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1.
 Sinkhole development along the western shore of the Dead Sea became a major concern in 1990 with the appearance of a series of holes 2–15 m diameter and up to 7 m deep in the Newe Zohar area. One of these sinkholes, below the asphalt surface of the main road along the western shore of the Dead Sea, was opened by a passing bus. Repeated infilling and collapse of these holes indicated the extent of this ongoing process and the significance of this developing hazard. Since then sinkholes have developed in other areas including Qalia, Ein Samar, Ein Gedi and Mineral Beach. Three main types of sinkholes have been recognized. Gravel holes occurring in alluvial fans, mud holes occurring in the intervening bays of clay deposits between fans and a combination of both types at the front of young alluvial fans where they overlap mud flats. Fossil, relict sinkholes have been observed in the channels of some old alluvial fans. Sinkhole development is directly related to the regression of the Dead Sea and the corresponding lowering of the regional water table. Continuation of this process widens the neritic zone enveloping the sea and increases the sinkhole hazard of the region. Received: 4 February 1999 · Accepted: 8 April 1999  相似文献   

2.
Abdo  Hazem Ghassan 《Natural Hazards》2020,104(1):681-703

Floods are one of the most severe hydrological hazards that cause an excessive threat to landscape stability, population welfare, infrastructure and spatial development in the Syrian coastal region. Al-Hussain river basin, like other Syrian coastal basins, is prone to a hazardous, frequent-flooding threat. However, investigating the probable areas of flooding risk is a difficult challenge that results from the almost complete absence of spatially distributed geo-hydrological measurements in Al-Hussain river basin. In this regard, geohydromorphometric parameters (Stream number Nu, Stream length Lu, Bifurcation ratio Rb, Form factor F, Elongation ratio Eb, Drainage density Dd, Stream frequency Fs, Drainage texture Td, Lemniscate ratio K, Compactness index C, Circulatory ratio Rc, Ruggedness number Rn, Basin relief Hr, and Relief ratio Rr) derived from remote sensing data in the GIS environment can provide a comprehensive and objective approach that can be utilized to map the spatial distribution of flood hazards at the level of delineated sub-basins. This being the case, the present research focuses on exploring the spatial distribution of flood risk in ten sub-basins belonging to Al-Hussain river basin by using spatial techniques tools in order to overall determine the hydro-prioritization of conservation. The geo-visualization map of generated flash flood susceptibility evaluates five degrees of the flood risk: very low, low, moderate, high, and very high. The flood risk map indicates that Qalea, and Talaa sub-basins have massive hydrodynamic risk, which, in turn, indicates the urgent need of soil and water maintaining measures. This hydrological dynamic in these sub-basins is explained by high values of Dd, F, Rr, Rn, Rc, and K, respectively. Overall, the spatial outcomes of the current work successfully proved the efficiency of extracted geohydromorphometric layers from RS data in the context of the spatial assessment of flash flood hazard; they also ensure ecological sustainability and productivity of the study basin.

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3.
《《幕》》2004,27(3):199-202
The Commission for the Geological Map of the World (CGMW), an IUGS affiliated body, has just issued the first edition of the Structural Map of the Indian Ocean which was presented during the 32nd IGC (Florence). During the 1980‘s, the Commission published the Geological Atlas of the World, which included the maps of the 5 oceans of the globe. Two decades have elapsed and the knowledge of the sea-floor experienced very significant progress; therefore some 5 years ago, the Commission decided to launch a new type of ocean mapping. The Structural Map of the Indian Ocean is the first of this new series of maps.  相似文献   

4.
The study deals spatial mapping of earthquake hazard parameters like annual and 100-years mode along with their 90% probability of not being exceeded (NBE) in the Hindukush–Pamir Himalaya and adjoining regions. For this purpose, we applied a straightforward and most robust method known as Gumbel’s third asymptotic distribution of extreme values (GIII). A homogeneous and complete earthquake catalogue during the period 1900–2010 with magnitude MW ⩾ 4.0 is utilized to estimate these earthquake hazard parameters. An equal grid point mesh, of 1° longitude X 1° latitude, is chosen to produce detailed earthquake hazard maps. This performance allows analysis of the localized seismicity parameters and representation of their regional variations as contour maps. The estimated result of annual mode with 90% probability of NBE is expected to exceed the values of MW 6.0 in the Sulaiman–Kirthar ranges of Pakistan and northwestern part of the Nepal and surroundings in the examined region. The 100-years mode with 90% probability of NBE is expected to exceed the value of MW 8.0 in the Hindukush–Pamir Himalaya with Caucasus mountain belt, the Sulaiman–Kirthar ranges of Pakistan, northwestern part of the Nepal and surroundings, the Kangra–Himanchal Pradesh and Kashmir of India. The estimated high values of earthquake hazard parameters are mostly correlated with the main tectonic regimes of the examined region. The spatial variations of earthquake hazard parameters reveal that the examined region exhibits more complexity and has high crustal heterogeneity. The spatial maps provide a brief atlas of the earthquake hazard in the region.  相似文献   

5.
Discovering points of interest from users’ map annotations   总被引：4，自引：0，他引：4  
One of the potential problems of volunteered geographic information (VGI) is ensuring its quality. Innocent mistakes and intentional falsehoods can reduce not only the quality of the information, but also people’s confidence in VGI as a legitimate source of data. We present a case study in VGI that addresses the quality problem by aggregating input from many different people. Specifically, we present a technique to maintain a comprehensive list of points of interest (POI) for digital maps. This is traditionally difficult, because new POI are created, because some POI are known only locally, and because some POI have multiple names. We address this problem by exploiting map annotations contributed by regular, online map users. Our institution’s mapping Web site allows users to create arbitrary collections of geographically anchored pushpins that are annotated with text. Our data mining solution finds geometric clusters of these pushpins and examines the pushpins’ text and other features for likely POI names. For instance, if a given text phrase is mentioned frequently in a cluster, but infrequently elsewhere, this increases our confidence that this phrase names a POI. We tested the quality of our results by asking 100 local residents whether or not the POI we found were correct, and our user study told us we were generally successful. We also show how we can use the same user-annotated pushpins to assess the popularity of existing POI, which is a guide for which ones to display on a map.  相似文献   

6.
A sound, evidence-based hazard mapping requires the analysis of stochastic processes taking place at critical configurations (e.g., bridges, levees) in order to reliably determine the spatial patterns of flood intensities and probabilities. Here, we discuss an approach aiming to support an enhanced determination of flood hazard patterns by identifying within alluvial fans and river corridors two main types of spatial domains based on the predictability of their dynamics, i.e., stochastic and quasi-deterministic domains. The former represents critical configurations whose dynamic evolution (e.g., clogging by large wood, failure due to breaching) cannot be realistically specified by deterministic models, whereas the latter refers to the part of the system where the flood propagation can be computed with sufficient precision and accuracy by hydrodynamic models. The applicability of the proposed approach is discussed on the basis of a case study in the Autonomous Province of Bolzano (Italy).  相似文献   

7.
Feng  Boyu  Wang  Jinfei  Zhang  Ying  Hall  Brent  Zeng  Chuiqing 《Natural Hazards》2020,100(3):1089-1104
Natural Hazards - Urban flooding is a reoccurring disaster, and its frequency and intensity are likely to increase in the future due to the increasing frequency of storm events. Up-to-date...  相似文献   

8.
Five similar glacial-lake outburst floods (GLOFs) occurred in April, October, December 2008, March and September 2009 in the Northern Patagonia Icefield. On each occasion, Cachet 2 Lake, dammed by the Colonia Glacier, released circa 200-million m3 water into the Colonia River. Refilling has occurred rapidly, such that further outbreak floods can be expected. Pipeflow calculations of the subglacial tunnel drainage and 1D hydraulic models of the river flood give consistent results, with an estimated peak discharge surpassing 3,000 m3 s?1. These floods were larger in magnitude than any flood on record, according to gauged data since 1963. However, geomorphological analysis of the Colonia valley shows physical evidence of former catastrophic outburst floods from a larger glacial-lake, with flood discharges possibly as high as 16,000 m3 s?1. Due to potential impacts of climate change on glacier dynamics in the area, jökulhlaups may increase future flood risks for infrastructure and population. This is particularly relevant in view of the current development of hydropower projects in Chilean Patagonia.  相似文献   

9.
Multiscale interaction between monsoonal circulation and the local topography causes the southern front of the Darjeeling–Bhutan Himalaya to receive one of the highest annual rainfalls (3000–6000 mm) and most frequent heavy rains (up to 800 mm day?1) along the whole southern Himalayan margin. An examination of the patterns of annual rainfall, rainfall concentration, overland flow generation and slope instability indices in the Darjeeling–Bhutan Himalaya for 1986–2015 indicates that the mountain front disturbs rainfall gradient between the Bay of Bengal and the Tibetan Plateau. The results show that the precipitation concentration indices are lowest at the Himalayan front where the annual rainfall and the number of rainy days are highest. The Himalayan front has the highest predisposition to produce overland flow compared to adjacent foreland and the mountain interior. The average probability of the rainfall initialising the shallow landslides increases from 0.6% for a 1-day rainfall threshold of 144 mm to 6.1% for a 4-day rainfall threshold of 193 mm in the study area. The highest probability (up to 10%) of 2-day and longer low-intensity storms at the mountain front indicate that its area is threatened with particularly larger and deeper landslides. The multivariate regression analysis reveals statistically significant linear relationships of rainfall hazard indices with elevation and the distance to the mountain front in the mountain foreland and Himalaya, respectively. Regionally, the Darjeeling Himalaya reveals lower values of rainfall hazard indices, in comparison to the Bhutan Himalaya.  相似文献   

10.
A reply essay is presented on the rebuttal article by Parise (Environ Earth Sci 75(23):1476, 2016) suggesting that qanat is not a hazard. It is presented as a refutation on the paper by Abbasnejad et al. (Environ Earth Sci 75:1306, 2016) in which the authors have explained the etiology, the impacts and remedies of a qanat hazard in Iranian urban areas. Since the majority of qanats in Iranian urban areas are abandoned, useless and threatening, according to definition and in comparison with similar features introduced as a hazard, they are considered as a hazard too. However, this does not mean, and Abbasnejad et al. (in Environ Earth Sci 75:1306, 2016) have not claimed, that all qanats are hazardous. In addition, the authors who have studied qanats in Iranian urban areas, before Abbasnejad et al. (in Environ Earth Sci 75:1306, 2016), have also considered qanats as a hazard.  相似文献   

11.
This study reports the results of a national representative survey in Taiwan on the primary and secondary school teachers’ perceptions toward and knowledge of climatic hazard mitigation (CHM). Climatic Hazard Mitigation Inventory (CHMI) was developed by the researchers and content validated by a panel of experts including three university professors and two high school teachers. The CHMI instrument consisted of five subtests (80 items) and was pilot tested to a group of 28 pre-service earth science teachers in a teacher education institute in Taiwan. It was thereafter revised and employed to survey 183 randomly selected in-service primary and secondary school teachers in Taiwan. Every eligible science teacher in the target population had a known, positive probability of being drawn into the sample. The CHMI instrument was found to be an appropriate measure to examine teachers’ perceptions toward and knowledge of CHM. The results of the survey also suggested that both primary and secondary school teachers possessed a reasonable level of CHM knowledge. However, significant differences existed in teachers’ CHM knowledge between primary and secondary school teachers. Overall, teachers held positive perceptions toward CHM.  相似文献   

12.
Mishra  Minakshi  Abhishek  Yadav  R. B. S.  Sandhu  Manisha 《Natural Hazards》2021,105(1):313-338
Natural Hazards - The Andaman–Nicobar–Sumatra (ANS) region is a very hazardous area on the globe, which has witnessed a megathrust earthquake of Mw 9.2 on 26 December 2004 and several...  相似文献   

13.
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14.
High rates of urbanization, environmental degradation, and industrial development in disaster-prone areas have all served to increase the extent of damage following catastrophes. Recently, losses from environmental hazards have escalated, which has resulted in a noticeable change in policy, with more emphasis on loss reduction through mitigation, preparedness, and recovery programs. This study focuses on natural disaster management in which the direct risks are posed by the natural disasters themselves. This paper presents a review of issues surrounding natural disaster risk control and insurance in Taiwan. It proposes the use of background information concerning risk control strategies as well as earthquake, typhoon, and flood insurance in Taiwan. Finally, an insurance case study is utilized to demonstrate the feasibility of the proposed methodology.  相似文献   

15.
Climate change brings uncertain risks of climate-related natural hazards. The US Federal Emergency Management Agency (FEMA in Climate change: long-term trends and their implications for emergency management, 2011. https://www.fema.gov/pdf/about/programs/oppa/climate_change_paper.pdf) has issued a policy directive to integrate climate change adaptation actions into hazard mitigation programs, policies, and plans. However, to date there has been no comprehensive empirical study to examine the extent to which climate change issues are integrated into state hazard mitigation plans (SHMPs). This study develops 18 indicators to examine the extent of climate change considerations in the 50 SHMPs. The results demonstrate that these SHMPs treat climate change issues in an uneven fashion, with large variations present among the 50 states. The overall plan quality for climate change considerations was sustained at an intermediate level with regard to climate change-related awareness, analysis, and actions. The findings confirm that climate change concepts and historic extreme events have been well recognized by the majority of SHMPs. Even though they are not specific to climate change, mitigation and adaptation strategies that can help reduce climate change risks have been adopted in these plans. However, the plans still lack a detailed assessment of climate change and more incentives for collaboration strategies beyond working with emergency management agencies.  相似文献   

16.
Bela Das 《Natural Hazards》2011,58(3):905-928
Hazards due to riverbank erosion, despite being considered usually as a natural phenomenon, have become a critical problem in recent times as introduction of new technology and one-sided engineering-based solution approach to combat natural hazards without taking into account of opinions of all categories of stakeholders, particularly of the hazard victims and policy makers, has aggravated the problem in many cases. The riverbank erosion hazard aggravated as a direct consequence of construction of Farakka Barrage on its upstream and downstream on the river Ganga has seriously affected the lifestyles of the people in the districts of Malda and Murshidabad in the state of West Bengal in India. In this paper, an attempt has been made to study the perceptions of different groups of stakeholders, particularly hazard victims and authority responsible for monetary investment, about causes of riverbank erosion and possible preventive and remedial measures required to solve such a complex and multi-dimensional problem. A questionnaire-based household survey has been conducted on a number of important issues of the problem among the directly affected hazard victims at a highly erosion-prone area in the Malda district. Different perceptions and their impacts on selection and implementation of anti-erosion measures are critically studied. Analysis of data as obtained from the representative sample of erosion victims as well as the secondary sources of data clearly indicates that the hazard victims are to face bad effects because of existence of perception gap and that a holistic approach considering the perception of erosion victims needs to be undertaken for a permanent solution of the problem.  相似文献   

17.
Soil erosion by water is recognised as a worldwide land degradation issue, particularly in arid and semi-arid regions. The aim of this study is to apply the powerful capabilities of advanced remote sensing and geographic information system techniques to identify the areas at risk to water erosion. This study presents the assessment of water erosion in mountainous areas (eastern Aures, Algeria) based on three main factors: the friability of the bedrock, degree of slope and density of vegetation cover. Alsat1 image was used to produce land use and vegetation (NDVI) maps. Digital elevation model was used in constructing the slope gradient map. The erosion risk map was obtained by the combination of indices assigned to thematic layers following multicriteria decision rules. Water erosion was generally not concerning in the eastern Aures (slight risk = 33 %, moderate risk = 44 % of the area). This simple–qualitative approach gave good results for assessing soil erosion equally to quantitative methods since 89.55 % of field verifications were accurate. The non-alarming state and the low rate of severe and extremely severe risk to erosion are due to (1) the low steep slopes, (2) the good quality of vegetation (forests with thick undergrowth), and which are occurring on (3) resistant materials of the substratum, and (4) the low human pressure. Results of this study, which may be conducted with reasonable costs and accuracy over large areas, are of significant help in prioritising areas in decision making and sustainable planning.  相似文献   

18.
Shi  Long  Wang  Dongyuan  Li  Kaichong 《Natural Hazards》2020,104(1):353-374
Natural Hazards - The Lanzhou–Wulumuqi high-speed railway is the first high-speed railway in China which extends through vast strong wind areas in Gobi Desert. To ensure the safety of train...  相似文献   

19.
The Andaman–Nicobar (A–N) Islands region has attracted many geo-scientists because of its unique location and complex geotectonic settings. The recent occurrence of tsunamis due to the megathrust tsunamigenic north Sumatra earthquake (Mw 9.3) with a series of aftershocks in the A–N region caused severe damage to the coastal regions of India and Indonesia. Several pieces of evidence suggest that the occurrence of earthquakes in the A–N region is related to its complex geodynamical processes. In this study, it has been inferred that deep-seated structural heterogeneities related to dehydration of the subducting Indian plate beneath the Island could have induced the process of brittle failure through crustal weakening to contribute immensely to the coastal hazard in the region. The present study based on 3-D P-wave tomography of the entire rupture zone of the A–N region using the aftershocks of the 2004 Sumatra–Andaman earthquake (Mw 9.3) clearly demonstrates the role of crustal heterogeneity in seismogenesis and in causing the strong shakings and tsunamis. The nature and extent of the imaged crustal heterogeneity beneath the A–N region may have facilitated the degree of damage and extent of coastal hazards in the region. The 3-D velocity heterogeneities reflect asperities that manifest what type of seismogenic layers exist beneath the region to dictate the size of earthquakes and thereby they help to assess the extent of earthquake vulnerability in the coastal regions. The inference of this study may be used as one of the potential inputs for assessment of seismic vulnerability to the region, which may be considered for evolving earthquake hazard mitigation model for the coastal areas of the Andaman–Nicobar Islands region.  相似文献   

20.
A map shows intrinsic vulnerability to pollution of the Chrzanów karst-fissured aquifer (273 km2) in the southern part of Poland. This aquifer is intensively drained by numerous intakes and Zn-Pb ore mines. A DRASTIC-type parametric system was applied for groundwater vulnerability evaluation. Vulnerability assessment is based on six factors (depth to groundwater table, lithology of the unsaturated zone, net recharge, hydraulic conductivity of the aquifer, groundwater flow velocity, aquifer thickness). For the final vulnerability map construction at the scale of 1:50,000, a combination of the aquifer simulation model (using MODFLOW) and a geographical information system was applied. Maps of the net recharge, hydraulic conductivity of the aquifer and groundwater flow velocity were derived by aquifer modelling. Based on the vulnerability index (21-182), six relative vulnerability classes were selected. Reliability of the map has been verified.  相似文献   

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