Hazard Zonation Map Research Articles

A Study on Flood Hazard Zonation Mapping Based on GIS-driven Approach using Remote Sensing Data and Weighted Overlay Analysis (Woa) Model

Flood hazard mapping is crucial for identifying flood-prone areas and developing effective mitigation strategies. This study utilized a Weighted Overlay Analysis, which is one of the subjective model derived from Multi-Criteria Decision Support System (MCDA), to assess flood hazards in the Auranga watershed, India. Six key flood-inducing factors were selected, including topographic data such as elevation, slope, river distance, and flow length derived from remote sensing data of Digital Elevation Model and classified Land use/Land cover data, along with hydro-meteorological data of precipitation. Each dataset was standardized to a common scale to facilitate comparison and integration. Weights were assigned to the layers like elevation, slope, river distance, flow length, Land use/Land cover, and precipitation according to their significance in contributing to flood risk. These weighted layers were then combined using GIS tools like ArcGIS, resulting in a composite map that delineates areas with varying flood hazard zones. The final flood hazard map identified that approximately 914 sq. km (60.0%) of the study area was at high to very high flood risk, particularly in regions close to rivers, while around 97 sq. km (6.4%) exhibited very low flood hazard. The GIS-Weighted Overlay Analysis method proved effective in flood hazard zone mapping, especially when incorporating a greater number of parameters. This approach is widely recognized in environmental planning and risk assessment, especially in areas vulnerable to natural disasters like floods.

Landslide hazard zonation (LHZ) mapping of Doon Valley using multi-criteria analysis method based on remote sensing and GIS techniques

The occurrence of landslides is a costly and cataclysmic natural hazard that mainly occurs in hilly areas due to factors like earthquakes, cloud burst, extreme rainfall, human pressure, etc. leading to loss of biodiversity, property, and life. Effective and comprehensive landslide risk management is crucial to address landslide susceptibility. Utilizing remote sensing and Geographic Information System (GIS) techniques, this work focuses on the landslide hazard zonation (LHZ) mapping. The study is specifically conducted in the Doon Valley. These advanced technologies help in identifying and categorizing the areas prone to landslides. The Shuttle Radar Topography Mission (SRTM) Digital Elevation Model (DEM) data at 30 m resolution and Sentinel-2B data at 10 m resolution were used to perform the remote sensing and GIS operations in ArcGIS Software. Thematic layers such as Land Use/Land Cover (LULC), Slope, Geology, Soil Type, Elevation, Drainage Density, Vegetation, and Aspect were produced utilizing remote sensing and GIS data. The weighted overlay, a multi-criteria analysis method, was applied to assign attribute values to each thematic layer based on their importance, which was then combined to calculate the landslide hazard zone. The findings of this study demonstrate that landslides are more likely to occur near and above the Main Boundary Thrust/Fault (MBT). The high to very high hazard zone covers 16.64% of the total area, making landslides occurring more frequently. Additionally, the study found that the Doon Valley rivers’ upper segments are more susceptible to landslides than their lower segments. By integrating Remote Sensing and GIS techniques, it is possible to obtain extensive knowledge of regions prone to landslides. This information will be helpful for decision-makers and planners to reduce the impact of landslides in the near future.

GIS-based MCDM approach for landslide hazard zonation mapping in east Gojjam zone, central Ethiopia

Landslides are prevalent in the Ethiopian highlands, particularly in the east Gojjam zone, which is highly affected by landslide problems. This research was carried out in the east Gojjam zone, northwestern Ethiopia. The study area is part of an economically important area in the country, and it is the main source of water for the Grand Ethiopian Renaissance Dam (GERD). The main objective of this work was to undertake a detailed inventory of past landslide locations and prediction of present and future landslide hazards, as well as the preparation of a landslide zonation map in the East Gojjam zone by using the Analytical Hierarchy Process (AHP) with the GIS technique. The parameters used for this study were slope degree, slope aspect, land use and land cover, road proximity, rainfall, lithology, altitude, and river proximity. The various causative parameters were collected from the field, and suitable modifications were made to the thematic maps. Finally, the ratings for various parameters were used as the basis to prepare the LHZ map in GIS windows. The landslide susceptibility and inventory mapping were produced in the GIS environment. The results of the study show that the main driving factors for the landslide hazards in the area were river proximity, rainfall, and manmade activities. Validation of this LHZ map revealed that more than 80% of past landslides match within the "high hazard zone" and reasonably accepted the rationality of the adopted methodology. The considered parameters, as well as their evaluation of the production of LHZ-Map, were confirmed. The produced landslide inventory map is very important for urban planners, agricultural studies, environmentalists, and future landslide hazardous prevention and mitigation strategies.

Flood hazard mapping using GIS‐based AHP approach for Krishna River basin

AbstractFlood hazard mapping is an essential tool for determining the risk and susceptibility of flood‐prone locations. This constitutes various criteria and factors that require a methodical and comprehensive decision‐making framework. The analytic hierarchy process (AHP), the popular multi‐criterion decision‐making (MCDM) technique, which deals with the complicated problems, including qualitative and quantitative factor, is utilized in this study for developing flood hazard maps in integration with geographic information system (GIS). Flood hazard maps are developed for the Krishna River basin using AHP‐GIS. Digital elevation model, rainfall data, soil data and Landsat images are used to extract the various hazard indicators. Nine hazard indicators are employed in this study to prepare the thematic layers, which includes Topographical Wetness Index, elevation, slope rainfall, LULC, Normalized Difference Wetness Index, distance from river, soil type and drainage density. The thematic layers are combined in Arc GIS using weighted overlay method to prepare the flood hazard zonation maps. The hazard maps are classified in three categories as low, moderate and high hazard zones. For the Krishna River basin, 30 percent area was found in high hazard. The outcomes derived from the AHP‐GIS method are validated by comparing them with situational reports pertinent to the area, showcasing a robust agreement with the available dataset.

Hazard Assessment of Debris Flow: A Case Study of the Huiyazi Debris Flow

The Bailong River Basin is situated at the northeastern edge of the Qinghai–Tibet Plateau and the western transition zone of the Loess Plateau, characterized by steep terrain and heavy rainfall. This area experiences frequent occurrences of debris flows, posing serious threats to towns and construction projects. Focusing on the Huaiyazigou debris flow in the Bailong River Basin, numerical simulations of debris flow processes were conducted using Digital Surface Model (DSM) data with a resolution of 5 m × 5 m for various recurrence periods. The simulation results indicate that the debris flow develops rapidly along the gully after formation, decelerating and beginning to deposit upon reaching the cement plant area near the mouth of the gully, eventually merging into the Bailong River. The primary destructive modes of debris flow disasters encompass impact and burial. When encountering buildings, their flow characteristics manifest as deposition and diversion. A debris flow hazard classification model, based on intensity and recurrence periods, was established according to Swiss and Austrian standards, dividing the hazard into low, medium, and high levels. This method generated a debris flow hazard zone map, offering guidance for risk prevention and monitoring. This research demonstrates that using high-precision Digital Surface Models (DSM) can accurately represent the digital information of debris flow gully terrains and buildings. During the simulation process, it realistically reflects the characteristics of the debris flow movement, allowing for the more precise delineation of hazard zones.

Seismic hazard zonation map and definition of seismic actions for Greece in the context of the ongoing revision of EC8

The Greek National Annex for current Eurocode 8 has adopted the seismic hazard zonation map published in 2003 as part of the modifications to the Greek Seismic Code EAK 2000 (EAK 2003). This map, which followed the catastrophic earthquakes that hit the country between 1978 and 2001, includes three seismic hazard zones with peak ground acceleration (PGA) ranging between 0.16 and 0.36 g. In this paper, following the significant progress that has been made worldwide in the last two decades towards the improvement of the definition of seismic actions and the seismic hazard maps using fully probabilistic models, we make a complete proposal for the Greek National Annex of the ongoing revision of Eurocode 8, which includes a new seismic hazard zonation map for Greece, as well as a novel site categorization scheme and related site amplification factors. To this end, we use the results of the European Seismic Hazard Model, ESHM20, as reported by Danciu et al. (The 2020 update of the European Seismic Hazard Model: Model Overview, 2021) which will be adopted as informative reference for the seismic hazard at European level in the forthcoming revision of Eurocode 8 (CEN/EC8). The herein proposed ground shaking zonation for rock conditions includes five zones with PGA values ranging between 0.13 and 0.37 g. For each zone, two newly proposed ground motion parameters, i.e., Sα,475 and Sβ,475, are provided, which are the two parameters used for anchoring the elastic response spectrum as defined in CEN/EC8, along with all the other necessary parameters for the definition of the elastic response spectrum, including site amplification. The proposal for the new seismic zonation is supported by a preliminary investigation of the impact of its adoption on the seismic design of new structures and on the seismic risk of the current building stock in Greece, to help gain a better insight on how important the differences imposed by the new zonation might be for the end-users and the administration.

InSAR-based landslide hazard mapping and identification of at-risk infrastructures in a selected district of North Shewa Zone, Ethiopia.

The devastating nature of landslides demands a thorough understanding of their spatial distribution and the risks they pose to human settlements and infrastructural assets. In this study, we employed a combination of Interferometric Synthetic Aperture Radar (InSAR) and Geographic Information System (GIS) techniques to explore the western escarpment of the Main Ethiopian Rift, with a focus on selected districts within the northern Shewa Zone, Ethiopia. By analyzing the SAR data, we derived 28 displacement maps and utilized them to create a comprehensive landslide hazard zonation map. The results indicated significant ground displacement, particularly along the rift margins and areas characterized by rugged terrain. The hazard zones were classified based on their level of risk, with 44% classified as very low, 24% as low, 5% as moderate, 13% as high, and 14% as very high hazard zones. The accuracy of our results was evaluated using receiver operating characteristic (ROC) analysis, which was conducted utilizing landslide inventory data. The analysis demonstrated a remarkable area under the curve (AUC) value of 0.848, providing strong evidence for the validity of our findings. Additionally, our study involved a spatial and statistical assessment of major infrastructure, revealing that 20 to 28% of these properties were in hazard zones ranging from moderate to very high levels, which calls for efficient risk-reduction actions. Therefore, this finding enables stakeholders to identify high-risk areas, prioritize mitigation efforts, and minimize the impact of landslide disasters.

A depth-averaged SPH-FV landslide dynamic model for evaluating hazard zones

Thousands of landslides worldwide lead to significant casualties and property damage. A numerical model is crucial for simulating the runout of possible future landslides and generating reliable hazard zone maps. Two main methods can be adopted to simulate motion: one based on the Eulerian description and the other based on the Lagrangian description. Each description offers varying adaptability to simulating landslides. In this paper, we proposed a method of coupling the depth-averaged smoothed particle hydrodynamics (SPH) method and a finite volume scheme with the van Leer splitting (FV-VLS). For the solid phase, we utilized the depth-averaged SPH method to simulate the movement process. The SPH method can track the movement of key parts. In contrast, we employed the FV-VLS based on the Eulerian description to reduce the calculation amount. In 1-D dam break simulation, both the depth-averaged SPH and FV-VLS methods yielded similar results. The 1-D two-phase dam break simulation shows that buoyancy reduces friction and lateral solid stress, increases hydraulic stress, and generates a complex motion process. The Yigong landslide simulation indicates that solid fractions will affect the motion trajectory in the 2-D simulation. A smaller solid fraction will cause the landslide to affect a larger area.

Tunnel Stability Analysis Under Seismic Load Using Finite Element Method: A Case Study of Spillway Tunnel, Sidan Dam, Bali, Indonesia

The location of the Sidan Spillway Tunnel, as shown on the Earthquake Hazard Zone Map of Bali Island, is in a moderate hazard zone. The support system of the spillway tunnel of the Sidan Dam, Indonesia, was empirically designed based on rock mass classification systems. The objective of this research was to verify the performance of the proposed support system by a numerical method considering the uncertainty in using rock mass classification systems for designing a tunnel support system. In addition, being located in an active seismic region, the seismic load was not considered in the empirical tunnel support design. The proposed tunnel support design was numerically modeled in two dimensions using a finite element method and subjected to a seismic load obtained from probabilistic seismic hazard analysis. A numerical analysis without seismic load was also conducted for comparison. Phase2 software was used for the tunnel stability analysis. The input parameters in the numerical analysis were derived from field investigations (surface engineering geological mapping and evaluation of drilling cores) and laboratory tests. The spillway tunnel area consists of pyroclastic rocks, and the Generalized Hoek-Brown Failure Criterion was selected for the strength parameter of rocks. The suggested support designs are systematic rock bolts (20 mm diameter fully grouted), wired mesh, shotcrete, and steel ribs at specific locations. The numerical models determined that applying the proposed tunnel support system recommended based on the empirical method resulted in a roof strength factor of more than 1.5 under static load & 1.1 under seismic load and roof displacements lower than a 10 cm maximum displacement at every stage of construction. The results verify that the tunnel construction will be stable and fulfill the required safety standard, both under and without seismic loads.

Landslide Hazard Zonation Mapping using MCDM Techniques – A study over Kodagu District, Karnataka

Landslides pose significant and recurring hazards in various parts of India, particularly during the rainy season, causing extensive damage to infrastructure and loss of life. To address this issue, it is crucial to map the hazardous zones, raise awareness among local communities and guide authorities in disaster management efforts. This study aimed to develop a landslide hazard zonation map using different thematic maps such as aspect, drainage density, geology, lineament density, land use land cover, rainfall, road network, slope and soil layers. The study employing methods such as AHP and a modified power method was based on AHP for the development of landslide hazard zonation maps. The findings indicated that the PM-AHP technique yielded superior results in identifying highly risky zones. According to this method, approximately 250.65 sq.km. of the area was classified as falling within the highly risky zone.

A Probabilistic Approach for Off-Stream Reservoir Failure Flood Hazard Assessment

Off-stream reservoirs are hydraulic structures that might cause severe flood damages in case of failure or improper operation. Their safety regulations usually require hydraulic studies for flood hazard and inundation zone mapping. The selection of the break point is not trivial because the topography in its surroundings is commonly highly anthropic. A wrong selection would not provide the worst scenario in terms of maximum flood hazard extent. This work presents a probabilistic approach based on a stochastic definition of the break point along the dyke. A number of failure scenarios are generated automatically, corresponding to different breach formations. Then, an in-cascade calculation process simulates each scenario, providing a framework to carry out statistical analysis. The simulation of the breach formation and the flood wave propagation is performed through a GPU parallelised two-dimensional hydraulic numerical model, which provides a probabilistic inundation zone and flood hazard mapping of all scenarios simulated in a suitable timeframe.

Landslide hazard zonation using Bivariate Frequency Ratio Method along National highway-1 from Baramulla-Uri Road stretch, North Kashmir Himalayas, India

The study focuses on the application of frequency ratio method (FRM) for the creation of landslide hazard map along the National Highway-1(NH-1) road between Baramulla and Uri in North Kashmir Himalaya, India. The landslide hazard zonation (LHZ) map was prepared by integrating all the landslide-inducing factors with frequency ratio values. A database of notable landslides in the study area was integrated with the hazard map for validation. The overall study showed that 22.28% of the study area falls under very high and high hazard zones. Finally, the output map was validated using the 40% landslide validation data. Moreover, ROC curve method was utilized to validate the model which showed the acceptable result of 0.803 AUC value for the landslide hazard map of the study area. Therefore, LHZ map produced by this study can be used to guide planners or engineers in identifying safe zones for carrying out development projects and for future risk assessment studies in the study region.

Risk assessment and management of vulnerable areas to flash flood hazards in arid regions using remote sensing and GIS-based knowledge-driven techniques

Earth Observation from space has allowed characterizing, detecting, and managing natural hazards in spatiotemporal scale. Flash flood is the most frequent natural disaster that causes destruction to human lives, the economy, and infrastructure. Thus, developing a flash flood hazard zone (FFHZ) map is significant for comprehensive flash flood risk assessment and management to minimize its harmful effects, particularly in residential areas, because of climate change. Therefore, in this article, ten parameters derived from satellite images, including lithology, slope, topographic wetness index (TWI), Stream Power Index (SPI), Stream Transport Index (STI), Terrain Roughness Index (TRI), drainage density (Dd), distance to river, radar intensity map, and rainfall distribution map, were fused to predict the flood-vulnerable areas through GIS-based overlay analysis after normalization and assigning weight by applying Analytical Hierarchy Analysis (AHP). The findings allowed for the identification of the most vulnerable areas and provided an explanation for the flood's effects on New Qena City (NQC). The output FFHZs of the Wadi Qena Basin (WQB) were divided into six hazard zones, i.e., extreme hazard (6.86%), very strong (15.04%), strong (18.74%), moderate (22.58%), low (22.80%), and very low (13.98%) susceptibility. Furthermore, approximately 35% of the under-construction NQC is subject to the extreme to very serious hazards, as opposed to the extension area to NQC east of the Qena-Safaga Road. Interferometry Synthetic Aperture Radar (InSAR) change detection coherence (CCD) and spatiotemporal analysis of Landsat and Sentinel-2 data revealed steady changes in vegetation and infrastructure from 1984 to present. Based on GIS analyses about 10, and 14% of the NQC can be inundated if the flood extends 500, and 1000 m around the flood canal, respectively. Thus, several strategies were advised to safeguard the development projects, particularly the residential sections of the under construction NQC, including erecting four dams with a total capacity of 300 million m3, reinforce the dam at Wadi Shahadein, constructing concrete chevron bunds along the flood zone, and extending the depths of the flooding canal.

Hazard assessment of potential debris flow: A case study of Shaling Gully, Lingshou County, Hebei Province, China

The debris flows in the Taihang Mountain region in North China are basically triggered by rainstorms. Firstly, the debris flow susceptibility of the Shaling Gully, Lingshou County, Hebei Province, China was analyzed in this paper to evaluate its hazard and effect on the downstream proposed structures. Secondly, the maximum flow depth and velocity of the potential debris flow in Shaling Gully were numerically simulated based on the FLO-2D model, and the simulation results indicate that the flow depths under the 50-year and 100-year rainstorms will have some effect on the downstream proposed structures. With debris flow intensity classification, the hazard of potential debris flow in Shaling Gully was classified. According to the flow depths and velocities simulated by FLO-2D model, the ARCGIS10.8 software was adopted to optimize the hazard zones, and therefore the hazard zonation map was established. With consideration of simulation results under natural conditions and other factors such as gully feature, a 4 m high and 40 m wide retaining dam was designed. The numerical simulation results show that the retaining dam may decrease the debris flow hazard to a negligible level, which offers some beneficial reference to the subsequent engineering design for Shaling Gully.

Landslide Hazard Zonation of Tehri Reservoir Rim Area Using Modified LHEF Rating Scheme

The study aimed to utilize the capabilities of geospatial technology for landslide hazard evaluation factor (LHEF) scheme recorded in the Bureau of Indian Standard (BIS) code to prepare a landslide hazard zonation (LHZ) map of the Tehri reservoir rim area at the macro-scale. Multisource remote sensing data were visually and digitally interpreted to produces thematic layers and slope facet as recorded in BIS method. LHEF method is suited for meso and macro scale mapping thus, to broaden the scope of LHEF scheme, novel approaches were adopted namely, the mapping unit ‘slope facet’ was more precisely extracted through digital and visual interpretation of remote sensing data, the structural favorability map was extracted using photo-lineament density criteria. Additionally, two external factors, rainfall and seismicity were incorporated in LHEF rating scheme and used a matrix-based system to propose their combined rating. With the modified LHEF rating scheme, we have succeeded in identifying LHZ with reasonable accuracy. The bar chart method used to validate LHZ results that clearly indicated a high number of landslides falling in high to very high hazard zone conversely, very few landslides observed in low to very low hazard zone identified from current approach.

A Case Study on Watershed Study for Flood Mitigation of Belgavi Region, Karnataka, India using ArcGIS

During the monsoon season, many regions in India are prone to floods among which Belagavi district, Karnataka (the study area) is one of the most affected. It has suffered huge lives and property losses. This study focuses on areas of rainfall analysis, watershed area mapping, flood vulnerable areas mapping and possible mitigation measures. DEM analysis is used to understand flood risk assessment. The rainfall data is collected for three taluks which are more prone to flood. These are Athani, Chikodi, and Raibagh in Belgavi regions. The study area was analyzed by generating maps for soil type, lithology, geomorphology, land use, and land cover using ArcGIS software. Maps were obtained for the percentage of land contributing to each attribute. Further flood vulnerability mapping has to be done by creating weightage map considering factors such as drainage density, soil type,, precipitation, land use land cover, slope, and watershed compressed together by weighted overlay analysis, and the flood hazard zone map is developed to classify the areas into zones according to the risk of flooding which helps to suggest various non-structural mitigation measures.

Flood Hazard Zone Mapping of Kasari River Basin (Kolhapur, India), Using Remote Sensing and GIS Techniques

Flood Hazard Zone Mapping of Kasari River Basin (Kolhapur, India), Using Remote Sensing and GIS Techniques

Measurement of surface deformation related to the December 2018 Mt. Etna eruption using time-series interferometry and magma modeling for hazard zone mapping

Measurement of surface deformation related to the December 2018 Mt. Etna eruption using time-series interferometry and magma modeling for hazard zone mapping

Development and Application of Models for Landslide Hazards in Northern Pakistan

In this paper, new models were investigated and developed for landslide hazards in Muzaffarabad District, located in the Azad Jammu and Kashmir region of Pakistan. The influential factors used in the landslide modelling were land use/landcover (LULC), elevation, slope, slope aspect, rainfall, drainage, road, surface roughness, and topographic index. The GIS-based Analytic Hierarchy Process (AHP) model was applied by utilizing the database of 35 active landslides and their pixels present in classes of all influential factors. The mean landslide hazard values, obtained from the mean landslide hazard analysis, were used as hazard weightages in the AHP model for development of a landslide hazard zone map. The highest mean hazard values for: (i) bare soil in LULC was 14.6%; (ii) 600–800 m in elevation was 6.89%; (iii) 30°–35° in slope was 6%; (iv) S and SW in slope aspect was 9.01%; (v) 1350–1405 mm/yr in rainfall was 9.03%; (vi) 40–80 m in buffered drainage was 12.83%; (vii) 40–80 m in buffered road was 12.48%; (viii) 60–138 in surface roughness index was 10.99%; (ix) −1.74–−1.25 in topographic position index was 13.07%. The percentages of very low, low, moderate, high, and very high landslide hazard zones were 1.48%, 11.80%, 39.36%, 37.36%, and 9.57% respectively. The co-efficient of the determination (r2) value of 0.96 indicated a strong relationship between the model development and validation. Thus, landslide hazard zone map models and methodology indicated a very high accuracy. This landslide hazard zone map could be utilized for the landslide damages’ reduction and the planning and development of road and building infrastructures in the study area. Additionally, this research could be replicated in other landslide prone areas of Pakistan for the minimizing the damages of landslides.

Flood Risk Analysis of Upper Krishna Sub-Basin using GIS

Abstract: Floods are the most and repeatedly occurring destructive natural disaster due to an overflow of water submerges land which is basically dry. Generally, floods are occurring due to heavy rainfall or cloud bursting or manmade disturbance to nature, fast snowmelt, global warming or tropical cyclone or tsunami. In 2019, the Krishna River has faced very heavy rainfall and major floods which took the lives of approximately 500 people and nearly isolating 350 villages and leaving millions homeless. Here we studied the previous flood disaster at the basin of the Krishna River and processed the GIS environment using software tools. This facilitates exploring the data and methods that are mostly unexplored, and areas that have not lightened in the field of flood studies in Krishna basin. It is impossible to avoid floods and risk associated with flood, however it is possible to work on the flood reduction. Flood hazard mapping is to identify comparatively safe sites in high elevation with low risk is one of the powerful tools for this purpose. Flood hazard mapping flash flood will be beneficial for risk assessment. Management and emergency services during flood events. The objective of this paper is to generate flood hazard zonation maps of Upper Krishna sub-basin using GIS tools and satellite images. To do so, we use spatial data and SRTM DEMs with accuracy assessment is achieved by using check points, obtained by GPS observations. Runoff, surface slope, drainage density, distance to main channel and land use were considered causative factors. All used data are processed and integrated in an ArcMap and QGIS to prepare a final flood hazard map for Upper Krishna sub-basin. The areas in high risk flood zones are obtained by overlaying the flood hazard index map with the zone boundaries layer