Analysis of the susceptibility of interdependent infrastructures using fuzzy input–output inoperability model: the case of flood hazards in Tehran

Natural Hazards - Advancement in technology has contributed to increment in complexity of systems and infrastructures. Furthermore, it has complicated the management of systems to deal with natural...     

Geochemistry of mafic dykes from the Southeast Anatolian ophiolites,Turkey: Implications for an intra-oceanic arc–basin system

The Late Cretaceous–Tertiary accretionary prism in Eastern Turkey includes several ophiolitic megablocks and/or tectonic slivers (Mehmetalan, Mollatopuz and Alabayir) within a mélange complex, mainly comprising harzburgite, dunite and cumulate-textured gabbro. The diabases, which are the main focus of this study, cut across the ophiolites as parallel and variably thick dyke-swarms. Geochemistry of the diabases reveals three distinct groups, including a) supra-subduction zone (SSZ) type, which is characterized by marked Nb-anomaly and normal mid-ocean ridge basalt (N-MORB) like HFSE distribution, b) enriched MORB (E-MORB) type, showing some degree of enrichment relative to N-MORB, c) oceanic-island basalt (OIB) type with characteristic hump-backed trace element patterns, coupled with fractionated REE distribution. Among these groups, SSZ- and E-MORB-type signatures are acquired from the Mehmetalan and Mollatopuz suites, whereas OIB-type characteristics are found in the Alabayir suite. The melting models indicate involvement of both depleted and enriched sources for the genesis of the studied dykes. The close spatial relationship, similar ages (based on Ar–Ar dating) and the presence of variable subduction component displayed by Mehmetalan and Mollatopuz suites may indicate melt generation in an intra-oceanic SSZ within the southern branch of Neotethys. In spite of the solely OIB-like character of the Alabayir suite, the similar age obtained from these dykes may suggest their formation in a similar SSZ setting. Alternatively, the Alabayir suite may have represented an oceanic island or seamount formed in an intra-plate setting with or without plume influence. We suggest that decompression melting triggered by slab roll-back mechanism during the closure of the southern branch of the Neotethys during the Late Cretaceous may have been the main process that led to generation of magmas of both depleted and enriched characteristics.     

Risk assessment of flood disaster in Shanghai based on spatial–temporal characteristics analysis from 251 to 2000

As one of the top 20 cities exposed to flood disasters, Shanghai is particularly vulnerable because it is exposed to powerful floods and poorly prepared. However, it is unclear to understand the evolution process of floods and the variation of flood risk in Shanghai during the past 1,000 years. This paper analyzed the spatial–temporal characteristics of flood disaster and evaluated the integrated risk of flood disaster in Shanghai based on the historical flood data from 251 to 2000. The results show that flood disaster in Shanghai was divided into storm surge-induced flood, rainstorm-induced flood and overbank flood. Flood disaster in Shanghai presents rising trend with time and mainly occurs in summer and autumn. Moreover, the flood disaster is dominated by rainstorm-induced flood, especially after the establishment of the People’s Republic of China in 1949. Additionally, flood risk in different areas of Shanghai between the years 251–1949 and 1950–2000 changed significantly. Shanghai urban area, Jinshan District and Chongming County belong to increased flood risk area; Baoshan, Jiading, Qingpu, Songjiang, Fengxian, Pudong and Minhang District belong to decreased flood risk area. The integrated risk of flood disaster in Shanghai has presented spatial disparities evidently at present. Shanghai urban area is most likely to suffer flood disaster; Baoshan, Jiading and Minhang District have medium flood risk rank; and Jinshan, Songjiang, Fengxian, Pudong, Qingpu and Chongming County show low flood risk at present. The combined effect of urbanization, sea-level rise, land subsidence and the poor capacity of flood prevention facilities will give rise to the risk of flood in the next several decades. These results provide very important information for the local government to improve flood risk management.     

Interpretation of grouting characteristics in unsaturated sand from the perspective of water–air interface

The design of grouting engineering in practice is either based on conventional soil mechanics or empirical procedures ignoring the effect of degree of saturation (water content). In this study, a series of laboratory-pressurized grouting tests were conducted on unsaturated sand to reveal the influence of soil water content on the grouting characteristics. With combination of direct shear tests at constant water content, water retention tests as well as microscopy observations, the mechanisms that controlling the strength and in turn the grouting characteristics in unsaturated sand were interpreted from the perspective of water–air interface. It was found that the non-monotonic phenomena of grouting characteristics (injectability and diffusion characteristics) with increasing water content were strongly dependent on the shear strength, which is influenced by the apparent cohesion induced by capillary mechanisms relating to the water–air interface. The threshold value of the injectability and diffusion pattern is corresponding to the boundary of the two transition zones (two different desaturation mechanisms) in the water retention curve. In the primary transition zone, the water phase is interconnected with air bulbs entrapped. With the drainage of bulk water in the large pores, the amount of water menisci increases, generating larger and larger surface tension force between particles. Therefore, less and less grout was injected as the bearing capacity and shear strength increase. However, in the second transition zone, with the drainage of menisci water, the menisci area of each pores decreases, inducing less and less surface tension force. Thus, more and more grout was injected as the bearing capacity and shear strength decrease. It is hoped that the work in this study will facilitate researching the grouting mechanisms in unsaturated soil, thus optimizing the grouting parameters in engineering practice.

     

Analysis of historical drought and flood characteristics of Hengshui during the period 1649–2018: a typical city in North China

Natural Hazards - The objective of this study was to reconstruct the long-term drought and flood time series to analyze their changing characteristics in Hengshui City of North China. Disaster...     

On the value of dolines in gypsum terrains as a “Geological Heritage”: an example from Sivas basin, Turkey

Karst topography is a landscape shaped by the dissolution of a layer or layers of soluble bedrock, usually limestone and evaporites. Karstification in the Sivas basin (Turkey) has sculpted a beautiful landscape with a distinctive beauty and appeal for both local inhabitants and visitors. Dolines are very special geological landscape features found in karst regions, and the Sivas basin has several giant dolines amongst its thousands of smaller dolines. The basin constitutes a distinctive karst architecture with a system of collapse and/or dolines and caves. Anyone who walks along the shores of a lake resulting from the collapse, in this gypsum terrain, will be amazed with the lake and rocks that surround them. In this paper, dolines in the gypsum terrain are evaluated and discussed according to their value as a “Geological Heritage”. Three main characteristics of dolines, namely their scientific, aesthetic and ecosystem importance are considered and discussed. Dolines and karstified areas as representative examples of landform types possess the three attributes for them to be considered as a Geological Heritage in that they demonstrate the effect of erosion on the landform, geomorphic processes that are still active and a range of features characteristic of the rock unit involved.     

Petrogenesis of the Neogene volcanic units in the NE–SW-trending basins in western Anatolia,Turkey

The western Anatolian volcanic province formed during Eocene to Recent times is one of the major volcanic belts in the Aegean–western Anatolian region. We present new chemical (whole-rock major and trace elements, and Sr, Nd, Pb and O isotopes) and new Ar/Ar age data from the Miocene volcanic rocks in the NE–SW-trending Neogene basins that formed on the northern part of the Menderes Massif during its exhumation as a core complex. The early-middle Miocene volcanic rocks are classified as high-K calc-alkaline (HKVR), shoshonitic (SHVR) and ultrapotassic (UKVR), with the Late Miocene basalts being transitional between the early-middle Miocene volcanics and the Na-alkaline Quaternary Kula volcanics (QKV). The early-middle Miocene volcanic rocks are strongly enriched in large ion lithophile elements (LILE), have high ⁸⁷Sr/⁸⁶Sr_(i) (0.70631–0.71001), low ¹⁴³Nd/¹⁴⁴Nd_(i) (0.512145–0.512488) and high Pb isotope ratios (²⁰⁶Pb/²⁰⁴Pb = 18.838–19.148; ²⁰⁷Pb/²⁰⁴Pb = 15.672–15.725; ²⁰⁸Pb/²⁰⁴Pb = 38.904–39.172). The high field strength element (HFSE) ratios of the most primitive early-middle Miocene volcanic rocks indicate that they were derived from a mantle source with a primitive mantle (PM)-like composition. The HFSE ratios of the late Miocene basalts and QKV, on the other hand, indicate an OIB-like mantle origin—a hypothesis that is supported by their trace element patterns and isotopic compositions. The HFSE ratios of the early-middle Miocene volcanic rocks also indicate that their mantle source was distinct from those of the Eocene volcanic rocks located further north, and of the other volcanic provinces in the region. The mantle source of the SHVR and UKVR was influenced by (1) trace element and isotopic enrichment by subduction-related metasomatic events and (2) trace element enrichment by “multi-stage melting and melt percolation” processes in the lithospheric mantle. The contemporaneous SHVR and UKVR show little effect of upper crustal contamination. Trace element ratios of the HKVR indicate that they were derived mainly from lower continental crustal melts which then mixed with mantle-derived lavas (~20–40%). The HKVR then underwent differentiation from andesites to rhyolites via nearly pure fractional crystallization processes in the upper crust, such that have undergone a two-stage petrogenetic evolution.     

Assessing the vulnerability of social–environmental system from the perspective of hazard,sensitivity, and resilience: a case study of Beijing,China

Despite a recent increase in the number of vulnerability analyses there has been relatively little discussion of vulnerability assessment of social–environment system, especially when they face multiple hazards. In this study, we developed an applicable and convenient method to assess vulnerability of social–environment system at a regional scale. Vulnerability is quantified by measuring three critical elements (i.e. hazards, sensitivity, and resilience) through some key variables. The results showed that vulnerability is high in Miaofeng Mountain in Mengtougou District, the hills of Pinggu County and the riparian zones of the lower courses of the Beiyun and Yongding Rivers; but low in the city of Beijing and the southwestern part of the Fangshan District. Areas of very high, high, medium, and low-vulnerability account for 6.19, 25.48, 33.06, and 35.27% of the total area, respectively. The degree of vulnerability decreases in a northwest direction in mountainous areas and declines from watercourses to riparian zones along a lateral direction in the plain. Some adaptive strategies are also proposed.     

Satellite-based assessment of large-scale land cover change in Asian arid regions in the period of 2001–2009

Arid regions in Asia are commonly characterized by rapidly growing populations with limited land resources and varying rainfall frequencies under climatic change. Despite being one of the most important environmental challenges in Asia, the changing aridity in this region, particularly due to large-scale land cover change, has not been well documented. In this study, we used rainfall data and a new land heterogeneity index to identify recent trend in land cover changes in the Asian arid regions. The result indicates a significant decreasing trend of barren lands and an increasing trend of vegetated lands. Although the potential land cover change is commonly believed to be strongly sensitive to rainfall change, such sensitivity has not been observed during the nine-year period (2001–2009) analyzed. Through the analyses of two separate periods (2001–2005 and 2005–2009), the sensitivity of rainfall to land cover change in arid regions is found to be dependent on the initial spatial heterogeneity of vegetated land cover. The approach used and the findings in this study represent an important step toward better understanding of large-scale land cover change in the Asian arid regions, and have the potential to predict future land cover change under various climate change scenarios.     

Environmental impact assessment of structural flood mitigation measures: a case study in Šiba,Slovakia

The proposed flood mitigation measures in the Slovak Republic are subject of environmental impact assessment (EIA) process before its approval. The paper elaborates and demonstrates the application of the risk analysis method for evaluating alternatives, which is core in EIA. Risk analysis is an appropriate tool to determine the level of the risk of the proposed flood mitigation measures and through which it is possible to choose the alternative with the lowest level of risk for the environment. The article presents the application of the developed methodology based on universal matrix of risk analysis in ?iba village that is in existing flood risk. It analyses and discusses the results of the impact assessment from EIA practice in the Slovakia. The aim of the work is to improve existing qualitative and quantitative methods for assessing the impacts of proposed activities on the environment. Developed methodology stimulates creative approaches in searching of the best alternative to proposed activities (constructions) that are environmentally friendly. Innovation in this paper is presented by an implementation of universal matrix of risk analysis for flood mitigation measures (developed by the authors) for the purposes of EIA process.     

Pervasive rehydration of granulites during exhumation – an example from the Pulur complex, Eastern Pontides, Turkey

Summary High-grade gneisses from the Pulur complex in NE Turkey bear evidence for biotite-dehydration melting at 820°C and 0.7–0.8GPa, melt segregation and near-isothermal decompression to 0.4–0.5GPa. During further exhumation, the rocks underwent secondary pervasive rehydration at temperatures between 400 and 230°C and fluid pressures between 0.3 and 0.1GPa. Metamorphic peak conditions are dated at 331–327Ma, while hydrothermal retrogression occurred significantly later at 315–310Ma under static conditions. During the rehydration event, primary high-grade mineral assemblages including garnet, cordierite, sillimanite, spinel, biotite, plagioclase and ilmenite were extensively replaced by muscovite, paragonite, margarite, corundum, diaspore, chlorite, kaolinite, pumpellyite, prehnite, epidote, titanite, anatase, pyrite and chalcopyrite. Secondary mineral assemblages indicate that the infiltrating fluids were characterized by low fO₂, very low X_CO2 (<0.002), variable activities of Ca²⁺, K⁺, Na⁺ and H⁺ and relatively high activities of H₂S and CH₄. Quartz veins that might have acted as pathways for the fluids are rare. Ubiquitous veinlets consisting of (i) albite, (ii) chlorite+calcite+quartz or (iii) K-feldspar+calcite+quartz were formed after the pervasive rehydraton event by precipitation from aqueous solutions that were somewhat richer in CO₂.     

Inferred phase relations in part of the system Au–Ag–Te: an integrated analytical study of gold ore from the Golden Mile, Kalgoorlie, Australia

Summary Integrated X-ray powder diffraction, scanning electron microscopy, electron probe, and transmission electron microscopy studies have identified the rare contact assemblage calaverite–sylvanite–hessite in a sample of gold ore from the Golden Mile deposit, Kalgoorlie, Australia. The presence of coexisting calaverite–hessite at Kalgoorlie is a non-equilibrium assemblage whereby the stable hessite-bearing assemblage is hessite–sylvanite, which formed from the breakdown of the -phase or -phase below 120°C, stützite+-phase, or sylvanite+stützite+-phase, as predicted by Cabri (1965).     

The relevance of flood hazards and impacts in Turkey: What can be learned from different disaster loss databases?

Turkey has been severely affected by many natural hazards, in particular earthquakes and floods. Especially over the last two decades, these natural hazards have caused enormous human and economic damage. Although there is a large body of literature on earthquake hazards and risks in Turkey, comparatively little is known about flood hazards and risks. Therefore, this study aims to investigate the severity of flooding in comparison with other natural hazards in Turkey and to analyse the flood patterns by providing an overview of the temporal and spatial distribution of flood losses. These will act as a metric for the societal and economic impacts of flood hazards in Turkey. For this purpose, Turkey Disaster Database (TABB) was used for the years 1960–2014. As input for more detailed event analyses, the most severe flood events in Turkey for the same time interval will also be retrieved. Sufficiency of the TABB database to achieve the main aim of the study in terms of data quality and accuracy was also discussed. The TABB database was analysed and reviewed through comparison, mainly with the Emergency Events Database (EM-DAT), the Global Active Archive of Large Flood Events—Dartmouth Flood Observatory database, news archives and the scientific literature, with a focus on listing the most severe flood event. The comparative review of these data sources reveals big mismatches in the flood data, i.e. the reported number of events, number of affected people and economic loss all differ dramatically. Owing to the fact that the TABB is the only disaster loss database for Turkey, it is important to explore the reasons for the mismatches between TABB and the other sources with regard to aspects of accuracy and data quality. Therefore, biases and fallacies in the TABB loss data are also discussed. The comparative TABB database analyses show that large mismatches between global and national databases can occur. Current global and national databases for monitoring losses from national hazards suffer from a number of limitations, which in turn could lead to misinterpretations of the loss data. Since loss data collection is gaining more and more attention, e.g. in the Sendai Framework for Disaster Risk Reduction 2015–2030, this study offers a framework for developing guidelines for the Turkey Disaster Database (TABB), implications on how to standardize national loss databases and implement across the other hazard events in Turkey.     

An assessment of the carrying capacity of groundwater resources in North China Plain region–Analysis of potential for development

Over-exploitation of groundwater in North China Plain (NCP) has resulted in a series of eco-environment problems. Sustainable use of groundwater resources in NCP, in particular management of groundwater resource carrying capacity (GRCC), faces an unprecedented challenge. Here we define GRCC, and a new assessment method is tentatively proposed and applied to evaluate GRCC based on the whole NCP, city administrative units and county administrative units. Our study divided the NCP into three zones, i.e. non-overexploited non-overloaded zone (NNZ), overexploited but non-overloaded zone (ONZ), and overexploited overloaded zone (OOZ). Results confirmed 27.6% of counties belonged to NNZ. However, 58.9% of counties and NCP as a whole belonged to ONZ, and 13.5% of counties belonged to OOZ. Spatially, NNZs were mainly distributed in Beijing, parts of eastern coastal cities and Henan Province. OOZs were mostly distributed in middle-eastern part of Cangzhou, parts of Dezhou, Tianjin and Binzhou, and the remaining areas belonged to ONZs. We suggest two approaches for enhancing GRCC, i) increasing the amount of available groundwater and ii) improving the water use efficiency. An increase of 11.0 billion cubic meters to the available groundwater levels combined with water use efficiency improvements up to 479 CNY per cubic meter of the world mean, the gross domestic product (GDP) sustained by groundwater in the NCP could reach 11.1 trillion CNY and maintain a 20 years of GDP development assuming the current rate of growth.     

September, 2012 landslide events in Okhimath, India—an assessment of landslide consequences using very high resolution satellite data

The Okhimath area in the Uttarakhand state of India witnessed a large-scale occurrence of landslides on 14 September 2012 due to intense rainfall. As per news reports, this event resulted in the death of 51 people and a significant loss of property. In this study, the damage assessment results of the Okhimath landslides derived from the analysis of very high resolution (VHR) images received from Cartosat-2, Resourcesat-2, Kompsat-2 and GeoEye-1 satellites are presented. These datasets were acquired through a coordinated effort of the Indian Space Research Organisation and International Charter Space and Major Disasters. A total of 126 buildings, 34.5 ha of agricultural land and 7.78 km of road were identified as damaged through the VHR satellite data analysis. Using a semi-automatic landslide detection technique, 473 landslides covering a 2.25-km² area were also identified. Villages such as Mangali, Chunni, Brahman Kholi, Semla, Paldwadi, Saari and Giriyagaon are found to be most affected due to this event. The damage is mainly attributed to rock slides which originated in the escarpment zone which later converted to debris flows by scouring the material along the run-out zone.     

Provenance of the Early–Middle Devonian Shugouzi Formation in the Quruqtagh, Northeastern Xinjiang: Constraints from Sandstone Geochemistry and Heavy Mineral Analysis

The Early-Middle Devonian Shugouzi Formation in the Quruqtagh block consists mainly of clastic rocks.However,their provenance has been scarcely studied since it was named.Geochemistry of clastic rocks was commonly used to interpret the provenance.Detrital heavy mineral analyses help frame the U-Pb age from zircon grains,integrated with geochemical data from detrital tourmaline and spinels.These techniques were used to characterize components of the sediment flux and define erosion areas in the Qurugtagh block,further providing evidence about the tectonic evolution of the South Tianshan and Tarim plate.The maximum depositional age constrained by detrital zircon dating was Early-Middle Devonian.Multiple diagrams for sedimentary provenance using major and trace elements indicate that continental island arc-related felsic rocks were the major source rocks for the Shugouzi Formation.Detrital tourmalines are dravite and schorl.The results of detrital tourmaline electron probe microanalysis(EPMA)show that the source rocks are mainly metasedimentary rocks and granitoids.The detrital chromian spinels within the sediments are characterized by high chroumium(Cr^#)and varying magnesium(Mg^#).The discrimination plots reveal that these spinels were sourced from island arc magmatic rocks.The laser ablation inductively-coupled plasma mass spectrometry(LA-ICP-MS)U-Pb chronology of detrital zircons suggests that the sediments were derived mainly from 414-491 Ma and 744-996 Ma magmatic rocks.Paleocurrent restoration,sandstone geochemistry,EPMA,and detrital zircon geochronology indicate that the source rocks were predominantly derived from Late Ordovician and Devonian magmatic rocks and subordinately from recycled Neoproterozoic magmatic rocks.Comprehensive analyses of the source areas suggest that a remnant arc still existed in the Early Devonian and the Shugouzi Formation was deposited in a passive continental margin.     

Public health in the regions of Russia at the beginning of the twenty-first century: Medical–geographical assessment

Doklady Earth Sciences - The level of public health in the regions of Russia in the years 2002–2012 is characterized based on the indices of life expectancy of men and women, as well as...