The study was carried out at Abujubeha area (10? 52 48.17 ‐11? 23 08.79 N and 30? 00 05.99 ‐ 31? 28 04.91’ E) in Northeast Nuba Mountain, South Kordofan region, Sudan. In order to investigate the soil degradation aspects in the study area, its causal, rate per time and mapping; the remote sensing and GIS technologies were used beside the routine soil survey and laboratory analyses. Quantitative information on soils degradation and vegetation cover changes was acquired. Using multi‐spectral satellite imagery the most dynamic land cover types have been able to be mapped with 64% accuracy (Dense Forest, Moderate Forest, Light Forest, Fallow and Bare soils). The result showed that 38% of the forested areas were lost in the last two decades at annual rate of 1.8%. Forest clearance in the last 5 (199‐2005) years equal two times the clearance happened in the previous 15 years (1986‐1999). The geostatistical characterization of soil variability showed that soil properties are highly spatially dependent, with significant sensitivity to soil‐forming factors. Soils dynamic are affected by land use system as well as with soil physiographic position. The Red soils (Gardud) are more dynamic than the Dark clayey soils. The Universal Soil Loss Equation (USLE) was used; the result revealed that the study area is potentially susceptible to be eroded by water. The Erosion rate was measured in term of erosion Risk Assessment. The model indicated that the overall average of soil loss is 1.32 t/ha /y.

Orientador: Marlene Cristina Alves / Banca: Mario Luiz Teixeira de Moraes / Banca: Hélio Ricardo Silva / Banca: Reges Heinrichs / Banca: Gilberto Colodro / Resumo: A utilização incorreta dos solos e grandes construções no meio rural vêm causando alterações no mesmo, tornando-os menos produtivos, aumentando assim as áreas degradadas. Técnicas que visam à restauração ecológica de solos degradados têm sido investigadas. Neste sentido investigaram-se as mudanças positivas no ambiente edáfico de um solo decapitado que está sob intervenção antrópica com técnicas para recuperação há 17 anos, tendo sido utilizado adubos verdes, correção do solo, gesso e pastagem. O delineamento experimental utilizado foi inteiramente casualizado com nove tratamentos e quatro repetições. Os tratamentos implantados em 1992 foram: Solo mobilizado (vegetação espontânea); Mucuna-preta (MP); Guandu (G) até 1994, após substituído por Feijão-de-porco (FP); Calcário+MP; Calcário+Gesso até 1994, após substituído por FP; Calcário+Gesso+MP; Calcário+Gesso+G até 1994, após substituído por FP e, para controle duas testemunhas T1: solo exposto (sem práticas de recuperação) e T2: Vegetação nativa de Cerrado. Os tratamentos permaneceram por sete anos, e em 1999 implantou-se a B. decumbens em toda área experimental. No ano de 2010 e 2011, em três camadas do solo, de 0,00-0,10; 0,10-0,20 e de 0,20-0,40 m, foram estudadas as propriedades físicas: porosidade do solo; densidade do solo; distribuição e estabilidade dos agregados em água; retenção de água no solo, resistência do solo à penetração, umidade do solo, infiltração de água no solo, temperatura do solo, armazenamento de água no solo e, químicas: cátions trocáveis; C orgânico, nitrogênio, pH, matéria orgânica e acidez potencial, calculadas a SB, CTC e V %. Foram avaliados o desenvolvimento das espécies arbóreas, que se regeneraram naturalmente, e massa seca da parte aérea e das raízes da B. decumbens. Em relação aos organismos... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Incorrect use of land and large buildings in rural areas has caused the same changes, making them less productive, thus increasing the degraded areas. Techniques aimed at ecological restoration of degraded soils have been investigated. In this sense we investigated the positive changes in the soil environment of a soil that is beheaded in human intervention techniques for recovery for 17 years, having been used green manures, soil amendment, gypsum and pasture. The experimental design was completely randomized with nine treatments and four repetitions. The treatments were: control (soil mobilized) until 1999, after deployed Brachiaria decumbens; Stizolobium aterrimum (Piper & Tracy) until 1999, after replaced by B. decumbens; Cajanus cajan (L.) until 1994, after replaced by Canavalia ensiformis (L.) and from 1999 replaced by B. decumbens; Lime+S. aterrimum until 1999 when was replaced by B. decumbens; Lime+C. cajan until 1994, after replaced by C. ensiformis from 1999 and replaced by B. decumben; Lime+ Gypsum+S. aterrimum until 1999, after was replaced by B. decumbens; Lime+Gypsum+C. cajan until 1994, after replaced by C. ensiformis, and two witnesses: Soil exposed (without recovery technique) and native vegetation (savannah). These treatments were used for seven years and in 1999 Brachiaria decumbens was used throughout the experimental area. In 2010, in soil depths layers of 0.00-0.10; 0.10-0.20 and 0.20-0.40 m, were evaluated for the following properties: total porosity, soil bulk density, stability of aggregates, water retention in the soil, and soil resistance to penetration and soil moisture, water infiltration into the soil, soil temperature, soil water storage, and chemical, exchangeable cations, organic C, pH, organic matter and potential acidity, calculated SB, CEC and V%. In relation to the plants... (Complete abstract click electronic access below) / Doutor

[pt] A perfuração de poços marítimos em águas profundas e ultra-profundas é feita por sondas de perfuração flutuantes, que se conectam ao poço no leito marinho por meio do riser de perfuração. Essa conexão transmite esforços dinâmicos para a cabeça de poço e revestimentos, provocando fadiga nessa estrutura. Levantou-se a hipótese de que as características dinâmicas do sistema mudam quando há aplicação de um carregamento elevado devido à deriva da sonda após uma falha do sistema elétrico, alterando o dano acumulado por fadiga. A primeira etapa do trabalho envolveu a simulação estática deste carregamento extremo em um modelo solo-estaca em elementos finitos 3D. Com base nos resultados obtidos, realizou-se uma análise dinâmica para dois tipos de solo e duas lâminas d água diferentes. Concluiu-se que o solo menos rígido sofre pouca influência sobre o dano acumulado, enquanto que para o solo mais rígido aumenta-se em cerca de 50 por cento o dano acumulado. / [en] The drilling of offshore oilwells in deep and ultra-deep waters is done by floating drilling rigs, which connect to the well in the seabed through the drilling riser. This connection transmits dynamic efforts to the wellhead and casings, causing fatigue in this structure. We formulated the hypothesis that dynamic characteristics of the system change when a high load is applied if the rig drifts after a blackout, changing the accumulated damage from fatigue. At first, we have simulated the consequences of this extreme load using a soil-pile model in Abaqus, a 3D finite element software. Based on the results obtained, a dynamic analysis was performed for two different soil types and two different water depths. It was concluded that the less rigid soil is only a little sensitive to the degradation of soil condition, meanwhile the more rigid soil increases the accumulated damage by about 50 percent.

Chan, Wing Shing. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2007. / Includes bibliographical references (leaves 201-222). / Abstracts in English and Chinese. / Abstract --- p.i / Abstract (in Chinese) --- p.iv / Acknowledgements --- p.vi / Table of contents --- p.viii / List of tables --- p.xii / List of figures --- p.xiv / List of plates --- p.xvi / Chapter Chapter One --- Introduction / Chapter 1.1 --- Introduction --- p.1 / Chapter 1.2 --- Research background --- p.2 / Chapter 1.3 --- Conceptual framework --- p.6 / Chapter 1.4 --- Objectives of the study --- p.10 / Chapter 1.5 --- Significance of the study --- p.11 / Chapter 1.6 --- Organization of the thesis --- p.12 / Chapter Chapter Two --- Literature Review / Chapter 2.1 --- Land degradation: an overview --- p.14 / Chapter 2.2 --- Land degradation in Hong Kong --- p.17 / Chapter 2.3 --- Ecological rehabilitation --- p.20 / Chapter 2.4 --- Role of plantation in ecological rehabilitation --- p.22 / Chapter 2.5 --- Reforestation history in Hong Kong and species selection --- p.25 / Chapter 2.6 --- Nutrient requirements of native species --- p.31 / Chapter 2.7 --- The geology and soils of Hong Kong --- p.35 / Chapter 2.7.1 --- Geology --- p.35 / Chapter 2.7.2 --- Soils --- p.35 / Chapter 2.8 --- Greenhouse approach in nutrient requirement study --- p.37 / Chapter 2.9 --- Nitrogen mineralization --- p.38 / Chapter 2.10 --- Chlorophyll fluorescence --- p.40 / Chapter 2.11 --- Summary --- p.41 / Chapter Chapter Three --- Inherent Characteristics and Properties of Decomposed Granite and Fire-affected Soil / Chapter 3.1 --- Introduction --- p.42 / Chapter 3.2 --- Materials and methods --- p.42 / Chapter 3.2.1 --- Sources of soil and sampling --- p.43 / Chapter 3.2.2 --- Soil pre-treatment --- p.44 / Chapter 3.3 --- Laboratory analysis --- p.45 / Chapter 3.3.1 --- Reaction pH and conductivity --- p.45 / Chapter 3.3.2 --- Texture --- p.46 / Chapter 3.3.3 --- Organic carbon --- p.46 / Chapter 3.3.4 --- Total Kjeldahl nitrogen (TKN) --- p.47 / Chapter 3.3.5 --- Carbon: nitrogen ratio --- p.47 / Chapter 3.3.6 --- Total phosphorus (TP) --- p.47 / Chapter 3.3.7 --- Exchangeable Al and H --- p.48 / Chapter 3.3.8 --- "Exchangeable cations, base saturation percentage (BSP) and exchangeable Al percentage" --- p.48 / Chapter 3.4 --- Results and discussion --- p.49 / Chapter 3.4.1 --- Texture --- p.49 / Chapter 3.4.2 --- Reaction pH and conductivity --- p.49 / Chapter 3.4.3 --- "Soil organic matter, total Kjeldhal nitrogen and total phosphorus" --- p.51 / Chapter 3.4.4 --- Exchangeable cations --- p.52 / Chapter 3.4.5 --- DG as a representative soil of soil destruction sites --- p.54 / Chapter 3.4.6 --- FAS as a representative soil of vegetation disturbance sites --- p.56 / Chapter 3.5 --- Summary --- p.58 / Chapter Chapter Four --- Nitrogen Fluxes of Decomposed Granite and Fire-affected Soil Amended with Urea / Chapter 4.1 --- Introduction --- p.59 / Chapter 4.2 --- Materials and methods --- p.62 / Chapter 4.2.1 --- Experimental design --- p.62 / Chapter 4.2.2 --- Soil incubation and sampling --- p.63 / Chapter 4.2.3 --- Analysis of mineral nitrogen (NH4-N and NO3-N) --- p.64 / Chapter 4.2.4 --- Statistical analysis --- p.64 / Chapter 4.3 --- Results and discussion --- p.64 / Chapter 4.3.1 --- Variation of NH4-N in DG and FAS --- p.64 / Chapter 4.3.2 --- Variation of N03-N in DG and FAS --- p.68 / Chapter 4.3.3 --- Variation of mineral N in DG and FAS --- p.74 / Chapter 4.3.4 --- NH4-N fluxes in DG and FAS --- p.78 / Chapter 4.3.5 --- NO3-N fluxes in DG and FAS --- p.80 / Chapter 4.3.6 --- Mineral N fluxes in DG and FAS --- p.82 / Chapter 4.4 --- Summary --- p.86 / Chapter Chapter Five --- Growth Performance of Native Species in Decomposed Granite and Fire-affected Soil / Chapter 5.1 --- Introduction --- p.88 / Chapter 5.2 --- Materials and methods --- p.91 / Chapter 5.2.1 --- Experimental design --- p.91 / Chapter 5.2.2 --- Nitrogen treatments --- p.94 / Chapter 5.2.3 --- Post-planting care --- p.95 / Chapter 5.2.4 --- "Measurement of survival rate, height, basal diameter, aboveground biomass and foliar nitrogen" --- p.95 / Chapter 5.2.4.1 --- Survival rate --- p.96 / Chapter 5.2.4.2 --- Height and basal diameter --- p.96 / Chapter 5.2.4.3 --- Aboveground biomass --- p.96 / Chapter 5.2.4.4 --- Foliar sampling --- p.97 / Chapter 5.2.4.5 --- Determination of foliar nitrogen --- p.97 / Chapter 5.2.5 --- Statistical analysis --- p.97 / Chapter 5.3 --- Results and discussion --- p.98 / Chapter 5.3.1 --- Survival rate --- p.98 / Chapter 5.3.2 --- Height growth of species in DG --- p.105 / Chapter 5.3.3 --- Effect of nitrogen on species height growth in DG --- p.112 / Chapter 5.3.4 --- Height growth of species in FAS --- p.117 / Chapter 5.3.5 --- Effect of nitrogen on species height growth in FAS --- p.118 / Chapter 5.3.6 --- Effect of DG and FAS on species height growth --- p.120 / Chapter 5.3.7 --- Basal diameter growth of species in DG --- p.122 / Chapter 5.3.8 --- Effect of N on basal diameter growth of species in DG --- p.124 / Chapter 5.3.9 --- Basal diameter growth of species in FAS --- p.126 / Chapter 5.3.10 --- Effect of N on basal diameter growth of species in FAS --- p.127 / Chapter 5.3.11 --- Effect of DG and FAS on species basal diameter growth --- p.127 / Chapter 5.3.12 --- Overall height and basal diameter growth of species in DG . --- p.129 / Chapter 5.3.13 --- Overall height and basal diameter growth of species in FAS --- p.131 / Chapter 5.3.14 --- Aboveground biomass of species in DG --- p.133 / Chapter 5.3.15 --- Effect of N on aboveground biomass of species in DG --- p.135 / Chapter 5.3.16 --- Aboveground biomass production in FAS --- p.138 / Chapter 5.3.17 --- Effect of N on aboveground biomass of species in FAS --- p.139 / Chapter 5.3.18 --- Effect of DG and FAS on aboveground biomass of species --- p.141 / Chapter 5.3.19 --- Foliar nitrogen --- p.143 / Chapter 5.3.19.1 --- Foliar N of species grown in DG --- p.143 / Chapter 5.3.19.2 --- Effect of N amendment on foliar N of species in DG --- p.147 / Chapter 5.3.19.3 --- Foliar N of species in FAS --- p.149 / Chapter 5.3.19.4 --- Effect of N amendment on foliar N of species in FAS --- p.151 / Chapter 5.3.19.5 --- Effect of DG and FAS on the foliar N of species --- p.152 / Chapter 5.4 --- Summary --- p.155 / Chapter Chapter Six --- Photosynthetic Efficiency of Native Species / Chapter 6.1 --- Introduction --- p.158 / Chapter 6.2 --- Materials and methods --- p.160 / Chapter 6.2.1 --- Measurement of chlorophyll fluorescence --- p.160 / Chapter 6.2.2 --- Statistical analysis --- p.162 / Chapter 6.3 --- Results and discussion --- p.162 / Chapter 6.3.1 --- Photosynthetic efficiency of species in DG --- p.162 / Chapter 6.3.2 --- Photosynthetic efficiency of species in FAS --- p.170 / Chapter 6.3.3 --- Effect of DG and FAS on photosynthetic efficiency of Species --- p.172 / Chapter 6.4 --- Summary --- p.175 / Chapter Chapter Seven --- Conclusions / Chapter 7.1 --- Introduction --- p.178 / Chapter 7.2 --- Summary of major findings --- p.179 / Chapter 7.3 --- Implications of the study --- p.187 / Chapter 7.3.1 --- Species selection for the rehabilitation of soil destruction sites --- p.187 / Chapter 7.3.2 --- Species selection for the rehabilitation of vegetation disturbance sites --- p.191 / Chapter 7.3.3 --- Fertilization practice in different degraded lands --- p.193 / Chapter 7.3.4 --- The importance of soil test in ecological rehabilitation Planting --- p.195 / Chapter 7.4 --- Limitations of the study --- p.197 / Chapter 7.5 --- Suggestions for further study --- p.198 / References --- p.201 / Appendices --- p.223

O encrostamento superficial é um dos fatores de favorecimento da erosão e degradação dos solos. O estudo e monitoramento das crostas superficiais são importantes para o manejo e conservação do solo e da água, principalmente em regiões de clima tropical, onde a degradação do solo é mais intensa e percebe-se um descuido em relação à proteção do ambiente. O presente projeto teve como objetivo o monitoramento da formação e evolução das crostas superficiais para solos de texturas contrastantes. Foram monitoradas as modificações ocorridas nos solos escolhidos para cada evento chuvoso acima de 25 mm/h durante os meses de dezembro de 2008 a maio de 2009. O projeto foi composto por três tipos de solo Argissolo Vermelho-Amarelo de textura média, Latossolo Vermelho-Amarelo e Nitossolo Vermelho eutroférrico argiloso e ocorreram concomitantemente em diferentes áreas. O delineamento experimental escolhido foi blocos ao acaso. Para monitoramento da formação de crosta associada a ocorrência de eventos chuvosos foram coletadas amostras deformadas e indeformadas para análises físicas e químicas de rotina, medidas da densidade do solo, confecção de curvas de retenção de água e para análises micromorfológicas e de imagens. Em campo foi realizado o monitoramento da infiltração de água e da rugosidade superficial do solo. A redução na rugosidade do solo pode ser observada já nas primeiras chuvas e ocorreu de maneira rápida para todos os tipos de solo. As crostas superficiais foram formadas para todos os solos, porém sem causar modificações significativas na porosidade total, na condutividade hidráulica e nas curvas de retenção de água. Sendo assim, as crostas observadas para os solos estudados são formadas pela reorganização estrutural e mobilização do material do solo sem, no entanto, interferir nas características hídricas dos solos. / Soil crusting is one of the main negative effects of human beings on soil degradation. This process of physical origin diminishes soil water infiltration increasing runoff and consequently soil loss by water erosion and soil degradation. The study and monitoring of soil crusts is important for soil management and conservation, mainly in tropical regions in which research is scarce in this field of study. The purpose of this study was to monitor the formation and evolution of crusts in soils with contrasting particle size distributions. Soil crusts were monitored on a sandy/sandy loam Argissolo Vermelho-Amarelo (Typic Hapludult), sandy loam Latossolo Vermelho-Amarelo (Typic Hapludox) and a clayey Nitossolo Vermelho eutroférrico (Rhodic Kandiudalf). Sampling and soil data were taken after 0, 3, 5 and 10 rain storms with intensities above 25 mm.h-1 during the period from December 2008 to May 2009. Soil routine chemical and particle size distribution analysis were performed for soil characterization. To monitor the soil changes caused by the rainfall determination of the soil roughness, hydraulic conductivity, soil water characteristic curves and micromorphological analysis were performed. The reduction of soil roughness and the formation of soil crusts were observed for all the studied soils during the different rainfall events. The formation of the soil crusts did not significantly change the total porosity and pore morphology and distribution, and, consequently, the hydraulic conductivity and soil water retention of the surface layers of the studied soils.

Thesis (MTech (Chemistry))--Cape Peninsula University of Technology, 2016. / Polycyclic aromatic hydrocarbons (PAHs) are an alarming group of organic substances for humans and environmental organisms due to their ubiquitous presence, toxicity, and carcinogenicity. They are semi-volatile substances which result from the fusion of carbon and hydrogen atoms and constitute a large group of compounds containing two to several aromatic rings in their molecule. Natural processes and several anthropogenic activities involving complete or incomplete combustion of organic substances such as coal, fossil fuel, tobacco and other thermal processes, generally result in the release of the PAHs into the environment. However, the fate of the PAHs is of great environmental concern due to their tendency to accumulate and their persistence in different environmental matrices and their toxicity. Animal studies have revealed that an excessive exposure to PAHs can be harmful. Evidence of their carcinogenic, mutagenic, and immune-suppressive effects has been reported in the literature. In the soil environment, they have the tendency to be absorbed by plants grown on soil being contaminated by the PAHs. It is, therefore, important to evaluate their occurrence levels in different environmental matrices such as soil concentrations.

A dinâmica dos sistemas naturais se constrói na integração de todos os elementos pertencentes ao ambiente. Caso o conhecimento do meio físico e da influência das atividades antrópicas nesta dinâmica não sejam considerados em conjunto com o uso e ocupação, problemas ambientais de difícil recuperação, como as voçorocas, podem ser gerados, prejudicando a própria manutenção e expansão das atividades humanas. Neste sentido, o objetivo desta pesquisa foi avaliar de forma integrada os condicionantes geológicos e geotécnicos e as propriedades que interferem na drenagem da água superficial e subsuperficial em uma voçoroca do município de Nazareno, no estado de Minas Gerais (voçoroca do Córrego do Cravo). Diante disso, foram elaborados mapas com a utilização de SIG para levantamento e análise das características da bacia do Córrego do Cravo e da bacia de contribuição da voçoroca. Ensaios em laboratório (permeabilidade, erodibilidade, parâmetros físico-químicos, matéria orgânica, MCT e MEV/EDS) foram realizados para caracterização geológica e geotécnica, assim como o tratamento de dados pluviométricos e o programa ABC 6, para estudo do comportamento e da vazão das chuvas. Por fim, para avaliação das propostas de macrodrenagem na bacia de contribuição da voçoroca do Córrego do Cravo, utilizou-se o programa Canal. Os resultados apontaram que, nesta região, as elevadas declividades e susceptibilidade do solo saprolítico (Cambissolo) são os principais condicionantes do ambiente, sendo a intensidade das chuvas, as direções do fluxo superficial, sua concentração (originada pela retirada da cobertura vegetal e manejo inadequado do solo tanto pelas atividades agropecuárias como pela implantação de obras de infraestrutura, como estradas, por exemplo), e a exposição do nível d\'água subterrâneo no interior da voçoroca, os principais fatores que proporcionam o desenvolvimento e retorno dos processos erosivos. Dessa forma, a redução do volume e da energia do escoamento superficial em direção ao solo saprolítico, concomitante ao recolhimento e disciplinamento da água subsuperficial no interior da voçoroca, são consideradas imprescindíveis à estabilização dos processos erosivos. As propostas de macrodrenagem, de maneira geral, poderão ser aplicadas, não somente na voçoroca do Córrego do Cravo, mas também em outras voçorocas de Nazareno com propriedades geológicas-geotécnicas similares. / The dynamics of natural systems are based on the integration of all environmental elements. If the knowledge of physical conditions and of the influence of anthropogenic activities are not considered jointly with land use difficult environmental problems, as gullies, are generated and may cause damages both on maintenance and on expansion of human activities. Thus, this research aims to evaluate the geological and geotechnical constraints and properties which interfere in the superficial and subsuperficial drainage systems of a gully in the Nazareno municipality, at Minas Gerais state, Brazil (Córrego do Cravo gully). Therefore, maps to survey data from the Córrego do Cravo basin and the gully contribution area were made, using GIS tools. In addition, laboratory tests (permeability, erodibility, physical-chemical parameters, organic matter, MCT and SEM/EDS) were conducted for a geological and geotechnical characterization, as well as a study of the precipitation data was done and the software ABC 6 was used to evaluate rainfall and flow. Finally, for the macro drainage system assessment the software Canal was used. The results showed that the steep slopes and the saprolite soil susceptibility (Cambisol) are the main environmental constraints, and the rainfall intensity, the flow directions and its concentration (that is generated by the removal of vegetation and inadequate land use, both urban and agricultural), and the exposure of the water table level in the gully are the main factors that developed and brought the erosive processes back. Hence, both flow volume and energy towards the saprolite soil, in addition with subsuperficial water collection and its discipline inside the gully, are considered indispensable to stabilize of the erosive processes. The macro drainage system proposition can be applied in other gullie areas with similar geological and geotechnical properties.

O encrostamento superficial é um dos fatores de favorecimento da erosão e degradação dos solos. O estudo e monitoramento das crostas superficiais são importantes para o manejo e conservação do solo e da água, principalmente em regiões de clima tropical, onde a degradação do solo é mais intensa e percebe-se um descuido em relação à proteção do ambiente. O presente projeto teve como objetivo o monitoramento da formação e evolução das crostas superficiais para solos de texturas contrastantes. Foram monitoradas as modificações ocorridas nos solos escolhidos para cada evento chuvoso acima de 25 mm/h durante os meses de dezembro de 2008 a maio de 2009. O projeto foi composto por três tipos de solo Argissolo Vermelho-Amarelo de textura média, Latossolo Vermelho-Amarelo e Nitossolo Vermelho eutroférrico argiloso e ocorreram concomitantemente em diferentes áreas. O delineamento experimental escolhido foi blocos ao acaso. Para monitoramento da formação de crosta associada a ocorrência de eventos chuvosos foram coletadas amostras deformadas e indeformadas para análises físicas e químicas de rotina, medidas da densidade do solo, confecção de curvas de retenção de água e para análises micromorfológicas e de imagens. Em campo foi realizado o monitoramento da infiltração de água e da rugosidade superficial do solo. A redução na rugosidade do solo pode ser observada já nas primeiras chuvas e ocorreu de maneira rápida para todos os tipos de solo. As crostas superficiais foram formadas para todos os solos, porém sem causar modificações significativas na porosidade total, na condutividade hidráulica e nas curvas de retenção de água. Sendo assim, as crostas observadas para os solos estudados são formadas pela reorganização estrutural e mobilização do material do solo sem, no entanto, interferir nas características hídricas dos solos. / Soil crusting is one of the main negative effects of human beings on soil degradation. This process of physical origin diminishes soil water infiltration increasing runoff and consequently soil loss by water erosion and soil degradation. The study and monitoring of soil crusts is important for soil management and conservation, mainly in tropical regions in which research is scarce in this field of study. The purpose of this study was to monitor the formation and evolution of crusts in soils with contrasting particle size distributions. Soil crusts were monitored on a sandy/sandy loam Argissolo Vermelho-Amarelo (Typic Hapludult), sandy loam Latossolo Vermelho-Amarelo (Typic Hapludox) and a clayey Nitossolo Vermelho eutroférrico (Rhodic Kandiudalf). Sampling and soil data were taken after 0, 3, 5 and 10 rain storms with intensities above 25 mm.h-1 during the period from December 2008 to May 2009. Soil routine chemical and particle size distribution analysis were performed for soil characterization. To monitor the soil changes caused by the rainfall determination of the soil roughness, hydraulic conductivity, soil water characteristic curves and micromorphological analysis were performed. The reduction of soil roughness and the formation of soil crusts were observed for all the studied soils during the different rainfall events. The formation of the soil crusts did not significantly change the total porosity and pore morphology and distribution, and, consequently, the hydraulic conductivity and soil water retention of the surface layers of the studied soils.

The aim of this research is to assess various options for the management of topsoil stockpiles on disturbed lands and to evaluate the viability and germinability over time of the seedbanks in these stockpiles for use in rehabilitation. To predict their success, experimental trials were designed and conducted.

This research aims to develop the present knowledge of arid zone rehabilitation by scientifically testing topsoiling and seeding treatments on the Eyre Peninsula, South Australia, in a way that enables the widest application and comparison to other mining leases throughout the arid lands.