1,256 research outputs found
Hydro-meteorological characterization of major floods in Spanish mountain rivers
No full textSpain, one of the most mountainous countries in Europe, suffers from frequent river flooding due to specific climatic and topographic features. Many headwaters of the largest rivers in Spain are located in mountainous areas of mid-to-high elevation. These include the Pyrenees, the Central System, and the Cantabrian mountains, that have a sustained snowpack during the winter months. Most previous research on flood generation in Spain has focused on intense rainfall events, and the role of snowmelt has been ignored or considered marginal. In this paper we present a regional-scale study to quantify the relative importance of rainfall versus snowmelt in the largest floods recorded in mountain rivers in Spain during the last decades (1980–2014). We further analyzed whether catchments characteristics and weather types may favor the occurrence of rainfall or snowmelt induced floods. Results show that in 53% of the 250 analyzed floods the contribution of rainfall was larger than 90%, and in the rest of events snowmelt contribution was larger than 10%. Floods where snowmelt was the main contributor represented only 5% of the total events. The average contribution of snowmelt represents 18% of total runoff in floods that were analyzed. The role of snowmelt in floods, rather than triggering the event, was usually amplifying the duration of the event, especially after the peak flow was reached. In general, the importance of snowmelt in floods is greater in catchments with characteristics that favor snow accumulation. However, this does not apply to floods where contribution of snowmelt was larger than 90%, which tend to occur at catchments at mid-elevations that accumulate unusual amounts of snow that melt rapidly. Floods were more frequent under both cyclonic and anticyclonic synoptic situations over the Iberian Peninsula, as well as under advection of western and eastern flows. Our results contribute to the ongoing improvement of knowledge about the role of snow in the hydrology of Spanish rivers and on the importance of mountain processes on the hydrology of downstream areas.This Project has been funded with HIDROIBERNIEVE Project (CGL2017-82216-R) by the Ministry of Science, Innovation and Universities. Author EMT was founded by Ministry of Education, Science and Sport, through the program Programa Estatal de Promoción y Talento y su Empleabilidad en I+D+I, Subprograma Estatal de Movilidad, del Plan Estatal de Investigación Científica y Técnica y de Innovación 2013–2016.Peer reviewe
Informal gold mining and mercury pollution in Brazil
No full textThe Amazon region has been responsible for a major share of Brazilian gold production in recent years. The region has witnessed a sizable gold rush comparable only to the California gold rush last century. The gold rush has spawned a powerful informal mining sector and has attracted many people - some who have come to the region in search of wealth and some who were already there but were displaced from other, unsuccessful economicactivities. What these people encounter at the mining sites are dreadful living and working conditions. Gold mining also causes substantial environmental problems, which may persist whether gold deposits do or not. The author discusses the environmental effects of gold mining in the region, focusing on mercury pollution. Mercury, an important input in gold extraction, is being discharged into the atmosphere and the rivers at alarming rates. The environmental costs of the present extraction, is being discharged into the atmosphere and the rivers at alarming rates. The environmental costs of the present extraction technology will be faced primarily by future generations, because of natural chemical processes. Although removing the mercury already discharged from the Amazonian environment may be an enormous task, at least future discharges should be curtailed through the use of appropriate technology, environmental education, and a combination of command and control measures and market-based incentives. The author describes the gold extraction process and the extent of mercury use and contamination. He analyzes key elements of the environmental problem, especially the informal miner and the fish economy. Finally, he suggests a combination of command and control regulations and market-based incentives adapted to the informal gold mining economic environment. He emphasizes the need for an education campaign about the perils of using mercury and the availability of more appropriate, and inexpensive, alternative extraction technologies.Mining&Extractive Industry (Non-Energy),Montreal Protocol,Water and Industry,Coastal and Marine Resources,Primary Metals
Bullying and homophobia in UK schools: A perspective on factors affecting resilience and recovery
No full textThis article reports the results of a three-year study focusing on the experiences of a sample of lesbian, gay, and bisexual (LGB) people in the United Kingdom who were victimized by their peers at school. Data collected from 190 LGBs suggested that experiences of victimization at school were both long-term and systematic, and were perpetrated by groups rather than by individuals. Subsequently, data collected from a sub-sample of 119 participants indicated that over 50 percent had contemplated self-harm of suicide at the time they were being harassed, and that 40 percent had engaged in such behavior at least once. As adults, participants were found to exhibit symptoms associated with negative affect when contrasted with heterosexual and non-victimized LGB peers. Seventeen percent exhibited symptoms associated with PTSD. However, the results also demonstrated that the majority of participants did not differ significantly from comparison groups in terms of self-esteem, and they had a positive attitude towards their sexual orientation. These findings are discussed with reference to the current literature about the development of resilience following exposure to violence and trauma
An Empirical Validation of the Primary and Moderating Effects of Income and Capital on Familiarity and Participation of Limited Resource Farm Producers (LRFPs) in USDA Agricultural Programs
No full textWe present empirical findings on the problem of low participation rate of Limited Resource Farm Producers (LRFPs)1 in USDA programs. Our analysis is based on survey data directly sourced from LRFP population spread across twenty counties in Southern Virginia. The findings revealed that familiarity with and participation in USDA programs varied by type of farmers. While familiarity was moderate, participation was low. These main effects were moderated by access to capital. Our results broadly agree with findings from similar studies done on the subject in the past with an additional empirical insight that access to capital can enhance participation in USDA programs. We conclude the study with several practical ways for improving LRFP participation in USDA agricultural program
Sources and impacts of inorganic and organic fine sediment in salmonid spawning gravels in chalk rivers
No full textPoor salmonid spawning habitat due to excessive fine sediment inputs has been identified as a major factor limiting survival in chalk rivers. A lack of knowledge about the complex processes and factors affecting survival was the driver for this study and gaps in the research were identified concerning the sources of fine sediment and the impact organic material had on salmonid survival in chalk streams. Consequently the main objectives of this study were to characterise spawning habitat quality of a chalk catchment, assess the sources of sediments accumulating within artificial redds, describe the composition of organic sediments using emerging technology and to create a novel method to assess the sediment oxygen consumption of those sediments. Methods were based around a catchment wide field based monitoring programme, consisting of artificially constructed spawning gravels which allowed hyporheic measurements to be taken, and sediment analysis and sediment oxygen consumption methods were carried out using different laboratory methods. Spawning habitat characteristics of the chalk catchment were found to exhibit; low sediment accumulation rates although original levels of fine sediment were high, high organic matter content, variable intra-gravel flow and intra-gravel oxygen concentrations and groundwater influences. Primary sources of fine sediment accumulating in spawning gravels and suspended sediments were found to be attributed to catchment surface sources, namely pasture (50-68%) and arable (32-50%) using inorganic and organic parameters. Organic composition of redd gravels was found to be dominated by protein material rather than humic substances, the more commonly found fluorescent compound in freshwater systems and the sediment oxygen consumption of sediments varied throughout the catchment and was found to consume the greatest oxygen in <63?m size fraction. Application of sediment oxygen consumption rates to existing parameter based models that predict salmonid survival, highlighted the need to address the sensitivity of current models to rivers experiencing low sediment accumulation rates. Outcomes of this study further the knowledge of the sources, organic composition and sediment oxygen consumption capacity of fine sediments accumulating in spawning gravels which can lead to appropriate mitigation on chalk rivers to improve salmonid spawning habitat
The impact of the newer knowledge of nutrition: nutrition science and nutrition policy, 1900-1939.
No full textIdeas concerning relationships between diet and health in the UK are
traced from the 1904 Comittee on Physical Deterioration to the outbreak
of World War II. Archive material is used to describe the often
conflicting views of the Medical Research Council and the Ministry of
Health and Board of Education concerning the public health applications
of nutrition science. In particular, the work of the Ministry of
Health's first Advisory Comittee on Nutrition, which was appointed in
1931, is reviewed and evaluated. The debate among public healh
practitioners over the nature, cause and extent of the 'nutrition
problem' is documented and the role in this debate of official dietary
guidelines which appeared during the 1930s, is assessed.
The Impact of the Newer Knowledge of Nutrition on welfare feeding policy
Is evaluated in the context of the official promotion of milk feeding in
schools. In particular, Corry Mann's experimental evidence which was
used to endorse this policy, is reconsidered, and it is shown that the
NRC view that the trial was proof of the presence in milk of a "growth
factor" which produced preferential growth efficiency in adequately fed
children , was in error. From a re-evaluation of the evidence it is
suggested that the experiment merely recorded catch-up growth in a group
of poorly nourished children. The view that there existed an extensive
nutritional problem due to poor quality diets is examined and
challenged.
Both dietary survey data and anthropometric evidence are used to present
the case that there was throughout the period studied a widespread
problem of underfeeding among the poor and that intervention strategies
based on the Newer Knowledge were not an appropriate method of dealing
with this problem. This casts doubts on the widely held view that there
was a need for nutrition education and suggests that the problem was one of poverty rather than Ignorance. Disaggregated anthropometric data
located by the author are analysed according to NCHS standards to assess
the prevalence of underfeeding. Significantly higher prevalences of
stunting than low weight-for-age exist in all data sets; this phenomenon
is considered in detail and low weight-for-age is proposed as the
preferred index of malnutrition in 20th Century historical studies.
Attention is drawn to the relevance of these studies for the current
nutrition and public health debate
Perry Anderson: populismo y calidad democrática
No full textEl estudio de la democracia en América Latina ha pasado por diversos momentos o fases, que van desde aquel que busca explicar los distintos motivos que dificultan su consolidación en la región, otros relacionados con la transición y la consolidación de la democracia, éstos principalmente durante las últimas dos décadas del siglo XX, hasta llegar a los más recientes que apuntan a medir las dimensiones que definen su calidad. Es en este sentido, las ideas de Perry Anderson, expuestas en una conferencia dictada en el marco de la carrera de Sociología de la Universidad de Buenos Aires, el 16 deoctubre de 1987, son significativamente actuales, pues si bien introduce el concepto de“inflexión populista” como causa que da origen a las dictaduras militares de los años70, el autor hace una caracterización del populismo en la región, en términos de su origen, su desarrollo y materialización en clave de “dictadura plebiscitaria” endetrimento de una democracia representativa genuina (Anderson, 1988, p.6).The study of democracy in Latin America has come across diverse moments and phases, from purposes that make it difficult to explain its consolidation in the region to othersrelated with transition and consolidation of democracy within the last who decades.More recently, there is a concern about the quality of democracy and the variables that should be taken into account in order to measure it. In this sense, Perry Anderson’s ideas exposed on a conference, on November 16th 1987 at the Universidad de Buenos Aires, are currently significant. There, he introduced the concept of “populism inflection” as the cause that gives origin to military dictatorshipsin the 70’s. The author makes a characterization of populism in the region, studying itsdevelopment and materialization in a “plebiscitary dictatorship” in detriment of agenuine representative democracy (Anderson, 1988, p. 6)
Comparison of ovarian cycles of Hungarian riverine fish species representing different spawning strategies
No full textInvestigations on the ovarian cycle of fish species that inhabit Hungarian rivers are necessitated by both environmental and economic reasons. The objective of our research was to explore new fundamental knowledge concerning the ovarian cycle of the white bream (Blicca bjoerkna, Linnaeus, 1758), barbel (Barbus barbus, Linnaeus, 1758), orfe (Leuciscus idus, Linnaeus, 1758) and nase (Chondrostoma nasus, Linnaeus, 1758). Histological investigation of ovaries and determination of proportions of oocytes in different stages of development is an appropriate method for the description of spawning characteristics of these species. Our results show that the GSI value for all four investigated species starts to increase at the end of summer and reaches its maximum before spawning. In the barbel and white bream, the presence of oocytes in the stage of cortical alveoli and the heterogeneous size of oocytes in the stage of vitellogenesis in the pre-spawning period indicate that barbel and white bream are multiple spawners. In contrast, in the orfe and nase, the absence of oocytes in the stage of cortical alveoli and the homogeneous size of cells in the stage of vitellogenesis indicate that orfe and nase are single spawners
River Recovery: A pilot for making healthy rivers in Europe
No full textOnly 1% of the surface water in the Netherlands has been classified as ‘good’, making it the EU member state with the worst quality of surface water (Didde, 2022). Polluted rivers cause problems such as worsened human health, reduced biodiversity, and poor soil fertility. To comply with the Water Framework Directive, there is an urgent need to transform water management in the Netherlands. This report adopts a research-by-design approach to address the issue of water pollution on a pilot project scale, specifically the river Eem in the Netherlands. The policies and interventions implemented in the river Eem area are categorised according to their transferability to different programming areas, namely urban, industry, or agriculture, creating a toolbox that can be used to upscale the same approach in various parts of the Eurodelta. The report answers the following research question: How can the transformation of the Eem Valley turn the river Eem into the healthiest river in Europe as a pilot for the Eurodelta? It catalyses rethinking pollution flows from human activities, industries, and agricultural practices. The goal is to develop sustainable practices for the land surrounding the river and create a synergy between improved soil and water quality. Finally, the report concludes with a toolbox of interventions and policies that contribute to improving river water quality. The toolbox forms the basis for implementing this small-scale approach on a larger scaleAR2U086 R&D Studio – Spatial Strategies for the Global MetropolisAR2U088 R&D Methodology for UrbanismArchitecture, Urbanism and Building Science
Police note on cleaning streets and rivers
No full textLa imagen contiene una noticia acerca de una nota sobre la policía y el aseo de calles y ríos, emitida por el Estado Mayor de la 1ª División de los Estados Unidos de Colombia. El autor de la nota, preocupado por la salubridad de Bogotá, solicita al Secretario de Gobierno del Estado de Cundinamarca la implementación de una policía activa para limpiar las calles y los ríos de la ciudad. Destaca la acumulación de inmundicias, especialmente en el río San Agustín, como una fuente de gases nocivos que propagan enfermedades. Propone utilizar una sección del presidio para este fin, con la custodia de tropas, y pide la aprobación del Presidente del Estado para llevar a cabo esta medida. Noticia publicada en el Registro Oficial. Marzo 31 de 1867.The image contains a news item about a note about the police and the cleaning of streets and rivers, issued by the General Staff of the 1st Division of the United States of Colombia. The author of the note, concerned about the health of Bogotá, requests the Secretary of Government of the State of Cundinamarca to implement an active police force to clean the streets and rivers of the city. The accumulation of filth stands out, especially in the San Agustín River, as a source of harmful gases that spread diseases. He proposes using a section of the prison for this purpose, with the custody of troops, and requests the approval of the President of the State to carry out this measure. News published in the Official Registry. March 31, 1867
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