Entry word 'geo' means the relations between the earty surface layer and its surroundings.The existence and development of humanity are in progress on certain spatial places and duringspecific time series. It...Entry word 'geo' means the relations between the earty surface layer and its surroundings.The existence and development of humanity are in progress on certain spatial places and duringspecific time series. It is not only philosophic truth but also objective reality. People always define theinteraction between human society and natural world as man-land relationship. which contains eitherthe tangible habitat of human being or the intangible bearing got involved in it. So far asgeoenvironment is an enlarged geographic surroundings, from macroscopic cosmos to elementaryparticle without exception. The purpose of thes paper is to expound the relationship for human beingwith its factors affiliated on global surface. The authors firmly believe that humankind possesses threeoverlapping levels of environment on earth enclosure including physical (natural), economic(artificial) and humanistic (ideological) spheres.展开更多
This study is conducted to evaluate the ongoing geoenvironmental impacts of Brahmaputra-Jamuna (BJ) River around the Jamuna Bridge (JB) site which was modified prior to the construction of Jamuna Bridge in 1996. Remot...This study is conducted to evaluate the ongoing geoenvironmental impacts of Brahmaputra-Jamuna (BJ) River around the Jamuna Bridge (JB) site which was modified prior to the construction of Jamuna Bridge in 1996. Remote sensing and GIS techniques are adopted to evaluate the temporal and spatial geohazards. This study shows that the intensity of channel shifting has been increased due to regulation of river width at Sira-jganj–Bhuiyapur section from 11 km to 4.8 km. Planform analysis shows that the major channel has been stressed to migrate (315 m/year) eastwards. The phenomena of channel changes are predicted to be the con-sequences of interaction of water flow, sedimentation and channel corridor. The erosion and deposition have complicated variations over time and space due to the abrupt changes of flow and sedimentation around the regulated section. Due to width reduction, the bridge site in the braided system acts as sluice gate which can not accommodate the entire flow to release downstream properly. The helical flow developed with the inter-action of guide bund creates local scours and helps to shift the river bank eastward.展开更多
This work focused on the prediction modeling of Cerrado occurrences in the Atlantic Rainforest predominance in the São Paulo Metropolitan Region (SPMR), the fourth largest urban area, in the city of Guarulhos...This work focused on the prediction modeling of Cerrado occurrences in the Atlantic Rainforest predominance in the São Paulo Metropolitan Region (SPMR), the fourth largest urban area, in the city of Guarulhos, southeastern Brazil. The methodology was based on the selection of records of occurrence of Cerrado in georeferenced databases, thematic maps of geoenvironmental layers, and modeling of the distribution of species through the MaxEnt tool. Besides that, field research confirmed the presence or not of the species in the areas with a high probability of occurrence of Cerrado (≥0.7). As a result, the model observed a great capacity for the prediction of the occurrence of Cerrado in Ecotonal and anthropic regions (AUC = 0.82), revealing important hotspots such as relics from the past or Cerrado enclaves of high biodiversity. The work also points priority areas for the conservation and preservation of this increasingly endangered biome.展开更多
Expansive soils are problematic due to the performances of their clay mineral constituent, which makes them exhibit the shrink-swell characteristics. The shrink-swell behaviours make expansive soils inappropriate for ...Expansive soils are problematic due to the performances of their clay mineral constituent, which makes them exhibit the shrink-swell characteristics. The shrink-swell behaviours make expansive soils inappropriate for direct engineering application in their natural form. In an attempt to make them more feasible for construction purposes, numerous materials and techniques have been used to stabilise the soil. In this study, the additives and techniques applied for stabilising expansive soils will be focused on,with respect to their efficiency in improving the engineering properties of the soils. Then we discussed the microstructural interaction, chemical process, economic implication, nanotechnology application, as well as waste reuse and sustainability. Some issues regarding the effective application of the emerging trends in expansive soil stabilisation were presented with three categories, namely geoenvironmental,standardisation and optimisation issues. Techniques like predictive modelling and exploring methods such as reliability-based design optimisation, response surface methodology, dimensional analysis, and artificial intelligence technology were also proposed in order to ensure that expansive soil stabilisation is efficient.展开更多
Placer diamond mining in the Anabar area involves various operations that cause long-term (nearly a quarter of a century) environmental impacts. The long history of mining activities, the technology used to mine the p...Placer diamond mining in the Anabar area involves various operations that cause long-term (nearly a quarter of a century) environmental impacts. The long history of mining activities, the technology used to mine the placers, as well as the poor assimilative capacity of the natural systems can result in serious environmental impacts in the area. The primary geochemical processes in the diamond-bearing area are affected by the occurrence of permafrost and relict ice, the lengthy duration of ice cover in water bodies, and the widespread development of cryogenic processes. This promotes physical migration of contaminants, cryogenic metamorphization of waters, and long-term accumulation of organic contaminants in low-temperature, reduction and sedimentation barriers. In this paper, some environmental and geochemical effects of diamond mining in the Arctic area are discussed.展开更多
文摘Entry word 'geo' means the relations between the earty surface layer and its surroundings.The existence and development of humanity are in progress on certain spatial places and duringspecific time series. It is not only philosophic truth but also objective reality. People always define theinteraction between human society and natural world as man-land relationship. which contains eitherthe tangible habitat of human being or the intangible bearing got involved in it. So far asgeoenvironment is an enlarged geographic surroundings, from macroscopic cosmos to elementaryparticle without exception. The purpose of thes paper is to expound the relationship for human beingwith its factors affiliated on global surface. The authors firmly believe that humankind possesses threeoverlapping levels of environment on earth enclosure including physical (natural), economic(artificial) and humanistic (ideological) spheres.
文摘This study is conducted to evaluate the ongoing geoenvironmental impacts of Brahmaputra-Jamuna (BJ) River around the Jamuna Bridge (JB) site which was modified prior to the construction of Jamuna Bridge in 1996. Remote sensing and GIS techniques are adopted to evaluate the temporal and spatial geohazards. This study shows that the intensity of channel shifting has been increased due to regulation of river width at Sira-jganj–Bhuiyapur section from 11 km to 4.8 km. Planform analysis shows that the major channel has been stressed to migrate (315 m/year) eastwards. The phenomena of channel changes are predicted to be the con-sequences of interaction of water flow, sedimentation and channel corridor. The erosion and deposition have complicated variations over time and space due to the abrupt changes of flow and sedimentation around the regulated section. Due to width reduction, the bridge site in the braided system acts as sluice gate which can not accommodate the entire flow to release downstream properly. The helical flow developed with the inter-action of guide bund creates local scours and helps to shift the river bank eastward.
文摘This work focused on the prediction modeling of Cerrado occurrences in the Atlantic Rainforest predominance in the São Paulo Metropolitan Region (SPMR), the fourth largest urban area, in the city of Guarulhos, southeastern Brazil. The methodology was based on the selection of records of occurrence of Cerrado in georeferenced databases, thematic maps of geoenvironmental layers, and modeling of the distribution of species through the MaxEnt tool. Besides that, field research confirmed the presence or not of the species in the areas with a high probability of occurrence of Cerrado (≥0.7). As a result, the model observed a great capacity for the prediction of the occurrence of Cerrado in Ecotonal and anthropic regions (AUC = 0.82), revealing important hotspots such as relics from the past or Cerrado enclaves of high biodiversity. The work also points priority areas for the conservation and preservation of this increasingly endangered biome.
文摘Expansive soils are problematic due to the performances of their clay mineral constituent, which makes them exhibit the shrink-swell characteristics. The shrink-swell behaviours make expansive soils inappropriate for direct engineering application in their natural form. In an attempt to make them more feasible for construction purposes, numerous materials and techniques have been used to stabilise the soil. In this study, the additives and techniques applied for stabilising expansive soils will be focused on,with respect to their efficiency in improving the engineering properties of the soils. Then we discussed the microstructural interaction, chemical process, economic implication, nanotechnology application, as well as waste reuse and sustainability. Some issues regarding the effective application of the emerging trends in expansive soil stabilisation were presented with three categories, namely geoenvironmental,standardisation and optimisation issues. Techniques like predictive modelling and exploring methods such as reliability-based design optimisation, response surface methodology, dimensional analysis, and artificial intelligence technology were also proposed in order to ensure that expansive soil stabilisation is efficient.
文摘Placer diamond mining in the Anabar area involves various operations that cause long-term (nearly a quarter of a century) environmental impacts. The long history of mining activities, the technology used to mine the placers, as well as the poor assimilative capacity of the natural systems can result in serious environmental impacts in the area. The primary geochemical processes in the diamond-bearing area are affected by the occurrence of permafrost and relict ice, the lengthy duration of ice cover in water bodies, and the widespread development of cryogenic processes. This promotes physical migration of contaminants, cryogenic metamorphization of waters, and long-term accumulation of organic contaminants in low-temperature, reduction and sedimentation barriers. In this paper, some environmental and geochemical effects of diamond mining in the Arctic area are discussed.
