Modeling and prediction of areas with high susceptibility to landslides in the high Atlas of Marrakech, Morocco: A case study of Rdat watershed

Ait Mlouk Mohamed, Algouti Abdellah, Algouti Ahmed, Elbadaoui Kamal and Farah Abdelouhed

Page No. 1-9

Landslides are usually natural disasters. However, they can also be induced by human activities. They appear in different geological and geomorphological contexts depending on the study area. This phenomenon, when triggered, can have a major effect on the environment and natural ecosystems as well as on human beings (loss of human life and economic losses in extreme cases). Basically, landslides susceptibility mapping in mountainous regions presents a challenge for researchers due to limited accessibility and unfavorable geomorphological conditions. This study aims to define factors that control landslides. In this study, landslides susceptibility mapping and modeling have been carried out in the High Atlas of Marrakech, Rdat watershed. The based methodology consists first of the preparation and processing of input data using satellite images and hydro-geomorphological data. These were processed by a GIS tool. Then, the causal factors that may trigger a landslide in the area are defined and the coefficient of each factor is calculated by a pair-wise comparison matrix. Finally, the SMCE approach was chosen to combine the different factors by considering their weights and establish the landslides susceptibility map.

The results show that the factors that most influence landslides susceptibility in the study area are slopes, rainfall and lithology respectively. Thus, areas with a high susceptibility to landslides are mainly located in the central part of the catchment area between the Touflihet region and Had Zarkten. This research provides insights into understanding and how to model and predict areas with high susceptibility to landslides in mountainous regions.

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The Role of Channel Migration and Structural Setup in Flood Hazard of Upper Ghaghara River from Bahraich to Faizabad in Uttar Pradesh, India using Geospatial Approach

Singh Ajay Pratap

Page No. 10-32

The upper course of the Ghaghara River in Uttar Pradesh is a very sensitive zone for flooding and the maximum area comes under the influence of high and very high risk zone. Active Flood Plains (AFP) along rivers play a major role in establishing fluvial dynamics. Their association to valley width, channel width, river sinuosity, escarpments and channel migration helps in understanding the physical processes and structural set up in a low dipping monotonous fluvial deposit. The Ghaghara River is one of the dynamic fluvial systems affected by flooding and causing major migrations and channel disruptions in its flow regime.

The present study incorporates the varying channel migration obtained from different spatial and temporal remote sensing (RS) satellite imageries of the upper regime of the Ghaghara River extending from Bahraich to Faizabad districts. The study punctuates the role of monsoonal activity in channel migration, channel width, valley width and prepared a flood hazard zone with the help overlay method through many factors viz. drainage density, soil texture, landuse-landcover (LULC), area of micro watersheds, soil moisture, slope and relief in Geographic Information System (GIS) application based approach. In the study, it is observed that the present stretch of Ghaghara River migrated in NNW-SSE and NNE-SSW in broad flood plains throughout past where the river is deeply entrenched, structurally controlled and provides implications to tectonic setup and climatic inferences by change in sudden deviation and flood situation along the stream flow path of Ghaghara river.

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Numerical Modeling of Tsunamis and Tsunami Vulnerability Analysis of Temon Coastal Region in Yogyakarta, Indonesia

Yulian Fauzi, Hartono and Widjo Kongko

Page No. 33-41

Tsunamis are deadly natural disasters in coastal areas and with rapid developments taking place in these regions, the tsunami vulnerability index is projected to increase. Tsunamis can be simulated as long waves and modeled using the Shallow Water Equations (SWE). This study simulates the run-up and inundation of tsunamis generated by earthquakes at the southern subduction zone for the coast in Temon, a district in Kulon Progo, Yogyakarta, Indonesia.

The purpose of this study is to assess the coastal vulnerability to tsunamis and to map the inundated areas. For this reason, we used an approach that implemented hydrodynamic simulations into numerical models from accurate bathymetry and topographic data. Digital Terrain Model (DTM) derived from Small-Format Aerial Topography and the National Bathymetry Data (BATNAS) were used to model the potential of tsunami propagation from the earthquake source. We defined vulnerability to tsunami as a function of population, roads, and infrastructure and analyzed it based on the maximum reach of inundation from the coastline in GIS software. Tsunami hazard is a combination of tsunami inundation area and maximum flow depth. Tentative vulnerability data, as identified using GIS software, was supported by data acquired during field survey and population data estimates. Our results were vulnerability maps showing that in daytime scenario, tsunamis affected more than 40,000 people.

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Studying gender issues around disaster management labs in Korea

Kyoo-Man Ha

Page No. 42-48

The study aims to provide an atypical alternative in the field of disaster management labs around Korea by examining gender issues. As a methodology, a literature review is used to compare the isolation approach and the inclusion approach in four types of labs, namely public, industrial, college, and joint international labs. The key tenet is that all four lab types must exert effort to transform their current isolation approach into a future-oriented inclusion approach to perform better disaster management research as well as achieve gender equity. This study serves as a pioneering research by providing an analytical framework for gender issues around Korean disaster management labs.

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Assessment of Liquefaction Hazard for Vadodara Region, Gujarat, India

Mehta Payal and Thaker T.P.

Page No. 49-61

The sudden seismic loading to saturated loose soil may cause large scale damages to the infrastructure due to instability of ground. The hazard due to soil liquefaction is the major concern of seismic microzonation study of any region. In present study, liquefaction hazard assessment has been carried out for Vadodara region considering seismicity, geotechnical and geophysical characteristics of the region. SPT and shear wave velocity-based methods have been adopted to assess the liquefaction potential of Vadodara region. The mapping of liquefaction potential has been carried out in terms of factor of safety which shows that central part near Vishwamitri River and south eastern areas of the city are susceptible to liquefaction due to very low SPT-N values and high-water table.

Further, the liquefaction potential has been assessed using measured shear wave velocity profiles that have been generated by conducting multichannel analysis of surface wave (MASW) test at 64 locations of Vadodara city. The locations in the central part of the city near Vishwamitri River are having possibility of liquefaction using shear wave velocity-based method. Further, the severity of liquefaction has also been quantified considering liquefaction potential index (LPI) approach. The results of liquefaction hazard mapping will be useful in city planning for future development.

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Prioritization of watersheds based on morphometric characteristics of Achara basin, India using AHP technique

Chougule V.A. and Sapkale J.B.

Page No. 62-70

Soil is one of the most precious resources for life on the earth. The quality of the soil is dynamically reformed under the process of soil erosion which is determined by the topographical and hydrological characteristics of the region. River basin can be focused as a conservation unit to get rid of the problem of land degradation. The intensity of soil erosion can be determined through the analysis of linear, areal, and relief morphometric parameters of the basin.

AHP method (analytical hierarchy process method) is an effective decision-making tool used for watershed prioritization of Achara River basin. The evaluation of morphometric parameters of the basin provides the general ideas of the vulnerability of the soil erosion process and also helps to mitigate the natural disasters. Micro-level ranking of sub-watersheds can play a vital role in the planning and management of Achara basin.

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Flood risk modelling using hydrologic data, HECRAS and GIS tools: Case of Toudgha River (Tinghir, Morocco)

Elbadaoui Kamal, Algouti Ahmed, Algouti Abdelah, Aitmlouk Mohamed and Farah Abdelouhed

Page No. 71-81

The model created in HEC-RAS software using the data collected enabled the water level in the stream profiles, flow rate and velocity and finally the potential extent of flooding to be determined. The benefit of this research lies in the exact identification of the flood risk areas along the course of the Toudgha river through the city of Tinghir, using a flood model of the area created on a Geographic Information System platform. By its geographical position on the southern flank of the Central High Atlas of Morocco, the valley of Toudgha is classified among the sites with a particular vulnerability to flooding (almost every year). Toudgha River was under constant threat of flooding, mainly during torrential rainstorms, endangering the inhabitants and their property. Over the course of several years, they have suffered many floods, the most severe extreme events in August 2014 and September 2019 (torrential floods) caused devastating damages.

Understanding the spatial and temporal dynamics of floods is important for disaster risk and water resources management. Sustainable Development Goal number 13, Climate Action, supports the need for disaster risk reduction, early warning systems, adaptation to climate change and strengthened resilience7. This study allowed us to simulate spatiotemporal flood level, one of the most frequent natural disasters in Tinghir valley, using statistical methods, identifying floodplains and determining the different water levels for the modeled section of Toudgha River. The causes and impacts of floods in the Toudgha River are investigated. The principal aim of this study is to specialize the flood’s extent of this river through the contribution of HECRAS software and GIS tools.

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Global Warming, Impacts and Mitigation Measures: An Overview

Paras Manoj Kumar and Rani Pooja

Page No. 82-96

Global warming is the rise in global average temperature near the surface of earth. It is primarily caused due to the emission of Green House Gases like water vapors, carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), ozone (O3) and chlorofluorocarbon (CFC) etc. in the atmosphere. These gases allow the incoming sunlight to pass through the atmosphere but absorb and reradiate the energy corresponding to longer wavelength (infra-red) reflected by the earth’s surface. This process makes our earth warm and is called Green House Effect. However, it has been noticed and reported by numerous researchers that over the last century, the Green House Effect has enhanced due to the increased amount of Green House Gases especially CO2 gas in the atmosphere. CO2 alone produces roughly more than two-third of the enhanced Green House Effect. CO2 is released in the atmosphere primarily from the burning of fossil fuels (coal, oil and gas), deforestation and other land use change activities.

According to recent Intergovernmental Panel on Climate Change (IPCC) report 2018, the earth’s average temperature has raised ∼1 ℃ over the past century (1850-2018) and it is further expected to temperature rise of 2.5℉ to 10℉ over the next century. The possible consequences of global warming include rising sea level due to the melting of the polar ice caps, increase the global mean rates of precipitation and evaporation, increase in lightning activity, forest fires, drought, longer spell of dry heat waves, changes in biosphere and other severe weather events. In this study, we will discuss the cause of global warming, the role of global warming in climate change and its various impacts on the planet earth.

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