maiores valores (0,35 e 0,34) encontrados nas estações secas e menores nas estações chuvosas (0,15 e 0,16). Ao analisar sistemas que influenciam e os períodos de chuva e de seca das regiões, foi observado a relação da concentração de aerossóis com a precipitação, pois os valores máximos de aerossóis acontecem nas estações secas e esse padrão se repete em todas regiões com exceção da região Nordeste onde fatores além dos climatológicos parecem ter uma maior influencia. é levantada como uma das hipóteses a influencia antropogênica tendo em vista os altos níveis de emissões das grandes capitais no litoral da região.

Abstract This work aims to evaluate the behavior of AOD (aerosol optical depth) over South American regions (Southern Cone, Legal Amazon, Northeastern Brazil and Southern Brazil), with different climate characteristics, analyzing their average behavior for the period from 2005 to 2019. The data are collected from OMI (Ozone Monitoring Instrument) sensor of NASA (National Aeronautics and Space Administration) aboard the Aura satellite with spatial resolution of 1° x 1° and daily temporal resolution. From the data used, were made averages and percentiles, it was observed that there is a seasonal behavior in all the analyzed locations, with highest values (0.35 and 0.34) being found in the dry seasons and lowest in the rainy seasons (0.15 and 0.16). When analyzing influencing systems and the periods of rain and drought in the regions, it was possible to observe the relationship between the concentration of aerosols and precipitation, as the maximum values of aerosols occur in the drier seasons and this pattern is repeated in all regions except from the Northeastern region where other factors than climatological seem to have a greater influence, the anthropogenic influence is one of the hypotheses due to the location of the largest capitals of the region at the coast.

ABSTRACT The production of second-generation biofuels requires raw materials that meet certain characteristics, among which stand out availability, price, fast growth, easy manipulation, among others. Opuntia ficus-indica was analyzed in this work given its wide world distribution, tolerance to extreme environments of drought and temperature, as well as its high yield as a crop. In addition, in times of pruning, the cladodes are abandoned on the site generating pollution problems so it is necessary to generate usage proposals. The production of bioethanol from cactus cladodes has been previously proposed but a hydrothermal pretreatment (HTP) in a high-pressure reactor (HPR) has not been applied. The use of high pressures is a method used with relative success in the pretreatment of other lignocellulosic substrates. In this work, the effect of temperature (150, 175, 185 and 205 º C), the addition of H2SO4 (0, 0.5, 1, 1.5 and 2 %) and the residence time in a HPR (1, 5 and 15 min) was studied. The solid residue obtained in the HTP was subjected to an enzymatic treatment to improve high-pressure hydrolysis of this raw material; finally, an alcoholic fermentation was carried out with Saccharomyces cerevisiae. The results showed significant time saving by applying a HTP compared to a conventional pretreatment (carried out in autoclaves). A final hydrolysis of 70.4 % of the nopal cladodes (combination of thermal pretreatment and enzymatic hydrolysis) and bioethanol production of 6.6 g/L were achieved.

RESUMEN La producción de biocombustibles de segunda generación requiere de materias primas que reúnan ciertas características, entre las que destacan disponibilidad, precio, rápido crecimiento, fácil manipulación, entre otras. Opuntia ficus-indica fue analizada en este trabajo dada su amplia distribución en México, tolerancia a ambientes extremos de sequía y temperatura, así como su alto rendimiento como cultivo; aunado a esto, en periodos de poda, los cladodios son abandonados en el sitio generando problemas de contaminación por lo que es necesario generar propuestas de aprovechamiento. Se utilizaron cladodios de nopal como materia prima para la producción de etanol, utilizando un pretratamiento hidrótérmico (PTH) en un reactor de alta presión (RAP) para favorecer la hidrólisis de mucílago y fibras. Se estudió el efecto de la temperatura (150, 175, 185 y 205 ºC), la adición de H2SO4 (0, 0.5, 1, 1.5 y 2 %) y el tiempo de residencia en el RAP (1, 5 y 15 min). El residuo sólido obtenido del PTH fue sometido a un tratamiento enzimático, a fin de mejorar la hidrólisis y aprovechar en su totalidad esta materia prima. Finalmente se realizó una fermentación alcohólica con Saccharomyces cerevisiae. En los resultados obtenidos destaca el ahorro de tiempo por la aplicación del PTH en comparación con el pretratamiento tradicional, alcanzándose una hidrólisis final del 70.4 % de los cladodios de nopal (combinación de los pretratamiento térmico e hidrólisis enzimática) y una producción de bioetanol de 6.6 g/L.

Water is an essential but scarce resource. Worldwide, an estimated 663 million people do not have access to sufficient and safe water for domestic use, and the demand is on the increase. It is estimated that the world will have to cope with a 40 per cent water supply shortfall by 2030, which will unavoidably affect the availability of drinking water, sanitation and food production. South Africa faces a particularly gloomy water reality. Not only is South Africa plagued by severe drought conditions, but it also has a poor record of water conservation, outdated and inadequate water treatment infrastructure, and lingering concerns about the quality and degradation of the already limited volume of available water. South Africa's political history, characterised by a reality of unequal access to water, adds additional and unique challenges as far as water resource regulation is concerned. Following the advent of the constitutional era, a novel legal framework for water resources regulation was developed in South Africa. The National Water Act 36 of 1998 (NWA) was promulgated with the primary aim of reforming the law relating to water resources. The NWA broke new ground by inter alia introducing the concept of public trusteeship into the South African water law. Section 3 of the NWA provides that all water use rights fall under the centralised control of the state, or public trustee, to improve the distribution, management, use, conservation and equitability of access to this scarce resource. Although the concept of public trusteeship entered the South African legal realm without much fanfare, it fundamentally changed the foundation and regulatory practices of the South African water law dispensation. The water regulatory framework changed from one that linked access to water to land ownership and differentiated between private and public water, to a framework that applies to "all water " in South Africa and that acknowledges that the country's water "belongs to all people". Accordingly, the old system that provided for exclusive water use rights, and that was generally to the detriment of the majority of South Africans, has been replaced by a system that provides for water allowances granted at the discretion of government. The introduction of the notion of public trusteeship therefore denotes a major transformation in which existing property rights are re-defined. With this new system of the NWA, the South African government has effectively nationalised all of the nation's water resources. It has been almost 20 years since the transformation of South Africa's water regulatory framework, but the reality is that, despite the transformation brought about by the NWA, studies show a decline in the quantity and quality of South Africa's water resources. Adding to the problem that South Africa is a water scarce country, the demand for water is on the increase. Severe pollution such as the fact that approximately 4 billion litres of raw or partially purified sewage are discharged daily into South Africa's dams and rivers, as well as the widespread destruction of wetlands by mining and agricultural activities continue to impact negatively on the quality of the scarce water resource. One of the consequences of this is the growing presence of toxic blue-green algae in the water resources of South Africa, with an estimated 62per cent of aquatic bodies already contaminated with cyanobacteria - the highest incidence in the world. In light of this water crisis, some may argue that the new regulatory framework, with its statutory objectives and strategies, is flawed. In order to determine whether the new regulatory framework for South Africa's water resources is indeedflawed, or whether the NWA is rather a beacon of hope amid the country's water crisis, this article analyses the novel water regulatory framework with specific reference to the concept ofpublic trusteeship. In the second part, the article scientifically describes the state of South Africa's water resources. The third and last part of the article provides a legal response to the growing pressure on South Africa's water resources. It considers how the public trusteeship paradigm can be used to ensure that water is protected, used, developed, conserved, managed and controlled in a sustainable manner, for the benefit of all persons. The article confirms that the public trust regulatory regime is sufficientfor water regulation in South Africa, and particularly relevant to a solution to the country's water crisis, as it offers the necessary mechanisms to achieve lasting protection for water resources, and ultimately to enhance sustainable water resource management.

Suid-Afrika se toekoms word wesentlik bedreig deur 'n uiters beperkte water-hulpbron wat vanweë 'n lae reënvalsyfer en onvoorspelbare droogtes vergelyk kan word met van die droogste lande ter wêreld. Suid-Afrika het boonop 'n swak rekord van waterbesparing, die behandeling van afvalwater asook die instandhouding van waterinfrastruktuur. Hierdie gebreke lei tot groeiende kommer oor die land se beskikbare volume water, asook die gehalte daarvan. Die Nasionale Waterwet 36 van 1998 (NWW) is uitgevaardig met die primêre doel om die reg rakende Suid-Afrika se waterhulpbronne fundamenteel te verander. Die aanhef van die NWW verklaar dat water "'n skaars nasionale hulpbron is" en "'n natuurlike hulpbron is wat aan alle mense behoort". Artikel 3 van die NWW brei hierdie standpunt uit deur te bepaal dat alle watergebruiksregte onder die gesentraliseerde beheer van die nasionale regering as openbare trustee val om onder meer die verspreiding, bestuur, gebruik en bewaring van en gelyke toegang tot dié skaars hulpbron te verseker. Die inkorporering van die konsep van openbare trusteeskap het 'n paradigmaskuif in die waterreguleringsraamwerk meegebring, met die gevolg dat alle privaat regte in water afgeskaf is en dat alle water effektief genasionaliseer is. Ten spyte van hierdie statutêre hervorming dui beskikbare data daarop dat die toestand van waterhulpbronne in Suid-Afrika besig is om gaandeweg en voortdurend te verswak. Hierdie artikel het ten doel om te bepaal of die nuwe waterreguleringsraamwerk van Suid-Afrika, geskoei op die konsep van openbare trusteeskap, voldoende oplossings vir Suid-Afrika se groeiende waterkrisis bied. Die artikel ontleed derhalwe Suid-Afrika se waterreguleringsraamwerk, met spesifieke verwysing na die konsep van openbare trusteeskap. Die verswakkende toestand van die land se water word vervolgens bespreek, waarna die artikel afsluit met n gefundeerde opinie oor of die waterreguleringsraamwerk, geskoei op die konsep van openbare trusteeskap, geskik is om Suid-Afrika se waterhulpbron op n volhoubare en billike wyse te bestuur en te beskerm.

Abstract Urban trees and the services they provide (e.g., evapotranspirational cooling, shading, recreation, carbon storage, air pollution filtering) can have major effects on the microclimate of a city, although the growth conditions are often inadequate to ensure tree vitality and growth, negatively affecting their beneficial effects. In a worldwide dendrochronological study on ten urban tree species in four climatic zones, the growth and impacts of common urban tree species were assessed. This paper focuses on the results for Robinia pseudoacacia L. in the Mediterranean climate city of Santiago de Chile, highlighting the faster growth of the studied black locust trees since 1960 than its growth in the years before 1960. Furthermore, black locust displayed the best growth when situated closer to the city center than the city periphery and when in the northern and western parts of Santiago de Chile. The species characteristics of black locust also revealed an immediate negative growth reaction to drought events, followed by a rapid recovery, which was similarly influenced by the direction from and distance to the city center of the growing site. The results underline the overall worldwide findings on urban tree growth that indicate that a city climate with an extended growing season and increased temperatures can lead to improved growth of urban trees in the Mediterranean climatic zone. However, with increased growth, more rapid ageing and tree death might follow, leading to increased costs for new plantings and tree management.

Resumen Los árboles urbanos y los servicios que proporcionan (ej.: enfriamiento por evapotranspiración, sombra, recreación, acumulación de carbono y purificación del aire) pueden tener impactos significativos en el microclima de una ciudad. Ello, a pesar que las condiciones en las urbes, suelen ser inadecuadas para asegurar la vitalidad y el crecimiento de los árboles, disminuyendo sus efectos benéficos. En un estudio dendrocronológico mundial, se evaluó el impacto de las tendencias climáticas en el crecimiento de diez especies urbanas, en cuatro condiciones climáticas. Los resultados obtenidos al estudiar ejemplares de Robinia pseudoacacia L. plantados en Santiago de Chile muestran un mayor crecimiento de los árboles desde el año 1960, comparado con años anteriores, con mayores incrementos desde la periferia hacia el centro de la ciudad, así como en las zonas norte y oeste de ésta. En repuesta a sequías, la especie presenta disminuciones inmediatas en el crecimiento de los árboles, seguidas de una rápida recuperación, dependiendo de su ubicación geográfica y del distanciamiento al centro de la ciudad. Los resultados evidencian la tendencia global de que el clima urbano, con una estación de crecimiento más larga y temperaturas más altas, puede causar que los árboles urbanos, en la zona climática mediterránea, crezcan más rápido. Este crecimiento mayor podría ser seguido por un envejecimiento más rápido y la muerte de los árboles, provocando aumentos en los costos de reforestación y manejo de los árboles.

RESUMO Este trabalho teve como objetivo avaliar a primeira carga de lavagem de uma bacia urbana da cidade de Natal, Rio Grande do Norte, por meio da quantificação de cargas poluentes contidas nos deflúvios superficiais em decorrência de nove eventos de precipitação pluviométrica, monitorados ao longo do ano de 2013. As variáveis analisadas foram: sólidos totais, sólidos suspensos totais, demanda química de oxigênio, fósforo total e teor de óleos e graxas. Foi realizada a avaliação dos eventos de precipitação/escoamento, mediante amostragem progressiva do runoff, monitorado por meio de amostrador automático (ISCO 6712), situado no exutório da bacia, sendo analisados os primeiros 24 minutos do escoamento superficial, com amostras coletadas a cada minuto ao longo do evento. A variação da concentração dos poluentes associada à variação temporal dos deflúvios durante eventos de precipitação foi analisada para a verificação da ocorrência do fenômeno first flush ou primeira carga de lavagem. O período monitorado caracterizou-se por apresentar baixo intervalo de dias de estiagem entre os eventos. Foi observada a ocorrência de primeira carga de lavagem em cinco dos eventos monitorados. Dessa forma, evidenciou-se que para a bacia estudada o conceito de first flush pode ser aplicado nas estratégias de manejo de águas pluviais, para implementação de boas práticas de manejo, que vêm sendo amplamente difundidas no que concerne à drenagem urbana.

ABSTRACT The aim of this study was to evaluate the first wash load of an urban catchment located in the city of Natal, Rio Grande do Norte, Brazil, by quantifying pollution loads contained in surface run-offs from nine rainfall events, monitored throughout the year 2013. The variables analyzed were: total solids, total suspended solids, chemical oxygen demand, total phosphorus and oil and grease content. We conducted the evaluation of precipitation/runoff events through progressive sampling of runoff, monitored by autosampler (ISCO 6712), and located at the outlet of the drainage basin. The first 24 minutes of runoff were analyzed, with samples collected every minute throughout the event. The variation of the pollutants concentration associated with the temporal run-offs variation during precipitation was analyzed to verify the occurrence of the first flush phenomenon. The monitored period was characterized by having a low number of drought days between events. The occurrence of the first flush was observed in five of the monitored events. Thus, it became clear that for the studied basin, the concept of first flush could be applied in rainwater management strategies for the implementation of best management practices, which have been widely disseminated regarding urban drainage.

Resumo O uso da cafeína como um indicador para a poluição das águas superficiais por esgoto doméstico foi avaliado neste estudo. Concentrações de cafeína foram determinadas em amostras coletadas no rio Paquequer, localizado em Teresópolis, uma cidade de médio porte do Estado do Rio de Janeiro, Brasil, e foram comparadas com outros parâmetros convencionais de qualidade da água (fosfato, nitrato e amônio), de modo a caracterizá-la como um indicador eficaz da poluição antrópica do ambiente aquático urbano. O rio Paquequer nasce em uma área de preservação ambiental, o Parque Nacional da Serra dos Órgãos (PARNASO) e atravessa a área urbana da cidade de Teresópolis. Amostras foram coletadas em sete pontos ao longo do rio, considerando-se os períodos de chuva (verão) e seca (inverno) e os diferentes usos da terra. A cafeína foi determinada utilizando as técnicas de extração por fase sólida (SPE) e cromatografia líquida de alta eficiência (HPLC). As concentrações de cafeína foram encontradas numa faixa de 0,16-47,5 mg L-1. Os resultados mostram uma relação positiva entre as concentrações de cafeína, fosfato, nitrato e amônia, e o aumento da carga de esgoto, o que sugere que a cafeína pode ser utilizada como um possível indicador de contaminação por esgoto doméstico em águas superficiais.

Abstract This study assessed the suitability of caffeine as an indicator for surface water pollution by domestic wastewaters. Caffeine concentrations determined in samples collected in the Paquequer River, located at the city of Teresópolis, a medium-sized city in the State of Rio de Janeiro, Brazil, were compared to other conventional water quality parameters such as phosphate, nitrate and ammonium concentrations to determine whether it as an efficient indicator of anthropic pollution of an urban aquatic environment. The Paquequer River originates in a pristine area called Parque Nacional da Serra dos Órgãos (PARNASO) and it crosses the urban area of the city of Teresópolis. Water samples were collected at seven points along the river, considering the periods of rain (summer) and drought (winter) and the different uses of land. Caffeine was measured using Solid Phase Extraction (SPE) and High Performance Liquid Chromatography (HPLC). Caffeine concentrations were found in a range from 0.16 to 47.5 µg L-1. The results show a positive relation between caffeine, phosphate, nitrate and ammonium concentrations and the increase of wastewater load, suggesting that caffeine can be used as an indicator of surface water pollution by domestic wastewaters.

Abstract The basin of Ambi river is located on Imbabura province, due to its proximity to the city of knowledge “Yachay” and considering that it aims to boost agricultural and livestock production with the allocation of 1,000 hectares for the development of experimental agriculture and agro-industrial. The study of the water quality of Ambi river for agricultural uses and variations of the concentrations of the ions over time is essential, considering these aspects the objectives of this research were to perform a multi-temporal analysis in 2014, 2015 and 2016 of representative sample points took along hydrographic system of Ambi river, to observe changes in concentrations of pH, EC and Cl in intermediate and rainy seasons, and relate the average monthly rainfall of a series of rainfall data from 30 years of three stations located in the study area, finally compare the results obtained at these points with the permissible limits for agricultural use, according TULSMA 2015 regulations. The tested concentrations were higher in 2014, this year corresponding to intermediate season, the relation of precipitation and concentrations were inverse, the pH in intermediate season were found near the maximum allowable limit under the regulation, EC in the waters of Ambi river were highly saline, type C3, in the case of chlorides the points taken in the lower basin during times of drought were in the mild to moderate range according TULSMA 2015, being Pinguinchuela ravine higher than the allowable limit. In general, during times of drought the level of water pollution of Ambi river for agricultural use was more critical.

Resumen La subcuenca del río Ambi se encuentra ubicada en la provincia de Imbabura, por su proximidad a la ciudad de conocimiento Yachay y considerando que la misma pretende potenciar la producción agrícola y pecuaria con la destinación de 1.000 ha para el desarrollo de la agricultura experimental y agroindustrial. El estudio de la calidad del agua del río Ambi para usos agrícolas y las variaciones de las concentraciones de los iones a través del tiempo resulta esencial, por estas razones los objetivos de esta investigación fueron realizar un análisis multitemporal en los años 2014, 2015 y 2016 de puntos representativos muestreados a lo largo del sistema hidrográfico del río Ambi, para observar las variaciones de concentraciones de pH, conductividad eléctrica (CE) y Cl en épocas intermedias y de lluvias , y relacionarlos con la precipitación promedio mensual de una serie de datos pluviométricos de 30 años de tres estaciones localizadas en la zona de estudio, finalmente comparar los resultados obtenidos en dichos puntos con los limites admisibles para uso agrícola, según la normativa TULSMA 2015. Las concentraciones analizadas resultaron ser mayores en el año 2014, época intermedia de precipitaciones , la relación precipitación concentraciones fue inversa , el pH en épocas intermedias se encontraron cercanos al límite admisible máximo según TULSMA, la CE de las aguas del río Ambi en promedio fueron altamente salinas tipo C3, en el caso de los cloruros los puntos tomados en la cuenca baja en épocas intermedias estuvieron en el rango leve a moderado según la normativa, siendo la quebrada de Pinguinchuela mayor al límite permisible. De manera general en épocas intermedias se tuvo un nivel más crítico de contaminación de las aguas del río Ambi desde el punto de vista agrícola.

Water quality assessment requires the use of statistical tools that facilitate the interpretation and taking of decision. The water quality indices has been promoted with the aim of contribute with water condition reports to society, while multivariate techniques, such as discriminant analysis (DA) are tools that enable the analysis of large number of samples and factors that allow the identification of sources of pollution affecting the water characteristics and offer a valuable and reliable tool for the management of water resources. This study is the result of water quality evaluations corresponding to two periods (2005 and 2009-2010), and aims to compare the water quality of Yuriria lake before and after the actions taken for restoration; for this, 21 parameters were analyzed including a water quality index and DA to determine the spatial and temporal variation of water quality. Our results show that the lake has a high level of eutrophication, with organic matter and fecal pollution; temporal variations in water quality were found, that manifest the effect of drought and rainy seasons. A severe drought in the second period was detected, which contributed to the concentration of nutrients and other parameters like total suspended solids provided by the tributaries. It was detected that La Cinta channel provides water of low quality and that the existence of villages are a determinant factor in space water quality variations. No recovery was observed in water quality between the study periods. The effects of drought can mask the effects of the strategies, actions and measures taken for the preservation and restoration of Yuriria lake, so different management actions at the basin level are suggested to allow a faster and efficient recovery of the aquatic environment.

El estudio de la calidad del agua requiere del uso de herramientas estadísticas que faciliten la interpretación y toma de decisiones. Los índices de calidad del agua (ICA) se han promovido con el objeto de coadyuvar en la comunicación de reportes de la condición del agua a la sociedad, mientras que las técnicas multivariadas, como el análisis de discriminantes (AD) son herramientas que permiten el análisis de un gran número de muestras y factores que ayudan en la identificación de fuentes de contaminación que afectan la calidad de agua y ofrecen un instrumento valioso y fiable para la gestión de los recursos hídricos. El presente estudio es resultado de valoraciones de las características físicas y químicas del agua correspondientes a dos periodos (2005 y 20092010), y cuyo objetivo es comparar las condiciones del agua de la Laguna de Yuriria antes y después de las acciones tomadas para su restauración; para ello, se analizaron 21 parámetros físicos y químicos del agua mediante técnicas estadísticas incluyendo un ICA y el AD para determinar la variación espacial y temporal de las características del agua. Los resultados revelan que la laguna presenta un alto grado de eutrofización, con aportes de materia orgánica y fecal; se encontraron variaciones temporales en la calidad del agua que manifiestan los efectos de las estaciones de estiaje y la de lluvias. Se detectó una sequía extrema en el segundo período de estudio, lo que contribuyó a la concentración de los nutrientes y otros factores como los sólidos suspendidos que aportan los tributarios. Se observó que el canal La Cinta aporta aguas de muy mala calidad y que la existencia de poblados litorales representan un factor determinante en la variación espacial de las características del agua. No se observó una recuperación en la calidad del agua para el segundo periodo de estudio. El impacto de la sequía puede enmascarar los efectos de las estrategias, acciones y medidas tomadas para la preservación y restauración de la Laguna de Yuriria, por lo que se sugieren diferentes acciones de manejo a nivel de cuenca que permitan una recuperación más rápida del ambiente acuático.