JOURNAL OF NATURAL ENVIRONMENT HAZARDS
Year:2020 | Volume:9 | Issue:23|Papers Count:11

Natural hazards such as flooding, earthquakes, droughts, etc., in geographic areas, especially rural areas, in most cases cause plenty of irreparable damage and seriously impede the sustainable development of human societies. The purpose of this study is to measure and analyze the resilience of rural communities against environmental hazards and effective factors on it in rural areas of Sistan. The research method is applied-developmental and descriptive-analytical with a quantitative survey approach. The statistical population of this study was 373 people (from villages over 50 households) by using Cochran formula 189 people were selected by stratified random sampling in proportion to the size of the population. At first, using the library method, indicators and factors affecting rural resilience of the Sistan area were identified and then the information was collected by questionnaire and field operations. Findings were analyzed by SPSS software and show that amount of β indicates that the Managerial factors, institutional factors, Economic factors and physical factors that were equal to 0. 079., 0. 075., 0. 122 and 0. 024 respectively with a significant level of 0. 331, 0. 327, 0. 886 and 0. 743, greater than 0. 05, (0. 05

Natural hazards are threatening events which result in a large number of casualties and major financial losses. Therefore, it is necessary to carry out scientific studies and research on this subject. The current study aims at identifying and zoning the environmental hazards influencing the physical expansion of Ilam City based on a descriptive analytical methodology and field observations. The area selected for the study is the City of Ilam and the statistical population of the study includes the experts of urban management and crisis management whose comments and opinions will be used for determining the importance of the selected criteria. The data analysis methodology in this study involves combining digital layers in GIS, fuzzy hierarchical analysis, and TOPSIS. The results of the study show that among all the natural hazards common to the middle section of the Zagros Mountains, Ilam City is mainly influenced by the danger of flooding. After evaluating the lands in the urban area of Ilam, it is observed that the expansion path Ilam City has gone through during the recent decades has beenwithout any consideration for this major phenomenon and the physical expansion of the city has been in the areas with a high risk of flooding. Two areas with very high risk, with the total area of 5. 33 and 2. 18 hectares, are the regions of the city which suffered severe damages in the recent flooding and they are still facing a very high risk of flooding. The safest areas for expansion in Ilam City are the southern zones of the city (towards Cheshmeh Kaboud Village) which have a desirable physiographical state and acceptable risk level against flooding.

Wetlands are sensitive and valuable ecosystems but today their safety and their sustainability have been harshly influenced by various natural and human factors. Using environmental risk assessment is an important tool in studies of environmental management and recognition and reduction of the potentially harmful environmental factors to achieve sustainable development. This research was conducted to identify and assess the risks and grading of environmental sustainability of the international wetlands of the southern coast of Iran in the provinces of Khuzestan and Hormozgan. Accordingly, to identify and prioritize the risks the Delphi methodology, to prioritize and calculate the weight of the indicators the Analytical Hierarchy Process (AHP) process, and the ELECTRE technique were used to rank the wetlands based on unfavorable environmental conditions. The results showed that 27 factors of pressure and threat were identified for The International Wetland of Shadegan, Khur_e_ Omayyeh and Khur_e_Mousa Estuary, Khur-e-khuran International wetland, Salty, Sweet and Minab Rivers International Wetlands, Gaz and Hara Rivers Estuary International wetland and Shidvar International Wetland. The results of the paired comparisons between the threats of the studied wetlands show that the first to fifth ranking threats are related to the discharge and disposal of waste in the wetland, climate change and drought, oil pollution, dam construction, and the reduction of vegetation density, and other indicators are in the next ranks. Finally, the analysis and comparison for the ranking of the studied wetlands based on the ELECTRE method showed that The International Wetland of Shadegan, Khur_e_ Omayyeh and Khur_e_Mousa Estuary suffer the highest threat and pressure and Shidvar International Wetland has a more favorable ecological condition.

Fractal geometry is a method for describing a self-similar or a self-affine property in complex landforms and explanation of surface complexities and roughness. In the present study, the surface fractal dimensions (SFDs) were investigated by a cellular model by covering the divider method. Results indicated that geological and geomorphological processes change the character of the fractal dimension of the landforms. Changes in lithologic boundaries and faults influence changes in the fractal dimension and their mode of influence vary according to the topographic characters such as frequency, amplitude, and types of formations. In lithologic units with hard limestone formations, the fractal dimension is low, while in alluvial formations, the fractal dimension increases. The drainage network density and tributaries margins affect the fractal dimension. Moreover, homogeneity of the lithologic units decreases the fractal dimension. In this study, the lowest fractal dimension is associated with the integrated units of Mesozoic orbitolina limestones on the border of the two structural zones of Sanandaj-Sirjan and High Zagros belt. However, friable and sensitive to erosion formations of the quaternary increase the fractal dimension. The succession of the hard and friable layers is effective on the local scale on the fractal dimension. Furthermore, mountains have lower fractal dimensions than lowlands. Generally, there is an inverse relationship between the fractal dimension and elevation and this relationship there is about the roughness index in the basin. The results illustrated that changes in the surface fractal dimension were dependent on a set of lithologic, tectonic, and geomorphologic factors. Also in complex topographic zones investigation of changes in the fractal dimension can be a useful and effective instrument for detecting and surveying of the surface anomalies.

Floods are a natural phenomenon that causes heavy losses of life and property and human societies every year and people have accepted it as an inevitable event. In this research, to predict the flooding in Sardabrood basin SWAT hydrological model was used. Information needed for this research, including topographic maps, land use, soil data, and meteorological data, data about daily rainfall, temperature, and flow rate were prepared beforehand. SUFI2 program was used for model calibration. After the calibration and optimization of the model, validation of the model in the study area was done. The calibration of the model wad performed for the years 2003 to 2009 and validation was performed for the years 2010 to 2013. To analyze the results of statistical indicators R2, bR2, and Nash Sutcliffe coefficient were used. After model calibration the respective coefficients were, 0. 77, 0. 63, and 0. 77 and the respective validation coefficients were 0. 79, 0. 76, and 0. 71. The sensitivity results of 31 parameters that are influential on runoff water showed that fixed parameters of groundwater base flow, its time, and the minimum amount of water necessary for groundwater base flow are more sensitive than other parameters. Number Sardabrood parameter curves were used for flood basin. Sardabrood basin was divided into 24 areas to study the flooding pattern. Finally using the above mentioned models it was concluded that sub basin No. (6) had the first-rank with runoff 123. 05, sub basin No. (10) had the second rank with runoff in terms of flooding and sub basin No. 1 with a 12. 33 has the least amount of runoff.

Land degradation is one of the major threats to ecosystems, especially in arid areas due to drought and wind erosion. Dust characteristics can indicate the extent of land degradation. The aim of this study is an assessment of some chemical characteristics and amounts of some nutrient elements of dust in the Sistan Plain. Twenty-five half-spindle shaped dust samplers were installed in the cities of the Sistan region. The dust samples were collected monthly from early April until late September in 2015. Topsoil samples from erodible or susceptible areas to erosion were taken (20 samples) from different parts of Hamoun wetlands (as the main origin of dust). After that pH, EC, organic matter, soil texture, and amount of soil nutrient elements including P, K, Na, Ca, and Mg were analyzed in samples. The Ca was the maximum nutrient elements associated with dust (average 700. 28 mg/kg), and the minimum was P (average 33. 76 mg/kg). The highest amount of Total (P, K, Ca, Mg and Na) nutrient elements were observed in August+September (461. 43 mg/kg) and the minimum amount in May+June (353. 78 mg/kg). The highest amount of OM, P, K, and Mg have observed in dust loaded over Zabol city (25. 88 mg/kg, 45. 75 mg/kg, 365. 8 mg/kg and 667. 32 mg/kg respectively), and the maximum amount of Ca was observed in Hamoun city (813. 06 mg/kg) and the maximum amount of Ca was observed in Nimruz city (629. 48 mg/kg). The highest amount of enrichment ratio belonged to P (6. 002) and the lowest enrichment ratio belonged to Na (0. 707). The results showed soil textures of Hamoun wetland beds are susceptible to erosion and its chemical properties showed salinization and alkalization and loss of vegetation cover. Characteristics of the dust carried over the cities of Sistan plain reflected the conditions of dust origin and indicated the expansion of land degradation in these areas.

The dust storm has caused huge losses in Iran, especially in Khuzestan province. The agricultural sector of the province is no exception. The strategic analysis method is a useful analytical model for identifying the strengths, weaknesses, opportunities, and threats existing in the region to control the effects of the crises of the microspheres. Therefore, identifying the strengths, weaknesses, opportunities, and threats of the crises of the microstates on the agriculture sector of Khuzestan and developing appropriate strategies for providing management solutions are considered as the main goals of this research. A library study, a questionnaire, and interviews with experts (34 experts) were used to collect data. Components of internal factors including 10 strengths, 18 weaknesses, and external factors including 20 threats and 11 opportunities were determined. To determine the final weight of each point using the AHP method, the final weight of each factor was determined. The results of the study indicate that surface water and runoff waters for supplying the water of the wetlands of the region as the most important strongpoint with a final weight of 0. 807, adverse climatic conditions (climate change and periodic drought) As the most important weakness with a final weight of 0. 145, the implementation of optimal management plans for natural resources (wetlands, etc. ) as the most important opportunity with a final weight of 0. 765 and lack of international and national cooperation to cope with the microgravity, it was considered as the most important threat with a final weight of 0. 140. Also, based on the results, the final score of the internal factor assessment matrix was 2. 432 and the final score of the external factors evaluation matrix was 2. 629. Finally, the defensive strategy was introduced as the main strategy of the research, from the final score of these matrices.

The purpose of this study is to identify and detect changes in rainfall extremes as indicators of climate change in Iran. To conduct this research daily rainfall data of 76 synoptic stations were used from 1986 to 2016. The results show that the trend of the number of days with heavy rainfall was about 7 percent of Iran's negative and 93 percent of it was not observed. The trend of successive dry days in 28% of Iran is a positive trend and 37% there is a negative trend. The wet succession days in most areas of Iran are not trendy. The trend of the total amount of rainy days is about 99% of Iran's negative range. The maximum negative slope of Iran's annual precipitation was observed at Masjed-e-Soleiman Station with a slope of-8. 26 and there is a positive trend in the Bandar-e-Anzali. The trend of very wet days is about 78 percent of Iran is negative and about 14 percent is positive and 8 percent of it is trendless. The trend of very wet days in about 70 percent of Iran is negative. The highest wet days are observed in Khorramabad with a gradient of 1. 4 and the highest decreasing trend in Sarpole-Zahab with a gradient of 2. 78. Also, in 22% of Iran's range, there is no particular trend. The trend of one-day' precipitation in about 47% of Iran's negative and in 47% is without trend and 6% of it is positive. The trend of the maximum amount of 5-day precipitation about 73% of Iran is negative and in 2% it is positive and 25% of it is without a trend. The slope of the decreasing trend in Fasa and Masjed Soleiman stations is-2. 4 and-1. 9 respectively.

This research aims to explain the resilience of rural areas against natural hazards with emphasis on the flood. The overall research approach is a type of quantitative research, and in terms of data collection method, it is based on library and field data. The statistical population consists of 12 villages in the central basin of Qaen city which are at high risk of flooding. The statistical sample of the research consisted of 10 natural hazards specialists and 335 villagers. In this research, geographic information system (GIS) and AHP technique were used for zoning flood risk villages that showed the criterion of earth slope with the weight of 0. 280 was the most important factor and the criteria for the point of concentration and height of each with weights of 0. 224 and 0. 150 were studied from the main factors of incident and flood occurrence in the range. Data collected from residents' questionnaires were performed using descriptive statistics indices such as frequency distribution and inferential statistical tests such as single sample T-test, Chi-square, and Kruskal Wallis. Overall, the results show that the resilience of the studied villages is moderate. However, the resilience of the villages is different; So that the villages of Varzgar from the social and infrastructural perspective and the village of Ali Abad from the economic perspective are the most resilient. The villages of Ali Zangi and Fath Abad, situated in the high-risk area, have the least resilience.

The study of factors that control volcanoes can help analysesize the risk of triggering an the next eruption. Taftan is a Quaternary volcano of southeast Iran, formed as the result of subduction of Oman oceanic lithosphere underneath the continental Iranian plate that emplaced onto compressional tectonic setting such as strongly folded and faulted Eocene flysch and Cretaceous ophiolites. This volcano has several centers that are directed along a northeast to southwest from old to new. In order to investigate the role of the tectonic regime to evolution of Taftan volcano, structural elements such as Dikes, Fractures, crater opening of Anjerk amphitheater, the direction of centers and direction of springs have been studied. The resulting data of these elements represent a northeast-southwest directed extensional stress in the Taftan body which has created an extension area in the northwest-southeast direction. But earthquakes and structural trends of pre volcanic rocks underlying Taftan show a maximum regional compressional northeast-southwest striking. Recent relevant data such as structural analysis, analog modeling, field data demonstrating that volcanism can occur in compressional tectonic settings associated with thrust faulting. In other words magma can transport beneath the volcano to the surface along the thrust faults. Based on these data we proposed a model that demonstrates the substrate thrust fault (as magma path) splits into two faults within the volcano: A shallow-dipping one, with reverse movement, propagates towards the volcano flank, and a steeper-dipping one, with normal movement, propagates upwards and causes northeast-southwest extensional area along the centers parallel to thrust fault of substrata. The suggested model in this study proposes a next eruption point in the southeast of the currently active point.

To identify the physicochemical and atmospheric conditions of a dust storm at the Dezful station (As Dezful Regional Representative), at first the frequency of the dust storm phenomena was investigated at the Dezful station in Twenty years (1994-2013). During three events on June 24, July 21, and July 28, 2018, dust samples were collected with sediment traps and physical condition was performed with X-ray diffraction device and chemical analysis of the elements and heavy metals detected by flame atomic absorption and dust particles were evaluated with the Igeo index. Also, the atmospheric circulation in the middle level of the atmosphere and sea level surface that led to a dust storm was identified by using ECMWF ERA-Interim meteorological data. The distribution of dust particles was detected with aerosol optic depth (AOD), and the pathway of dust particles was examined by the HYSPLIT model. The results represented that frequency of dust storm is an increasing trend which has led to a decrease in horizontal visibility in Dezful. The maximum of dust storm phenomena is in summer time and July; The minimum in the autumn time and January. The mean distribution of dust particles in Dezful showed that PM10 was dominant in the size of the silicate tissue. The elements of dominant were Mn, Zn, Pb, and Cd was 491, 311, 32. 9, and 1. 41 mg/kg respectively, which indicates moderate to severe contamination compared to the standard level. Among the soluble elements, Ca, K, Na, and Mg had the highest concentrations; the presence of these elements is evidence of their desert dust particles. Tracing and calculation of their backward pathway showed that the alluvial deposits of the Tigris and Euphrates in Iraq were its main focus.