Geosciences

Research

Jump to: Review

14 pages, 8677 KiB

Open AccessArticle

Hazard Assessment of Storm Events for the Portuguese Northern Coast

by Mariana Peixoto Gomes, Lara Santos, José Luís Pinho and José S. Antunes do Carmo

Geosciences 2018, 8(5), 178; https://doi.org/10.3390/geosciences8050178 - 14 May 2018

Cited by 9 | Viewed by 3874

Abstract

Coastal zones currently face severe weaknesses and are subject to high-risk situations. Tropical storm events can contribute to the occurrence of these high-risk situations by causing storm surges with high water levels and, consequently, episodes of wave-overtopping and coastal flooding. This work considers [...] Read more.

Coastal zones currently face severe weaknesses and are subject to high-risk situations. Tropical storm events can contribute to the occurrence of these high-risk situations by causing storm surges with high water levels and, consequently, episodes of wave-overtopping and coastal flooding. This work considers a series of storm scenarios and analyzes their impacts through numerical modeling. Firstly, historical storm tracks and intensities are characterized for the Portuguese northern coast in terms of probability of occurrence. Secondly, several storm events with a high potential of occurrence are generated using a specific tool of the DelftDashboard interface for Delft3D software. Hydrodynamic models are then used to generate an ensemble of simulations to assess the storms’ effects on coastal water levels. Based on the statistical data of the numerical modeling results, a synthesis of the coastal storms’ impacts at different locations within the study area is performed. Depending on the storm category, surge heights can reach 1.10 m above tide levels under simulated conditions on the Portuguese northwestern coast. Full article

(This article belongs to the Special Issue Natural Hazards and Risks Assessment)

► Show Figures

Figure 1

19 pages, 17798 KiB

Open AccessArticle

Implications of Landslide Typology and Predisposing Factor Combinations for Probabilistic Landslide Susceptibility Models: A Case Study in Lajedo Parish (Flores Island, Azores—Portugal)

by Rui Fagundes Silva, Rui Marques and João Luís Gaspar

Geosciences 2018, 8(5), 153; https://doi.org/10.3390/geosciences8050153 - 27 Apr 2018

Cited by 10 | Viewed by 5153

Abstract

The main objective of this study is to better understand and quantify the consequences for landslide susceptibility assessment caused by (i) the discrimination (or not) of landslide typology and (ii) the use of different predisposing factor combinations. The study area for this research [...] Read more.

The main objective of this study is to better understand and quantify the consequences for landslide susceptibility assessment caused by (i) the discrimination (or not) of landslide typology and (ii) the use of different predisposing factor combinations. The study area for this research was Lajedo parish (Flores Island, Azores—Portugal). For the landslide susceptibility modeling, 12 predisposing factors and a historical landslide inventory with a total of 474 individual landslide rupture areas were used as inputs, and the Information Value method was then applied. It was concluded that susceptibility models developed specifically for each landslide typology achieve better results when compared to the model developed for the total inventory, which suffers from a bias caused by the strong spatial abundance of one landslide typology. A total of 4095 susceptibility models were tested for each typology, and the best models were selected according to their goodness of fit. The best model for both falls and slides has seven predisposing factors, some of which do not correspond to the factors that have the best individual discriminatory capabilities. The number of expected and observed unique terrain conditions for each model allowed us to conclude that with the successive addition of predisposing factors, there is an inability of the territory to generate new observed unique terrain conditions. This consequence was directly related to the inability to increase the goodness of fit of the computed models. For each landslide typology, the predictive capacity of the best susceptibility model was assessed by computing the Prediction Rate Curves and the Area Under the Curve. Full article

(This article belongs to the Special Issue Natural Hazards and Risks Assessment)

► Show Figures

Figure 1

22 pages, 6457 KiB

Open AccessArticle

Regional Scale Sea Cliff Hazard Assessment at Sintra and Cascais Counties, Western Coast of Portugal

by Fernando Marques

Geosciences 2018, 8(3), 80; https://doi.org/10.3390/geosciences8030080 - 26 Feb 2018

Cited by 12 | Viewed by 5847

Abstract

Mass movements of different types and sizes are the main processes of sea cliff evolution, being a considerable natural hazard, the assessment of which is a relevant issue in terms of human loss prevention and land use regulations. To predict the occurrence of [...] Read more.

Mass movements of different types and sizes are the main processes of sea cliff evolution, being a considerable natural hazard, the assessment of which is a relevant issue in terms of human loss prevention and land use regulations. To predict the occurrence of future failures affecting the cliff top in slow retreating cliffs, a study was made using the logistic regression statistical method, a set of predisposing factors mainly related with geology (lithology, structure, faults), geomorphology (maximum, mean and standard variation of slope angle, height, aspect, curvatures, toe protection) and near offshore mean annual wave power, which were correlated with an aerial photo interpretation based inventory of cliff failures occurred in a 63 years period (1947–2010). The susceptibility model was validated against the inventory data using standard Receiver Operator Curves, which provided area under the curve (AUC) values higher than 0.8. In spite of the room for improvement of cliff failure inventories and predisposing factors to be used in these types of studies, namely those related to the rock mass strength and wave power nearshore, the results obtained indicate that the proposed approach is an effective contribution for objective and quantitative hazard assessment. Full article

(This article belongs to the Special Issue Natural Hazards and Risks Assessment)

► Show Figures

Figure 1

20 pages, 34738 KiB

Open AccessArticle

Probabilistic Approach to Provide Scenarios of Earthquake-Induced Slope Failures (PARSIFAL) Applied to the Alcoy Basin (South Spain)

by Salvatore Martino, Simona Battaglia, Josè Delgado, Carlo Esposito, Guido Martini and Cristina Missori

Geosciences 2018, 8(2), 57; https://doi.org/10.3390/geosciences8020057 - 6 Feb 2018

Cited by 14 | Viewed by 5053

Abstract

The PARSIFAL (Probabilistic Approach to pRovide Scenarios of earthquake-Induced slope FAiLures) approach was applied in the basin of Alcoy (Alicante, South Spain), to provide a comprehensive scenario of earthquake-induced landslides. The basin of Alcoy is well known for several historical landslides, mainly represented [...] Read more.

The PARSIFAL (Probabilistic Approach to pRovide Scenarios of earthquake-Induced slope FAiLures) approach was applied in the basin of Alcoy (Alicante, South Spain), to provide a comprehensive scenario of earthquake-induced landslides. The basin of Alcoy is well known for several historical landslides, mainly represented by earth-slides, that involve urban settlement as well as infrastructures (i.e., roads, bridges). The PARSIFAL overcomes several limits existing in other approaches, allowing the concomitant analyses of: (i) first-time landslides (due to both rock-slope failures and shallow earth-slides) and reactivations of existing landslides; (ii) slope stability analyses of different failure mechanisms; (iii) comprehensive mapping of earthquake-induced landslide scenarios in terms of exceedance probability of critical threshold values of co-seismic displacements. Geotechnical data were used to constrain the slope stability analysis, while specific field surveys were carried out to measure jointing and strength conditions of rock masses and to inventory already existing landslides. GIS-based susceptibility analyses were performed to assess the proneness to shallow earth-slides as well as to verify kinematic compatibility to planar or wedge rock-slides and to topples. The experienced application of PARSIFAL to the Alcoy basin: (i) confirms the suitability of the approach at a municipality scale, (ii) outputs the main role of saturation in conditioning slope instabilities in this case study, (iii) demonstrates the reliability of the obtained results respect to the historical data. Full article

(This article belongs to the Special Issue Natural Hazards and Risks Assessment)

► Show Figures

Figure 1

11 pages, 6689 KiB

Open AccessCommunication

Landslide Event on 24 June in Sichuan Province, China: Preliminary Investigation and Analysis

by Wanlin Meng, Yeshuang Xu, Wen-Chieh Cheng and Arul Arulrajah

Geosciences 2018, 8(2), 39; https://doi.org/10.3390/geosciences8020039 - 23 Jan 2018

Cited by 16 | Viewed by 6403

Abstract

This paper reports on a massive landslide event, in which 8 million cubic meters of earth and rocks slid down from the top of a mountain in the village of Xinmo, located in the county of Maoxian, in the province of Sichuan, China, [...] Read more.

This paper reports on a massive landslide event, in which 8 million cubic meters of earth and rocks slid down from the top of a mountain in the village of Xinmo, located in the county of Maoxian, in the province of Sichuan, China, on 24 June 2017. This landslide resulted in 10 fatalities and 73 people were reported as missing. This paper details the preliminary investigation, the joint-force rescue activity, and the analysis of the nearby topography, rainfall, and seismic fracture zone. The combined effects of large amounts of rainwater, steep topography, deep-seated sliding interface, and significant altitude difference between the highest point of the mountain and the Xinmo villagers’ houses are considered as the main influencing factor that triggered this landslide event. To develop geological disaster-prone areas in the future, four main recommendations to reduce casualties and environmental impacts are provided in this paper. Full article

(This article belongs to the Special Issue Natural Hazards and Risks Assessment)

► Show Figures

Figure 1

24 pages, 27705 KiB

Open AccessArticle

Kinematic Reconstruction of a Deep-Seated Gravitational Slope Deformation by Geomorphic Analyses

by Stefano Morelli, Veronica Pazzi, William Frodella and Riccardo Fanti

Geosciences 2018, 8(1), 26; https://doi.org/10.3390/geosciences8010026 - 18 Jan 2018

Cited by 24 | Viewed by 6779

Abstract

On 4 November 2010, a deep-seated gravitational slope deformation (North Italy) reactivated with sudden ground movement. A 450,000 m² mountainous area moved some metres downslope, but the undeniable signs were only connected to the triggering of a debris flow from the bulging [...] Read more.

On 4 November 2010, a deep-seated gravitational slope deformation (North Italy) reactivated with sudden ground movement. A 450,000 m² mountainous area moved some metres downslope, but the undeniable signs were only connected to the triggering of a debris flow from the bulging area’s detrital cover and the presence of a continuous perimeter fracture near the crown area. Based on two detailed LiDAR surveys (2 m × 2 m) performed just a few days before and after the event, a quantitative topographic analysis was performed in a GIS environment, integrating morphometric terrain parameters (slope, aspect, surface roughness, hill shade, and curvature). The DEMs analysis highlighted some morphological changes related to deeper as well as shallow movements. Both global and sectorial displacements were widely verified and discussed, finally inferring that the geometry, persistence, and layout of all movements properly justify each current morphostructure, which has the shape of a typical Sackung-type structure with impulsive kinematics. Moreover, a targeted field survey allowed specific clues to be found that confirmed the global deduced dynamics of the slope deformation. Finally, thanks to a ground-based interferometric radar system (GB-InSAR) that was installed a few days after the reactivation, the residual deep-seated gravitational slope deformation (DSGSD) movements were also monitored. In the landslide lower bulging area, a localized material progression of small entities was observed for some months after the parossistic event, indicating a slow dissipation of forces in sectors more distant from the crown area. Full article

(This article belongs to the Special Issue Natural Hazards and Risks Assessment)

► Show Figures

Figure 1

19 pages, 5292 KiB

Open AccessArticle

Landslide Change Detection Based on Multi-Temporal Airborne LiDAR-Derived DEMs

by Omar E. Mora, M. Gabriela Lenzano, Charles K. Toth, Dorota A. Grejner-Brzezinska and Jessica V. Fayne

Geosciences 2018, 8(1), 23; https://doi.org/10.3390/geosciences8010023 - 16 Jan 2018

Cited by 43 | Viewed by 7354

Abstract

Remote sensing technologies have seen extraordinary improvements in both spatial resolution and accuracy recently. In particular, airborne laser scanning systems can now provide data for surface modeling with unprecedented resolution and accuracy, which can effectively support the detection of sub-meter surface features, vital [...] Read more.

Remote sensing technologies have seen extraordinary improvements in both spatial resolution and accuracy recently. In particular, airborne laser scanning systems can now provide data for surface modeling with unprecedented resolution and accuracy, which can effectively support the detection of sub-meter surface features, vital for landslide mapping. Also, the easy repeatability of data acquisition offers the opportunity to monitor temporal surface changes, which are essential to identifying developing or active slides. Specific methods are needed to detect and map surface changes due to landslide activities. In this paper, we present a methodology that is based on fusing probabilistic change detection and landslide surface feature extraction utilizing multi-temporal Light Detection and Ranging (LiDAR) derived Digital Elevation Models (DEMs) to map surface changes demonstrating landslide activity. The proposed method was tested in an area with numerous slides ranging from 200 m² to 27,000 m² in area under low vegetation and tree cover, Zanesville, Ohio, USA. The surface changes observed are probabilistically evaluated to determine the likelihood of the changes being landslide activity related. Next, based on surface features, a Support Vector Machine (SVM) quantifies and maps the topographic signatures of landslides in the entire area. Finally, these two processes are fused to detect landslide prone changes. The results demonstrate that 53 out of 80 inventory mapped landslides were identified using this method. Additionally, some areas that were not mapped in the inventory map displayed changes that are likely to be developing landslides. Full article

(This article belongs to the Special Issue Natural Hazards and Risks Assessment)

► Show Figures

Figure 1

13 pages, 4584 KiB

Open AccessArticle

Meteorological Patterns Linked to Landslide Triggering in Asturias (NW Spain): A Preliminary Analysis

by Pablo Valenzuela, Miguel Iglesias, María José Domínguez-Cuesta and Manuel Antonio Mora García

Geosciences 2018, 8(1), 18; https://doi.org/10.3390/geosciences8010018 - 10 Jan 2018

Cited by 13 | Viewed by 4941

Abstract

Asturias is one of the most landslide prone areas in the north of Spain. Most landslides are linked to intense and continue rainfall events, especially between October and May. This fact points out precipitation as the main triggering factor in the study area. [...] Read more.

Asturias is one of the most landslide prone areas in the north of Spain. Most landslides are linked to intense and continue rainfall events, especially between October and May. This fact points out precipitation as the main triggering factor in the study area. Thirteen rainfall episodes that caused 1064 landslides between 2008 and 2016 have been selected for its study. Landslide records come from the Principality of Asturias Landslide Database (BAPA) and meteorological data from the Spanish Meteorological Agency (AEMET). Meteorological conditions which took place during each period have been characterized by using NCEP/NCAR Reanalysis data. Four main landslide-triggering meteorological patterns have been identified for the Asturian territory: Strong Atlantic Anticyclone pattern (SAA), Atlantic Depression pattern (AD), Anticyclonic ridge pattern (AR) and Cut-off Low pattern (CL). Full article

(This article belongs to the Special Issue Natural Hazards and Risks Assessment)

► Show Figures

Figure 1

18 pages, 12975 KiB

Open AccessArticle

Earthquake Magnitude and Shaking Intensity Dependent Fragility Functions for Rapid Risk Assessment of Buildings

by Marie-José Nollet, Ahmad Abo El Ezz, Oliver Surprenant, Alex Smirnoff and Miroslav Nastev

Geosciences 2018, 8(1), 16; https://doi.org/10.3390/geosciences8010016 - 9 Jan 2018

Cited by 5 | Viewed by 5589

Abstract

An integrated web application, referred to as ER² for rapid risk evaluator, is under development for a user-friendly seismic risk assessment by the non-expert public safety community. The assessment of likely negative consequences is based on pre-populated databases of seismic, building inventory [...] Read more.

An integrated web application, referred to as ER² for rapid risk evaluator, is under development for a user-friendly seismic risk assessment by the non-expert public safety community. The assessment of likely negative consequences is based on pre-populated databases of seismic, building inventory and vulnerability parameters. To further accelerate the computation for near real-time analyses, implicit building fragility curves were developed as functions of the magnitude and the intensity of the seismic shaking defined with a single intensity measure, input spectral acceleration at 1.0 s implicitly considering the epicentral distance and local soil conditions. Damage probabilities were compared with those obtained with the standard fragility functions explicitly considering epicentral distances and local site classes in addition to the earthquake magnitudes and respective intensity of the seismic shaking. Different seismic scenarios were considered first for 53 building classes common in Eastern Canada, and then a reduced number of 24 combined building classes was proposed. Comparison of results indicate that the damage predictions with implicit fragility functions for short (M ≤ 5.5) and medium strong motion duration (5.5 < M ≤ 7.5) show low variation with distance and soil class, with average error of less than 3.6%. Full article

(This article belongs to the Special Issue Natural Hazards and Risks Assessment)

► Show Figures

Figure 1

3322 KiB

Open AccessArticle

Understanding Constraints and Triggering Factors of Landslides: Regional and Local Perspectives on a Drainage Basin

by Carlos César Jesus, Sérgio C. Oliveira, Clara Sena and Fernando Marques

Geosciences 2018, 8(1), 2; https://doi.org/10.3390/geosciences8010002 - 26 Dec 2017

Cited by 8 | Viewed by 4679

Abstract

The Grande da Pipa River (GPR) basin (Portugal) has natural conditions that favor the occurrence of landslides. The hydrological year 2009/10 was characterized by high amounts of rainfall, which led to the occurrence of an also high number of landslides in this basin. [...] Read more.

The Grande da Pipa River (GPR) basin (Portugal) has natural conditions that favor the occurrence of landslides. The hydrological year 2009/10 was characterized by high amounts of rainfall, which led to the occurrence of an also high number of landslides in this basin. The hydrodynamic character of the GPR basin was analyzed through a lumped parameter model of daily sequential water balances, in order to understand its influence in the stability of natural slopes. Results from the model were confronted to the inventory of landslides that occurred in the basin during the hydrological year 2009/10. Morphological, geotechnical, and hydrological local conditions affecting slope stability were also analyzed through back-analyses of two selected deep-seated landslides. Data here presented shows that the rise of water table is an important triggering factor for landslides. The most important constraint for landslides in the area is the degree of weathering and thickness of the upper layer of degraded marls. In most of the basin, the degraded layer is less than 5 m deep, causing the occurrence of shallow and intermediate landslides. However, deep-seated landslides were also found in areas, even with degraded marls that were less than 5 m-thick, where landslides have also occurred in the past. Full article

(This article belongs to the Special Issue Natural Hazards and Risks Assessment)

► Show Figures

Figure 1

4392 KiB

Open AccessArticle

Engineering Applications Using Probabilistic Aftershock Hazard Analyses: Aftershock Hazard Map and Load Combination of Aftershocks and Tsunamis

by Byunghyun Choi, Akemi Nishida, Tatsuya Itoi and Tsuyoshi Takada

Geosciences 2018, 8(1), 1; https://doi.org/10.3390/geosciences8010001 - 22 Dec 2017

Cited by 6 | Viewed by 4926

Abstract

After the Tohoku earthquake in 2011, we observed that aftershocks tended to occur in a wide region after such a large earthquake. These aftershocks resulted in secondary damage or delayed rescue and recovery activities. In addition, it has been reported that there are [...] Read more.

After the Tohoku earthquake in 2011, we observed that aftershocks tended to occur in a wide region after such a large earthquake. These aftershocks resulted in secondary damage or delayed rescue and recovery activities. In addition, it has been reported that there are regions where the intensity of the vibrations owing to the aftershocks was much stronger than those associated with the main shock. Therefore, it is necessary to consider the seismic risk associated with aftershocks. We used the data regarding aftershocks that was obtained from the Tohoku earthquake and various other historically large earthquakes. We investigated the spatial and temporal distribution of the aftershocks using the Gutenberg–Richter law and the modified Omori law. Subsequently, we previously proposed a probabilistic aftershock occurrence model that is expected to be useful to develop plans for recovery activities after future large earthquakes. In this study, the probabilistic aftershock hazard analysis is used to create aftershock hazard maps. We propose a hazard map focusing on the probability of aftershocks on the scale of the main shock for use with a recovery activity plan. Following the lessons learned from the 2011 Tohoku earthquake, we focus on the simultaneous occurrence of tsunamis and aftershocks just after a great subduction earthquake. The probabilistic aftershock hazard analysis is used to derive load combination equations of the load and resistance factor design. This design is intended to simultaneously consider tsunamis and aftershocks for tsunami-resistant designs of tsunami evacuation buildings. Full article

(This article belongs to the Special Issue Natural Hazards and Risks Assessment)

► Show Figures

Figure 1

505 KiB

Open AccessArticle

Mainstreaming Multi-Risk Approaches into Policy

by Anna Scolobig, Nadejda Komendantova and Arnaud Mignan

Geosciences 2017, 7(4), 129; https://doi.org/10.3390/geosciences7040129 - 12 Dec 2017

Cited by 41 | Viewed by 7241

Abstract

Multi-risk environments are characterized by domino effects that often amplify the overall risk. Those include chains of hazardous events and increasing vulnerability, among other types of correlations within the risk process. The recently developed methods for multi-hazard and risk assessment integrate interactions between [...] Read more.

Multi-risk environments are characterized by domino effects that often amplify the overall risk. Those include chains of hazardous events and increasing vulnerability, among other types of correlations within the risk process. The recently developed methods for multi-hazard and risk assessment integrate interactions between different risks by using harmonized procedures based on common metrics. While the products of these assessments, such as multi-hazard and -risk indexes, maps, cascade scenarios, or warning systems provide innovative and effective information, they also pose specific challenges to policy makers and practitioners due to their novel cross-disciplinary aspects. In this paper we discuss the institutional barriers to the adoption of multi-risk approaches, summarizing the results of the fieldwork conducted in Italy and Guadeloupe and of workshops with disaster risk reduction practitioners from eleven European countries. Results show the need for a clear identification of responsibilities for the implementation of multi-risk approaches, as institutional frameworks for risk reduction remain to this day primarily single-risk centered. Authorities are rarely officially responsible for the management of domino effects between e.g., tsunamis and industrial accidents, earthquake and landslides, floods and electricity network failures. Other barriers for the implementation of multi-risk approaches include the limited measures to reduce exposure at the household level, inadequate financial capacities at the local level and limited public-private partnerships, especially in case of interactions between natural and industrial risks. Adapting the scale of institutions to that of multi-risk environments remains a major challenge to better mainstream multi-risk approaches into policy. To address it, we propose a multi-risk governance framework, which includes the phases of observation, social and institutional context analysis, generation of multi-risk knowledge and stakeholder engagement processes. Yet, more research is needed in order to test the framework and to identify the hallmark characteristics of effective multi-risk governance. Full article

(This article belongs to the Special Issue Natural Hazards and Risks Assessment)

► Show Figures

Figure 1

10311 KiB

Open AccessArticle

Slope Stability Assessment Using Trigger Parameters and SINMAP Methods on Tamblingan-Buyan Ancient Mountain Area in Buleleng Regency, Bali

by I Nengah Sinarta, Ahmad Rifa’i, Teuku Faisal Fathani and Wahyu Wilopo

Geosciences 2017, 7(4), 110; https://doi.org/10.3390/geosciences7040110 - 28 Oct 2017

Cited by 18 | Viewed by 6112

Abstract

The mapping of soil movement was examined by comparing an extension of the deterministic Soil Stability Index Mapping (SINMAP) method, and an overlay method with trigger parameters of soil movement. The SINMAP model used soil parameters in the form of the cohesion value [...] Read more.

The mapping of soil movement was examined by comparing an extension of the deterministic Soil Stability Index Mapping (SINMAP) method, and an overlay method with trigger parameters of soil movement. The SINMAP model used soil parameters in the form of the cohesion value (c), internal friction angle (φ), and hydraulic conductivity (k_s) for the prediction of soil movement based on the factor of safety (FS), while the indirect method used a literature review and field observations. The weightings of soil movement trigger parameters in assessments were based on natural physical aspects: (1) slope inclination = 30%; (2) rock weathering = 15%; (3) geological structure = 20%; (4) rainfall = 15%; (5) groundwater potential = 7%; (6) seismicity = 3%; and (7) vegetation = 10%. The research area was located in the Buleleng district, in particular in the ancient mountain area of Buyan-Tamblingan, in the Sukasada sub-district. The hazard mapping gave a high and very high hazard scale. The SINMAP model gave a validation accuracy of 14.29%, while the overlay method with seven trigger parameters produced an accuracy of 71.43%. Based on the analysis of the very high and high hazard class and the validation of the landslide occurrence points, the deterministic method using soil parameters and water absorption gave a much lower accuracy than the overlay method with a study of soil motion trigger parameters. Full article

(This article belongs to the Special Issue Natural Hazards and Risks Assessment)

► Show Figures

Figure 1

3766 KiB

Open AccessArticle

Comparison of Flood Frequency Analysis Methods for Ungauged Catchments in France

by Jean Odry and Patrick Arnaud

Geosciences 2017, 7(3), 88; https://doi.org/10.3390/geosciences7030088 - 18 Sep 2017

Cited by 21 | Viewed by 5860

Abstract

The objective of flood frequency analysis (FFA) is to associate flood intensity with a probability of exceedance. Many methods are currently employed for this, ranging from statistical distribution fitting to simulation approaches. In many cases the site of interest is actually ungauged, and [...] Read more.

The objective of flood frequency analysis (FFA) is to associate flood intensity with a probability of exceedance. Many methods are currently employed for this, ranging from statistical distribution fitting to simulation approaches. In many cases the site of interest is actually ungauged, and a regionalisation scheme has to be associated with the FFA method, leading to a multiplication of the number of possible methods available. This paper presents the results of a wide-range comparison of FFA methods from statistical and simulation families associated with different regionalisation schemes based on regression, or spatial or physical proximity. The methods are applied to a set of 1535 French catchments, and a k-fold cross-validation procedure is used to consider the ungauged configuration. The results suggest that FFA from the statistical family largely relies on the regionalisation step, whereas the simulation-based method is more stable regarding regionalisation. This conclusion emphasises the difficulty of the regionalisation process. The results are also contrasted depending on the type of climate: the Mediterranean catchments tend to aggravate the differences between the methods. Full article

(This article belongs to the Special Issue Natural Hazards and Risks Assessment)

► Show Figures

Figure 1

10619 KiB

Open AccessArticle

Historical Monitoring of Shoreline Changes in the Cua Dai Estuary, Central Vietnam Using Multi-Temporal Remote Sensing Data

by Nguyen Quang Tuan, Hoang Cong Tin, Luong Quang Doc and Tran Anh Tuan

Geosciences 2017, 7(3), 72; https://doi.org/10.3390/geosciences7030072 - 18 Aug 2017

Cited by 18 | Viewed by 6626

Abstract

Cua Dai is one of the major estuarine areas in Central Vietnam that plays a significant role in local maritime transport, fisheries, and tourism activities. This paper presents a study that monitored the shoreline dynamics of the Cua Dai estuary over a period [...] Read more.

Cua Dai is one of the major estuarine areas in Central Vietnam that plays a significant role in local maritime transport, fisheries, and tourism activities. This paper presents a study that monitored the shoreline dynamics of the Cua Dai estuary over a period of 50 years (1964–2014) by using field survey data, geographic information systems techniques, and multi-temporal satellite remote sensing images (ALOS-AVNIR2 and Landsat imageries). The assessment of shoreline changes was divided into three phases: 1964–1980, 1981–2000, and 2001–2014. The results revealed that over the last 50 years, shoreline changes dramatically occurred between 1964 and 1980. The general trends of erosion and accretion at the Cua Dai estuary show that the river mouth moved towards the south due to the erosion of shorelines in the north and the river bank in the south of the Cua Dai estuary. The study outcomes can provide essential information for planning, zoning, and sustainable development activities of the coastal zones in the context of climate change. Full article

(This article belongs to the Special Issue Natural Hazards and Risks Assessment)

► Show Figures

Figure 1

Review

Jump to: Research

50687 KiB

Open AccessReview

Analysis of Slope Sensitivity to Landslides by a Transdisciplinary Approach in the Framework of Future Development: The Case of La Trinité in Martinique (French West Indies)

by Yannick Thiery, Pierre-Alexandre Reninger, Frederic Lacquement, Anne Raingeard, Maeva Lombard and Aude Nachbaur

Geosciences 2017, 7(4), 135; https://doi.org/10.3390/geosciences7040135 - 19 Dec 2017

Cited by 13 | Viewed by 6415

Abstract

Landslide hazard and risk assessment (LHA & LRA) in the French West Indies is a big challenge, particularly in Martinique, where several factors contribute to high slope sensitivity to landslides. This sensitivity is particularly due to volcanic ground, hurricane seasons, and growing pressure [...] Read more.

Landslide hazard and risk assessment (LHA & LRA) in the French West Indies is a big challenge, particularly in Martinique, where several factors contribute to high slope sensitivity to landslides. This sensitivity is particularly due to volcanic ground, hurricane seasons, and growing pressure from urban development. Thus, to protect future goods and inhabitants and avoid increased slope sensitivity to landslide, it is necessary to analyze by different ways and complementary approaches the future planned areas. This research focuses on a site the City Council of ‘La Trinité’ wishes to develop. The goals consist of locating landslide-prone areas and providing some recommendations/indications for future projects. The site is characterized by a hilly topography alternating steep slopes, gentle slopes, and eroded areas and is located on a complex lithology (i.e., andesite, basalt, and weathered materials). By combining several approaches and techniques (geology, geomorphology, geophysics, and modeling), it is demonstrated that some areas are particularly susceptible to landslide, notably where colluviums are juxtaposed to highly weathered materials. The different documents produced, based on modeling and expert knowledge, combined with indications should allow the definition of new susceptibility classes, taking into account probable anthropic influence and development. Even if the temporal probability of the experimental documents is not taken into account, they help with refining knowledge of landslide-prone areas and different types of instability. The documents should be discussed with end users for future planning. Full article

(This article belongs to the Special Issue Natural Hazards and Risks Assessment)

► Show Figures

Figure 1

Journal Menu

Journal Browser

Natural Hazards and Risks Assessment

Share This Special Issue

Special Issue Editor

Special Issue Information

Keywords

Benefits of Publishing in a Special Issue

Published Papers (16 papers)

Research

Review

Further Information

Guidelines

MDPI Initiatives

Follow MDPI