Assessment of Areas Vulnerable to Natural Hazards (Case Study: Rural
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Assessment of areas vulnerable to natural hazards: A Case study on Rural areas of Azna County, Iran Hamed Abbasi1, Siyamack Sharafi1, Zohreh Maryanaj2 Date of submission: 18 June 2018, Date of acceptance: 18 Oct. 2018 Original Article Abstract BACKGROUND: Rural areas, usually when compared to other natural events, have the greatest vulnerability of human settlements. The aim of this study was to evaluate natural hazards as earthquakes, landslides, floods and identify high-risk zone in relation to the rural areas of the central township of Azna County, Iran. METHODS: Topographic and geology maps, elevation digital model, and seismic and meteorological data along with field studies to investigate the location of villages in terms of natural hazards of earthquakes, landslides, and flood were used. Then, effective factors were identified in each of the hazards, and grouped in separate layers. The Arc GIS software was used to develop and integrate maps; AHP model and paired comparison method were used to weight effective factors in expecting any of the natural hazards, and to compare the criteria one by one; fuzzy logic model was used to standardize the layers in Arc GIS software; and the overlay model index was used to integrate final layers of natural hazards and determine high-risk zones. RESULTS: 49 percent of villages in privacy due to the major and minor faults were in the zone of high earthquake risk. The risk of landslides in areas where rural areas were based, due to the low gradient very low and only 10% of the villages are at risk of landslides. 14% of the villages in the privacy due to the major rivers, flood risk and the risk of flooding is very high. Prioritization of rural areas in terms of natural hazards by using AHP model shows that the 8 villages were located in high-risk areas. CONCLUSION: Providing maps of potential natural hazards can be helpful in crisis management and identification of the high-risk settlements. Keywords: Natural hazards, Rural areas, Seismicity, High-risk areas, Iran Downloaded from jorar.ir at 14:29 +0430 on Monday September 16th 2019 How to cite this article: Abbasi H, Sharafi S, Maryanaj Z. Assessment of areas vulnerable to natural hazards: A Case study on Rural areas of Azna County, Iran. Sci J Rescue Relief 2018; 10(3): 42-9. Introduction elements that are harmful to humans and are created atural hazards have existed throughout by external forces superior to human power (3). Due human life, however due to the rapid to their unforeseen nature, these risks often cause N growth of population and human density numerous financial and human losses (4,5). The in all areas of life, especially in high-risk areas, available evidence suggests a continuous increase in today, human beings are experiencing major various natural hazards in terms of intensity and disasters such as tsunamis, tornadoes, and frequency (6,7). Natural hazards are identifiable earthquakes with significant casualties even in before they can be defined (8). developing countries (1,2). Natural hazards are In many cases, these hazards have devastating the ones that occur abruptly and cause damage to impacts on human communities, both urban and humans and the environment; in other words, rural, and their consequences on the natural hazards are the environmental physical environmental, social, economic, and 1- Assistant Professor, Department of Geography, Lorestan University, Lorestan, Khorramabad, Iran 2- Assistant Professor, Department of Geography, Sayyed Jamaleddin Asadabadi, Asadabad, Iran Correspondence to: Hamed Abbasi, Email: [email protected] 42 Sci J Rescue Relief 2018; Volume 10; Issue 3 http://joraren.ir 15 Dec. Hamed Abbasi, et al. psychological dimensions in the field of human management and crisis of environmental and settlements have been evident for many years (9). natural hazards. Faraji et al. (5) performed a In fact, these types of hazards create a wide range spatial analysis of the impacts of natural hazards of unforeseen threats to human beings and human in rural areas using principal component analysis habitats (10). Human settlements, and particularly (PCA) model of geographical weight. Taheri rural ones, are vulnerable to degradation at certain Nejad (20) examined landslides using remote times due to inevitable location in beds with a sensing data. Souri et al. (10) performed zoning naturally hazardous infrastructure (11-13). landslide risk using artificial neural network Geological evidence indicates that the Earth (ANN). Fazelinia et al. (21) carried out zoning of has been severely threatened throughout its life by risks in rural areas using geographic information natural forces, with the earthquake perhaps being system (GIS) with an emphasis on landslides. the most destructive of these forces (14). Floods Pour Taheri et al. (9) examined the role of and landslides are also among the most capacity creation in reducing the effects of natural devastating natural hazards (15-17). hazards (earthquakes) in rural areas. Sadeghloo Iran has experienced more natural disasters and Sajasi Cidari (22) studied risk management throughout the history of natural disasters, strategies in rural areas using SWOC-TOPSIS especially earthquakes and floods, due to its model. Nasrinnejad et al. (23) carried out zoning position in the Alpine-Himalayan orogenic belt, as flood potential using fuzzy hierarchy analysis well as due to its varying climate and temporary method. Salahshoor and Vafaeejad (24) surveyed and transient instabilities (18). Lorestan province, the changes of floods of Plains of the Karkheh located in western Iran and in the Zagros River due to the construction of Karkheh mountainous region, has witnessed numerous Reservoir dam using remote sensing and GIS. In natural disasters and floods in the past few years, all the above studies, it was concluded that flood with the earthquakes, landslides, and floods being and landslide risks are more likely to occur in Iran. the most notable of them. The diversity of hazards In addition, the human factor is the most important in this province is due to its different geological factor in the extent of landslide damage and the and climatic characteristics as well as its existing potential for diminishing the earthquake topography. Examples of hazards in recent years impacts and vulnerability is not sufficient. include earthquakes and landslides in Boroujerd Natural hazards are a major challenge in rural and Dorood in 2006, flood in Kouhdasht City in areas and these areas are usually the most 2015, and devastating flood in April 2019 that vulnerable and with the least self-consideration in caused many financial and life casualties in the natural events (25-28), and predicting the exact province. The city of Azna in the eastern part of time of natural hazards is beyond the reach of Downloaded from jorar.ir at 14:29 +0430 on Monday September 16th 2019 the province has also experienced a variety of current human science. Therefore, identifying hazards, especially geological hazards, which can vulnerable and susceptible areas of natural cause devastation and financial loss, particularly hazards can partially prevent the hazards of these in less strong rural areas. disasters. Accordingly, this study was performed Geographical research on natural hazards has a aiming to identify the potential of natural hazards long history, beginning with a focus on physical of earthquakes, floods, and landslides and villages processes and going through its evolutionary trend exposed to natural hazards in the central township with enhancing recognition of the interaction of Azna county in Lorestan province. This city between the physical and the human environment contains 2 rural districts and 49 villages with a (19). Today, with the advancement of science and population of about 21123 people. The lowest and technology and the use of quantitative and highest points of the study area are respectively qualitative models in natural hazard assessment, a 1703 and 4040 m high with an average height of variety of studies have been carried out regarding 2790 m. The mean annual precipitation and the the types of hazards internally and internationally, mean annual temperature of the region are about with a particular emphasis on hazard assessment 415 mm and 12.5 °C, respectively. and its impact on human settlements. Numerous studies have been accomplished in Materials and Methods different parts of Iran in this regard. Negaresh and The present study was conducted in several Yasmine (13) performed an analysis on the risk stages. In the first stage, field studies were carried Sci J Rescue Relief 2018; Volume 10; Issue 3 43 http://joraren.ir 15 Dec. Assessment of areas vulnerable to natural hazards out to investigate the location of the villages hazard and calculating the final weight of the under study in relation to the potential for natural effective factors, using the AHP tool in Arc GIS, hazards of earthquakes, landslides, and floods. In the final weight of each factor was multiplied by the second stage, factors affecting the occurrence the final raster layer of the associated factor in the of natural hazards (earthquake, landslide, and environment of the Spatial Analyst tool. In this flood) were determined using the results of way, the final map of the landslide and flood previous studies and expert opinions. These hazards was prepared. It should be noted that the factors include faults, earthquakes taken place and earthquake hazard zoning was prepared using a earthquake accelerographs, topography (slope, map provided by the International Earthquake slope direction, and elevation), geological Research Institute, fault layers, and seismicity formations, drainage network (river), mean history database. After preparing the final map of monthly and annual rainfall, maximum 24-hour the earthquake, landslide, and flood hazards, the rainfall, land use, access roads, and soil (Table 1). layers were integrated using the index overlay Then vector layers such as geology, soil, and land model and the final map of natural hazards was use were converted into raster layers using the prepared.