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Dinâmica da água em terraços de infiltração.; Water dynamics in level terraces.

Castro, Luciana Gomes
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 14/12/2001 PT
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O terraceamento é uma prática de conservação do solo que visa reduzir a perda de água e solo pela interceptação de enxurradas que ocorrem quando a intensidade da chuva supera a capacidade de infiltração de água no solo. Atualmente, o dimensionamento dos terraços tem sido feito com base em conhecimento empírico; no entanto, um conhecimento mais detalhado da física dos processos que regem o funcionamento dos terraços possibilitaria otimizar o dimensionamento dos terraços. No presente estudo foi avaliada a capacidade de infiltração de água no canal de um terraço em nível pelos métodos da densidade de fluxo e da armazenagem de água em diferentes condições de manejo agrícola (solo nu, solo gramado e solo sob preparo convencional e plantio direto para a implantação da cultura de milho) num Latossolo vermelho com declividade média de 0,08 m m-1. Em cada tratamento foram instaladas sondas de TDR em três pontos de observação no centro do canal do terraço (distanciados de 4 m entre si e considerados como repetições), nas rofundidades de 0,05, 0,10, 0,20, 0,40, 0,60 e 0,80 m. Nestas mesmas profundidades amostras indeformadas de solo foram retiradas para determinação da densidade e curva de retenção de água no solo. As leituras das guias de onda do TDR foram feitas automaticamente e a intensidade de chuva monitorada por um pluviômetro automatizado. Ao final de cada evento de chuva erosiva a deposição de solo foi medida por meio de 14 pontos de observação dispostos ao longo do centro do canal do terraço de cada tratamento. Durante a estação seca (julho-agosto)...

Rodas compactadoras e aterradoras na qualidade de acabamento de semeadura direta

Soares, Tatiane Aparecida
Fonte: Universidade Estadual Paulista (UNESP) Publicador: Universidade Estadual Paulista (UNESP)
Tipo: Tese de Doutorado Formato: xvii, 95 f. : il.
POR
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES); Pós-graduação em Agronomia (Ciência do Solo) - FCAV; O plantio direto consiste em um sistema de manejo conservacionista da produção agrícola, que promove a melhoria das condições físicas, químicas e biológicas do solo. Desta forma, o objetivo do presente trabalho foi a avaliação de sistemas de acabamento de semeadura existentes no mercado nacional, utilizados em semeadoras de precisão para plantio direto, assim como novas propostas, levando em conta fatores que afetam a germinação das sementes e a emergência das plântulas no campo. O experimento foi conduzido na Fazenda Experimental do Instituto Agronômico do Paraná – IAPAR, em Londrina, utilizando-se o delineamento experimental em blocos ao acaso, com oito tratamentos e quatro repetições para a cultura do feijão e três repetições para a cultura da soja. Os tratamentos foram constituídos de oito sistemas de acabamento de semeadura, dotados de componentes com e sem aterramento, sistemas de controle de profundidade de sementes e rodas compactadoras. Foram avaliadas variáveis do solo, das sementes e parâmetros de desempenho das unidades semeadoras. Conclui-se que os discos aterradores melhoram os resultados das unidades de semeadura...

Metodologia para determinação de volume de detenção em pequenas bacias urbanas: o caso do córrego Wenzel, Rio Claro/SP

Guerzoni Filho, Jônatas
Fonte: Universidade Estadual Paulista (UNESP) Publicador: Universidade Estadual Paulista (UNESP)
Tipo: Trabalho de Conclusão de Curso Formato: 51 f.
POR
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With the accelerated urbanization process of Brazil from the 50s, there was a disorderly occupation of spaces and consequent soil sealing. Unlike this growth, the support capacity of urban environments has not evolved in the same way, generating negative environmental impacts to the citizens. Among these impacts are the effects of flooding. In order to minimize the negative effects of extreme precipitation over cities, the government invests in corrective measures, like compensatory techniques on urban drainage, which have as a basic principle the retention and infiltration of the rainfall, dampening the peak flow and runoff. An example of applying these techniques in urban areas are the detention basins, commonly called large pools. The hydraulic design of these structures is dependent of complex data and variables, and projects involving small areas generally use simplified methods for defining the reservoirs volume of the storage (Tassi, 2005). One of these methods is presented in this study, which relates to the percentage of soil sealing to the specific storage volume (m³/ha) in combination by applying the hydrological model of the Rational Method and analyzing regional rainfall and soil occupation over the basin. Within this context...

Avaliação da qualidade do solo urbano utilizando SIG

Rodrigues, Sónia Alexandra Morais
Fonte: Universidade de Aveiro Publicador: Universidade de Aveiro
Tipo: Dissertação de Mestrado
ENG
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26.4%
Espera-se que esta dissertação constitua uma base sólida para o estabelecimento de relações entre a investigação científica e a tomada de decisão em áreas urbanas. Os resultados de estudos científicos nem sempre são suficientes, apropriados ou possuem o formato adequado para responder às necessidades de planeamento e gestão. Este estudo pretende criar um “continuum” de informação entre investigadores, cientistas e gestores de áreas urbanas. O produto final desta investigação é uma análise documentada de parâmetros de qualidade de solo urbano como base para práticas de gestão que visem o desenvolvimento sustentável em áreas urbanas, assente em metodologias consistentes e transparentes para os decisores. Os seguintes objectivos orientaram esta investigação: descrição dos efeitos dos processos de urbanização no solo urbano; a definição de qualidade de solo urbano; a descrição de um caso de estudo de avaliação da qualidade ambiental de solos urbanos utilizando Sistemas de Informação Geográfica (SIG) para a elaboração de mapas de variabilidade de parâmetros indicadores; dar exemplos da utilização de certas ferramentas de análise geoestatística e de interpolação dados em estudos de qualidade de solos; desenvolver uma estrutura conceptual para avaliação da qualidade de solo urbano. A associação entre a urbanização insustentável e a degradação do recurso “solo urbano” foi discutida neste estudo. A perturbação do “solo” em áreas urbanas contribui para um acréscimo da heterogeneidade desta matriz. As pressões antropogénicas nas cidades têm impactos na funcionalidade do solo que resultam em degradação (erosão...

Preserving Ecosystem Services in Urban Regions: Challenges for Planning and Best Practice Examples from Switzerland

Tobias, Silvia
Fonte: John Wiley & Sons, Inc. Publicador: John Wiley & Sons, Inc.
Tipo: Artigo de Revista Científica
EN
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This article presents a literature review that explores the challenges for planning in urban regions in connection with the preservation of ecosystem services. It further presents some best practice examples for meeting these challenges. The demand for the provision of ecosystem services within urban regions changed during the transition from a largely agrarian society to an industrial society and, most recently, to a service society. Although in the past, provisioning services such as food production or the provision of raw material were decisive for urban development, today cultural services, e.g., clear views or nearby recreation areas, have become increasingly important. According to the literature, soil sealing is the greatest threat urbanization poses toward ecosystem services, as it compromises all of them. Spatially extensive cities with a high building density particularly inhibit regulating services like the regulation of temperature or water surface runoff. Conversely, scattered settlement patterns may lead to very small remnants of open space that cannot reasonably serve as natural habitat, agricultural land, or recreation area. The challenges for planning in urban regions are: 1) specifying regulations that define outer limits to the development of each settlement unit...

Assessment of Soil Sealing Management Responses, Strategies, and Targets Toward Ecologically Sustainable Urban Land Use Management

Artmann, Martina
Fonte: Springer Netherlands Publicador: Springer Netherlands
Tipo: Artigo de Revista Científica
EN
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Soil sealing has negative impacts on ecosystem services since urban green and soil get lost. Although there is political commitment to stop further sealing, no reversal of this trend can be observed in Europe. This paper raises the questions (1) which strategies can be regarded as being efficient toward ecologically sustainable management of urban soil sealing and (2) who has competences and should take responsibility to steer soil sealing? The analyses are conducted in Germany. The assessment of strategies is carried out using indicators as part of a content analysis. Legal-planning, informal-planning, economic-fiscal, co-operative, and informational strategies are analyzed. Results show that there is a sufficient basis of strategies to secure urban ecosystem services by protecting urban green and reducing urban gray where microclimate regulation is a main target. However, soil sealing management lacks a spatial strategically overview as well as the consideration of services provided by fertile soils.

Density and Stability of Soil Organic Carbon beneath Impervious Surfaces in Urban Areas

Wei, Zongqiang; Wu, Shaohua; Yan, Xiao; Zhou, Shenglu
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Publicado em 09/10/2014 EN
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Installation of impervious surfaces in urban areas has attracted increasing attention due to its potential hazard to urban ecosystems. Urban soils are suggested to have robust carbon (C) sequestration capacity; however, the C stocks and dynamics in the soils covered by impervious surfaces that dominate urban areas are still not well characterized. We compared soil organic C (SOC) densities and their stabilities under impervious surface, determined by a 28-d incubation experiment, with those in open areas in Yixing City, China. The SOC density (0–20 cm) under impervious surfaces was, on average, 68% lower than that in open areas. Furthermore, there was a significantly (P<0.05) positive correlation between the densities of SOC and total nitrogen (N) in the open soils, whereas the correlation was not apparent for the impervious-covered soils, suggesting that the artificial soil sealing in urban areas decoupled the cycle of C and N. Cumulative CO2-C evolved during the 28-d incubation was lower from the impervious-covered soils than from the open soils, and agreed well with a first-order decay model (Ct = C1+C0(1-e-kt)). The model results indicated that the SOC underlying capped surfaces had weaker decomposability and lower turnover rate. Our results confirm the unique character of urban SOC...

Aggregate Breakdown and Soil Surface Sealing under Rainfall

Geeves, Guy William
Fonte: Universidade Nacional da Austrália Publicador: Universidade Nacional da Austrália
Tipo: Thesis (PhD); Doctor of Philosophy (PhD)
EN
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36.79%
Aggregate breakdown is an important process controlling the availability of fine soil material necessary for structural sealing of soil surfaces under rainfall. It may be caused by slaking resulting from rapid soil wetting and by physical dispersion resulting from direct and indirect energetic raindrop impacts. Relationships have been proposed by others predicting steady infiltration rate and saturated hydraulic conductivity from final aggregate size following high energy rainfall on initially dry, uncovered soil surfaces. Under these extreme conditions, both rapid wetting and energetic raindrop impact result in maximum aggregate breakdown and surface sealing. ¶ This study has isolated and quantified effects of rapid soil wetting and energetic raindrop impact on aggregate breakdown and surface sealing. Simulated rainfall was applied to re-packed soils from differing tillage treatments on light textured soils from near Cowra and Condobolin in New South Wales, Australia. ...; yes

Effects of dispersible soil clay and algae on seepage prevention from small dams

Rengasamy, P.; McLeod, A.; Ragusa, S.
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
Publicado em //1996 EN
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A field experiment was conducted on a red-brown earth (Natrixeralf) to find the effectiveness of spontaneously dispersed clay from sodic soils and mechanically dispersed clay (by puddling) from calcic and sodic soils in reducing the seepage loss of water from a series of small dams (pits). The effect of inoculating algae in the pits on reducing seepage was also investigated. A plastic lined pit was used for water balance control to measure incoming rainfall and evaporative loss. The results showed the effectiveness of dispersed soil clay in sealing the surface soil materials in the banks and beds of the pits. The dispersed clays from sodic soils were very effective in reducing the seepage to zero. When the clay concentration was above 8 g L−1 the sealing was complete, irrespective of spontaneous or mechanical dispersion from sodic soils. The mechanically dispersed clay from calcic soils were less effective in sealing because of the deposition of flocculated materials in the pore systems formed domains and generated microporosity. In calcic pits, the inoculation of algae reduced the seepage by 13 to 23% and increase in biopolymer (chlorophyll and polysaccharide) production was only small.; P. Rengasamy, A.J. McLeod and S.R. Ragusa

Strengthening Optimal Food Chain Element Transport by Minimizing Soil Degradation - Reccommendation for Soil Threats Identification on Different Scales in the European Union

TOTH GERGELY; MONTANARELLA LUCA; VARALLYAY Gyorgy; TOTH Tibor; FILIPPI Nicola
Fonte: CEREAL RES INST Publicador: CEREAL RES INST
Tipo: Contributions to Conferences Formato: Printed
ENG
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In the context of communication “Towards a Thematic Strategy for Soil Protection” by the European Commission (COM 179/2002), major threats have been identified representing the most important hazards endangering the functioning of soils. According to current proposals, that would aim to strike the right balance between EU action and subsidiarity, Member States of the EU shall identify the location and boundaries of land areas in risk of degradation, for each major area-dependent threats to soils. Five major threats have been identified, which are soil and area specific in their appearance: (1) soil organic matter decline (2) erosion (3) compaction (4) salinisation/sodification and (5) landslides. (Soil sealing and contamination as well represent major risks for soil functions, however, the probability of occurrence of these threats are mainly independent from soil and land characteristics.) With the collaboration of the Joint Research Centre (JRC) and the European Soil Bureau Network (ESBN), the Soil Information Working Group (SIWG) has been established to prepare a proposal with identification of common criteria to delineate risk areas on different scales (JRC-IES 2005). Present paper summarizes the main conclusions drawn by the SIWG and attempts to estimate the applicability of the approach.; JRC.H.7-Land management and natural hazards

Agri-Environmental Soil Quality Indicator in the European Perspective

TOTH Gergely
Fonte: Organisation for Economic Co-operation and Development (OECD) Publicador: Organisation for Economic Co-operation and Development (OECD)
Tipo: Contributions to Conferences Formato: Printed
ENG
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Soil quality is an account of the soil¿s ability to provide ecosystem and social services through its capacities to perform its functions under changing conditions (after Tóth et al. 2007.) The concept of soil quality expressed by this definition allows practical applications with regards to targeted social and/or ecosystem services, including agri-environmental services. The Thematic Strategy for Soil Protection of the European Union (COM 2006/231) identifies key soil functions of which the maintenance and improvement have to be considered in soil-related policies of the EU. Among the main soil functions several have agri-environmental relevance, which has to be taken into account when developing an Agri-environmental Soil Quality Indicator (AE-SQI). For agronomic purposes the biomass production function of soil is of absolute importance. This function, however, can be performed under varying external influences. The two main factors conditioning the performance of biomass production of soil are climate and management. During the evaluation of production function, the reacting capacities of soil to these factors need to be considered. Indication of soil quality from environmental point of view in the agricultural context can relate to off side environmental effects of soil condition and land management practices. The soil¿s capacity to store...

Threats to the Soil Resource Base of Food Security in China and Europe. A report from the Sino-EU Panel on Land and Soil

AKHTAR-SCHUSTER Mariam; E.H. BLUM Winfried; HE Chunyuan; JONES Arwyn; KISMÁNYOKY Tamás; KONG Xiangbin; LIU Guobin; MONTANARELLA Luca; NORTCLIFF S.; SHEN Renfrang; WEI Jianbing; WU Zhifeng; YANG Qingyuan; ZANG Bo; ZHANG Ganling
Fonte: Publications Office of the European Union Publicador: Publications Office of the European Union
Tipo: EUR - Scientific and Technical Research Reports Formato: Online
ENG
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To secure adequate food supply is the major challenge for humanity in the 21st century. Growing world population and its urbanization put pressure on this basic need, which is further threatened by the constant loss of fertile land. The assessment of sustainability of food supply under increasing pressure on land resources has been selected as one of the most important priority topics of the activities of Sino-EU Panel on Land and Soil (SEPLS). The Panel has performed a number of related researches and discussed the results on a scientific seminar in January 2012 in Nanjing, China. This report is an output of this seminar with a summary of the structured discussions on the below issues. 1. Urban and peri-urban development (soil sealing and loss of land functions) Urbanization and the linked spread of infrastructural development mean sealing of soil surfaces. Soil sealing is the most rapidly growing limitation for soil functions (including biomass production function) both in China and Europe. Soil sealing in China has been taking dramatic degree in the last two decades and the process is estimated to continue in the coming period as well. While urban and peri-urban development is looked as a necessity for social development, its negative effect on natural resources are inevitable. 2. Land degradation Despite the widely recognized importance of land degradation in the unsustainability of economic development and implementation of various policies to halt degradation (e.g. green for grain programme in China; cross-compliance measures in the EU)...

Soil Degradation and Soil Quality in Western Europe: Current situation and future perspectives

VIRTO Iñigo; IMAZ María José; FERNANDEZ UGALDE OIHANE; GARTZIA-BENGOETXEA Nahia; ENRIQUE Alberto; BESCANSA Paloma
Fonte: MDPI AG Publicador: MDPI AG
Tipo: Articles in periodicals and books Formato: Online
ENG
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Abstract: The extension and causes of soil chemical, physical and biological degradation, and of soil loss, varies greatly in different countries in Western Europe. The objective of this work was to review these issues, the strategies for soil protection, and the future perspectives for soil quality evaluation, under the light of present legislation for soil protection. Agriculture and forestry are responsible for many of them, especially for physical degradation, erosion and organic matter loss. Land take and soil sealing have increased in the last decades and can enhance these problems. In agricultural land, conservation farming, organic farming and other soil-friendly practices have been seen to have site-specific effects, depending on the characteristics of soils and the particularities of land uses and land users. No single soil management strategy suitable for all regions, soil types and soil uses exists. Except for soil contamination, specific legislation for soil protection is lacking in the region. The development of a Thematic Strategy for Soil Protection in the European Union has produced valuable information and the development of networks and databases. However, soil degradation is addressed only indirectly in environmental policies...

Estimación del sellado del suelo mediante técnicas de análisis espectral

Tomás, Alberto de; Salas, Francisco Javier; Santos, César; Garzón, Antonio; Moreno, Victoriano
Fonte: Universidad de Alcalá. Servicio de Publicaciones Publicador: Universidad de Alcalá. Servicio de Publicaciones
Tipo: Artigo de Revista Científica Formato: application/pdf
SPA
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El crecimiento de las superficies artificiales urbanas lleva asociado la impermeabilización del medio natural, conocida como sellado del suelo, que provoca una serie de efectos perjudiciales sobre el medio ambiente. Este artículo trata de desarrollar un método para facilitar la estimación de estas superficies y poder establecer medidas de control al respecto. Las técnicas de teledetección ofrecen interesantes posibilidades de clasificación en entornos urbanos. En este trabajo se ha evaluado la utilización de las técnicas espectrales Análisis Lineal de Mezclas Espectrales (ALME) y Sequential Maximum Angle Convex Cone (SMACC) sobre una imagen multiespectral SPOT-5, correspondiente al sector nororiental del municipio de Madrid. Finalmente se ha aplicado la técnica SMACC, en combinación con otras variables extraídas de la imagen, obteniendo una capa de sellado con una fiabilidad global del 83,75%. Los resultados obtenidos se comparan con los de la capa de sellado europea para España1, la cual obtiene una precisión global del 69,5% siguiendo el mismo método de validación utilizado en este trabajo.; Increasing artificial surface, associated with urban growth, produces soil imperviousness, known as soil sealing, which causes a number of adverse effects on the environment. This paper aims to develop a methodology to facilitate the estimation of this surface type...

Crecimiento urbano (1965-2005) y sellado antropogénico del suelo en el municipio de Alacant

Valera Lozano, Antonio; Añó Vidal, Carlos; Sánchez Díaz, Juan
Fonte: Universidad de Alcalá. Servicio de Publicaciones Publicador: Universidad de Alcalá. Servicio de Publicaciones
Tipo: Artigo de Revista Científica Formato: application/pdf
SPA
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36.19%
En la Comunitat Valenciana el cambio en los usos del suelo provocado por la urbanización acelerada ha sido especialmente intenso en los centros metropolitanos costeros; llanos litorales que acogen los suelos con mayor capacidad de uso agrícola y que concentran la mayor parte de la población y las actividades económicas. En este trabajo se analiza la dinámica espacio-temporal de los usos urbanos durante la segunda mitad del siglo XX en el municipio de Alacant, perteneciente al entorno metropolitano de Alacant-Elx. El estudio, metodológicamente, se ha desarrollado en un entorno SIG. A partir de fotogramas aéreos correspondientes a las fechas de 1956, 1985, 1998 y 2005 y mediante métodos de análisis cartográficos con Sistemas de Información Geográfica, se han establecido los cambios acumulativos de los usos urbanos del suelo a escala detallada (1:10.000). Las tipologías de usos seleccionadas han sido tres, dos de ellas urbanas y una tercera no urbana. Las áreas urbanas en las que la superficie construida es superior al 80% se han considerado de Alta Densidad (UAD), clasificándose como Urbanas de Baja Densidad (UBD) las inferiores al 80%. La diferencia entre las dos clases urbanas responde al mayor o menor porcentaje de vegetación o suelo desnudo en la matriz construida. Los resultados muestran la gran expansión de los usos urbanos y el consecuente retroceso de los agrícolas y forestales. El ritmo de crecimiento fue especialmente rápido durante el periodo 1998-2005. Estos cambios se relacionan con las dinámicas económicas y demográficas regionales. La población se ha multiplicado por 3 en los últimos 50 años...

Characterization of Soil Surface Roughness Effects on Runoff and Soil Erosion Rates under Simulated Rainfall

Vermang, J.; Norton, L. D.; Huang, C.; Cornelis, W. M.; Silva, A. M. da; Gabriels, D.
Fonte: Soil Sci Soc Amer Publicador: Soil Sci Soc Amer
Tipo: Artigo de Revista Científica Formato: 903-916
ENG
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This study aims at identifying the influence of soil surface roughness from small to large aggregates (random roughness) on runoff and soil loss and to investigate the interaction with soil surface seal formation. Bulk samples of a silty clay loam soil were sieved to four aggregate-size classes of 3 to 12, 12 to 20, 20 to 45, 45 to 100 mm, and packed in soil trays set at a 5% slope. Rainfall simulations using an oscillating nozzle simulator were conducted for 90 min at an average rainfall intensity of 50.2 mm h(-1). Soil surface roughness was measured using an instantaneous profile laser scanner and surface sealing was studied by macroscopic analysis of epoxy impregnated soil samples. The rainfall simulations revealed longer times to initiate runoff with increasing soil surface roughness. For random roughness levels up to 6 mm, a decrease in final runoff rate with increasing roughness was observed. This can be attributed to a decreased breakdown of the larger roughness elements on rougher surfaces, thus keeping infiltration rate high. For a random roughness larger than 6 mm, a greater final runoff rate was observed. This was caused by the creation of a thick depositional seal in the concentrated flow areas, thus lowering the infiltration rates. Analysis of impregnated soil sample blocks confirmed the formation of a structural surface seal on smooth surfaces...

Soil sealing and flood risks in the plains of Emilia-Romagna, Italy

PISTOCCHI Alberto; Calzolari Costanza; MALUCELLI Francesco; UNGARO Fabrizio
Fonte: ELSEVIER Publicador: ELSEVIER
Tipo: Articles in periodicals and books Formato: Online
ENG
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Study region The plains of Emilia Romagna, Italy. Study focus Urban expansion is among the main causes of increase in flood frequency and intensity in small rural catchments in Europe, and our study region is paradigmatic in this respect. We present here a regional screening-level assessment of soil sealing impacts in terms of increased flood peak discharges and flooding volumes on the secondary drainage network of the plains. We estimate flood peak discharges and flooding volumes through a simple kinematic model with runoff coefficients for the land use of 2008 and 1976. Additionally, we calculate an equivalent compensatory flood detention volume that would enable preserving flood peak discharges as prior to soil sealing (principle of “hydraulic invariance”). The proposed approach is simple and readily applicable to any region facing similar issues, for screening-level assessment of flood hazards over an extended stream network. New hydrological insights for the region The analysis highlights a significant increase in flood hazards throughout the secondary stream network. The impact. Widespread and relatively uniform, is more apparent in smaller catchments and in the case of more permeable soils. This demands retrofitting of the majority of the drainage network and/or significantly higher costs from flooding damages. The analysis suggests that costs of additional flooding after soil sealing may be higher than those of soil sealing impacts compensation through flood detention (hydraulic invariance).; JRC.H.1-Water Resources

Complex Patterns, Unpredictable Consequences : The Distribution of Sealed Land along the Urban-rural Gradient in Barcelona

Ranalli, Flavia; Salvati, Luca
Fonte: Universidade Autônoma de Barcelona Publicador: Universidade Autônoma de Barcelona
Tipo: Artigo de Revista Científica Formato: application/pdf
Publicado em //2015 ENG
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The present study explores the spatial pattern of selected soil sealing indicators in the province of Barcelona as a contribution to the debate on land consumption driven by urban growth in southern Europe. Four indicators of soil sealing (percentage of pervious land, per-capita sealed land, soil sealing intensity and diversity in soil sealing intensity) were derived from a high-resolution topographic map at the municipal scale using multivariate statistics and spatial analysis. All the indicators were correlated with the distance from Barcelona. Our results show that sealing patterns in Barcelona reflect distinct urbanization phases observed in the aftermath of World War II and may describe the rapid transition from a mono-centric and compact form observed in the 1950s to a more scattered and dispersed morphology. Soil sealing indicators proved to be effective proxies for the assessment of land-use changes in Mediterranean urban regions.; El patró espacial dels indicadors seleccionats de segellament del sòl s’ha explorat a la província de Barcelona com una contribució al debat sobre el consum de sòl impulsat per la urbanització a l’Europa mediterrània. Mitjançant l’ús de tècniques d’exploració multidimensional i d’anàlisi espacial...

Elementary processes of soil-water interaction and thresholds in soil surface dynamics: A review

Greene, Richard; Hairsine, Peter
Fonte: John Wiley & Sons Inc Publicador: John Wiley & Sons Inc
Tipo: Artigo de Revista Científica
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Elementary processes of soil-water interaction and the thresholds to these processes are important to understand as they control a range of phenomena that occur at the soil surface. In particular processes involved with wetting by rainfall that lead to particle breakdown are critical. This breakdown causes soil detachment and crust formation, which are both key elements in erosion. This paper reviews the range of approaches that have been taken in describing the processes associated with the wetting of a soil surface by rainfall. It assembles the studies that emphasize soil physics, soil chemistry, and erosion mechanics in a framework to enable a balanced consideration of important processes and management strategies to control erosion for a particular situation. In particular it discusses the factors associated with the two basic processes of soil structural breakdown, i.e. slaking and dispersion, and how these processes are critical in particle detachment, transport and surface crust formation. Besides the balance between the exchangeable cation composition and electrolyte concentration (measured as the sodium adsorption ratio (SAR) and total cation concentration (TCC) respectively) of the soil, the importance of energy input and soil organic matter content in controlling clay dispersion is emphasized. Based on the balance between these factors...

Influência do preparo do solo e da natureza do fertilizante nitrogenado na cultura do milho; Influence of soil tillage and source of nitrogen fertilizer on corn productivity

Favarin, J.L.; Fancelli, A.L.
Fonte: Universidade de São Paulo. Escola Superior de Agricultura Luiz de Queiroz Publicador: Universidade de São Paulo. Escola Superior de Agricultura Luiz de Queiroz
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; ; ; ; ; Formato: application/pdf
Publicado em 01/01/1992 POR
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Foi instalado um ensaio de campo, em solo Podzólico Vermelho-Escuro latossólico (PELa), para avaliar a influência do preparo do solo e a natureza da fonte do fertilizante nitrogenado, para adubação em cobertura, na cultura do milho. Os tipos de preparo do solo avaliados foram o convencional e o plantio direto. Em relação às fontes de nitrogênio, foram utilizadas: uma sólida, o sulfato de amônio (20%N), e outra fluida, o uran (32%N), aplicados à superfície do solo sem incorporação. A absorção de nitrogênio (mg/planta) foi determinada nas folhas, colmos, panículas e espigas, aos 53 e 67 dias após a emergência das plântulas. Na colheita, após a maturidade fisiológica, foi determinada a quantidade de nitrogênio acumulado e exportado, bem como a produção de grãos e alguns de seus componentes. O tipo de preparo do solo não apresentou influência na produção no primeiro ano de sua implantação. Entretanto, o plantio direto permitiu o aproveitamento do nitrogênio, mesmo quando se verificou redução na disponibilidade da água, estimada, através do balanço hídrico.; The effect of soil tillage and source of nitrogen fertilizer applied as sidedressing on corn was studied by means of a field trial conducted on a latosolic Darkred Podzolic soil (PELa). Soil tillage treatments were conventional and notillage soil seed-bed preparation. Nitrogen sources were ammonium sulfate (solid...