Modeling soil erosion and reservoir sedimentation at hillslope and catchment scale in semi-arid Burkina Faso

Soil erosion is a major factor of land degradation in Sub-Saharan Africa. The loss of nutrient-rich topsoil from hillslopes causes severe agricultural problems for an extremely vulnerable agricultural society that depends on soil quality as a fundamental base for its livelihood. The removal of soil in source areas leads to sediment accumulation in sink areas such as dammed reservoirs. Especially the siltation of small reservoirs is seen as a serious environmental threat in Burkina Faso, where more than a thousand dams have been built to store unevenly distributed rainwater for the dry season. These dams are in danger of losing their function as essential water reservoirs for domestic use, irrigation and stock watering in the near future. This study presents an integrative, scale-dependent approach to assess on-site and off-site impacts of soil erosion by quantifying the magnitude and intensity of soil loss/deposition at hillslope and catchment scales and by considering the spatial dimension of these processes in a complex landscape system in southwestern Burkina Faso. At the hillslope scale, the spatial variability of soils is analyzed by soil profile investigations along a catena and subsequently considered in soil erosion simulations by the physically-based WEPP model. WEPP model predictions indicate that although average soil loss rates simulated for the entire hillslope are comparatively low, they can be forty times higher at particular hillslope positions. These spatial differences, even in the relatively flat terrain of Burkina Faso, are also confirmed by Cs-137 measurements with averaged soil loss rates of less than 5 t/ha/yr and maximum erosion rates of more than 50 t/ha/yr in erosion hotspots. The identification of such hazard zones can be used to target site-specific land management options. WEPP model simulations show that the application of stone lines, minimum tillage, contour farming and residue management could reduce soil loss by up to 95 %, 70 %, 55 % and 45 % at these erosion-prone hillslope positions. At the catchment scale, sedimentation rates of three reservoirs are analyzed by bathymetric surveys, sediment core sampling and sediment yield calculations using the soil erosion and sediment delivery model WaTEM/SEDEM. For the model, a digital elevation models is generated and land-cover maps are derived from remote sensing images. A comparison between the initial and actual reservoir bed morphology shows that the reservoirs have lost approximately 10-15 % of their original storage capacity and more than 60 % of their inactive storage volume in the last 15 to 20 years. During that period, a sedimentation layer of 0.3 m to 0.5 m thickness has accumulated on the reservoir bed. This was verified by stratigraphical changes and downcore variations in sediment properties and Cs-137 concentrations. Predictions by WaTEM/SEDEM show similar magnitudes of siltation with specific sediment yield rates of 0.5 t/ha/yr to 3.4 t/ha/yr. These results indicate that the half-life of the dams might be reached in about 25 years assuming constant siltation rates under current conditions. In order to identify the sediment source areas and the potential soil-erosion risk zones leading to these high siltation rates, a spatially-explicit soil erosion and deposition hazard maps generated by WaTEM/SEDEM can be used. These hazard maps present a powerful tool to support policy makers in their decisions on which landscapes are primarily at risk and where action plans for sustainable soil and water conservation should be implemented.Modellierung von Bodenerosion und Sedimentation von Stauseen auf Hang- und Wassereinzugsgebietsebene im semi-ariden Burkina Faso Die Bodenerosion hat einen wesentlichen Einfluss auf die Landdegradierung semi-arider Gebiete in Afrika südlich der Sahara. Der Abtrag von humusreichem Oberboden am Hang verursacht schwerwiegende landwirtschaftliche Probleme, insbesondere für eine fragile Ackerbaugesellschaft, die von einer guten Bodenqualität zur Sicherung ihrer Existenzgrundlage abhängig ist. Der Abtrag von Bodensedimenten aus Quellgebieten hat gleichzeitig die Akkumulation von Sedimenten in Zielgebieten wie beispielsweise eingedämmten Rückhaltebecken zur Folge. Insbesondere die Verschlämmung von Kleinstauseen stellt für das Land Burkina Faso, in dem über tausend Staudämme gebaut worden sind, um das Regenwasser der uneinheitlich verteilten Niederschläge für die Trockenzeit stauen zu können, ein zunehmendes Umweltproblem dar. In naher Zukunft drohen diese Staudämme ihre Funktion als unverzichtbare Wasserspeicher für Haushalt, Bewässerungsfeldbau und Viehzucht zu verlieren. Um die Auswirkungen von Bodenerosion sowohl on-site als auch off-site zu bewerten, verfolgt die vorliegende Arbeit einen integrativen, skalenabhängigen Ansatz, bei dem einerseits das Ausmaß und die Intensität von Bodenerosion und deren Ablagerung auf Hang- und Einzugsgebietsebene quantifiziert werden und bei der andererseits die räumliche Dimension dieser Prozesse in einem komplexen Landschaftssystem im Südwesten Burkina Fasos berücksichtigt wird. Auf der Hangebene wird die räumliche Variabilität von Boden anhand von Bodenprofilen entlang einer Catena untersucht und in die Erosionsmodellierung mittels des physikalisch-basierten WEPP-Model miteinbezogen. Die Ergebnisse der Modellierung verdeutlichen, dass, obwohl die simulierten Abtragsraten für den Gesamthang als vergleichsweise gering einzuschätzen sind, diese bis zu vierzigfach erhöht an einzelnen Hangbereichen auftreten können. Auch Cs-137 Messungen bestätigen mit durchschnittlichen Abtragsraten von weniger als 5 t/ha/yr für den Gesamthang und maximalen Abtragsraten von mehr als 50 t/ha/yr in gefährdeten Zonen diese hohen, räumlichen und für die verhältnismäßig flache Landschaft Burkina Fasos auffälligen Differenzen. Die Identifikation dieser Gefährdungszonen kann jedoch einer standortspezifischen Anpassung von Landnutzungsmethoden dienen. Die Simulationsergebnisse des WEPP-Models zeigen, dass durch die Anlegung von Steinwällen, weniger intensiven Bodenbearbeitungsmethoden, Konturpflügen und Mulchsaat der Bodenabtrag an diesen besonders erosionsgefährdeten Hangbereichen um bis zu 95 %, 70 %, 55 % und 45 % reduziert werden könnte. Auf Wassereinzugsgebietsebene wird die Sedimentationsrate von drei Kleinstaudämmen durch bathymetrische Methoden, Sedimentbohrungen und die Berechnung der Sedimentfracht anhand des Bodenerosions- und Sedimentaustragsmodelles WaTEM/SEDEM ermittelt. Für die Modellierung wird ein digitales Höhenmodel erstellt, Landbedeckungskarten werden wiederum von Fernerkundungsbildern abgeleitet. Ein Vergleich zwischen der ursprünglichen und aktuellen Stauseemorphologie zeigt, dass die Staubecken in den letzten 15 bis 20 Jahren zwischen 10-15% ihrer gesamten Speicherkapazität und mehr als 60% ihres inaktiven Speichervolums eingebüßt haben. In diesem Zeitraum hat sich auch eine Sedimentschicht von 0.3 m bis 0.5 m Mächtigkeit auf dem Stauseeboden abgelagert, was mittels stratigraphischer Analysen und Veränderungen sedimentspezifischer Eigenschaften sowie Cs-137 Konzentrationen im Bohrkern belegt wird. Modellberechnungen mit WaTEM/SEDEM bestätigen einen ähnlich hohen Verschlämmungsgrad mit spezifischen Sedimentfrachtraten von 0.5 t/ha/yr bis 3.4 t/ha/yr. Die Ergebnisse verdeutlichen, dass - setzt man gleichbleibende Sedimentationsraten unter den heutigen Bedingungen voraus - die Halbzeit der prognostizierten Lebensdauer der Staudämme in etwa 25 Jahren erreicht sein wird. Um Sedimentbereitstellungsgebiete und potentielle Erosionsrisikobereiche, die zu diesem hohen Sedimenteintrag in Stauseen führen, zu identifizieren, dienen räumlich-detaillierte Bodenabtrags- und Akkumulationsgefahrenkarten, die mit WaTEM/SEDEM erstellt werden. Diese Gefahrenkarten können schließlich von Entscheidungsträgern als sinnvolle Planungsgrundlage genutzt werden, um festzulegen, welche Landschaftsbereiche vorrangig als Risikogebiete ausgewiesen werden sollten, um dort nachhaltige Boden- und Wasserschutzmaßnahmen zu implementieren

Gestão educacional: interlocuções entre escola e classe hospitalar acerca de um aluno-paciente com altas habilidades/superdotação

This study aims to verify the dialogues between the school management and educational coordinator of the Hospital Class about a student-patient with giftedness. The research is constituted as a qualitative case study where semi-structured interviews with the director, vice director, educational coordinator of the school, pedagogical coordinator of the Educational Sector of the University Hospital of Santa Maria and the student’s responsible are held. The school management has a brief knowledge about giftedness. Although the school management promotes dialogical exchange with its pedagogical team, there was no dialogue between the school and the Education Sector. Therefore urge public policies that promote information about giftedness and it is very important dialogue between managers that contribute to the learning gifted students.Key-words: educational management; school; hospital class; giftedness; dialogic exchanges.O objetivo desse estudo foi verificar como ocorrem as interlocuções entre as gestoras da escola e a coordenadora pedagógica da classe hospitalar acerca de um aluno-paciente com AH/SD. Assim, a pesquisa definiu-se como qualitativa do tipo estudo de caso, sendo realizadas entrevistas semiestruturadas com as gestoras da escola, do Setor Educacional do HUSM e com a responsável pelo aluno. A equipe gestora da escola apresentou breve conhecimento sobre as AH/SD. Ainda, apesar das gestoras promoverem as trocas dialógicas com a sua equipe pedagógica, esse diálogo não ocorreu entre a escola e o Setor Educacional. Logo, urgem políticas públicas que promovam informações sobre as AH/SD e é de suma importância o diálogo e as interlocuções, entre os gestores, para a aprendizagem do aluno com AH/SD.Palavras-chave: gestão educacional; escola; classe hospitalar; altas habilidades/superdotação; trocas dialógicas

Educational level and alcohol use in adolescence and early adulthood-The role of social causation and health-related selection-The TRAILS Study

Both social causation and health-related selection may influence educational gradients in alcohol use in adolescence and young adulthood. The social causation theory implies that the social environment (e.g. at school) influences adolescents’ drinking behaviour. Conversely, the health-related selection hypothesis posits that alcohol use (along other health-related characteristics) predicts lower educational attainment. From past studies it is unclear which of these mechanisms predominates, as drinking may be both a cause and consequence of low educational attainment. Furthermore, educational gradients in alcohol use may reflect the impact of ‘third variables’ already present in childhood, such as parental socioeconomic status (SES), effortful control, and IQ. We investigated social causation and health-related selection in the development of educational gradients in alcohol use from adolescence to young adulthood in a selective educational system. We used data from a Dutch population-based cohort (TRAILS Study; n = 2,229), including measurements of educational level and drinking at ages around 14, 16, 19, 22, and 26 years (waves 2 to 6). First, we evaluated the directionality in longitudinal associations between education and drinking with cross-lagged panel models, with and without adjusting for pre-existing individual differences using fixed effects. Second, we assessed the role of childhood characteristics around age 11 (wave 1), i.e. IQ, effortful control, and parental SES, both as confounders in these associations, and as predictors of educational level and drinking around age 14 (wave 2). In fixed effects models, lower education around age 14 predicted increases in drinking around 16. From age 19 onward, we found a tendency towards opposite associations, with higher education predicting increases in alcohol use. Alcohol use was not associated with subsequent changes in education. Childhood characteristics strongly predicted education around age 14 and, to a lesser extent, early drinking. We mainly found evidence for the social causation theory in early adolescence, when lower education predicted increases in subsequent alcohol use. We found no evidence in support of the health-related selection hypothesis with respect to alcohol use. By determining initial educational level, childhood characteristics also predict subsequent trajectories in alcohol use

Representação dos Estados de Acoplamento Atmosférico Através de um Modelo de Coluna Simples

É utilizado um Modelo de Coluna Simples com o propósito de reproduzir os estados de acoplamento atmosférico na Camada Limite Planetária em condições muito estáveis. O modelo é composto por equações prognósticas para algumas componentes médias e por uma equação para o balanço de energia em superfície. Verifica-se que os esquemas são capazes de reproduzir o processo de acoplamento, contudo apenas para valores muito altos de vento geostrófico

As altas habilidades/superdotação no município de Agudo: aspectos a serem (re) pensados acerca de matrículas e do atendimento educacional

Esta pesquisa foi pensada a partir de inquietações a respeito da realidade no número de matrículas de alunos com Altas Habilidades/Superdotação (AH/SD) no município de Agudo, localizado no interior do Rio Grande do Sul. Sabe-se que a temática vem ganhando espaço na sociedade e, aos poucos, a preocupação e as discussões sobre quem são esses alunos e o que precisam para seu desenvolvimento educacional estão presentes em vários espaços escolares. Dessa forma, o presente estudo teve como objetivo problematizar o Atendimento Educacional ao aluno com AH/SD no município de Agudo a partir do mapeamento de matrículas na rede municipal e estadual de educação. Como embasamento teórico, buscou-se a teoria de Renzulli (2004, 2014), bem como Freitas e Pérez (2012, 2016), Virgolim (2007), Sabatella e Cupertino (2007) e políticas públicas sobre a inclusão desse alunado (BRASIL, 2001, 2008, 2011). O estudo é delimitado como qualitativo, do tipo estudo de caso, tendo como sujeito de pesquisa cinco Educadoras Especiais da rede municipal e estadual de educação de Agudo, as quais responderam a entrevistas semiestuturadas. As Educadoras Especiais apontaram o baixíssimo número de alunos identificados com AH/SD ou que estão passando pelo processo de identificação. Constatou-se a falta de maiores conhecimentos por parte dos professores, a demanda acentuada de alunos com outras especificidades sendo atendidos no Atendimento Educacional Especializado, a falta de tempo para um trabalho voltado para às AH/SD dentro das escolas e a necessidade de maior investimento da Secretaria Municipal de Educação do referido município

ADHD Symptoms and Educational Level in Adolescents:The Role of the Family, Teachers, and Peers

Few studies have explored the contribution of family and school factors to the association between ADHD symptoms and lower education. Possibly, having more ADHD symptoms contributes to poorer family functioning and less social support, and consequently a lower educational level (i.e., mediation). Moreover, the negative effects of ADHD symptoms on education may be stronger for adolescents with poorer family functioning or less social support (i.e., interaction). Using data of the Dutch TRAILS Study (N = 2,229), we evaluated associations between ADHD symptoms around age 11 and educational level around age 14, as well as between ADHD symptoms around age 14 and 16 years and subsequent changes in educational level around age 16 and 19, respectively. We assessed the potential mediating role of family functioning, and social support by teachers and classmates, all measured around ages 11, 14, and 16, while additionally evaluating interactions between ADHD symptoms and these hypothesized mediators. ADHD symptoms were associated with poorer family functioning, less social support by teachers and classmates, and lower education throughout adolescence. No conclusive evidence of mediation was found, because unique associations between family functioning and social support by teachers and classmates and education were largely absent. Furthermore, we found no interactions between ADHD symptoms and family functioning and social support by teachers and classmates. Although social support by teachers and classmates and good family functioning may benefit the wellbeing and mental health of adolescents with high levels of ADHD symptoms, they will not necessarily improve their educational attainment.</p

O PAPEL DAS GESTORAS DE UMA ESCOLA FRENTE À ENFERMIDADE DE UM ALUNO COM ALTAS HABILIDADES/SUPERDOTAÇÃO

Este estudo disserta sobre a atuação de professores gestores na sociedade atual. Dessa forma, a escrita teve como objetivo descrever o papel desenvolvido pela equipe gestora de uma escola da rede regular de ensino de um município do interior do Rio Grande do Sul, em relação a um aluno em tratamento de saúde, que apresenta Altas habilidades/Superdotação. A pesquisa delimitou-se como qualitativa, do tipo estudo de caso, e foi realizada por meio de observação e de entrevistas semiestruturadas com a equipe gestora da referida escola: diretora, vice-diretora e supervisora, bem como com a mãe do aluno Público-alvo da Educação Especial. Em relação aos achados, realizou-se uma análise qualitativa, referenciada por meio de teóricos e da legislação que discorrem sobre o assunto (LÜCK, 2006; LIBÂNEO, OLIVEIRA, TOSCHI, 2005; BRASIL, 2002; BRASIL, 2008). Verificou-se que as gestoras buscaram saber a respeito do tratamento de saúde do menino, questionando a mãe acerca do diagnóstico. Quanto às questões pedagógicas, a equipe gestora buscou informar os professores sobre a situação do adolescente, assim como, encaminharam o material pedagógico para o aluno realizar de maneira domiciliar. As gestoras procuraram desenvolver um bom papel diante da realidade vivenciada, porém, conforme as próprias entrevistadas, faltaram conhecimentos e maior disponibilidade de tempo para atender, de forma mais significativa, às necessidades do aluno

ANÁLISE DE MÉTODOS PARA O PREENCHIMENTO DE FALHAS APLICADOS EM SÉRIES DE DADOS PLUVIOMÉTRICOS DO ESTADO DO PARANÁ (BRASIL)

Em virtude de a Climatologia necessitar de uma série de dados consistente e sem falhas para análises climáticas e devido à grande quantidade de dados com falhas disponibilizados no Brasil, faz-se necessário avaliar métodos de preenchimento de falhas para viabilizar a utilização de séries longas de dados. O artigo objetiva avaliar qual método de preenchimento de falhas é mais adequado para estações meteorológicas localizadas no estado do Paraná. Para tanto, foram testados quatro métodos de preenchimento de falhas aplicados a 10 estações meteorológicas do Estado, integrantes de cinco regiões homogêneas de precipitação. Os métodos testados foram IDW, Inverso da Distância, Média e Ponderação Regional. Foram suprimidos os dados diários de anos classificados como habituais pelo método gráfico cronológico de tratamento da informação (MGCTI) e posteriormente preenchidos com os métodos sob análise. Posteriormente os valores preenchidos foram comparados com os valores removidos (registrados na estação). O método de preenchimento de falhas que demonstrou melhor associação com os dados registrados foi o IDW, seguido da Média. De forma geral os métodos de preenchimento de falhas testados subestimam os valores diários superiores a 20mm e superestimam os menores de 20mm, sendo que o IDW foi o que mais se aproximou dos valores acima de 40mm. Os métodos tiveram mais sucesso em preencher falhas nas estações da faixa sul do Estado, enquanto nas estações próximas ao litoral foram registradas as maiores diferenças entre os valores preenchidos e registrados