| 1. |
- Aiyelokun, Oluwatobi, et al.
(författare)
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Credibility of design rainfall estimates for drainage infrastructures : extent of disregard in Nigeria and proposed framework for practice
- 2021
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Ingår i: Natural Hazards. - : Springer Science and Business Media LLC. - 0921-030X .- 1573-0840. ; 109:2, s. 1557-1588
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Tidskriftsartikel (refereegranskat)abstract
- Rainfall intensity or depth estimates are vital input for hydrologic and hydraulic models used in designing drainage infrastructures. Unfortunately, these estimates are susceptible to different sources of uncertainties including climate change, which could have high implications on the cost and design of hydraulic structures. This study adopts a systematic literature review to ascertain the disregard of credibility assessment of rainfall estimates in Nigeria. Thereafter, a simple framework for informing the practice of reliability check of rainfall estimates was proposed using freely available open-source tools and applied to the north central region of Nigeria. The study revealed through a synthesis matrix that in the last decade, both empirical and theoretical methods have been applied in predicting design rainfall intensities or depths for different frequencies across Nigeria, but none of the selected studies assessed the credibility of the design estimates. This study has established through the application of the proposed framework that drainage infrastructure designed in the study area using 100–1000-year return periods are more susceptible to error. And that the extent of the credibility of quantitative estimates of extreme rains leading to flooding is not equal for each variability indicator across a large spatial region. Hence, to optimize informed decision-making regarding flood risk reduction by risk assessor, variability and uncertainty of rainfall estimates should be assessed spatially to minimize erroneous deductions.
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| 2. |
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| 3. |
- Boda, Chad, et al.
(författare)
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Forgotten coast, forgotten people: sustainable development and disproportionate impacts from Hurricane Michael in Gulf County, Florida
- 2022
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Ingår i: Natural Hazards. - : Springer Science and Business Media LLC. - 0921-030X .- 1573-0840. ; :111, s. 877-899
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Tidskriftsartikel (refereegranskat)abstract
- A central challenge for sustainable development is how societies are to avoid, minimize or address impacts from anthropogenic climate change. However, competing perspectives on “what should be sustained” lead to widely different understandings of what mitigation, adaptation and loss and damage entail and how best to approach them. We provide a novel conceptual and empirical comparison of two contrasting sustainable development-based approaches to the study of impacts from climate-related extreme events: Capital Theory and capability-based Human Development. We use our analysis of immediate residential property value and housing capacity impacts caused by Hurricane Michael in Gulf County, Florida, to demonstrate how the sustainable development theory used to assess and interpret impacts greatly affects the identification of whom and where is objectively “most impacted.” Through a comparison of the two approaches, we identify relative advantages and disadvantages, emphasizing that while both provide coherent, comprehensive, and integrative approaches to climate-related impact assessment, the capability approach is much less likely to lead researchers and practitioners to overlook the most disadvantaged communities when compared to Capital Theory.
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| 4. |
- Cáceres, Diego, et al.
(författare)
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Seismic Hazard of Honduras
- 2000
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Ingår i: Natural Hazards. - 0921-030X .- 1573-0840. ; 22:1, s. 49-69
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Tidskriftsartikel (refereegranskat)abstract
- In this paper we have described the proceduresused, input data applied and results achieved in ourefforts to develop seismic hazard maps of Honduras.The probabilistic methodology of Cornell is employed.Numerical calculations were carried out by making useof the computer code SEISRISK III. To examine theimpact of uncertainties in seismic and structuralcharacteristics, the logic tree formalism has beenused. We compiled a de-clustered earthquake cataloguefor the region comprising 1919 earthquakes occurringduring the period from 1963 to 1997. Unified momentmagnitudes were introduced. Definition of aseismotectonic model of the whole region under review,based on geologic, tectonic and seismic information,led to the definition of seven seismogenetic zones forwhich seismic characteristics were determined. Fourdifferent attenuation models were considered. Resultsare expressed in a series of maps of expected PGA for60% and 90% probabilities of nonexceedence in a50-year interval which corresponds to return periodsof 100 and 475 years, respectively. The highest PGAvalues of about 0.4g (90% probability ofnon-exceedence) are expected along the borders withGuatemala and El Salvador.
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| 5. |
- Chen, Feng, et al.
(författare)
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Annual precipitation variation for the southern edge of the Gobi Desert (China) inferred from tree rings: linkages to climatic warming of twentieth century
- 2016
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Ingår i: Natural Hazards. - : Springer Science and Business Media LLC. - 0921-030X .- 1573-0840. ; 81:2, s. 939-955
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Tidskriftsartikel (refereegranskat)abstract
- We developed a new reconstruction of annual precipitation (August–July) for the Helan Mountains near the southern edge of the Gobi Desert, using a regional tree-ring width chronology. The reconstruction explained 52.1 % of the observed precipitation variance during the period 1953–2008. In addition to the new precipitation reconstruction for the Helan Mountains, two previously published annual precipitation reconstructions from the same region were also used to infer the large-scale precipitation signal of the southern edge of the Gobi Desert. Spatial correlation analyses with gridded precipitation data showed that the tree-ring records were indeed able to capture much of the regional interannual precipitation variability. Using principal component analyses on the precipitation reconstructions and documentary records, 29 large-scale dry events were found during the period AD 1760–2006. Many of these dry events have had profound impacts on the people of the study area over the past several centuries. A notably good agreement with a temperature reconstruction for Zhangye suggests that the precipitation of the Gobi Desert has the characteristics of monsoon rainfall variability (wet–warm and cold–dry). Our precipitation reconstruction exhibited a downward trend during the last two decades, a trend also found in northern and eastern China. It might be caused by a weakening of the Asian summer monsoon induced by global warming (especially increased sea surface temperature).
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| 6. |
- Collenteur, R. A., et al.
(författare)
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The failed-levee effect : Do societies learn from flood disasters?
- 2015
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Ingår i: Natural Hazards. - : Springer Science and Business Media LLC. - 0921-030X .- 1573-0840. ; 76:1, s. 373-388
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Tidskriftsartikel (refereegranskat)abstract
- Human societies have learnt to cope with flood risks in several ways, the most prominent ways being engineering solutions and adaptive measures. However, from a more sustainable point of view, it can be argued that societies should avoid or at least minimize urban developments in floodplain areas. While many scientists have studied the impact of human activities on flood risk, only a few studies have investigated the opposite relationships, i.e. the impacts of past flood events on floodplain development. In this study, we make an initial attempt to understand the impact of the occurrence of flood disasters on the spatial distribution of population dynamics in floodplain areas. Two different methodologies are used to uncover this relationship, a large-scale study for the USA and a case-study analysis of the 1993 Mississippi flood. The large-scale analysis is performed at county level scale for the whole of the USA and indicates a positive relationship between property damage due to flood events and population growth. The case-study analysis examines a reach of the Mississippi river and the territory, which was affected by flooding in 1993. Contrary to the large-scale analysis, no significant relationship is found in this detailed study. However, a trend of dampened population growth right after the flood followed by an accelerated growth a decade later could be identified in the raw data and linked to explanations found in the literature.
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| 7. |
- Di Baldassarre, Giuliano, et al.
(författare)
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Probability-weighted hazard maps for comparing different flood risk management strategies : a case study
- 2009
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Ingår i: Natural Hazards. - : Springer Science and Business Media LLC. - 0921-030X .- 1573-0840. ; 50:3, s. 479-496
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Tidskriftsartikel (refereegranskat)abstract
- The study proposes an original methodology for producing probability-weighted hazard maps based on an ensemble of numerical simulations. These maps enable one to compare different strategies for flood risk management. The methodology was applied over a 270-km2 flood-prone area close to the left levee system of a 28-km reach of the river Reno (Northern Central Italy). This reach is characterised by the presence of a weir that allows controlled flooding of a large flood-prone area during major events. The proposed probability-weighted hazard maps can be used to evaluate how a structural measure such as the mentioned weir alters the spatial variability of flood hazard in the study area. This article shows an application by constructing two different flood hazard maps: a first one which neglects the presence of the weir using a regular levee system instead, and a second one that reflects the actual geometry with the weir. Flood hazard maps were generated by combining the results of several inundation scenarios, simulated by coupling 1D- and 2D-hydrodynamic models.
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| 8. |
- Eklund, Lina, et al.
(författare)
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Meteorological, agricultural and socioeconomic drought in the Duhok Governorate, Iraqi Kurdistan
- 2015
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Ingår i: Natural Hazards. - : Springer Science and Business Media LLC. - 0921-030X .- 1573-0840. ; 76:1, s. 421-441
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Tidskriftsartikel (refereegranskat)abstract
- Drought is a recurrent natural hazard that is expected to increase in the future due to anthropogenic climate change. The Middle East region witnessed a drought period between 2007 and 2009 that has been reported to have severe consequences for the population, especially in Syria and Iraq. This study seeks to assess the spatial and temporal characteristics of the drought in the Duhok Governorate in Northern Iraq, focusing on meteorological, agricultural and socio-economic drought at province and village level. Satellite based precipitation data, validated by station data, were used in a meteorological drought assessment. To estimate the decreased precipitation’s effects on vegetation, an agricultural drought assessment was performed using Enhanced Vegetation Index (EVI) from multi-temporal satellite data. Vegetation anomalies were studied at provincial level, and also at village level where the anomalies were compared with survey data showing the socio-economic susceptibility to drought. The study confirms that precipitation dropped by approximately 50%, leading to a negative anomaly in vegetation conditions for 62% of Duhok Governorate’s area in 2008. Out of 50 assessed villages, 46 experienced a negative vegetation anomaly during the drought year, and three of those experienced a strong negative anomaly. Reports of drought as a problem were frequently recorded in the exposed villages, but was also related to the level of agricultural involvement. This study emphasizes the importance of understanding drought from both physical and socio-economic perspectives. Moreover, discrepancies in the datasets make a multi-source approach essential to avoid erroneous interpretations.
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| 9. |
- ElSayed, A, et al.
(författare)
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Distribution of the energy release, b-values and seismic hazard in Egypt
- 1996
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Ingår i: NATURAL HAZARDS. - : KLUWER ACADEMIC PUBL. - 0921-030X. ; 13:2, s. 133-150
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- A review of the seismicity and seismic history of Egypt indicates areas of high activity concentrated along Oligocene-Miocene faults. This supports the idea of recent activation of the Oligocene-Miocene stress cycle. There are similarities in the spatial
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| 10. |
- ELSAYED, A, et al.
(författare)
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SEISMIC HAZARD OF EGYPT
- 1994
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Ingår i: NATURAL HAZARDS. - : KLUWER ACADEMIC PUBL. - 0921-030X. ; 10:3, s. 247-259
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Earthquake hazard parameters such as maximum expected magnitude, M(max), annual activity rate, lambda, and b value of the Gutenberg-Richter relation have been evaluated for two regions of Egypt. The applied maximum likelihood method permits the combinatio
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| 11. |
- Fuchs, Sven, et al.
(författare)
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The ambiguity in IPCC's risk diagram raises explanatory challenges
- 2024
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Ingår i: Natural Hazards. - : Springer. - 0921-030X .- 1573-0840.
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Tidskriftsartikel (refereegranskat)abstract
- The concept of risk remains a key aspect in the recently published 6th Assessment Report of the Intergovernmental Panel on Climate Change (IPCC). The IPCC risk diagram shows risk as a function of three elements: hazard, exposure and vulnerability. While this relationship is undisputed, simply superimposing the individual risk factors as presented in the IPCC diagram does not do justice to the underlying definitions of the terms. This diagram can thus confuse more than it clarifies and, we argue, should be reconsidered.
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| 12. |
- Gao, Ge, et al.
(författare)
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Synergistic effects of environmental regulations on carbon productivity growth in China's major industrial sectors
- 2019
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Ingår i: Natural Hazards. - : SPRINGER. - 0921-030X .- 1573-0840. ; 95:1-2, s. 55-72
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Tidskriftsartikel (refereegranskat)abstract
- It is crucial that the implementation of environmental regulations have a positive synergistic effect on carbon productivity growth (i.e., environmentally adjusted productivity growth with the consideration of carbon emissions) for China to realize its sustainable development goals because the country is currently under tripartite pressures of economic growth, carbon emissions control, and environmental pollution reduction. This paper investigates the impact of changes in environmental regulation stringency on industrial-level carbon productivity growth in China. Through utilizing the information entropy method, a new index of environmental regulation stringency is established by taking into account the effects of both pollution reduction consequences and pollution reduction measures. In addition, based on the data envelopment analysis method, a Malmquist carbon productivity index is proposed to estimate the industrial carbon productivity growth of 21 major industrial sectors in China's 30 provinces over 2004-2014. Finally, an econometric regression model is applied to test the synergistic effects of environmental regulations on carbon productivity in China's major industrial sectors. The results show that (1) a stringent environmental regulation is associated with an increase in overall industrial carbon productivity growth in China; (2) there exist significant pass-through effects in China's major industrial sectors that technology can transmit effectively from leader to follower; (3) there also exist obvious follow-up effects in China's major industrial sectors, i.e., the industrial sectors that have larger technological gaps with the leaders catch up faster than others; and (4) the environmental regulations have different effects on industrial sectors with different polluting levels, i.e., there is a positive linear relationship between environmental regulation stringency and industrial-level carbon productivity growth in low-polluting industrial sectors, a parabolic nonlinear relationship between them in high-polluting industrial sectors, and an inverted U-shaped relationship between them in moderate-polluting industrial sectors.
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| 13. |
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| 14. |
- Garcia-Urquia, Elias
(författare)
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Establishing rainfall frequency contour lines as thresholds for rainfall-induced landslides in Tegucigalpa, Honduras, 1980-2005
- 2016
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Ingår i: Natural Hazards. - : Springer Science and Business Media LLC. - 0921-030X .- 1573-0840. ; 82:3, s. 2107-2132
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, a method to derive rainfall thresholds based on the relationship between daily and the antecedent rainfall up to 6 days prior to landslide occurrence is proposed for the analysis of 134 landslide days in Tegucigalpa, Honduras, during the years 1980-2005. Based on a simple graphical procedure, rainfall frequency contour lines have been drawn in the daily versus antecedent rainfall plots to connect rainfall combinations relatively having the same frequency of occurrence. A two-bound threshold has been established: Below the lower bound, rainfall events are so frequent that any landslide day may only occur due to a significant anthropogenic disturbance, while, above the upper bound, rainfall alone is capable of inducing landslide days. Contour lines originating at the same daily rainfall value in all plots were then grouped together to form a threshold set, for which the number of well-predicted landslide days and false alarms was determined. It has been determined that 16 and 84 landslide days have fallen below the lower bound and above the upper bound, respectively. In addition, this method has been proven effective in the distinction between days with and without landslides, since it has led to a 23 % reduction in the number of false alarms per well-predicted landslide day when compared to a previously established threshold line for Tegucigalpa.
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| 15. |
- Garcia-Urquia, Elias, et al.
(författare)
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The use of press data in the development of a database for rainfall-induced landslides in Tegucigalpa, Honduras, 1980–2005
- 2014
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Ingår i: Natural Hazards. - : Springer Science and Business Media LLC. - 0921-030X .- 1573-0840. ; 73:2, s. 237-258
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Tidskriftsartikel (refereegranskat)abstract
- The capital city of Honduras, Tegucigalpa, suffers from the occurrence of destructive landslides on a yearly basis. During the rainy season, damages to infrastructure as well as injuries, casualties and homeless individuals resulting from landslides are reported in the press. This paper presents the development of a database for rainfall-induced landslides for the period 1980–2005, based on the news reported by two local newspapers. The editions comprehended during the study period have been scrutinized, and articles focusing on landslides, tropical storms, hurricanes, floods and vulnerability of the city have been collected. The interpretation of these archives has allowed the compilation of valuable data of approximately 400 landslides. The analyses of monthly and annual precipitation during the study period show how extreme rainfall events like Hurricane Mitch in October of 1998 have significantly contributed to the initiation of landslides. In addition, the assessment of the slums and neighborhoods affected by landslides during the study period reveals an evident link between the social and physical vulnerability of Tegucigalpa. In order to estimate the reliability of this press-based database, the set of landslides that have been reported as a result of Hurricane Mitch in the press archives has been compared with two inventories based on the interpretation of aerial photographs taken in 1999 and 2001. It is shown that the analysis of the landslide damage left after the hurricane can be enriched with the detailed temporal data provided in the archives and the precise location of these events determined by the aerial photographs. Despite the difficulties faced in the compilation of this database, a good comprehension of the temporal and spatial distribution of landslides in Tegucigalpa has been achieved.
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| 16. |
- Gössling, Stefan, et al.
(författare)
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Weather, climate change, and transport : a review
- 2023
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Ingår i: Natural Hazards. - : Springer. - 0921-030X .- 1573-0840. ; 118, s. 1341-1360
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Tidskriftsartikel (refereegranskat)abstract
- Transportation is affected by weather and extreme weather events, and there is evidence that heatwaves, heavy precipitation, storms, wildfires, and floods increasingly affect transport infrastructures, operations, and travel behavior. Climate change is expected to reinforce this trend, as mean weather parameters change, and the frequency and intensity of extreme events increases. This paper summarizes interrelationships of weather and transport for different transport modes from both supply and demand side perspectives on the basis of a literature review. To further explore the complexity of these interrelationships, it also evaluates news items (n = 839) in a sample of global media news outlets covering the world and population-dense world regions. Results confirm that extreme events have become disruptive of transport systems at the micro and macro scale, also affecting transport behavior. There are implications for environment, economy, technology, health, and society. Interrelationships are illustrated and discussed: Climatic impact drivers can be expected to increase transport vulnerabilities and risks, and have relevance for transport planning and adaptation.
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| 17. |
- Hagos, Lijam, et al.
(författare)
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Application of the spatially smoothed seismicity and Monte Carlo methods to estimate the seismic hazard of Eritrea and the surrounding region
- 2006
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Ingår i: Natural Hazards. - : Springer Science and Business Media LLC. - 0921-030X .- 1573-0840. ; 39:3, s. 395-418
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Tidskriftsartikel (refereegranskat)abstract
- The region of interest is characterized by incomplete data sets and little information about the tectonic features. Therefore, two methodologies for estimating seismic hazard were used in order to elucidate the robustness of the results: the method of spatially smoothed seismicity introduced by Frankel (1995) and later extended by Lapajne et al. (1997) and a Monte Carlo approach presented by Ebel and Kafka (1999). In the first method, fault-rupture oriented elliptical Gaussian smoothing was performed to estimate future activity rates along the causative structures. Peak ground accelerations were computed for a grid size of 15 km x 415 km assuming the centre of the grids as epicentres, from which the seismic hazard map was produced. The attenuation relationship by Ambraseys et al. (1996) was found suitable for the region under study. PGA values for 10% probability of exceedence in 50 years (return period of 475 years) were computed for each model and a combined seismic hazard map was produced by subjectively assigning weights to each of these models. A worst-case map is also obtained by picking the highest value at each grid point from values of the four hazard maps. The Monte Carlo method is used to estimate seismic hazard, for comparison to the results from our previous approach. Results obtained from both methods are comparable except values in the first set of maps estimate greater hazard in areas of low seismicity. Both maps indicate a higher hazard along the main tectonic features of the east African and Red Sea rift systems. Within Eritrea, the highest PGA exceeded a value 25% of g, located north of Red Sea port of Massawa. In areas around the capital, Asmara, PGA values exceed 10% of g.
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| 18. |
- Hamilton, ARL, et al.
(författare)
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The role of emergency medical teams in disaster response: a summary of the literature
- 2022
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Ingår i: NATURAL HAZARDS. - : Springer Science and Business Media LLC. - 0921-030X .- 1573-0840. ; 110:3, s. 1417-1426
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Forskningsöversikt (övrigt vetenskapligt/konstnärligt)abstract
- In the aftermath of natural disasters, emergency medical teams (EMTs) are dispatched to help local rescue efforts. While some impact evaluations of EMTs are available, few comprehensive evaluations of the implementation of EMTs in natural disasters, have been published to date. As a result, the evidence base to inform global guidelines and best practices, is remarkably thin. This paper aims to provide a better understanding of the role of EMTs, by summarizing recent reports and case studies. Specifically, this summary aims to identify key improvement areas, as well as obstacles and opportunities for improvement. After a search of the literature, 40 publications met the inclusion criteria, and were included in this summary of the literature. The effective functioning of EMTs is codependent on interactions between different actors, including national governments, international organizations, NGOs, local government agencies, community stakeholders and the private sector. Five key improvement areas were identified: (1) coordination and integration of EMTs and other actors; (2) systematic classification and registration of EMTs; (3) national stewardship; (4) community engagement; (5) research and data collection. As the prevalence of natural disasters rise, effective disaster response will be an increasingly important component of global health in the coming decades. To optimize EMT efficiency, there needs to be increased recognition of the different actors involved, increased cooperation amongst EMTs under the coordination of international rosters, and increased research efforts to evaluate challenges to and opportunities for improved disaster response.
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| 19. |
- Hassel, Henrik
(författare)
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Risk and vulnerability analysis in practice: evaluation of analyses conducted in Swedish municipalities
- 2012
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Ingår i: Natural Hazards. - : Springer Science and Business Media LLC. - 0921-030X .- 1573-0840. ; 63:2, s. 605-628
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Tidskriftsartikel (refereegranskat)abstract
- isk and vulnerability analysis (RVA) can benefit the process of preventing and preparing for disasters, both by generating a basis for making decisions and by enhancing risk awareness, safety culture and response capacity through the RVA process itself. In studying and understanding the practices related to RVA, insights can be gained regarding ways in which the RVA can be improved in society, as well as into how methods for RVA can be designed to suit the particular context. However, studies of this sort are rare. This paper presents an evaluation of RVA performed by Swedish municipalities, which are important actors in the Swedish emergency management system. This is done by employing a systematic, design science approach outlined in the paper. Document studies and interviews were used to collect data on the analyses performed by the municipalities, and the evaluation shows that there is room for improvement. The results can be especially relevant for municipalities developing their RVA practices, as well as for other actors performing similar types of analyses.
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| 20. |
- Keskitalo, E Carina H, et al.
(författare)
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Adaptation to climate change in the insurance sector : examples from the UK, Germany and the Netherlands
- 2014
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Ingår i: Natural Hazards. - : Springer Science and Business Media LLC. - 0921-030X .- 1573-0840. ; 71:1, s. 315-334
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Tidskriftsartikel (refereegranskat)abstract
- Adaptation to climate change, particularly flood risks, may come to pose large challenges in the future and will require cooperation among a range of stakeholders. However, there presently exists little research especially on the integration of the private sector in adaptation. In particular, recently developed state programs for adaptation have so far been focused on the public sector. Insurance providers may have much to contribute as they offer other parts of society services to appropriately identify, assess and reduce the financial impacts of climate change-induced risks. This study aims to explore how the institutional distribution of responsibility for flood risk is being renegotiated within the UK, Germany and Netherlands. Examining how the insurance industry and the public sector can coordinate their actions to promote climate change adaptation, the study discusses how layered natural hazard insurance systems may result from attempts to deal with increasing risks due to increasing incidences of extreme events and climate change. It illustrates that concerns over the risks from extreme natural events have prompted re-assessments of the current systems, with insurance requiring long-term legislative frameworks that defines the objectives and responsibilities of insurers and the different political authorities.
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| 21. |
- Lodh, Abhishek, et al.
(författare)
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Investigating the impact of tropical deforestation on Indian monsoon hydro-climate: a novel study using a regional climate model
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Ingår i: Natural Hazards. - 0921-030X.
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Tidskriftsartikel (refereegranskat)abstract
- This study uses a state-of-the-art regional climate model (RCM) to examine how tropical deforestation affects the meteorology of the Indian Summer Monsoon (ISM). Incorporating insights from existing research on deforestation by climate scientists, alongside evidence of environmental deterioration in semi-arid, hilly and tropical regions of Southeast Asia, this research seeks to elucidate the critical influence of anthropogenic reasons of climate change on the hydroclimate of ISM. Employing “tropical deforestation” design experiments with the ICTP-RegCMv4.4.5.10 RCM the study evaluates the effects on meteorological parameters including precipitation, circulation patterns and surface parameters. This experimental design entails substituting vegetation type in the land use map of RegCMv4.4.5.10 model, such as deciduous and evergreen trees in Southeast Asia with “short grass” to mimic tropical deforestation. Findings reveal that deforestation induces abnormal anti-cyclonic circulation over eastern India curtails moisture advection, diminishing latent heat flux and moisture transport, leads to a decrease in precipitation compared to control experiment scenario. Alterations in albedo and vegetation roughness length attributable to deforestation impact temperature, humidity, precipitation, consequently exacerbating drought and heatwave occurrences. Additionally, the study also explores deforestation-induced feedback on ISM precipitation variability. The study concludes that deforestation substantially alters land-surface characteristics, water and energy cycle, and atmospheric circulation, thereby influencing regional climate dynamics. These findings offer foundational insights into comprehending land-use and land-cover changes and their implications for climate change adaptation strategies.
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| 22. |
- Mazzoleni, Maurizio, et al.
(författare)
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Testing UAV-derived topography for hydraulic modelling in a tropical environment
- 2020
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Ingår i: Natural Hazards. - : Springer. - 0921-030X .- 1573-0840.
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Tidskriftsartikel (refereegranskat)abstract
- The past few years have seen the raise of unmanned aerial vehicles (UAV) in geosciences for generating highly accurate digital elevation models (DEM) at low costs, which promises to be an interesting alternative to satellite data for small river basins. The reliability of UAV-derived topography as input to hydraulic modelling is still under investigation: here, we analyse potentialities and highlight challenges of employing UAV-derived topography in hydraulic modelling in a tropical environment, where weather conditions and remoteness of the study area might affect the quality of the retrieved data. We focused on a stretch of the Limpopo River in Mozambique, where detailed ground survey and airborne data were available. First, we tested and compared topographic data derived by UAV (25 cm), RTK-GPS (50 cm DEM), LiDAR (1 m DEM) and SRTM (30 m DEM); then, we used each DEM as input data to a hydraulic model and compared the performance of each DEM-based model against the LiDAR based model, currently used as benchmark by practitioners in the area. Despite the challenges experienced during the field campaign—and described here—, the degree of accuracy in terrain modelling produced errors in water depth calculations within the tolerances adopted in this typology of studies and comparable in magnitude to the ones obtained from high-precision topography models. This suggests that UAV is a promising source of geometric data even in natural environments with extreme weather conditions.
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| 23. |
- Michailov, D., et al.
(författare)
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Influence of local geological conditions on the macroseismic effects in the town of Strazhitza
- 1990
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Ingår i: Natural Hazards. - 0921-030X .- 1573-0840. ; , s. 153-160
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Tidskriftsartikel (refereegranskat)abstract
- Damage caused by the earthquake of 7 December 1986 (M = 5.7) and its aftershocks in low-storey residential buildings in the town of Strazhitza, Bulgaria, situated in the epicentral zone are systematized. A scale of damages is compiled for two types of buildings which is coordinated with the MSK-64 scale. The territorial distribution of the seismic intensity is compared with the results of the detailed engineering-geological study. A correlation between the Quarternary deposit thickness and the observed seismic intensity is obtained
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| 24. |
- Mohamadi, Sedigheh, et al.
(författare)
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Zoning map for drought prediction using integrated machine learning models with a nomadic people optimization algorithm
- 2020
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Ingår i: Natural Hazards. - Germany : Springer. - 0921-030X .- 1573-0840. ; 104:1, s. 537-579
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Tidskriftsartikel (refereegranskat)abstract
- The modelling of drought is of utmost importance for the efficient management of water resources. This article used the adaptive neuro-fuzzy interface system (ANFIS), multilayer perceptron (MLP), radial basis function neural network (RBFNN), and support vector machine (SVM) models to forecast meteorological droughts in Iran. The spatial–temporal pattern of droughts in Iran was also found using recorded observation data from 1980 to 2014. A nomadic people algorithm (NPA) was utilized to train the ANFIS, MLP, RBFNN, and SVM models. Additionally, the NPA was benchmarked against the bat algorithm, salp swarm algorithm, and krill algorithm (KA). The hybrid ANFIS, MLP, RBFNN, and SVM models were used to forecast the 3-month standardized precipitation index. New evolutionary algorithms were utilized to improve the convergence speed of the soft computing models and their accuracy. First, random stations, namely, in Azarbayjan (northwest Iran), Khouzestan (southwest Iran), Khorasan (northeast Iran), and Sistan and Balouchestan (southeast Iran) were selected for the testing of the models. According to the results obtained from the Azarbayjan station, the Nash–Sutcliffe efficiency (NSE) was 0.93, 0.86, 0.85, and 0.83 for the ANFIS–NPA, MLP–NPA, RBFNN–NPA, and SVM–NPA models, respectively. For Sistan and Baloucehstan, the results indicated the superiority of the ANFIS–NPA model, followed by the MLP–NPA model, compared to the RBFNN–NPA and SVM–NPA models, and suggested that the hybrid models performed better than the standalone MLP, RBFNN, ANFIS, and SVM models. The second aim of the study was to capture the relationship between large-scale climate signals and drought indices by using a wavelet coherence analysis. The general results indicated that the NPA and wavelet coherence analysis are useful tools for modelling drought indices.
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| 25. |
- Montesarchio, Valeria, et al.
(författare)
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Comparison of methodologies for flood rainfall thresholds estimation
- 2015
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Ingår i: Natural Hazards. - : Springer Netherlands. - 0921-030X .- 1573-0840. ; 75:1, s. 909-934
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Tidskriftsartikel (refereegranskat)abstract
- A flood warning system based on rainfall thresholds makes it possible to issue alarms via an off-line approach. This technique is useful for mitigating the effects of flooding in small-to-medium-sized basins characterized by an extremely rapid response to rainfall. Rainfall threshold values specify the amount of precipitation that occurs over a given period of time and are dependent on both the amount of soil moisture and the spatiotemporal distribution of the rainfall. The precipitation generates a critical discharge in a particular river cross section. Exceeding these values can produce a critical situation in river sites that make them susceptible to flooding. In this work, we present a comparison of methodologies for estimating rainfall thresholds. Critical precipitation amounts are evaluated using empirical data, hydrological simulations and probabilistic methods. The study focuses on three small-to-medium-sized basins located in central Italy. For each catchment, historical data are first used to theoretically evaluate the empirical rainfall thresholds. Next, we calibrate a semi-distributed hydrological model that is validated using rain gauge and weather radar data. Critical rainfall depths over 30 min and 1, 3, 6, 12 and 24 h durations are then evaluated using the hydrological simulation. In the probabilistic approach, rainfall threshold values result from a minimization of two different functions, one following the Bayesian decision theory and the other following the informative entropy concept. In order to implement both functions, it is necessary to evaluate the joint probability function. The joint probability function is built up as a bivariate distribution of rainfall depth for a given duration with the corresponding flow peak value. Finally, in order to assess the performance of each methodology, we construct contingency tables to highlight the system performance.
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| 26. |
- Nyberg, Rolf, et al.
(författare)
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Indicators of road network vulnerability to storm-felled trees
- 2013
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Ingår i: Natural Hazards. - : Springer. - 0921-030X .- 1573-0840. ; 69:1, s. 185-199
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, we exemplify the use of simple indicators of wind storm vulnerability of the road network that can be derived from existing geographic datasets. We point out the possible utilization of the datasets, applying GIS techniques, for highlighting road sections that, due to adjacency of high forest stands, are sensitive to closure by stormfelled trees. Indicators reflecting the reduced access to different areas or to the population in need of emergency aid can be derived based on the parameter tree height along roads and road network analysis. As a case in this study, the methodology is applied to elderly people (?80 years) with possible need of daily care at home following a severe storm. A comparison to the extreme 2005 storm felling in southern Sweden reveals that only limited estimates of road network disruption due to storm-felled trees are possible using the indicators, as other factors, for example, wind direction, which determine the exact impact of a particular storm are not taken into account. However, the indicators and network analysis also provide a possibility to draw attention to locations where disruptions of the road network would have significant effects on the accessibility to large surrounding areas. Potential critical road closures can be identified and preventive measures considered locally at these points.
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| 27. |
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| 28. |
- Paryani, Sina, et al.
(författare)
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Hybrid-based approaches for the flood susceptibility prediction of Kermanshah province, Iran
- 2023
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Ingår i: Natural Hazards. - : Springer Science and Business Media LLC. - 0921-030X .- 1573-0840. ; 116:1, s. 837-868
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Tidskriftsartikel (refereegranskat)abstract
- This study aims at optimizing the support vector regression (SVR) model using four metaheuristic methods, Harris hawks optimization (HHO), particle swarm optimization (PSO), gray wolf optimizer (GWO), and bat algorithm (BA). The intent is to create a reliable flood susceptibility map (FSM). In this regard, a flood inventory map for 617 flood locations was generated from the Google earth engine (GEE). Four hundred and thirty-two random locations (70%) were used for spatial flood susceptibility modeling, and 185 random locations (30%) were selected for testing hybrid approaches. Based on the available data and literature, the following eleven factors were selected: altitude, slope angle, slope aspect, plan curvature, stream power index (SPI), topographic wetness index (TWI), distance to river, lithology, drainage density, land use, and rainfall. The normalized frequency ratio (NFR) method was used to obtain a weight for each class of each factor. Next, flood susceptibility maps were produced by SVR-HHO, SVR-PSO, SVR-GWO, and SVR-BA hybrid models. The prediction power of hybrid models was assessed using various indicators of sensitivity, specificity, accuracy, kappa coefficient, receiver operating curve (ROC) diagram, mean square error (MSE), and root-mean-square error (RMSE). Validation results indicated the area under the curve (AUC) of 85.8%, 85.7%, 85.5%, and 84.6% for the SVR-HHO, SVR-GWO, SVR-BA, and SVR-PSO hybrid models, respectively. The results from testing phase reveal the best performance of the SVR-HHO model (RMSE = 0.401, MSE = 0.160, sensitivity = 0.822, specificity = 0.800, accuracy = 0.811, and kappa = 0.622). The SVR-PSO model had a poor performance (RMSE = 0.406, MSE = 0.164, sensitivity = 0.827, specificity = 0.773, accuracy = 0.80, and kappa = 0.60). It can be concluded that the map produced by SVR-HHO is a feasible approach for modeling flood susceptibility.
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| 29. |
- Prütz, Ruben, et al.
(författare)
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A GIS-based approach to compare economic damages of fluvial flooding in the Neckar River basin under current conditions and future scenarios
- 2021
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Ingår i: Natural Hazards. - : Springer Science and Business Media LLC. - 0921-030X .- 1573-0840. ; 108:2, s. 1807-1834
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Tidskriftsartikel (refereegranskat)abstract
- Fluvial floods can cause significant damages and are expected to increase in magnitude and frequency throughout the twenty-first century due to global warming. Alongside hazard characteristics, damage potentials depend on exposure and vulnerability, which are changing in the wake of socio-economic developments. In the context of continuously evolving damage-causing factors, assessments of future changes in flood damage potentials are increasingly asked for by decision-makers in flood risk management. This study addresses this need by (a) providing a systematic review of contemporary assessment approaches to quantitatively compare direct economic losses from fluvial flooding under current and future conditions and (b) combining the reviewed approaches to an applicable methodology which is used in a case study to quantify changing flood damage potentials in the Neckar River basin in southern Germany. Therefore, a scoping study of contemporary flood damage assessment approaches supported by geographic information systems (GIS) is performed. The subsequent case study of the Neckar River prognoses a significant increase in average annual flood damages in the study area throughout the twenty-first century. The case study produces valid results with regards to current precipitation data, whereas the absence of verification data makes the validation of projected scenarios more difficult. To account for uncertainties surrounding these future projections, a nascent qualitative confidence estimation is introduced to reflect on the strength of knowledge underlying the used flood damage assessment methodology.
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| 30. |
- Qasimi, Abdul Baser, et al.
(författare)
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Flood susceptibility prediction using MaxEnt and frequency ratio modeling for Kokcha River in Afghanistan
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Ingår i: Natural Hazards. - 0921-030X.
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Tidskriftsartikel (refereegranskat)abstract
- Flooding is a natural but unavoidable disaster that occurs over time. Flooding threatens human life, property, and resources and affects regional and national economies. Through frequency ratio and MaxEnt modeling, flood sensitivity was determined in the Amu Darya River Basin in Badakhshan Province, Afghanistan. Slope, plan curvature, distance to river, rainfall, aspect, land use, elevation, Normalized Difference Vegetation Index (NDVI), soil type, lithology, Topographic Humidity Index (TWI), and drainage density were used to quantify flood susceptibility. In total, 88 flood points collected from Google Earth were used to train the frequency ratio model to predict flood susceptibility, and 34 GPS-recorded points of the flooded area were used to evaluate the model’s performance. The frequency ratio model displayed a success rate of above 86%. However, using a jackknife entropy test, the MaxEnt model yielded a 97% success rate. The results showed that rainfall, land use, distance to river, and soil type were the most important parameters for evaluating flood sensitivity. The developed models can help planners and decision-makers perform flood susceptibility mapping in the region by determining locations of flooding sensitivity.
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| 31. |
- Rashidi, Amin, et al.
(författare)
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Tsunami hazard assessment in the Makran subduction zone
- 2020
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Ingår i: Natural Hazards. - : SPRINGER. - 0921-030X .- 1573-0840. ; 100:2, s. 861-875
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Tidskriftsartikel (refereegranskat)abstract
- The lack of offshore seismic data caused uncertainties associated with understating the behavior of future tsunamigenic earthquakes in the Makran subduction zone (MSZ). Future tsunamigenic events in the MSZ may trigger significant near-field tsunamis. Tsunami wave heights in the near field are controlled by the heterogeneity of slip over the rupture area. Considering a non-planar geometry for the Makran subduction zone, a range of random k(-2) slip models were generated to hypothesize rupturing on the fault zone. We model tsunamis numerically and assess probabilistic tsunami hazard in the near field for all synthetic scenarios. The main affected areas by tsunami waves are the area between Jask and Ormara along the shorelines of Iran and Pakistan and the area between Muscat and Sur along the Oman coastline. The maximum peak-wave height along the shores of Iran and Pakistan is about 16 m and about 12m for the Oman shoreline. The slip distributions control the wave height along the Makran coastlines. The dependency of tsunami height on the heterogeneity of slip is higher in the most impacted areas. Those areas are more vulnerable to tsunami hazard than other areas.
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| 32. |
- Risling, Axel, et al.
(författare)
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A comparison of global flood models using Sentinel-1 and a change detection approach
- 2024
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Ingår i: Natural Hazards. - : Springer Nature. - 0921-030X .- 1573-0840.
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Tidskriftsartikel (refereegranskat)abstract
- Advances in numerical algorithms, improvement of computational power and progress in remote sensing have led to the development of global flood models (GFMs), which promise to be a useful tool for large-scale flood risk management. However, performance and reliability of GFMs, especially in data-scarce regions, is still uncertain, as they are difficult to validate. Here we aim at contributing to develop alternative, more flexible, and consistent methods for GFM validation by applying a change detection analysis on synthetic aperture radar (CD-SAR) imagery obtained from the Sentinel-1 imagery, on a cloud-based geospatial analysis platform. The study addresses two main objectives. First, to validate four widely adopted GFMs with flood maps generated through the proposed CD-SAR approach. This exercise was conducted for eight different large river basins on four continents, to account for a diverse range of hydro-climatic environments. Second, to compare CD-SAR-derived flood maps with those obtained from alternative remote sensing sources. These comparative results offer valuable insights into the reliability of CD-SAR data as a validation tool, more specifically how it stacks up against flood maps generated by other remote sensing techniques.
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| 33. |
- Ronchi, E., et al.
(författare)
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The verification of wildland–urban interface fire evacuation models
- 2023
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Ingår i: Natural Hazards. - : Springer Science and Business Media LLC. - 0921-030X .- 1573-0840. ; 117:2, s. 1493-1519
-
Tidskriftsartikel (refereegranskat)abstract
- This paper introduces a protocol for the verification of multi-physics wildfire evacuation models, including a set of tests used to ensure that the conceptual modelling representation of each modelling layer is accurately implemented, as well as the interactions between different modelling layers and sub-models (wildfire spread, pedestrian movement, traffic evacuation, and trigger buffers). This work presents a total of 24 verification tests, including (1) 4 tests related to pedestrians, (2) 15 tests for traffic evacuation, (3) 5 tests concerning the interaction between different modelling layers, along with 5 tests for wildfire spread and trigger buffers. The evacuation tests are organized in accordance with different core components related to evacuation modelling, namely Population, Pre-evacuation, Movement, Route/destination selection, Flow constraints, Events, Wildfire spread and Trigger buffers. A reporting template has also been developed to facilitate the application of the verification testing protocol. An example application of the testing protocol has been performed using an open wildfire evacuation modelling platform called WUI-NITY and its associated trigger buffer model k-PERIL. The verification testing protocol is deemed to improve the credibility of wildfire evacuation model results and stimulate future modelling efforts in this domain.
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| 34. |
- Sköld Gustafsson, Viktor, et al.
(författare)
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Identifying decision support needs for emergency response to multiple natural hazards: an activity theory approach
- 2023
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Ingår i: Natural Hazards. - : Springer. - 0921-030X .- 1573-0840.
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Tidskriftsartikel (refereegranskat)abstract
- Planning and decision making in emergency response systems face new challenges due to climate changes and the increased risk of multiple or compound natural hazards. This is especially the case in areas with inexperience of such events. The aim of this paper is to identify important activities concerning planning and decision-making during responses to natural hazards, and their potential need for decision support. The knowledge base of the study consists of interviews with 12 representatives from the Swedish emergency response system, supplemented by documents covering policies, operations, and responsibility. Thematic coding was applied to the interview data for identification of important planning and decision activities. Needs of decision support were identified by applying activity theory to the identified activities. We found needs of decision support connected to eight identified key activities concerning consequence analysis, national reinforcements, and resource management. The results illuminate a lack of technology to support response activities during both single and multiple natural hazards. The findings can inform policy makers of emergency response of where to concentrate the development of tools for collaborative preparedness and response work to cope with future challenges from natural hazards.
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| 35. |
- Sonnek, Karin Mossberg, et al.
(författare)
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The impacts of a Laki-like eruption on the present Swedish society
- 2017
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Ingår i: Natural Hazards. - : SPRINGER. - 0921-030X .- 1573-0840. ; 88:3, s. 1565-1590
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Tidskriftsartikel (refereegranskat)abstract
- In this study, we analyse and discuss the possible impacts on the Swedish society of a volcanic eruption on Iceland, emitting ash particles and large quantities of sulphur dioxide. A scenario was developed, based on the historical Laki eruption of 1783-1784, to describe the content of a potential sulphur fog over time in Sweden. Due to its high complexity and the many uncertainties in the underpinning scientific data, the scenario was developed using a cross-disciplinary approach incorporating experts from different scientific fields. An analysis of the impacts of the hazard on human health, environment and technical equipment was then performed and, finally, representatives from national authorities assessed the overall societal challenges in responding to the consequences of a massive volcanic eruption. The analysis shows that it is the peak concentrations of sulphur dioxide and sulphuric acid rather than the longer periods of moderate concentrations that contribute most to the negative consequences for human health and environment. Altogether, three societal challenges were identified: the ability to compile and disseminate relevant information fast enough, to perform continuous measurements of concentrations of different substances in affected areas and to meet the large demand for medical care.
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| 36. |
- Soto Gómez, Agnes Jane
(författare)
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Deriving information on disasters caused by natural hazards from limited data : a Guatemalan case study
- 2015
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Ingår i: Natural Hazards. - : Springer Netherlands. - 0921-030X .- 1573-0840. ; 75:1, s. 71-94
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Tidskriftsartikel (refereegranskat)abstract
- This work proposes a method to overcome data limitations encountered when analyzing disasters at a local scale in disaster-prone areas. Research is required to understand the processes underlying the disasters in disaster-prone areas. However, many such areas lack sufficient data for the statistically significant studies that would strongly support disaster risk-reduction measures. Disasters are studied extensively at the national scale, but local-scale disaster research is greatly needed, specifically because the hazard exposures and vulnerabilities of populations are mainly site specific. The proposed method compiles data using two databases: the System of Information Management in case of Emergency or Disaster (SISMICEDE) and the Disaster Inventory System (DesInventar). SISMICEDE has a short time span and high spatial resolution, while DesInventar has a longer time span but low spatial resolution. SISMICEDE’s spatial distribution was used to sort DesInventar disaster data, analyzing them spatially and temporally at a local scale. The Samala River basin in Guatemala was selected to exemplify a disaster-prone area for which there are insufficient disaster data. The results indicate that it was useful to combine the two databases to optimally describe disasters over time and space in the studied area. The refinement of the disaster data highlighted the discrepancies between administrative boundaries and local particularities. The results indicate that the municipal scale is too sparse for spatial analyses and that specific location details are needed. According to the limited data available, disasters, during the rainy season, are increasing over time in the study area. This work demonstrates a way to perform local-scale disaster studies of areas for which data are not readily available. These local-scale studies would enable research and actions intended to improve disaster risk-reduction management and measures. This study could also help promote an improved information system in Guatemala that includes complete information useful for emergency response and post-disaster analyses.
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| 37. |
- Tiwari, S., et al.
(författare)
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Simultaneous measurements of black carbon and PM2.5, CO, and NOx variability at a locally polluted urban location in India
- 2015
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Ingår i: Natural Hazards. - : Springer Science and Business Media LLC. - 0921-030X .- 1573-0840. ; 75:1, s. 813-829
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Tidskriftsartikel (refereegranskat)abstract
- Black carbon, which is a by-product of incomplete combustion of carbon containing fuels, can alter atmospheric radiation property and make adverse impacts on human health. This paper shows the comparative study of particles and associated gaseous pollutants measurements at five observatories dispersed across central part of megacity Delhi, India, with high-temporal resolution (5 min) measurements. The mean +/- SD concentrations of black carbon (BC), fine particles (PM2.5), carbon monoxide (CO), and oxides of nitrogen (NOx) of the all five stations were 13.4 +/- 10, 149.6 +/- 109 mu g m(-3), 3.4 +/- 2 ppm, and 81.8 +/- 79 ppb, respectively. The mean mass concentration of PM2.5 was approximately four times and ten times in excess of annual average standards of Indian air quality (40 mu g m(-3)) and USEPA (15 mu g m(-3)) levels. Highest BC mass concentrations were recorded during winter (December) due to consistent with a shallower atmospheric boundary layer, lower wind speeds, and possibly larger biofuel burning in the coldest period. Also, the strong diurnal dynamics in boundary layer height had a large impact on the ground-level concentrations of all the pollutants. A significant difference in the emissions of atmospheric pollutants was observed over Delhi during weekdays and weekends during study period. There was a strong diurnal effect on BC and the other pollutants, presumably with mixing height as a strong driver. The 24-h cycle is characterized throughout the study by maximum concentrations around midnight and lowest concentrations at 1500-1700 hours local time (LT), with a local maximum between 0800 and 1000 hours LT, presumably due to morning rush hour. While the amplitude of the BC excursion was a factor of 2-3, the mixing height decreased by a factor of 12-14 from day to night. This monitoring program contributed to insights into the levels and dynamics of atmospheric pollutants in the New Delhi megacity over a 5-month period. The concentrations are varying over several timescales, consistent with both atmospheric mixing and variations in presumed emission source strengths.
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| 38. |
- With, Christoffer, et al.
(författare)
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A methodology for mapping of quick clay in Sweden
- 2022
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Ingår i: Natural Hazards. - : Springer Nature. - 0921-030X .- 1573-0840. ; 112:3, s. 2549-2576
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Tidskriftsartikel (refereegranskat)abstract
- Landslides may cause severe destruction that affects both the individuals and functions vital for society. Minor landslides in an area with quick clay may trigger secondary slides, influencing a much greater area compared to slides in areas with no quick clay. Today's expanding societies demand new areas for exploitation. To effectively meet this demand, there is an increased need to identify areas where quick clay may occur. Direct or indirect methods for assessing the presence of quick clay have previously been presented as well as a strategy for site investigations in quick clay areas. In this article, a methodology for mapping quick clays for the Swedish conditions with methods commonly available in this area is presented. The methodology presented in the article is structured in steps with different levels of detail and visualized with two conceptual flowcharts. Depending on the stage of planning, different types of surveys are recommended. The methodology has been applied at four sites where integrated interpretation of airborne and ground geophysical measurements as well as geotechnical investigations have been carried out. The results from two of these sites are presented here. The study reveals that all the methods used have their advantages and limitations. However, a combined use of the information provides much more accurate interpretation that can be used for a more cost-effective future planning and decision-making.
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