939 resultados para Rainfall indices
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Estudio dendrocronológico de estructuras arbóreas en alta montaña mediterránea.
Unravelling past flash flood activity in a forested mountain catchment of the Spanish Central System
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Flash floods represent one of the most common natural hazards in mountain catchments, and are frequent in Mediterranean environments. As a result of the widespread lack of reliable data on past events, the understanding of their spatio-temporal occurrence and their climatic triggers remains rather limited. Here, we present a dendrogeomorphic reconstruction of past flash flood activity in the Arroyo de los Puentes stream (Sierra de Guadarrama, Spanish Central System). We analyze a total of 287 increment cores from 178 disturbed Scots pine trees (Pinus sylvestris L.) which yielded indications on 212 growth disturbances related to past flash flood impact. In combination with local archives, meteorological data, annual forest management records and highly-resolved terrestrial data (i.e., LiDAR data and aerial imagery), the dendrogeomorphic time series allowed dating 25 flash floods over the last three centuries, with a major event leaving an intense geomorphic footprint throughout the catchment in 1936. The analysis of meteorological records suggests that the rainfall thresholds of flash floods vary with the seasonality of events. Dated flash floods in the 20th century were primarily related with synoptic troughs owing to the arrival of air masses from north and west on the Iberian Peninsula during negative indices of the North Atlantic Oscillation. The results of this study contribute considerably to a better understanding of hazards related with hydrogeomorphic processes in central Spain in general and in the Sierra de Guadarrama National Park in particular.
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Soil erosion is a serious environmental threat in the Mediterranean region due to torrential rainfalls, and it contributes to the degradation of agricultural land. Techniques such as rainwater harvesting may improve soil water storage and increase agricultural productivity, which could result in more effective land usage. Reservoir tillage is an effective system of harvesting rainwater, but it has not been scientifically evaluated like other tillage systems. Its suitability for the conditions in Spain has not been determined. To investigate and quantify water storage from reservoir tillage and how it could be adapted to improve infiltration of harvested rainwater, a laboratory-scale rainfall simulator was developed. Rainfall characteristics, including rainfall intensity, spatial uniformity and raindrop size, confirm that natural rainfall conditions are simulated with sufficient accuracy. The simulator was auto-controlled by a solenoid valve and three pressure nozzles were used to spray water corresponding to five rainfall intensities ranging from 36 to 112 mm h− 1 for 3 to 101-year return period with uniformity coefficients between 83 and 94%. In order to assess the reservoir tillage method under surface slopes of 0, 5, and 10%, three soil scooping devices with identical volume were used to make depressions in the following forms: a) truncated square pyramid, b) triangular prism, and c) truncated cone. These depressions were compared to a control soil surface with no depression. For the loam soil used in this study, results show that reservoir tillage was able to reduce soil erosion and surface runoff and significantly increase infiltration. There was significant difference between the depressions and the control. Compared to the control, depression (a) reduced surface runoff by about 61% and the sediment yield concentration by about 79%.
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The colony shape of four yeast species growing on agar medium wasmeasured for 116 days by image analysis. Initially, all the colonies are circular, with regular edges. The loss of circularity can be quantitatively estimated by the eccentricity index, Ei, calculated as the ratio between their orthogonal vertical and horizontal diameters. Ei can increase from 1 (complete circularity) to a maximum of 1.17–1.30, depending on the species. One colony inhibits its neighbour only when it has reached a threshold area. Then, Ei of the inhibited colony increases proportionally to the area of the inhibitory colony. The initial distance between colonies affects those threshold values but not the proportionality, Ei/area; this inhibition affects the shape but not the total surface of the colony. The appearance of irregularities in the edges is associated, in all the species, not with age but with nutrient exhaustion. The edge irregularity can be quantified by the Fourier index, Fi, calculated by the minimum number of Fourier coefficients that are needed to describe the colony contour with 99% fitness. An ad hoc function has been developed in Matlab v. 7.0 to automate the computation of the Fourier coefficients. In young colonies, Fi has a value between 2 (circumference) and 3 (ellipse). These values are maintained in mature colonies of Debaryomyces, but can reach values up to 14 in Saccharomyces.All the species studied showed the inhibition of growth in facing colony edges, but only three species showed edge irregularities associated with substrate exhaustion. Copyright © 2014 John Wiley & Sons, Ltd.
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The Iberian pig valued natural resources of the pasture when fattened in mountain. The variability of acorn production is not contained in any line of Spanish agricultural insurance. However, the production of arable pasture is covered by line insurance number 133 for loss of pasture compensation. This scenario is only contemplated for breeding cows and brave bulls, sheep, goats and horses, although pigs are not included. This insurance is established by monitoring ten-day composites Normalized Difference Vegetation Index (NDVI) measured by satellite over treeless pastures, using MODIS TERRA satellite. The aim of this work is to check if we can use a satellite vegetation index to estimate the production of acorns.
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Port. con grab. que representa el rostro de Santo Tomas
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One of the main concerns when conducting a dam test is the acute determination of the hydrograph for a specific flood event. The use of 2D direct rainfall hydraulic mathematical models on a finite elements mesh, combined with the efficiency of vector calculus that provides CUDA (Compute Unified Device Architecture) technology, enables nowadays the simulation of complex hydrological models without the need for terrain subbasin and transit splitting (as in HEC-HMS). Both the Spanish PNOA (National Plan of Aereal Orthophotography) Digital Terrain Model GRID with a 5 x 5 m accuracy and the CORINE GIS Land Cover (Coordination of INformation of the Environment) that allows assessment of the ground roughness, provide enough data to easily build these kind of models
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An extension of guarantees related to rainfall-related risks in the insurance of processing tomato crops hasbeen accompanied with a large increase in claims in Western Spain, suggesting that damages may havebeen underestimated in previous years. A database was built by linking agricultural insurance records,meteorological data from local weather stations, and topographic data. The risk of rainfall-related dam-ages in processing tomato in the Extremenian Guadiana river basin (W Spain) was studied using a logisticmodel. Risks during the growth of the crop and at harvesting were modelled separately. First, the riskrelated to rainfall was modelled as a function of meteorological, terrain and management variables. Theresulting models were used to identify the variables responsible for rainfall-related damages, with a viewto assess the potential impact of extending insurance coverage, and to develop an index to express thesuitability of the cropping system for insurance. The analyses reveal that damages at different stages ofcrop development correspond to different hazards. The geographic dependence of the risk influences the scale at which the model might have validity, which together with the year dependency, hampers the possibilityof implementing index based insurances is questioned.
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Funding The International Primary Care Respiratory Group (IPCRG) provided funding for this research project as an UNLOCK group study for which the funding was obtained through an unrestricted grant by Novartis AG, Basel, Switzerland. The latter funders had no role in study design, data collection and analysis, decision to publish or preparation of the manuscript. Database access for the OPCRD was provided by the Respiratory Effectiveness Group (REG) and Research in Real Life; the OPCRD statistical analysis was funded by REG. The Bocholtz Study was funded by PICASSO for COPD, an initiative of Boehringer Ingelheim, Pfizer and the Caphri Research Institute, Maastricht University, The Netherlands.
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While genome sequencing projects are advancing rapidly, EST sequencing and analysis remains a primary research tool for the identification and categorization of gene sequences in a wide variety of species and an important resource for annotation of genomic sequence. The TIGR Gene Indices (http://www.tigr.org/tdb/tgi.shtml) are a collection of species-specific databases that use a highly refined protocol to analyze EST sequences in an attempt to identify the genes represented by that data and to provide additional information regarding those genes. Gene Indices are constructed by first clustering, then assembling EST and annotated gene sequences from GenBank for the targeted species. This process produces a set of unique, high-fidelity virtual transcripts, or Tentative Consensus (TC) sequences. The TC sequences can be used to provide putative genes with functional annotation, to link the transcripts to mapping and genomic sequence data, to provide links between orthologous and paralogous genes and as a resource for comparative sequence analysis.
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A irrigação quando bem manejada, pode minimizar os riscos econômicos da atividade sucroalcooleira, particularmente em safras com presença de instabilidade climática onde a restrição hídrica, promovida pela diminuição no volume de chuvas, pode reduzir a produtividade dos canaviais. Dentre as ferramentas disponíveis para a gestão eficiente da água na agricultura irrigada, a técnica de irrigação sob déficit pode se tornar uma escolha acertada para a cana-de-açúcar, desde que sejam identificadas as fases fenológicas e épocas de cultivo onde a limitação da oferta de água não implique em reduções antieconômicas no rendimento da cultura. Diante disso, a hipótese que norteia essa pesquisa, é a de que existe uma estratégia de irrigação sob déficit, que associada a uma variedade com características específicas, possibilite a expressão de indicadores de produtividade tão satisfatórios quanto os obtidos em condições de irrigação plena. Nessa linha, os objetivos da pesquisa envolveram o estudo da dinâmica foliar, acúmulo e particionamento de biomassa e ainda, índices de produtividade da água para biomassa, açúcar e etanol de 1ª e 2ª geração de oito variedade de cana-de-açúcar, submetidas a diferentes condições de disponibilidade hídrica no solo em dois ciclos de cultivo (cana-planta e cana-soca). A pesquisa foi realizada na Escola Superior de Agricultura \"Luiz de Queiroz\", em Piracicaba/SP, onde foram estudados os dois primeiros ciclos de cultivo da cana-de-açúcar, sendo estes abordados nesta tese como Experimento 1 (cana-planta) e Experimento 2 (cana-soca). O delineamento experimental adotado para ambos os ciclos foi o de blocos casualizados, com três blocos completos. Os tratamentos foram compostos por três fatores em esquema de parcelas sub-subdivididas. Estas parcelas foram formadas por duas plantas (touceiras) alocadas em um vaso com aproximadamente 330 litros de solo. No Experimento 1, foram estudados três fatores, sendo o primeiro e segundo com quatro níveis e o terceiro com oito (4x4x8), totalizando assim 128 tratamentos, sendo eles: quatro níveis de irrigação ao longo do ciclo (125, 100, 75 e 50% da ETc); oito variedades comerciais de cana-de-açúcar e quatro procedimentos de maturação, impostos por meio de variações na intensidade do déficit hídrico aplicado. Para o Experimento 2, substitui-se o fator Maturação por Épocas de Corte, o qual consistiu em colheitas de um quarto do experimento a cada 90 dias. Os resultados encontrados apontaram que a área foliar responde positivamente a maior disponibilidade hídrica no solo, tendo sido verificado uma relação proporcional entre estes. Quanto ao acúmulo de biomassa, verificou-se que para as oito variedades estudadas houve incremento de biomassa a medida em que se aumentou o volume de água disponibilizado às variedades. No tocante ao particionamento, as folhas foram os drenos principais de fotoassimilados da planta até os 100 dias de cultivo, sendo que após este período, os colmos ocuparam o lugar de dreno preferencial. Os indicadores de produtividade da água apresentaram diferenças significativas para o fator lâmina, o que indica a existência de cultivares de cana-de-açúcar mais eficientes no uso da água. Por fim, observou-se que a produtividade da água para etanol total apresentou valores expressivos, com média para essa variável igual a 1,81 L m-3, o que denota o potencial de rendimento de etanol (1G + 2G) a partir da cana-de-açúcar quando é adotado o aproveitamento integral das plantas.
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El objetivo de este trabajo es el reconocimiento material de la islamización en la Cora o provincia de Tudmīr, a partir de la investigación arqueológica. Se realiza un balance crítico de una década de investigaciones individuales y colectivas, presentando las últimas novedades sobre el poblamiento y las formas de implantación territorial en el sudeste de al-Andalus. La arqueología, entendida como una de las fuentes históricas más innovadoras en la discusión sobre la formación de al-Andalus, se convierte en un valioso instrumento de caracterización material de la sociedad islámica y permite reconocer los indicadores sociales (urbanismo y espacios domésticos), culturales (islamización religiosa y arabización lingüística) y cronológicos (moneda, cerámica, etc.) del proceso de islamización.
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Biotic indices have been developed to summarise information provided by benthic macroinvertebrates, but their use can require specialized taxonomic expertise as well as a time-consuming operation. Using high taxonomic level in biotic indices reduces sampling processing time but should be considered with caution, since assigning tolerance level to high taxonomic levels may cause uncertainty. A methodology for family level tolerance categorization based on the affinity of each family with disturbed or undisturbed conditions was employed. This family tolerance classification approach was tested in two different areas from Mediterranean Sea affected by sewage discharges. Biotic indices employed at family level responded correctly to sewage presence. However, in areas with different communities among stations and high diversity of species within each family, assigning the same tolerance level to a whole family could imply mistakes. Thus, use of high taxonomic level in biotic indices should be only restricted to areas where homogeneous community is presented and families across sites have similar species composition.
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Purpose. To assess in a sample of normal, keratoconic, and keratoconus (KC) suspect eyes the performance of a set of new topographic indices computed directly from the digitized images of the Placido rings. Methods. This comparative study was composed of a total of 124 eyes of 106 patients from the ophthalmic clinics Vissum Alicante and Vissum Almería (Spain) divided into three groups: control group (50 eyes), KC group (50 eyes), and KC suspect group (24 eyes). In all cases, a comprehensive examination was performed, including the corneal topography with a Placidobased CSO topography system. Clinical outcomes were compared among groups, along with the discriminating performance of the proposed irregularity indices. Results. Significant differences at level 0.05 were found on the values of the indices among groups by means of Mann-Whitney-Wilcoxon nonparametric test and Fisher exact test. Additional statistical methods, such as receiver operating characteristic analysis and K-fold cross validation, confirmed the capability of the indices to discriminate between the three groups. Conclusions. Direct analysis of the digitized images of the Placido mires projected on the cornea is a valid and effective tool for detection of corneal irregularities. Although based only on the data from the anterior surface of the cornea, the new indices performed well even when applied to the KC suspect eyes. They have the advantage of simplicity of calculation combined with high sensitivity in corneal irregularity detection and thus can be used as supplementary criteria for diagnosing and grading KC that can be added to the current keratometric classifications.