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1.
Earth Science community depends on the exploration, analysis and reprocessing of high volumes of data as well as the modeling and simulation of complex coupled systems on multiple scales. The main aim of this article is to introduce a new hydrological modeling service based on the Soil and Water Assessment Tool (SWAT) (Arnold et al. J American Water Resour Assoc 34(1), 73–89, 1998 ; Arnold and Fohrer Hydrol Process 19(3), 563–572, 2005) model using high efficiency, resource sharing and low cost cloud computing resources (Astsatryan et al. International Journal of Scientific & Engineering Research 1(1), 1130–1133, 2014). Such a Desktop as a Service (DaaS) approach allowing users to work from anywhere, and gives centralized desktop management and great performance. Within the Spatial Data Infrastructure (SDI) and cloud platform, the DaaS service gives secure access to the model and a centralized data storage to get a SWAT model input. The article illustrates the analyses of the implementation of the SWAT model for the Sotk watershed of Lake Sevan in Armenia (Sargsyan 2007).  相似文献   

2.
Shallow aquifer vulnerability has been assessed using GIS-based DRASTIC model by incorporating the major geological and hydrogeological factors that affect and control the groundwater contamination in a granitic terrain. It provides a relative indication of aquifer vulnerability to the contamination. Further, it has been cross-verified with hydrochemical signatures such as total dissolved solids (TDS), \(\hbox {Cl}^{-},\, \hbox {HCO}_{3}^{-},\, \hbox {SO}_{4}^{2-}\) and \(\hbox {Cl}^{-}/\hbox {HCO}_{3}^{-}\) molar ratios. The results show four zones of aquifer vulnerability (i.e., negligible, low, moderate and high) based on the variation of DRASTIC Vulnerability Index (DVI) between 39 and 132. About 57% area in the central part is found moderately and highly contaminated due to the 80 functional tannery disposals and is more prone to groundwater aquifer vulnerability. The high range values of TDS (2304–39,100 mg/l); \(\hbox {Na}^{+}\)(239– 6,046 mg/l) and \(\hbox {Cl}^{-}\) (532–13,652 mg/l) are well correlated with the observed high vulnerable zones. The values of \(\hbox {Cl}^{-}/\hbox {HCO}_{3}^{-}\) (molar ratios: 1.4–106.8) in the high vulnerable zone obviously indicate deterioration of the aquifer due to contamination. Further cumulative probability distributions of these parameters indicate several threshold values which are able to demarcate the diverse vulnerability zones in granitic terrain.  相似文献   

3.
Due to anthropogenic influences and large amounts of pollutant released into the groundwater, it is vital to investigate groundwater quality and to characterize susceptible areas to contamination. In this paper, a new optimization-based methodology is proposed for determining groundwater risk using DRASTIC model based on genetic algorithm optimization model and Wilcoxon test. The correlation coefficient between DRASTIC/modified DRASTIC indices and nitrate concentrations in monitoring wells is used as a criteria for evaluating the efficiency of the proposed models. In this regard, because of the unsatisfactory original DRASTIC’s result, sensitivity analysis, genetic algorithm (GA), and Wilcoxon test (1945) are carried out to tackle the subjectivity associated with the original DRASTIC model and obtain better and reliable results. The results indicate that application of Wilcoxon test and GA optimization outperforms the others. Consequently, the correlation coefficient increased remarkably as compared to the original DRASTIC model (from 0.57 to 0.82). The proposed optimization process is adaptable to be applied in different case studies; mainly since it has the ability to optimize the weights of the model based on hydrogeological characteristics of the aquifer. Finally, the risk maps of the models are prepared using ArcGIS® to determine the most vulnerable areas.  相似文献   

4.
The echinoid fauna from the Miocene sedimentary succession cropping out south Wadi Tweirig, and Wadi Hommath, south Gebel Ataqa, NW Gulf of Suez, has been examined with the aim to known their stratigraphic and paleogeographic distribution. The Miocene succession includes two formations: Sadat Formation, unconformably overlying the middle/upper Eocene rocks at the base and Hommath Formation at the top. Twenty-eight echinoid species (8 regular and 20 irregular) belonging to 18 genera, 13 families, and 7 orders have been identified, systematically described, and illustrated in this work. Eleven species are recorded for the first time from Egypt: ten of these came from the Hommath Formation (Schizechinus cf. serresii Desor (1856), Schizechinus pentagonus Kier 1972, Clypeaster cf. martini des Moulins 1837, Scutella checchiae occidentalis Desio 1934, Scutella melitensis Airaghi 1902, Echinodiscus desori Duncan and Sladen 1883, Echinolampas cf. zeitensis Fourtau 1920, Schizaster lovisatoi Cotteau 1895, Agassizia (Agassizia) powersi Kier 1972, and Hemipatagus ocellatus Defrance (1827)), and one from the Sadat Formation (Clypeaster campanulatus Schlotheim (1820)). The identified fauna shows a strong affinity with the Mediterranean bio-province.  相似文献   

5.
The 2010 eruption of the Eyjafjallajökull volcano had a devastating effect on the European air traffic network, preventing air travel throughout most of Europe for 6 days (Oroian in ProEnvironment 3:5–8, 2010). The severity of the disruption was surprising as previous research suggests that this type of network should be tolerant to random hazard (Albert et al. in Nature 406(6794):378–382, 2000; Strogatz in Nature 410(6825):268–276, 2001). The source of this hazard tolerance lies in the degree distribution of the network which, for many real-world networks, has been shown to follow a power law (Albert et al. in Nature 401(6749):130–131, 1999; Albert et al. in Nature 406(6794):378–382, 2000). In this paper, we demonstrate that the ash cloud was unexpectedly disruptive because it was spatially coherent rather than uniformly random. We analyse the spatial dependence in air traffic networks and demonstrate how the combination of their geographical distribution and their network architectures jeopardises their inherent hazard tolerance.  相似文献   

6.
This study proposes a simplified 1-parameter SCS-CN model (M5) based on Mishra-Singh (2002) model and soil moisture accounting (SMA) procedure for surface runoff estimation and compares its performance with the existing SCS-CN method (SCS, 1956) (M1), Michel 1-P model (Water Resour Res 41:1-6, 2005) (M2), Sahu 1-P model (Hydrol Process 21:2872-2881, 2007) (M3), and Ajmal et al. model (J Hydrol 530:623-633, 2015) (M4) using large rainfall–runoff dataset of 48,763 events from123 USDA-ARS watersheds. The performance of models was evaluated using three statistical error indices such as Nash-Sutcliffe efficiency (NSE), root mean square error (RMSE), percentage bias (PBIAS), and rank and grading system (RGS). Based on the results obtained, the models can be ranked as follows: M5?>?M4?>?M3?>?M1?>?M2, i.e., model M5 outperformed all the remaining four models M1–M4 and hence is recommended for field applications.  相似文献   

7.
Groundwater is the most economic natural source of drinking in urban and rural areas which are degraded due to high population growth and increased industrial development. We applied a GIS-based DRASTIC model in a populated urban area of Pakistan (Peshawar) to assess groundwater vulnerability to pollution. Six input parameters—depth to phreatic/groundwater level, groundwater recharge, aquifer material, soil type, slope, and hydraulic conductivity—were used in the model to generate the groundwater vulnerable zones. Each parameter was divided into different ranges or media types, and ratings R?=?1?–?10 were assigned to each factor where 1 represented the very low impact on pollution potential and 10 represented very high impact. Weight multipliers W?=?1?–?5 were also used to balance and enhance the importance of each factor. The DRASTIC model scores obtained varied from 47 to 147, which were divided into three different zones: low, moderate, and high vulnerability to pollution. The final results indicate that about 31.22, 39.50, and 29.27% of the total area are under low, moderate, and high vulnerable zones, respectively. Our method presents a very simple and robust way to assess groundwater vulnerability to pollution and helps the decision-makers to select appropriate landfill sites for waste disposals, and manage groundwater pollution problems efficiently.  相似文献   

8.
An enhanced SMA based SCS-CN inspired model for watershed runoff prediction   总被引:1,自引:0,他引:1  
Incorporation of initial soil moisture (V 0) in the Soil Conservation Service Curve Number (SCS-CN) methodology helps to avoid the sudden jumps in Curve Number (CN) and, in turn, in computed runoff. It invoked the development of an enhanced (yet simple) Soil Moisture Accounting (SMA) procedure-based-SCS-CN inspired model, by incorporating initial moisture (V 0). Its performance is tested using a dataset of 152 small to large watersheds of USDA (total 38,169 storm events), and compared with original SCS-CN method, Mishra and Singh (Acta Geophys Polon 50(3):457–477, 2002), Michel et al. (Water Resour Res 41(2):W02011, 2005) and Singh et al. (Water Resour Manag 29(11): 4111–4127, 2015) model using four statistical indices (RMSE, R 2, PBIAS and NSE) and rank grading system (RGS). The proposed model scores highest (= 691 marks out of maximum 2280 marks) (Rank I) followed by Singh et al. (Water Resour Manag 29(11):4111–4127, 2015) model with 642 marks (Rank II), Michel et al. (Water Resour Res 41(2):W02011, 2005) model with 376 marks (Rank III) and Mishra and Singh model with 362 marks (= Rank IV). The original SCS-CN model, however, performs the poorest of all with 209 marks (Rank V).  相似文献   

9.
In this paper, we develop a multiscale model reduction technique that describes shale gas transport in fractured media. Due to the pore-scale heterogeneities and processes, we use upscaled models to describe the matrix. We follow our previous work (Akkutlu et al. Transp. Porous Media 107(1), 235–260, 2015), where we derived an upscaled model in the form of generalized nonlinear diffusion model to describe the effects of kerogen. To model the interaction between the matrix and the fractures, we use Generalized Multiscale Finite Element Method (Efendiev et al. J. Comput. Phys. 251, 116–135, 2013, 2015). In this approach, the matrix and the fracture interaction is modeled via local multiscale basis functions. In Efendiev et al. (2015), we developed the GMsFEM and applied for linear flows with horizontal or vertical fracture orientations aligned with a Cartesian fine grid. The approach in Efendiev et al. (2015) does not allow handling arbitrary fracture distributions. In this paper, we (1) consider arbitrary fracture distributions on an unstructured grid; (2) develop GMsFEM for nonlinear flows; and (3) develop online basis function strategies to adaptively improve the convergence. The number of multiscale basis functions in each coarse region represents the degrees of freedom needed to achieve a certain error threshold. Our approach is adaptive in a sense that the multiscale basis functions can be added in the regions of interest. Numerical results for two-dimensional problem are presented to demonstrate the efficiency of proposed approach.  相似文献   

10.
This study provides new insights into the relationship between radiation-dose-dependent structural damage due to natural U and Th impurities and the anisotropic mechanical properties (Poisson’s ratio, elastic modulus and hardness) of zircon. Natural zircon samples from Sri Lanka (see Muarakami et al. in Am Mineral 76:1510–1532, 1991) and synthetic samples, covering a dose range of zero up to 6.8 × 1018 α-decays/g, have been studied by nanoindentation. Measurements along the [100] crystallographic direction and calculations, based on elastic stiffness constants determined by Özkan (J Appl Phys 47:4772–4779, 1976), revealed a general radiation-induced decrease in stiffness (~54 %) and hardness (~48 %) and an increase in the Poisson’s ratio (~54 %) with increasing dose. Additional indentations on selected samples along the [001] allowed one to follow the amorphization process to the point that the mechanical properties are isotropic. This work shows that the radiation-dose-dependent changes of the mechanical properties of zircon can be directly correlated with the amorphous fraction as determined by previous investigations with local and global probes (Ríos et al. in J Phys Condens Matter 12:2401–2412, 2000a; Farnan and Salje in J Appl Phys 89:2084–2090, 2001; Zhang and Salje in J Phys Condens Matter 13:3057–3071, 2001). The excellent agreement, revealed by the different methods, indicates a large influence of structural and even local phenomena on the macroscopic mechanical properties. Therefore, this study indicates the importance of acquiring better knowledge about the mechanical long-term stability of radiation-damaged materials.  相似文献   

11.
Copper is a moderately incompatible chalcophile element. Its behavior is strongly controlled by sulfides. The speciation of sulfur is controlled by oxygen fugacity. Therefore, porphyry Cu deposits are usually oxidized (with oxygen fugacities > ΔFMQ +2) (Mungall 2002; Sun et al. 2015). The problem is that while most of the magmas at convergent margins are highly oxidized, porphyry Cu deposits are very rare, suggesting that high oxygen fugacity alone is not sufficient. Partial melting of mantle peridotite even at very high oxygen fugacities forms arc magmas with initial Cu contents too low to form porphyry Cu deposits directly (Lee et al. 2012; Wilkinson 2013). Here we show that partial melting of subducted young oceanic slabs at high oxygen fugacity (>ΔFMQ +2) may form magmas with initial Cu contents up to >500 ppm, favorable for porphyry mineralization. Pre-enrichment of Cu through sulfide saturation and accumulation is not necessarily beneficial to porphyry Cu mineralization. In contrast, re-melting of porphyritic hydrothermal sulfide associated with iron oxides may have major contributions to porphyry deposits. Thick overriding continental crust reduces the “leakage” of hydrothermal fluids, thereby promoting porphyry mineralization. Nevertheless, it is also more difficult for ore forming fluids to penetrate the thick continental crust to reach the depths of 2–4 km where porphyry deposits form.  相似文献   

12.
The groundwater vulnerability indices are valuable tools for the development of agrochemicals management strategies based on environmental/agricultural policies. The groundwater vulnerability methods of LOS, SINTACS, DRASTIC, Pesticide DRASTIC, GOD and AVI were applied for the agricultural fields of Sarigkiol basin (Northern Greece). The results of the aforementioned methods were examined and discussed in order to show how the dissimilarities in the vulnerability assessment approaches may become an advantage. The results of the methods were used to propose a combined conceptual approach which adds another two dimensions (depth and time) in the current two-dimensional vulnerability mapping (longitude, latitude) procedures. The LOS method provided information about the intrinsic vulnerability of the topsoil (30 cm) to water (+conservative pollutants) and nitrogen losses, and the AVI method described the vulnerability of the unsaturated zone to allow pollutants to reach the aquifer while the aquifer vulnerability was analysed using SINTACS, DRASTIC, Pesticide DRASTIC and GOD. In this study, the results of the SINTACS method were found more accurate to describe the local aquifer conditions. The final conceptual approach provided a stratified vulnerability (dimension of depth) of the overall hydrogeologic system using LOS for the topsoil, AVI for unsaturated zone and SINTACS for the aquifer. The dimension of time was introduced by the LOS and AVI methods, which provide quantitative results in time. The use of LOS method also highlighted the basic limitation of the other methods to describe the potential contribution to pollution of areas (especially upland areas) which are out of the aquifer boundaries.  相似文献   

13.
A new taxon, ?Crassodontidanus gen. nov. of Hexanchiformes (cow sharks) from the Jurassic of Germany is described. It is characterized by peculiar teeth combining apomorphic (serrated mesial cutting edge of the main cusp) and plesiomorphic features (deep root with convex mesial and distal margins in labial and lingual views; protruding lingual root bulge). This character combination readily distinguishes members of the new taxon from all other known extant (Heptranchias, Hexanchus, Notorynchus) and extinct (?Gladioserratus, ?Notidanodon, ?Notidanoides, ?Pachyhexanchus, ?Paraheptranchias, ?Weltonia) hexanchiforms. Currently, two species, ?C. serratus (type species; Late Jurassic, Late Kimmeridgian of Nusplingen, South Germany) and ?C. wiedenrothi (Early Jurassic, Early Pliensbachian of Gretenberg (Hanover), North Germany) are assigned to this taxon. ?Crassodontidanus gen. nov. is member of ?Crassonotidae fam. nov. and sister to ?Notidanoides Maisey, 1986 and ?Pachyhexanchus Cappetta, 1990. We consider ?Notidanus amalthei Oppel, 1854 from the Pliensbachian of South Germany, ?Notidanus insignis Seguenza, 1887 from the Oxfordian of Sicily (Italy) and ?Notidanus wagneri Agassiz, 1843 from the Early Tithonian of Solnhofen (South Germany) nomina dubia and nomina nuda, respectively. The family ?Crassonotidae comprises plesiomorphic hexanchiforms ranging from the Sinemurian (Early Jurassic) to the Hauterivian (Early Cretaceous).  相似文献   

14.
This paper presents a simulation of three components of near-field ground shaking recorded during the main shock at three stations of the September 16, 1978, Tabas (M w = 7.4), Iran, earthquake, close to the causative fault. A hybrid method composed of a discrete wavenumber method developed by Bouchon (Bouchon in Bull Seismol Soc Am 71:959–971, 1981; Cotton and Coutant in Geophys J Int 128:676–688, 1997) and a stochastic finite-fault modeling based on a dynamic corner frequency proposed by Motazedian and Atkinson (Bull Seismol Soc Am 95:995–1010, 2005), modified by Assatourians and Atkinson (Bull Seismol Soc Am 97:935–1949, 2007), is used for generating the seismograms at low (0.1–1.0 Hz) and high frequencies (1.0–20.0 Hz), respectively. The results are validated by comparing the simulated peak acceleration, peak velocity, peak displacement, Arias intensity, the integral of velocity squared, Fourier spectrum and acceleration response spectrum on a frequency-by-frequency basis, the shape of the normalized integrals of acceleration and velocity squared, and the cross-correlation with the observed time-series data. Each characteristic is compared on a scale from 0 to 10, with 10 being perfect agreement. Also, the results are validated by comparing the simulated ground motions with the modified Mercalli intensity observations reported by reconnaissance teams and showed reasonable agreement. The results of the present study imply that the damage distribution pattern of the 1978 Tabas earthquake can be explained by the source directivity effect.  相似文献   

15.
In mountainous areas, channelized rock avalanches swarm downslope leading to large impact forces on building structures in residential areas. Arrays of rock avalanche baffles are usually installed in front of rigid barriers to attenuate the flow energy of rock avalanches. However, previous studies have not sufficiently addressed the mechanisms of interaction between the rock avalanches and baffles. In addition, empirical design approaches such as debris flow (Tang et al., Quat Int 250:63–73, 2012), rockfall (Spang and Rautenstrauch, 1237–1243, 1988), snow avalanches (Favier et al., 14:3–15, 2012), and rock avalanches (Manzella and Labiouse, Landslides 10:23–36, 2013), which are applied in natural geo-disasters mitigation cannot met construction requirements. This study presents details of numerical modeling using the discrete element method (DEM) to investigate the effect of the configuration of baffles (number and spacing of baffle columns and rows) on the impact force that rock avalanches exert on baffles. The numerical modeling is firstly conducted to provide insights into the flow interaction between rock avalanches and an array of baffles. Then, a modeling analysis is made to investigate the change pattern of the impact force with respect to baffle configurations. The results demonstrate that three crucial influencing factors (baffle row numbers, baffle column spacing, and baffle row spacing) have close relationship with energy dissipation of baffles. Interestingly, it is found that capacity of energy dissipation of baffles increases with increasing baffle row numbers and baffle row spacing, while it decreases with increasing baffle column spacing. The results obtained from this study are useful for facilitating design of baffles against rock avalanches.  相似文献   

16.
Wang et al. (Contrib Mineral Petrol 171:62, 2016a) present data on composition of xenolith from Southern Tibet and conclude that ulrapotassic melts from the region formed by melting mantle, and complex interaction with a crustal component. In this discussion we demonstrate that numerous observations presented by Wang et al. (2016a) can be explained by partial melting of crust followed by interaction between that melt and the mantle. We show that this model can explain the variability of magmas in such suits without evoking occurrence of coincidental, unrelated events. Moreover we demonstrate that our model of a crustal origin of the proto-shoshonite melts is now supported by independent lines of evidence such as geochemistry of restites after high- and ultrahigh- pressure melting and melt inclusion studies.  相似文献   

17.
Scientists are deeply concerned by the state of vulnerability of groundwater reservoirs. It is a complex task because of the difficulties in determining the degree of pollution of the groundwater. Many methods have been adopted like (DRASTIC, GOD, SI, SINTACS…). Another method (Kherici et al. in Geogr Tech 1–14, 2010) is added to identify the vulnerability of groundwater reservoirs and control the evolution of pollutants. The present article targets the determination of the vulnerability and risks of pollution of groundwater reservoirs of a climatic Mediterranean region (Annaba–Bouteldja region). The device used is based on the combination of two criteria: natural factors (thickness of the unsaturated zone, geological facies and degree of self-purification) and the causes of vulnerability and the pollution risks entropic factors (caused by man). The application of Kherici’s method has revealed a distinction between the different degrees of pollution and has allowed a neat classification of the different reservoirs in the study. The results lead to a vulnerability map and the risks of pollution of Annaba–Bouteldja different aquifers. It has also led to the installation of protection areas; sustained by an efficient general evacuation plan of the sewerage net and the construction of treatment station of the sewage effluents in the urbanized areas.  相似文献   

18.
Extensive laboratory model tests have been carried out on a strip footing resting over dry sand bed subjected to eccentrically inclined load to determine the ultimate bearing capacity (Patra et al. in Int J Geotech Eng 6(3):343–352, 2012a.  https://doi.org/10.3328/IJGE.2012.06.03.343-352, Int J Geotech Eng 6(4):507–514, b.  https://doi.org/10.3328/IJGE.2012.06.04.507-514). Similarly, lower bound calculations based on finite element method were performed to compute the bearing capacity of a strip footing subjected to an eccentric and inclined load lying over a cohesionless soil with varying embedment depth and relative density (Krabbenhoft et al. in Int J Geomech ASCE, 2014.  https://doi.org/10.1061/(ASCE)GM.1943-5622.0000332). The load may be applied in two ways namely, towards the center line and away from the center line of the footing. Based on the results (both experimental and numerical analyses), a neural network model is developed to predict the reduction factor that will be used in computing the ultimate bearing capacity of an eccentrically inclined loaded strip footing. This reduction factor (RF) is the ratio of the ultimate bearing capacity of the footing subjected to an eccentrically inclined load to the ultimate bearing capacity of the footing subjected to a centric vertical load. A thorough sensitivity analysis is carried out to evaluate the parameters affecting the reduction factor. Based on the weights of the developed neural network model, a neural interpretation diagram is developed to find out whether the input parameters have direct or inverse effect on the output. A prediction model equation is framed with the trained weights of the neural network as the model parameters. The predictions from ANN, and those from other approaches, are compared with the results computed from both experimentation and FEM analyses. The ANN model results are found to be more accurate and well matched with other results.  相似文献   

19.
The garnet–orthopyroxene pairs are commonly found in the assemblages of basic granulites/charnockite and hence are suitable for estimating equilibrium temperature of these metamorphic rocks. At present, there are many calibrations of garnet–orthopyroxene thermometer that may confuse geologists in choosing a reliable thermometer. To test the accuracy of the garnet–orthopyroxene thermometers, we have applied 14 models formulated by a number of workers since 1980 to date. We have collated 51 samples from the literature all over the world, which has been processed through the “Gt-Opx.EXE” software. Based on the present study, we have identified a set of the best among all the 14 models which were considered under this comparative study. We have concluded that the five garnet–orthopyroxene (Gt-Opx) thermometers are the most valid and reliable of this kind of thermometer: Aranovich and Berman (Am Mineral 82:345–353, 1997), Raith et al. (Earth Sci 73:211–244, 1983), Harley (Contrib Mineral Petrol 86:359–373, 1984), Nimis and Grütter (Contrib Mineral Petrol 159:411–427, 2010), and Sen and Bhattacharya (Contrib Mineral Petrol 88:64–71, 1984).  相似文献   

20.
Frolova  N. I.  Larionov  V. I.  Bonnin  J.  Sushchev  S. P.  Ugarov  A. N.  Kozlov  M. A. 《Natural Hazards》2016,80(1):43-67
In 2012, the damage costs of floods in Russia amounted to about €300m, and these floods have caused nearly 200 fatalities (Kotlyakov et al. in Reg Res Rus 3(1):32–39, 2013). Risk assessment is one of the most pressing scientific topics in Russia, but most of the works are devoted to natural hazards assessment. The purpose of this work is to estimate the influence of hazardous hydrological phenomena on society. The field research was conducted in the Slavyansk municipal district in the Krasnodar region (the south-western part of Russia), which is a highly populated coastal territory with a high frequency of hazardous hydrological events. Modified methods of the Ministry of the Russian Federation for Affairs for Civil Defence, Emergencies and Elimination of Consequences of Natural Disasters (EMERCOM) were used for potential economic damage calculation. The paper did not only focus on direct, tangible risks, but also included social risk (i.e. risk to life and health). Social vulnerability has been calculated directly as a percentage of vulnerable people, estimated in opinion polls, while in many recent papers the social vulnerability index was calculated as a combination of several statistical indicators. The resulting percentage of vulnerable people was converted to numbers of potential victims. Finally, the social risk was expressed by financial indicators in terms of the cost of the value of statistical life lost (Mrozek and Taylor in J Policy Anal Manag 21(2):253–270, 2002; Viscusi and Aldy in J Risk Uncertain 27(1):5–76, 2003). Social risk can be underestimated in comparison with economic risk because of a low “value of life” in Russia (no life insurance, neglecting of basic safety rules, etc.) (Guriev in Myths of economics, Alpina Business Books, Moscow, 2009).  相似文献   

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