The Spectral Determination of Depths to Buried Magnetic Basement Rocks     

S. Treitel  W. G. Clement  R. K. Kaul 《Geophysical Journal International》1971,24(4):415-428

  相似文献   

Water use by intensively cultivated willow using estimated stomatal parameter values     

Harald Grip  Sven Halldin  Anders Lindroth 《水文研究》1989,3(1):51-63

Large land areas in Sweden are planned to be planted with high producing, short rotation forest stands of willow in the beginning of the 1990s. Since willow is a highly hydrophilic species, this new land use may have strong implications on water resources. To assess these implications, evaporation of Salix viminalis and Salix viminalis x caprea stands in lysimeters was analysed with the simple, yet physically realistic KAUSHA model. Parameter values for the Lohammar equation were deduced (b = 100 m³ kg^?1, k_max = 0.01 m s^?1), believed to be applicable to other sites. Simulated evaporation during the 1980 growth season for a normal stand with a production of 12 tonnes of dry matter per hectare per season was 526 mm, of which 375 mm was transpiration, 56 mm interception evaporation, and 95 mm soil evaporation. For an optimally irrigated 20-tonnes stand, the total evaporation was 584 mm, of which 430 mm was transpiration. As a comparison, Penman open water evaporation was 430 mm. To avoid soil water stress in the 20-tonnes stand, 140 mm was needed as irrigation, equivalent to 25 per cent of the mean annual precipitation. Since intensively cultivated willow plantations seemed to be using much water, it was concluded that introduction of this agri-forestry practice must be carefully planned to make use of this property, e.g. in biological filters or in reclaiming water-logged land.  相似文献   

Avalanche Hazard Mitigation Strategies Assessed by Cost Effectiveness Analyses and Cost Benefit Analyses—evidence from Davos,Switzerland     

Sven Fuchs  Magdalena Thöni  Maria Christina McAlpin  Urs Gruber  Michael Bründl 《Natural Hazards》2007,41(1):113-129

This paper demonstrates the application of cost effectiveness analysis and cost benefit analysis to alternative avalanche risk reduction strategies in Davos, Switzerland. The advantages as well as limitations of such analysis for natural hazards planning are discussed with respect to 16 avalanche risk reduction strategies. Scenarios include risk reduction measures that represent the main approaches to natural hazards planning in Switzerland, such as technical, organisational, and land use planning measures. The methodologies used outline how concepts and techniques from risk analysis, hazard mapping, Geographic Information System, and economics can be interdisciplinary combined. The results suggest important considerations, such as possible sources of uncertainty due to different choices in the calculation of cost effectiveness ratio and net present value. Given the parameters and assumptions, it seems as if the current approach to avalanche risk reduction in the study area approximates to economic and cost efficiency and serves the aim of reducing risk to human fatalities.  相似文献   

Discussion of “The effect of weathering on pore geometry and compressive strength of selected rock types from Turkey” by Tuğrul, Engineering Geology, 75: 215–227 (2004)     

Sven ke Larson  Eva-Lena Tullborg 《Engineering Geology》2006,82(4):268-269

  相似文献   

Modeling of groundwater flow at depth in crystalline rock beneath a moving ice-sheet margin, exemplified by the Fennoscandian Shield, Sweden     

Patrik Vidstrand  Sven Follin  Jan-Olof Selroos  Jens-Ove Näslund  Ingvar Rhén 《Hydrogeology Journal》2013,21(1):239-255

On-going geological disposal programs for spent nuclear fuel have generated strong demands for investigation and characterization of deep-lying groundwater systems. Because of the long time scales for which radiological safety needs to be demonstrated in safety assessment applications, an analysis of the hydrogeological performance of the geosphere system during glacial climate conditions is needed. Groundwater flow at depth in crystalline rock during the passage of an ice-sheet margin is discussed based on performed groundwater-flow modeling of two bedrock sites, Forsmark and Laxemar, in the Fennoscandian Shield, Sweden. The modeled ice sheet mimics the Weichselian ice sheet during its last major advance and retreat over northern Europe. The paper elaborates and analyzes different choices of top boundary conditions at the ice sheet–subsurface interface (e.g. ice-sheet thickness and ice-margin velocity) and in the proglacial area (presence or lack of permafrost) and relates these choices to available groundwater-flow-model hydraulic output and prevailing conceptual hydrogeochemical models of the salinity evolution at the two sites. It is concluded that the choice of boundary conditions has a strong impact on results and that the studied sites behave differently for identical boundary conditions due to differences in their structural-hydraulic properties.  相似文献   

Enriching the GIScience research agenda: Fusing augmented reality and location‐based social networks          下载免费PDF全文

Chengbi Liu  Sven Fuhrmann 《Transactions in GIS》2018,22(3):775-788

Augmented reality (AR) overlays real‐world views or scenes with virtual, computer‐generated objects that appear to visually coexist in the same space. Location‐based social networks (LBSNs) are platforms for individuals to be connected through the interdependency derived from their physical locations and their location‐tagged social media content. Current research and development in both areas focuses on integrating mobile‐based AR and LBSNs. Several applications (e.g., Sekai Camera and Wallame) have been developed and commercialized successfully. However, little research has been done on the potential impacts and successful evaluation methods of AR‐integrated LBSNs in the GIScience field. To close this gap, the article outlines the impacts and benefits of AR‐integrated LBSNs and highlights the importance of LBSNs in GIScience research. Based on the status quo of AR‐integrated LBSNs, this article discusses—from theoretical and application‐oriented perspectives—how AR‐integrated LBSNs could enrich the GIScience research agenda in three aspects: data conflation, platial GIS, and multimedia storytelling. The article concludes with guidelines on visualization, functionality, and ethics that aim to help users develop and evaluate AR‐integrated LBSNs.  相似文献   

Geothermal study to explain man-made permafrost in tailings with raised surface     

Roger Knutsson  Peter Viklander  Sven Knutsson  Jan Laue 《Environmental Earth Sciences》2018,77(7):288

Deposition of mine tailings in a cold climate requires precautions as temporary sub-zero temperatures can imply considerable consequences to the storage due to creation of permafrost. The risk of creating man-made permafrost lenses due to tailings deposition exists even in regions with no natural permafrost, as material being frozen during winter might not fully thaw by the following summer. When such frozen layers thaw during later longer warmer periods, excess pore water pressure and large settlements might develop. Such implications close to the dam structure have to be avoided and therefore the risk of generating permafrost should be reduced. This paper describes a geothermal model for one-dimensional heat conduction analysis. The model is able to simulate the temperature profile in tailings where the surface elevation is constantly increased due to deposition. At the tailings surface, the boundary condition is the air temperature changing over time during the year. Air temperatures, tailings deposition schedule and tailings properties are given as input to the model and can easily be changed and applied to specific facilities. The model can be used for tailings facilities in cold regions, where the effects of tailings deposition on the temperature regime are of interest. Findings can improve tailings management by explaining man-made permafrost generation. The model can also aid in setting up appropriate deposition schedules and to prevent generation of permafrost layers.  相似文献   

Water resources and climate change impact modelling on a daily time scale in the Peruvian Andes     

Norina Andres  Fernando Vegas Galdos  Waldo Sven Lavado Casimiro  Massimiliano Zappa 《水文科学杂志》2013,58(11):2043-2059

Abstract

Estimating water resources is important for adequate water management in the future, but suitable data are often scarce. We estimated water resources in the Vilcanota basin (Peru) for the 1998–2009 period with the semi-distributed hydrological model PREVAH using: (a) raingauge measurements; (b) satellite rainfall estimates from the TRMM Multi-satellite Precipitation Analysis (TMPA); and (c) ERA-Interim re-analysis data. Multiplicative shift and quantile mapping were applied to post-process the TMPA estimates and ERA-Interim data. This resulted in improved low-flow simulations. High-flow simulations could only be improved with quantile mapping. Furthermore, we adopted temperature and rainfall anomalies obtained from three GCMs for three future periods to make estimations of climate change impacts (Delta-change approach) on water resources. Our results show more total runoff during the rainy season from January to March, and temporary storages indicate that less water will be available in this Andean region, which has an effect on water supply, especially during dry season.

Editor Z.W. Kundzewicz; Associate editor D. Gerten  相似文献   

Monazite stability,composition and geochronology as tracers of Paleoproterozoic events at the eastern margin of the East European Craton (Taratash complex,Middle Urals)     

Sven Sindern  Axel Gerdes  Yuri L. Ronkin  Annika Dziggel  Ralf Hetzel  Bernd Aloys Schulte 《Lithos》2012

The Precambrian Taratash complex (Middle Urals) is one of the rare windows into the Palaeoproterozoic and earlier history of the eastern margin of the East European Craton. Monazite from intensively deformed rocks within a major amphibolite-facies shear zone in the Taratash complex has been investigated by means of electron-probe microanalysis and laser-ablation SF-ICP-MS.Metamorphic and magmatic cores of monazite from metasedimentary and metagranitoid rocks yield U–Pb ages of 2244 ± 19 and 2230 ± 22 Ma (± 2 σ) and record a previously unknown pre-deformational HT-metamorphic event in the Taratash complex. Subsequent dissolution–reprecipitation of monazite, during shear zone formation under amphibolite-facies conditions, caused patchy zonation and chemical alteration of the recrystallised monazite domains, leading to higher cheralite and huttonite components. This process, which was mediated by a probable (alkali + OH)-bearing metamorphic fluid also caused a total resetting of the U–Pb-system. The patchy domains yield concordant U–Pb-ages between 2052 ± 16 and 2066 ± 22 Ma, interpreted as the age of the shear zone. In line with previously published ages of high grade metamorphism and migmatisation, the data may point to a Palaeoproterozoic orogenic event at the eastern margin of the East European Craton.Post-deformational fluid-induced greenschist-facies retrogression caused partial to complete breakdown of monazite to fluorapatite, REE + Y-rich epidote, allanite and Th-orthosilicate.The retrograde assemblages either form coronas around monazite, or occur as dispersed reaction zones, indicating that the REE, Y, and Th were mobile at least on the thin section scale. The greenschist-facies metamorphic fluid was aqueous and rich in Ca. Monazite affected by advanced breakdown responded to the retrogression by incorporating the cheralite or huttonite components during a fluid-induced dissolution–reprecipitation process. This event did not reset the U–Pb-system but caused partial Pb loss reflected by discordant U–Pb-dates.  相似文献   

Mountain hazards: reducing vulnerability by adapted building design   总被引：4，自引：0，他引：4  

Markus Holub  Jürgen Suda  Sven Fuchs 《Environmental Earth Sciences》2012,66(7):1853-1870

Despite the long tradition of technical mitigation on a catchment scale in European mountain regions, losses due to mountain hazards are still considerably high in number and monetary loss. Therefore, the concept of technical mitigation had been supplemented by land-use planning and, more recently, local structural protection. Local structural protection includes measures directly implemented at or adjacent to endangered objects, and has proven to be particularly cost-effective with respect to integral risk management strategies. However, the effect of local structural protection in reducing the vulnerability of elements at risk, and the associated consequences with respect to a reduction of structural vulnerability have not been quantified so far. Moreover, there is a particular gap in quantifying the expenditures necessary for local structural protection measures. Therefore, a prototype of residential building adapted to mountain hazards is presented in this study. This prototype is equipped with various constructional elements to resist the incurring impact forces, i.e., of fluvial sediment transport and of snow avalanches. According to possible design loads emerging from these hazard processes, the constructive design necessary is presented, and the amount of additional costs required for such an adaptation is presented. By comparing these costs with quantitative loss data it is shown that adapted building design is particularly effective to reduce the consequences of low-magnitude, high-frequency events in mountain regions.  相似文献