High Hazard Zones Research Articles

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.

Preliminary Study of Landslide Hazard in Kutai Kartanegara Regency, East Kalimantan using Digital Elevation Model

The Kalimantan Island is part of the Sundaland crust, namely the Eurasian Continental Plate. The plate is moving to the southeast colliding with the Indo-Australian plate which is moving north. Whereas for Kutai Kartanegara Regency in the Kalimantan Island position is far from the collision zone, so it is relatively stable tectonically. This is important to research that is, due to tectonic processes that occurred earlier, resulting in the formation of geological structures, especially faults. The purpose of the study was to determine the morphotectonic and landslide hazards in the Kutai Kartanegara Regency, where this research was carried out quantitatively with data collection techniques, then analyse landslide hazards based on data; DEM (Digital Elevation Model) including the slope, slope direction, and slope length for vulnerability analysis, geological data from Regional Geological Maps, which include rock formations, distances from faults data and administrative boundary spatial data in the form of vector GIS for the preparation of landslide hazard maps. The result showing Kutai Kartanegara predominantly categorized as moderate to high hazard zone. The low hazard zone covering 9.88% area, moderate hazard zone covering 35.81% area, and 54.31% area is high hazard zone of landslide. The analysis showing that the hazard of the research area consist predominantly sedimentary rocks and controlled by structural geology identified as thrust fault, strike slip fault, and fold which include in Anticlinorium Samarinda. Those lithology and geological structure features along with the slope are identified as controlling factor to the landslide hazard in the research area.

Seismic performance of prefabricated steel tube-confined concrete circular pier

In this study, a prefabricated steel tube-confined concrete (PSTC) circular pier with a bottom grouted sleeve connection was developed to correct some limitations in typical precast concrete (PC) piers, such as over-dense grouting sleeves and insufficient energy dissipation capacity, thus promoting their use in high seismic hazard zones. To validate the performance of the proposed design, four scale models of an actual circular bridge pier, including two PSTC, one PC, and one cast-in-place (CIP) specimens, were fabricated and their seismic response under cyclic loading was investigated via quasi-static experimental and numerical tests. The seismic performance indices, hysteretic energy dissipation characteristics, skeleton curve, flexural strength, stiffness degradation, residual displacement, and ductility of the different specimens were compared. The experimental and numerical results indicated that, compared with the CIP and PC circular piers, the flexural strength and energy dissipation capacity of the PSTC piers were significantly improved owing to the confinement provided by the steel tube to the concrete core, their ductility and initial stiffness effectively increased, and the pier body stiffness (pier body curvature) was more uniformly distributed. Moreover, parametric finite element analyses of the PSTC pier under low-cycle reciprocating load were used to determine the influence of the steel tube thickness and strength on the seismic performance of the pier. It was found that an increase in the thickness and strength of the steel tube also increases the flexural strength, yield load, yield displacement and initial tangent stiffness of the PSTC circular pier. Consequently, this study demonstrates that PSTC piers are reliable and suitable for prefabricated bridge construction in high seismic hazard areas.

Social Distance detection using Deep Learning

Abstract: Our research paper presented below is about social distance among people in public places by utilizing Deep learning technique on captured video by at public place Camera for detecting and controlling distance between them so that virus spread can be contained. This application is created to give alarms to individuals for keeping social separation in jam-packed areas. The real time video used to analysis objects by using object detection method and YOLOv3 calculation. We can figure out whether individuals are following social separating or not and in view of that we are alarming by making alert. It is likewise chipping away at web cameras, CCTV, and so forth, and can identify individuals continuously. Thismight assist specialists with overhauling the design of public spots or to make preparatory moves to relieve high-hazard zones. The technology is useful in different fields likewise like independent vehicles, human activity acknowledgment, swarm investigation. Keywords: Social separating. Object identification. Swarm examination, Coronavirus

Zonation of Landslide Hazards Based on Frequency Ratio Modeling at Coonoor and Kothagiri Taluks of Nilgiri District, Tamil Nadu, India

A frequency ratio model is developed within the framework of a Geographic Information System (GIS) to map landslide hazards in a mountainous environment. The Nilgiri Hills (Mountains) of Tamil Nadu are prone to landslides; these landslides are typically the result of the structural failure of thick laterite soils that have been saturated by heavy rains during the monsoon season. The GIS based analysis in the present work incorporates the frequency ratio values from the existing landslides. The landslide inventory of paleoscars was located by a collection of existing historical reports. Detailed field surveys have been carried out in the study area. In the observation, 118 landslide locations were identified and mapped by GIS; out of that, 83 (70 %) locations were randomly selected for the training data set and the remaining 35 (30 %) cases were used for the model validation purposes. For spatial modeling, the landslide triggering parameters include active-passive slope, concave-plain-convex slope, drainage density, dissected-undissected slope, geology, geomorphology, lineament density, lineament frequency, lineament intersection density, land use / land cover, rainfall, regolith cover, shallow-moderate-steep slope, soil and water level for landslide hazard zonation. This model has been used to spatially classify the study area into three zones viz; high, moderate and low landslide hazard zones. The frequency ratio model was validated with the existing landslide location data using R-index method. The validation of the results showed that the values is 1115.23 in R-index as high hazard zone when R-index increases with the level of susceptibility. The obtained results will provide a basis for planning, risk reduction strategies and various developmental activities in the Nilgiri area.

Modified “Rockfall Hazard Rating System for Pakistan (RHRSP)”: An Application for Hazard and Risk Assessment along the Karakoram Highway, Northwest Pakistan

Rockfall is a natural mountain hazard posing a severe threat to people, infrastructure, and vehicles along the transportation corridors. In this research, the standard Rockfall Hazard Rating System (RHRS) is slightly modified for the mountainous terrains of Pakistan through the quantification of animal activity along the highways. In the modified Rockfall Hazard and Rating System for Pakistan (RHRSP), animal activity is scored based on permanent and random animal tracks, shallow and higher altitudes, and shoulder width. The model is applied along the Karakoram Highway (KKH), which traverses a suture between Besham and Dasu (≈78 km), for Rockfall hazard and risk assessment mapping. An inventory of rockfalls, topples, and debris slides is compiled at 30 stations. Results show that rockfalls are mostly of the wedge and topple type failures. Fifty-seven percent of the area falls under the very-high to high hazard zone, 18% under moderate hazard, and 25% covers the low to very low hazard zone. Sixty-seven percent of the stretch is at very-high to high risk, distributed from Dubair to Dasu. The main reason for this risk is associated with narrow road width and limited shoulder width for vehicles. The RHRSP model is also applicable for other highways with the same geological and morphological settings.

Landslide hazard zonation and evaluation around Debre Markos town, NW Ethiopia—a GIS-based bivariate statistical approach

The main purpose of this study was to perform landslide hazard zonation and evaluation around Debre Markos town, Northwest Ethiopia. This was achieved using a GIS-based bivariate statistical technique. Initially, a landslide inventory map containing information on past and active landslide locations was prepared. In this study, eight conditioning factors, including slope material (lithology and soil mass), elevation, aspect, slope, land use, land cover, curvature, distance to fault, and distance to drainage, were identified and integrated with the ArcGIS platform. Data were collected from field mapping, satellite images, and digital elevation models. All conditioning factors were statistically analyzed to determine their relationship to previous landslides. The hazard map revealed that 17.15% (40.60 km2) of the study area falls under no hazard zone, 25.53% (60.45 km2) in low hazard zone, 28.04% (66.39 km2) in moderate hazard zone, 18.93% (44.83 km2) in high hazard zone, and the remaining 10.36% (24.54 km2) in very high hazard zone. The validation of the landslide hazard zonation map shows that 94% of past landslides fall in high or very high hazard zones, while 3% fall in moderate hazard zone, 2% fall in low hazard zone, and 1% fall in no hazard zone. The validation of the LHZ map thus, reasonably showed that the adopted methodology produced satisfactory results. The delineated hazard zones may practically be applied for the regional planning and development of infrastructures in the area. The results also indicated that slope angle, distance to fault, distance to drainage, and slope material types were statistically significant in controlling the landslides.

Landslide Hazard Assessment and Zonation by using Slope Susceptibility Evaluation Parameter (SSEP) Rating Scheme- a Case from Debre Sina, Northern Ethiopia

Rainfall-induced landslides of different types and sizes frequently affect the hilly and mountainous terrains of the highlands of Ethiopia. The principal objective of the proposed research study was intended to prepare a landslide hazard zonation map of the area, particularly for hazardous zones. In the present study, the Slope Susceptibility Evaluation Parameter rating scheme has been implemented as a relevant approach to map the landslide hazard of the Debresina area, which has experienced slope failure problems for a long period of time. The geology of the area includes quaternary sediments, ignimbrite, rhyolite, different kinds of basalts, and tuff deposits, which are highly weathered and changed into unconsolidated sediments at some localities. Locally observed geological structures such as joints, dykes, and other discontinuities have a considerable role in the initiation of landslide hazards. As a general methodology, a facet map was prepared from a topographic map (1:50,000) and rating values were assigned to each causative parameter (both intrinsic and external) based on its severity in triggering landslide hazard. The study area was classified into three hazard classes, of which 25 % of the slopes fall into a moderate hazard zone, while 58 % and 17 %were found to be high and very high hazard zones, respectively. Validation of the landslide hazard zonation map with past landslide activities suggests the rationality of the considered governing parameters, the adopted technique, tools, and procedures in developing the study area's landslide hazard map. Further, in order to validate the landslide hazard map prepared during the present study, active landslide activities and potential instability areas, delineated through inventory mapping, were overlaid on it, which yielded promising results.

Implications and inclusion of size-dependent scenario earthquakes on landslide hazard zonation: A case study of the Indian Himalayas

Seismically induced landslide hazard zonation (LHZ) studies typically examine the correlation between the magnitude of a single earthquake event with the spatial patterns of coseismic landslides. However, studies on the impact of different scenario earthquakes (in terms of their return periods) on landslide hazards are found to be rare, especially in case of the Himalayas. The study presents a novel approach to integrate scenario earthquakes generated probabilistically for different return periods with the persistent landslide hazards in the Himalayas. The Peak Ground Acceleration (PGA) is estimated for scenario earthquakes with 10, 50, 100, 225, and 475 years return periods. A dynamic weightage system is developed to rank the scenario earthquakes. Subsequently five LHZ maps under different seismic conditions have been prepared. The results indicate that the maximum static Landslide Potential Index (LPI) for the study area increased by 25% and 35% respectively when scenario earthquakes with return periods of 225 and 475 years were considered. When the scenario earthquake with 475 years return period was considered, 51% of the total area fell in the very high landslide hazard zone. Even with a moderate earthquake size viz. 100 years’ return period, the seismic LHZ map demarcated 28% of the study area as very high landslide hazard zone. This was an approximately 211% spatial increment for the same zone corresponding to the static landslide susceptibility map that excluded the seismic factor. The trend (significant areal increments for the high and very high landslide hazard zones) remains the same in all scenario earthquakes. Based on the results, the study concludes that seismicity becomes the main landslide causative factor for moderate to great earthquakes. Thus, it is recommended to include earthquake parameters for a more pragmatic evaluation of the landslide hazard in seismically active mountain belts.

Numerical analyses of embankment dams containing plastic concrete cut-off walls using finite difference method (A case study: The Karkheh Embankment Dam)

In this paper, numerical analyses have been performed on the Karkheh embankment dam with a clayey core and plastic concrete cut-off wall during construction, impounding, and permanent seepage stages. The dam has 127 meters height and is located in a high seismic hazard zone in Iran. Different stages of construction, water impounding, and steady state seepage were modelled and analyzed using the hyperbolic and Mohr-Coulomb models with the two dimensional finite difference method (FDM). So, nonlinear analyses were performed using FLAC 2D to investigate the settlements and the pore water pressure changes in different zones of the dam during above-mentioned stages and the results were compared to those of the other studies. The results show that at the end of the construction stage, the maximum settlement equal to 1.45m occurs inside the clay core at the height of 65m. Then, after impounding of the reservoir and steady state stage, the maximum magnitude of the horizontal deformations occurs in the downstream of the dam equal to 0.55m; however, these magnitudes reach to 0.17m at the crest of the dam. Moreover, it was shown that the maximum horizontal displacement of the plastic concrete cut-off wall has happened at the top of the wall in the clay core which is in a good agreement with the other studies’ result.

Reducing sea cliffs hazards in pocket beaches through beach nourishment on the Barlavento Coast (Algarve, Portugal)

Tourism based on “sun and beach” is the main economic activity in the Algarve region. A considerable part of the beaches of the Barlavento coast corresponds to embedded sand accumulated along the irregular lacework-like coastline of rocky cliffs cut into Miocene calcarenites. The pattern of touristic occupation in the Algarve and the geodynamics of the rocky sea cliffs, characterized by discontinuous and intermittent occurrence of slope mass movements, result in a high level of risk to beach users along pocket beaches. In order to mitigate the risk associated with the cliff geodynamics, artificial beach nourishment was performed in Castelo and Coelha pocket beaches on the Barlavento Coast, in 2014, increasing the beach area by 3.5 times. The effects of the beach nourishment on the occupation patterns of those beaches along the 2006-2016 decade, before and after the beach nourishment, are herein presented and discussed. Occupancy data were obtained covering different seasons along the year, by counting the number of beach users, regardless of age, using periodic and systematic photographs taken at strategic points that provide full coverage of the beach areas. Before the beach nourishments the area of dry sand outside high and moderate hazard zones, measured at half-tide under average summer wave conditions was 500 m2 at Coelha beach and 800 m2 at Castelo beach. After beach nourishment the same area increased to 6700 m2 at Coelha beach and 7100 m2 at Castelo beach. Results show that, following the beach fill, beach occupation by recreational users naturally shifted seaward, moving out from the cliff hazard areas. After the intervention, the occupation of high and moderate hazard areas reduced significantly, from 37 % to 11 % in Castelo beach and from 59 % to 27 % in Coelha beach. Keywords: beach nourishment; hazard; rocky cliffs; Algarve; Portugal.

The Modeling of Tsunami Wave Run-Up and Vulnerability Zone Analysis In Cipatujah, Tasikmalaya District

Cipatujah is a sub-district in Tasikmalaya Regency, West Java Province, Indonesia, which is one of the areas affected by significant damage due to tectonic activity in the southern region of Java, namely an earthquake with a magnitude of 7.7 magnitude and West Java tsunami in 2006 after Nusa Kambangan and PangandaranThe purpose of this study is to estimate the tsunami travel time, wave heights distribution, coverage areas, and vulnerability zone based on the Java 17 July 2006 earthquake scenario in Cipatujah, Tasikmalaya Regency. The method used in this study is quantitative and requires bathymetry data, high points, earthquake parameters of July 17, 2006, tidal data, RBI maps, and land use data. Tsunami modeling with numerical simulations using COMCOT v 1.7 and MATLAB software, also Arc Map for mapping tsunami coverage and vulnerability zone areas. Based on data processing, it was found that the maximum wave speed of 3.92 m/s. In the 27th minute, the waves had reached the Cipatujah region, with a maximum run-up height of 6.115 meters and a maximum tsunami range on the land of 1.891 meters. The area affected by the tsunami based on the processing of tsunami coverage data in Cipatujah totals 11.64 km2. Whereas for tsunami vulnerability zone in Cipatujah, it is divided into 3 categories, namely low hazard zone, medium hazard zone, and high hazard zone. This indicates that the Cipatujah region is included in a high tsunami-prone zone. Based on the results of verification and validation with an RSR value of 0,073, then it is assumed that the height of the run-up model is sufficient by the run-up data that occurred during the event.

Investigation and simulation of flood inundation hazard in urban areas in Iran

Extensive impervious area and the man-made streams are the characteristics of urban areas. In recent years, rapid urbanization has led to change of rural areas into urban areas, and urban runoff will increase as the result of spread and growth of impervious areas. Land use changes, increasing urbanization, unauthorized construction, inefficiency of sewage system and increased impervious surface in urban areas have significant impacts on inundation hazard. Therefore, to manage urban areas and prioritize regions to inundation elimination problems, the area most affected by inundation should be determined. In this study, the Storm Water Management Model (SWMM) is used to simulate the rainfall-runoff in the study area. The simulated runoff in the SWMM model is used as input to the HEC-RAS model and determines inundation hazard zones in 5, 25 and 50 return periods. Then, six factors such as distance from the main channel, slope, land use, drainage density, the main channel slope and elevation were selected to determine inundation hazard map using Analytic Hierarchy Process (AHP). The results showed that the combined model (SWMM and HEC-RAS) was suitable to analyze urban inundation and determine inundation hazard zones on urban areas. Simulated results can be used to develop urban inundation hazard forecasts. In addition, the result of inundation hazard map indicates that 8.2% of the case study is determined as a high hazard zone.

Slip‐Rate on the Main Köpetdag (Kopeh Dagh) Strike‐Slip Fault, Turkmenistan, and the Active Tectonics of the South Caspian

AbstractWe provide the first measurement of strike‐slip and shortening rates across the 200‐km‐long right‐lateral strike‐slip Main Köpetdag Fault (MKDF) in Turkmenistan. Strike‐slip and shortening components are accommodated on parallel structures separated by ∼10 km. Using Infra‐red‐stimulated luminescence and reconstruction of offset alluvial fans we find a right‐lateral rate of 9.1 ± 1.3 mm/yr averaged over 100 ± 5 ka, and a shortening rate of only ∼0.3 mm/yr averaged over 35 ± 4 ka across the frontal thrust, though additional shortening is likely to be accommodated locally by folding and faulting, and regionally within the eastern Caspian lowlands to its south. The MKDF is estimated to have ∼35 km of cumulative right‐lateral slip which, if these geological measurements are correct, would accumulate in only 3–5 Ma at the rate we have determined, suggesting that the present tectonic configuration started within that time period. We use the MKDF slip‐rate to form a velocity triangle, from which we estimate the Iran‐South Caspian and Eurasia‐South Caspian shortening rates, and show that the South Caspian Basin moves at 10.4 ± 1.1 mm/yr in direction 333° ± 5 relative to Eurasia and at 4.8 ± 0.8 mm/yr in direction 236° ± 14 relative to Iran. In contrast to both the eastern Köpetdag and the Caspian lowlands the MKDF has little recent or historical seismicity. The rapid slip‐rate estimated here suggests that it is a zone of high earthquake hazard.

COVID-19 Social Distance Violation and Face Mask Detection in Workplaces

Social distancing is a suggested arrangement by the World Health Organization (WHO) to limit the spread of COVID-19 in broad daylight places. Most of governments and public wellbeing specialists have set the 2-meter physical removing as a compulsory security measure in retail outlets, schools, and other covered regions. In this exploration, we foster a conventional Deep Neural Network-Based model for mechanized individuals’ identification, following, and between individuals’ distances assessment in the group, utilizing basic CCTV surveillance cameras. The proposed model incorporates a YOLOv4-based system and opposite viewpoint planning for exact individuals’ identification and social removing checking in testing conditions, including individual’s impediment, incomplete perceivability, and lighting varieties. We additionally give an online danger appraisal conspire by factual examination of the Spatio-transient information from the moving directions and the pace of social removing infringement. We distinguish high-hazard zones with the most noteworthy chance of infection spread and diseases. This may assist specialists with updating the design of a public spot or to play it safe activities to relieve high-hazard zones. The effectiveness of the proposed approach is assessed on the Oxford Town Center dataset, with prevalent execution as far as precision and speed contrasted with three bests in class techniques.

ASSESSMENT OF VULNERABILITY IN AGRICULTURAL LAND IN FLOOD PRONE AREAS AND APPLICATION OF MOBILE SMART PHONE IN PROVIDING FLOOD HAZARD INFORMATION IN LAM RIVER BASIN (VIETNAM)

Floods are considered to be one of the most costly natural hazards in the Lam river basin causing infrastructure damages as well as devastating the affected area and relatively high death toll. So prevention is necessary for shielding lives and properties. The flood management on the Lam River basin has been considering for many years to minimize damages caused by flooding. The flood hazard zoning map is one of the indispensable tools to provide information about hazard and risk levels in a particular area and to perform the necessary preventive and preparedness procedures. The multicriteria decision analysis based on geographic information systems is used to build a flood hazard map of the study area. The analytic hierarchy process is applied to extract the weights of six criteria affecting the areas where are prone to flooding hazards, including rainfall, slope, relative slope length, soil, land cover, and drainage density. The results showed in 91.32 % (20103.83 km2) of the basin located in the moderate hazard zones to very high hazard zones. Accordingly, this study also determined 4 vulnerability levels to agricultural land including low, medium, high, and very high. About 94% of the total area of agricultural land in the basin are classified into moderate to the very high hazard of flood vulnerability. The paper presents a method that allows flood risk areas in the Lam River basin to receive information about flood risks on a smartphone, making them more aware.

Urban waterlogging risk as an undervalued environmental challenge: An Integrated MCDA-GIS based modeling approach

In the last few decades, rainfall-induced urban waterlogging has become a significant environmental barrier and acquired global prominence worldwide due to its frequent threat, which results in significant infrastructure damage and economic loss. This study aims to model and identify the waterlogging hazard, vulnerability, and risk zones in the unplanned city of Siliguri, ‘Gateway of North-east India’, with the help of an integrated Analytical hierarchy process (AHP) and GIS techniques. Due to the lack of a comprehensive database, a systematic waterlogging assessment in the Siliguri city has not yet been carried out. However, waterlogging is a seasonal phenomenon in the Siliguri city, especially during the monsoon seasons, when short-duration and high-intensity rainfall cause inundation in low-lying areas causing mayhem to the city. Therefore, in this present study, a primary field investigation was conducted to prepare waterlogging inventory map along with seventeen other parameters, including spatial and attribute data from the secondary sources to delineate waterlogging hazard, waterlogging vulnerability, and risk map. Further, the final risk map was integrated with the spatial distribution of the slums locations, revealing that a larger proportion of slum households are under high-risk zones. The results suggest that about 46% of the city is under high to very high waterlogging hazard zones, while 38% of the Siliguri is highly vulnerable to waterlogging. The final risk map reveals that around 35% of the study area is susceptible to threat of waterlogging, which is mostly concentrated in the central part of the city center. Besides, the consistency of the model was assessed by area under curve (AUC), which gives an accuracy of 0.782 or 78.2%. This study's overall strategy may be used for planning and mitigation efforts to reduce future waterlogging incidents all around the world.

Landslide hazard, vulnerability, and risk assessment (HVRA), Mussoorie township, lesser himalaya, India

In the present study, landslide hazard, vulnerability and the risk assessment of the Himalayan township Mussoorie, located in the lower part of the Lesser Himalaya has been undertaken. The area famous for tourism constitutes > 7000 buildings with ~ 30,000 habitations. Four bivariate statistical approaches viz. Weight of evidence (WoE), Frequency ratio (FR), Yule Coefficient (YC), and Information Value (InV) were used for landslide hazard assessment, and all these approaches with 75%—80% success and predication rate are found to be acceptable for landslide hazard mapping. The analyses indicate that the Nagar Palika Parisad ward, Library ward, Happy valley ward and Bhadraj ward exhibit the maximum area falling under the high and very high landslide hazard zones, whereas Landaur ward, Jalkii ward and Indra Colony ward exhibit a greater part of the area in the low and very low hazard zones. On the basis of the six elements at risk present in the study area viz. settlement, crop land, water body, roads, barren and degraded land, and dense forest, the ~ 40% of the area is very high and high vulnerable, ~ 11% moderate, and ~ 49% is low and very low vulnerable. High and very high vulnerable zones are located in the west and central portion mainly because of higher habitation and more anthropogenic activities. Finally, risk map prepared intersecting hazard and vulnerability maps exhibits that Nagar Palika Parisad ward has the largest part (~ 41%) of the area with 37% buildings falling in the high and very high risk zones, whereas the Landour ward is the safest ward having ~ 83% area in the low and very low risk. Overall ~ 1604 buildings with habitation of ~ 8,000 persons in the township, are prone to high and very high landslide risk. The results of this study may be utilized for further development and planning in the area.

Impact of Land use Changes on Landslides Occurrence in Urban Area: The Case of the Constantine City (NE Algeria)

The city of Constantine (NE Algeria), the third largest city of the country (2.374 inhabitants/km2) is facing frequent damaging landslides that constitute a constraint to future development and land use planning. The main goals of this study are to evaluate the effect of land use changes on the spatial distribution of landslide hazard occurrence and give an example of landslide hazard assessment as useful tool within the context of long-term land use planning in the urban area of Constantine. For this purpose, the adopted methodology requires four steps: (i) Data collection and construction of a spatial database related to the historical landslides, land use, building and population inventory; (ii) landslide inventory and land use mapping for the period of 1970 to 2011 based on the analysis of aerial photographs, high resolution satellite images, historical records verified and completed by extensive field observations, (iii) analysis of the effects of land use changes on the spatial distribution of landslide occurrence for different periods 1970 and 2011; (iv) landslide hazard map, obtained by using the frequency ration (FR) under GIS and (v) evaluate the impact of human-induced land use changes on hazard occurrence. For that, we, firstly, compared the landslide inventory map with land use maps of different periods of 1970 and 2011 that showed that since 1970, the density of landslides increases with increasing of urban areas. In 2011, the high landslide density is concentrated on the following four layers: the urban area layer (41%), the agriculture land layer (39%), the grass area layer (15%) and the forest land layer (5%). The effect of the expansion of urban zone in agriculture, grass and pasture area have increase landslide densities over time. Secondly, we compared the landslide hazard map to these land use maps and we found that 40% of the high hazard zones and 50% of the moderate hazard zones fall in the urbanized area. The obtained results show a clear impact of the changed land use where human action is an important triggering and/or accelerating factor of landslides in the urban area of Constantine. Nowadays, about 72,749 inhabitants and 25,255 buildings are located in landslides threatened area. Therefore, landslide hazard maps should, always, guide the land use and urbanization in landslides prone areas.

Deterministic seismic hazard analysis for assessing earthquake hazard in Sungai Penuh and Kerinci Regency

Assessment of seismic hazard is necessary in land use planning and hazard mitigation. It leading to subdivided a region into sub-region which different safeguards to prevent damage in case an earthquake is occurred. The quantitative assessment of seismic hazard is carried out in Sungai Penuh and Kerinci Regency using deterministic seismic hazard analysis (DSHA) method. Earthquake scenario of Mw 7 at depth of 10 km by Siulak fault source were used for analysis to estimate the ground motion over the investigated areas. The resulting DSHA map reveals high seismic hazard level in terms of PGA 49.8 – 71.9 gal alongside the active Siulak fault zones. The intensity of the region are dominated by VII-VII of MMI scale which puts in the high hazard zone.