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R. D. Schuiling 《Journal of Geochemical Exploration》1998,62(1-3)
Geochemical engineering makes use of optimized geochemical processes for the solution of environmental problems. It has developed in a few years from a collection of unrelated scientific and technological incidents into a coherent concept about how and where we can improve our geo-environment. All solutions to problems of pollution are based on neutralization/breakdown, concentration, dilution, isolation or immobilization, which serve to eliminate the pollutant, make it more manageable, or prevent its entry into the mobile phase, usually water, from which it can affect the biosphere. All of these solutions have their counterpart in nature, where many examples are found of high concentrations of potentially harmful substances. A major prerequisite of geochemical engineering solutions is that they should be compatible with the natural evolution of the system in its geo-environment. The advantages of this approach are that we can devise low-cost technologies (nature does most of the hard work itself), interfere least with nature, and quite often end up with useful by-products. Disadvantages are that technologies based on natural geochemical processes tend to be slow. The application of geochemical engineering concepts requires a better understanding of our environment and its ongoing processes than is necessary for a ‘classical' technology. In most environmental technologies the conditions are externally imposed on the system to be treated, and the natural evolution of the system is eliminated, or at best neglected. The concept of seeking a closer conformity with nature is paralleled in other disciplines like agriculture or the medical sector, where we see a similar evolution in the direction of techniques that are more in harmony with nature. Geochemical engineering brings many advantages, particularly in developing countries, or in countries where the state of the economy does not permit the introduction of expensive high-tech environmental technologies. So far, most of the applications of geochemical engineering concepts have focussed on solutions to environmental problems, but there are a number of cases where the environmental issue is more indirect, as e.g. in civil engineering. Geochemical engineering may be practised on a large, almost global scale, down to that of individual minerals, in accordance with the fact that geochemical processes also act on vastly different scales. An overview will be given of some of the problems that are being studied. 相似文献
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Nicolas Ferrer-Valero Luis Hernández-Calvento Antonio I. Hernández-Cordero 《地球表面变化过程与地形》2019,44(2):565-580
The Canary Islands form a volcanic archipelago in which a west–east (W–E) chain of progressively older and less active islands can be observed. In the Canary Islands, unlike most hot-spot archipelagos, certain geodynamic peculiarities have promoted longer periods of island survival, exceeding 20 Myr. This factor makes these islands a suitable context for this work, which aims to analyze extensively the coastal geomorphic structure on islands with different development states. For this, three islands in different volcanic phases were selected: La Palma (1.8 Myr), Gran Canaria (14.5 Myr) and Fuerteventura (22.6 Myr). An ad hoc landform-based hierarchical taxonomy was designed to analyze the coastal geomorphic structure of the three islands. Based on a multi-sourced analysis in geographic information system (GIS) and field recognition, a comprehensive cartographic database was collected using the coastline data-storing (CDS) method as a feature abundance proxy. Three different aspects of the geomorphological structure were compared and related between the islands: (i) composition, (ii) abundance and (iii) diversity. Through their comparison, we attempt to explore geomorphological aspects of coastal evolution over geological spatiotemporal scales. Composition was explored analyzing the distribution of the feature's longshore frequencies (p). Abundance, by metrics of local abundance (N∩) and whole density (NU). Diversity, through four indices: normalized richness (S) and Margalef index (M) to estimate richness; Simpson index (D) and Shannon index (H’) to estimate evenness. We identified a systematic transformation in the dominant landform composition and a systematic trend in increasing geomorphological abundance and diversity from younger to older islands. The results show a long-term structural pattern defined by the increase in coastal geomorphic complexity (abundance and diversity) over geological time, as the coasts evolve from predominantly rocky-erosive to increasingly clastic-depositional environments. This long-term geomorphological pattern may be a general aspect of hot-spot island archipelagos, which can bring a new perspective to the knowledge of their coastal evolution. © 2018 John Wiley & Sons, Ltd. 相似文献
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The study of the coastal landscapes of hotspot oceanic islands through comprehensive structural metrics and ecological estimators represents an opportunity to explore geomorphological transformations and broad spatiotemporal scale features of coastal evolution. As part of this approach, a new metrical comparative analysis is presented in this study, comprising four islands in different evolutionary stages. They belong to the Cape Verde archipelago, which forms a double insular chain in which an east–west gradient in age and evolution is particularly evident across the southern chain. A space-for-time (SFT) substitution approach is applied to the coasts of (1) Fogo, in the shield stage; (2) Santiago, in the early post-erosional stage; (3) São Vicente, in the advanced post-erosional stage; and (4) Boa Vista, in the last erosional stage. From the obtained spatial distributions and frequencies of landforms, the coastal landscapes of these islands are compared in relation to their (i) geomorphic composition, using similarity indices (Whittaker, βw, Sorensen, Cs) and nestedness estimators (NOFD, WNODF), (ii) geomorphic abundance, using morpho-assembling densities (Dgm), and (iii) geomorphic diversity, using six alpha-diversity indices (Richness, S, Menhinick, DMN, Simpson, D, Shannon, H', Berger-Parker, d, and Brillouin, HB). An advanced geomorphological taxonomy is implemented for areas with limited open-access data, including a set of planform features captured through scale-frequency decomposition. Photographic, cartographic and fieldwork data are used for landform identification at 1200 random sampling points, empirically determined by a bootstrap method. The results show a chronological ordering of the compared variables and a possible co-evolution towards an increase in organizational geomorphic complexity of coastal systems at broad space-timescales. The method proposed in this study can contribute, from a metrical perspective, to finding new long-term evolutionary features and constitutes an advance in the development of an integrated model of coastal evolution in oceanic islands. © 2019 John Wiley & Sons, Ltd. 相似文献
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Rivers with discontinuous watercourses are part of the spectrum of river diversity. Chain-of-ponds types contain irregularly spaced, steep-sided ponds that are separated by preferential flow paths on swampy valley fill. They often contain endangered ecological communities and are receiving greater attention for conservation and restoration. Very little is known about how these river types form, how they have evolved and how they function. Here we present the Late-Quaternary evolution of one of the last remaining large-scale chain-of-ponds systems in Australia, the Mulwaree Ponds. The chain-of-ponds was fully formed by 4.5 ka, with the position and alignment of the ponds being related to the position of pools of a palaeo-river that is up to 100 ka old. Contemporary hydrogeomorphic processes are insufficient to create the ponds, but sufficient to maintain and keep them open. The phases of evolution for this chain-of-ponds system are synchronous with Late-Quaternary changes in fluvial activity documented for other rivers in southeastern Australia. The ponds at Mulwaree have significant preservation potential over thousands of years. In the current landscape they are rare forms, providing significant grounds for conservation and protection of their distinctive geodiversity. © 2020 John Wiley & Sons, Ltd. 相似文献
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Geodiversity in the Yellow River source zone 总被引：5，自引：4，他引：1
It is a key premise of ＇ecosystem approaches＇ to natural resources management that we must have an appropriate understanding of biodiversity values, and controls upon them, if we wish to manage them effectively. These biodiversity values, and associated ecosystem functionality, vary with space and time and are tied directly to landscape-scale relationships and evolutionary traits. In riverine systems, nested hierarchical principles provide a useful platform to assess relationships between landscape components across a range of scales. These understandings are most instructively synthesized through catchment-scale analyses. This paper outlines a rationale for systematic catchment-wide appraisals of river geodiversity. An initial application of these principles is presented for the Yellow River source zone in Qinghai Province, western China. Geo-ecological relationships are outlined for five broad sections of the trunk stream, highlighting implications for the management of these individual landscape compartments and for the system as a whole. 相似文献
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C. A. Semeniuk 《Australian Journal of Earth Sciences》2019,66(6):837-853
A wide range of wetland types occur on the Swan Coastal Plain of Western Australia. They vary from basins, and flats, to slopes and channels, and vary in size, shape, water characteristics, sediment types, stratigraphy, vegetation, origin, and maintenance processes. The wetlands range from large linear lakes to small round or irregular seasonally damp wetland basins to seasonally flooded flats, to seasonally flooded or permanently flowing channels. Salinity ranges from fresh to saline to hyposaline; and recharge mechanisms from perching of surface-water to wetting and inundation by groundwater, as determined by regional features such as geology, geomorphology, soils, climate and hydrology, and local physical/chemical processes. The Swan Coastal Plain presents a bewildering array, diversity, and complexity of wetlands, but patterns and ordering can be recognised if the wetlands are aggregated into natural groups. The wetlands, in fact, have been aggregated into natural groupings termed ‘consanguineous suites’, resulting in some 30 different formally named wetland suites related to geomorphic setting varying, for instance, from interdune depressions on a beach-ridge plain (the Becher Suite), to karst-formed linear lakes in limestone-ridge country (the Yanchep Suite), to irregular to round, semi-interconnected basins on a quartz sand subdued dune system (the Jandakot Suite), to linear and round basins formed along the hydrological contact between limestone and quartz sand (the Bibra Suite), among others. The variety of wetland types on the Swan Coastal Plain represents geodiversity that needs to be addressed in geoheritage assessments of the State of Western Australia. Further, as repositories of Holocene to Pleistocene sedimentary sequences, the wetlands present significant reservoirs of information on wetland history, climate changes, and hydrochemical history, and are templates on wetland maintenance and functioning, diagnostic for their geologic/geomorphic setting useful for management of wetlands in Western Australia, nationally, and globally. From a global perspective, the diversity and array of consanguineous suites of the Swan Coastal Plain is unique. An understated aspect of the approach in identifying consanguineous suites of wetlands of the Swan Coastal Plain is that in their geological, geomorphological, and hydrological/hydrochemical setting they provide profound insights into gradual and uninterrupted wetland development, sedimentary filling and ecological functioning because, for a given east–west transect, they are located in the same climate setting but in different geologic/geomorphic and hydrochemical settings. They appear to be unrepresented globally, and therefore, in terms of geoheritage, are internationally significant. 相似文献
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Geodiversity is a landscape characteristic related to the heterogeneity of the physical properties of the earth surface. In this work, we quantify and compare geodiversity in several geodynamic zones of the Iberian Peninsula. For this purpose, we have developed a geographic information system (GIS) procedure to carry out a regional terrain classification based on geodiversity factors. A classification process helped to produce a morphometric map (10 classes), a morphoclimatic map (five classes) and a geological map (15 classes). These three maps were combined using an overlay operation (union) to obtain the final terrain classification (419 classes), which was then applied to calculate diversity landscape indices. The latter were calculated using common landscape diversity indices (Patch Richness Density, Shannon's Diversity Index, Shannon's Evenness Index, Simpson's Diversity Index and Simpson's Evenness Index), provided by FRAGSTATS free software. These indices were calculated for the whole landscape of the main Iberian geological regions, thus revealing a close relationship between some index values and the geological and geomorphological characteristics. The highest diversity values are associated with Alpine collisional orogens and reactivated chains of the Precambrian‐Palaeozoic massif. Intraplate orogen with sedimentary cover, characterized by extensive planation surfaces, have lower values. Mesozoic areas with no significant tectonic deformation and Cenozoic basins are characterized by the lowest diversity values. Amongst the latter, the major diversity is associated with the most dissected basins, which also present higher morphoclimatic variety. Though depending on the chosen scale and the landscape classification criteria, these indices provide an objective assessment of the regional geodiversity of Iberia. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
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Soil piping is a widespread, although often overlooked land degradation process. So far, subsurface soil erosion studies have been focused on the importance of soil piping in hydrological and geomorphological processes, and factors controlling piping processes. Nowadays, the environmental changes being caused by the Anthropocene have clearly demonstrated that society depends on soil more than ever before, so the traditional studies of soil erosion processes need to be redefined. In that sense, geomorphologists face to overcome new piping-related problems. In this article we identify new possible areas of research: (i) soil pipes and pipe collapses (PCs) as natural hazards, (ii) role of soil piping in carbon cycle, (iii) soil pipes and PCs and their relationships with biodiversity, and (iv) piping-affected areas as geodiversity sites. Only better recognition of natural hazards driven by soil piping, such as land subsidence and degradation, landslides, flooding and off-site sediment effects may result in better prevention and control measures in piping-affected areas. Moreover, in the context of Global Change the role of soil piping in carbon cycle should be raised. Land-use and land-cover changes, as well as climate change may affect piping dynamics in different morphoclimatic regions and soil loss due to piping may lead to carbon loss. Soil pipes and PCs are closely interlinked with biodiversity, both positively and negatively. Piping erosion may directly and indirectly destroy vegetation and animals, although in some cases piping erosion may create new habitats and provide favourable conditions for some species. However, soil piping is not only an environmental and societal problem, but it may also contribute to the world geodiversity, which is clearly observed in badland sites. Piping erosion may have a significant impact on environment and society, thus further research with new questions is essential to provide knowledge for sustainable development. 相似文献
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AbstractBrocx and Semeniuk’s (2019) paper is discussed, particularly in relation to the concept of geodiversity and their proposed sequence of ‘8Gs’. Their ideas on these topics are at odds with the majority of published papers and Internet sources on geodiversity. We argue that geodiversity as a concept has real value and that (a) the planet’s geodiversity occurs at all scales from global downwards, (b) it deserves an absolutely central place in any sequence of ‘Gs’ since it is the backbone of international and national geoheritage and geoconservation strategies, and the basis for geoheritage assessments, and (c) that as well as underpinning biodiversity, geodiversity is the source of many other geosystem services, including geotourism. Finally, a revised proposal for the relationship between geology, geodiversity, geoheritage, geoconservation and other ‘Gs’ is presented. 相似文献