No abstract

Dispersed urbanization, urban planning and management instruments such as zoning, and urban expansion zones, have become increasingly consistent in leading cities toward an uncertain and chaotic future. The urban perimeters of municipalities have been used increasingly in favor agents of the reproduction of unequal urban space, aggravating the process of socio-spatial segregation, the formation of urban gaps and real estate speculation. Inherent to this process, infrastructure, one of the most important components of urban land and one of the most costly for local governments, has become increasingly dispersed and obsolete in the midst of the disordered occupation of the city’s land. Based on the above, this paper aims to analyze the phenomenon of urban sprawl in the city of Londrina by means of geotechnologies and to identify the impacts that the form of land occupation the city has employed may cause on the current and future scenario of the municipality in general. To this end, thematic maps were drawn up from multiple sources, which, allied to a review of the literature, indicate that the municipality of Londrina exhibits intense characteristics of the phenomenon of urban sprawl, leading to consequences for territorial ordering and the egalitarian spatial distribution of essential services to the population

No abstract

Degradation of hydrological conditions can adversely impact water resource quality and quantity. This degradation can generate social and economic losses, including losses for users outside the basin area. Therefore, studies focusing on surface runoff and accelerated erosion processes are needed to enable interventions that address degradation-induced challenges.In the present study, the surface runoff and accelerated erosion potential of the Feijão River basin were presented in charts at a 1:50,000 scale. The Feijão River basin has an area of 243.16 km 2 and is used as the main water source for the city of São Carlos, Brazil. Geoenvironmental attributes, such as substrate, climate, relief, soil, water bodies and land cover and use, were integrated and assessed in a GIS environment, using a multicriteria analysis and weighted sum tool. The results show that a large part of the area (86.12% of the basin) exhibits a low surface runoff potential and a moderate accelerated erosion potential. Accelerated erosive processes are triggered by changes in soil cover and have a direct relationship with the removal of existing vegetation and implementation of anthropogenic activities. In this case, as well as for most of the areas in southeastern Brazil, extensive grazing followed by sugar cane cultivation was the main driving force of erosion, acting as trigger for accelerated erosive processes at the water source area.

ResumoEste trabalho analisa o comportamento colapsível de um solo tropical arenoso inundado com diferentes fluidos de saturação que constituem o esgoto doméstico.Para tal análise, foram levados em consideração parâmetros físicos e químicos e aspectos estruturais do solo no âmbito do fenômeno da colapsibilidade dos solos, assim como as principais características dos fluidos de inundação de água destilada, esgoto doméstico e algumas soluções à base de substâncias que compõem os esgotos e as deformações axiais do solo a um metro de profundidade em ensaios edométricos. As propriedades físicas e químicas dos fluidos de inundação e dos solos, bem como a combinação entre tais propriedades, desempenham relevante papel na compreensão do fenômeno do colapso, mostrando que a sua ocorrência não pode ser atribuída a um ou outro parâmetro do solo ou do fluido isoladamente.Palavras-chave: esgoto doméstico; constituintes do esgoto; colapso de solos; solos tropicais. AbstractThis article evaluates the collapsible behavior of a tropical sandy soil when exposed to different sewage constituent fluids as wetting fluids. The analysis considers the physical, chemical and structural properties of the soil, as well as soil collapsible behavior, the properties of wetting fluids distilled water, domestic sewage, and some solutions composed by substances that constitute sewage, measuring soil deformation in axial compression edometric tests. The physical and chemical properties of fluids and of the soil, as well as their combination, play a relevant role in the comprehension of collapse phenomena, which shows that its occurrence can not be attributed to isolated parameters of soil or fluid.

In recent decades, with the increasing global need for sustainable development, ecotourism has emerged as one of the most efficient activities that can be used to reconcile economic development with environmental conservation. A growing interest in the ecotourism and ecosystem services provided by landscapes makes such services increasingly necessary within municipal planning processes. This study aims to construct a geoenvironmental model based on geographic information systems (GISs) to spatially identify areas with greater capacity to promote ecotourism, with a practical case study of the city of Brotas, Brazil. The model can produce an integrated analysis of landscape components using geoenvironmental, topographic, and urban data. As a result, four zones were classified according to their ecotourism potential, with 81% of the overall local territory showing great potential, which not only reinforces the territory’s resilience regarding sustainable development, but also demonstrates that ecotourism should be included in discussions related to environmental planning in Brotas, as well as in other municipalities that have ecotourism potential.

O artigo avalia a capacidade de retenção de barreiras de proteção ambiental de misturas de solo-cimento (7% em massa) e solo cal (8% em massa) para substâncias de origem orgânica (chorume e água residuária) e inorgânica (soluções ricas em K+, Na+ e Cl- - com concentrações de 100ppm). Os ensaios foram conduzidos com dois tipos de corpos de prova: 5cm de altura por 5cm de diâmetro (miniatura) e 25cm de altura por 7cm de diâmetro (coluna). Os resultados mostram valores de retenção muito bons para as substâncias de origem orgânica e valores promissores para as soluções inorgânicas.

Assessment of groundwater contamination potential using geological, hydrological and hydrogeological attributes, is an efficient mechanism of sub-surface water resources protection and conservation. However, usually this method does not take into consideration the potentially polluting human activities, either in punctual or diffuse sources, or because the relative importance of the attributes are not considered. The paper proposes a multi-criteria approach as a way of solving this gap, reducing subjectivity and considering land use/cover due human actions influence in the process. The study was developed in Araras river watershed (Paraná Basin, Brazil) using rock, groundwater, relief, soils, and land use/land cover classification, employing multi-criteria analysis and data of contamination sources. The potential contamination classification showed the predominance (54% of the area) of very high and high potential, especially due to geological environment conditions (exploitation areas and groundwater recharge of the Itararé Aquifer -clastic sedimentary and free flow). The contaminant sources analyzed are located mainly in higher potential contamination areas. Keywords:Groundwater; Water quality; Water contamination; Multi-criteria analysis. RESUMOA avaliação do potencial de contaminação da água subterrânea a partir dos atributos geológicos, hidrológicos e hidrogeológicos, é reconhecida como um mecanismo eficiente de proteção e conservação dos recursos hídricos de subsuperfície. No entanto, tal método por vezes apresenta como deficiências a desconsideração das atividades humanas que são potencialmente contaminantes, seja na forma de fontes pontuais ou difusas, ou por não considerar a importância relativa dos atributos na análise. Visando contribuir para a solução dessa lacuna, o presente trabalho se valeu de análise multicritério como forma de reduzir a subjetividade dessa análise e de informações de uso e cobertura do solo e de fontes de contaminação para tratar os efeitos da ação humana no processo. O trabalho foi desenvolvido na Bacia Hidrográfica do rio das Araras (Bacia do Paraná, Brasil) a partir do tratamento dos dados de substrato rochoso, hidrografia, relevo, solos, classificação de uso e cobertura do solo usando análise multicritério e dados de fontes de contaminação. A classificação do potencial de contaminação mostrou a predominância (54% da área) de áreas classificadas como potencial muito alto e alto, especialmente em função do ambiente geológico (áreas de explotação e recarga do Aquífero Itararé, sedimentar clástico e livre). As fontes contaminantes analisadas se localizam principalmente nessas áreas com maiores potenciais de contaminação. Multi-criteria potential groundwater contamination and human activities: Araras watershed, Brazil Palavras