Document Type : Research Paper
Authors
1
Department of physical Geography, Faculty of Geographical Sciences, Kharazmi University, Tehran, Iran.
2
Department of physical Geography, Faculty of Geographical Sciences, Kharazmi University, Tehran, Iran
3
Assistant Professor, Faculty Geographic Science, Kharazmi University, Iran
Abstract
Many arid and semi-arid regions are also exposed to the risk of dust storms due to their fragile environmental stability. This environmental hazard has caused displacement of surface soil, damage to agricultural lands and vegetation and has affected the lives of people, especially vulnerable groups, close to critical centers and distant areas. The purpose of this research is to evaluate and analyze the vulnerability of social, economic and environmental criteria caused by dust storms in Kerman province. In this regard, social and economic criteria, including population density, gender structure, rural-to-urban population ratio, and rainfed agricultural lands have been considered. Also, the erodibility of geomorphological landforms, poor pastures and bare lands has been identified as an environmental criterion. The results of horizontal visibility (from weather stations) dispersion analysis show that there is a minimum average horizontal visibility in the center of the province. The amount of exposure to dust in Kerman province is between 0.73 and 8.7 meters, so the cities of Baft, Bardsir and Raber are the most exposed to this phenomenon. The results of ranking the Cocoso model showed that the cities of Kerman, Bam, Erzuye and Qalaganj are the most sensitive to dust. The results of the vulnerability of the dust phenomenon in Kerman province showed that all the cities of this province are not the same vulnerability to the dust phenomenon. The vulnerability of the dust phenomenon in Kerman province was obtained in 5 categories from very low to very high. 86% of Kerman province area is very high and high vulnerable to dust phenomenon. The results of this research can provide a basis for the development of dust storm reduction studies in order to reduce the vulnerability caused by dust storms in Kerman province for managers and decision makers.
Extended Abstract
1-Introduction
Rising greenhouse gases due to human and natural activity have caused climate change and global warming. Consequently, these changes have exacerbated natural events such as dust activity, droughts, floods, and other natural phenomena. Climate change has a remarkable impact on the earth's hydrological cycle, surface and groundwater quality, and vegetation, and changes in these parameters play a vital role in the spread of dust storms. Many scientists have conducted research related to spatial and temporal distribution, the number of dusty phenomena with emphasis on climatic conditions, transmission routes, chemical components, and numerical simulation. Power, water, road, and other important infrastructure failures might occur as a result of sand and dust storms which can interrupt the provision of vital and critical services for the community. All these impacts can affect the sustainability and resilience of infrastructure and small and big businesses. Spatial and seasonal variations of sand-dust events and their relation to atmospheric conditions and vegetation cover in semi-arid regions of central Iran by using the Ridge Regression (RR) method and seasonal variations of precipitation, surface winds speed, air temperature, and Enhanced Vegetation Index (EVI) with Dust Storm Index (DSI) for two different periods (2001–2008 and 2009–2016) showed that the activity of sand-dust storms in the second period was greater than the first period, especially in the border region of Iran and Turkmenistan. Although many studies have been conducted on the phenomenon of dust and its relationship with vegetation, wind speed, and the origin of fine dust in some parts of the study area, no research has been done on the estimation of the vulnerability of dust storms in Kerman province. Therefore, in the current research, the amount of exposure caused by dust storms in Kerman province will be estimated by using horizontal visibility data. Then we will assess and analyze the sensitivity and vulnerability of the social, economic, and environmental criteria of Kerman province to dust storms in recent years.
2-Materials and Methods
The data has been used in this research such as 1. the minimum, maximum, and average horizontal visibility data (m) of meteorological stations from 2009 to 2018. 2. Precipitation in 10 years (2009-2018). 3. Vegetation 1:100000. 4. Geomorphology 1:100000. 5. Geology 1:100000. 6. Digital Elevation Model (DEM) 12.5 m PALSAR radar sensor. To prioritize each of the social, economic, and environmental criteria, we will use the Cocoso model. Finally, using the weighted linear combination method, we will estimate the vulnerability caused by dust storms. The method of estimating dust storm vulnerability in Kerman province is described below.
The combined compromise solution (CoCoSo) is a multi-criteria decision-making method that was initially proposed by Yazdani et al (2018). This method is used to rank the sensitivity of the cities of Kerman province based on overlapping criteria. This method is an integration of simple additive weighting (SAW) and weighted product models (WPM). There are 5 steps to solve a CoCoSo decision problem. The first step is to form a decision matrix, the second step is to normalize the decision matrix, the third step is to calculate SAW and WPM, the fourth step: compute aggregation strategies, and the fifth step: determine the final score and rank the options.
Vulnerability to SDS is defined as a function of exposure, sensitivity, and adaptive capacity components. Exposure refers to the nature and degree to which elements of a system are at risk of a natural or human-induced hazard; Sensitivity is another concept related to vulnerability, defined as the degree to which a system is modified or affected by hazard stimuli; and while exposure and sensitivity determine the scale and nature of likely impacts caused by hazards/perturbations, the adaptive capacity of system quantifies its ability to cope with, manage, recover from, and adapt to the potential adverse impacts of hazardous phenomenon.
3- Results and Discussion
The amount of exposure to dust storms in the center of Kerman province is very high and it decreases with the distance from the center of Kerman province and reaches 7.8 meters. So, in the cities of Baft, Bardsir and Raber, they have the least exposure to dust storms. The sensitivity to dust storms is generally calculated from the integration of social, economic, and environmental criteria. Social and economic criteria include residential areas (rural and urban), population density, gender ratio (male-to-female ratio), rural-to-urban population ratio, and rainfed lands. Also, the environmental criteria that are sensitive to dust storms include bare lands, poor pastures, and erodible lands. The results of the vulnerability map in Kerman province show that there are 5 levels of vulnerability in the study area, including very low, low, medium, high, and very high. The area is very large and large, with an area of 8636470 and 6545769 hectares, respectively, in the cities of Raver, Kerman, Bam, Narmashir, Jiroft, Baft, Sirjan, Shahrbabak, Rafsanjan, Bardsir, Raber, Zarand and Kohbanan. The cities of Anar, Anbarabad, Faryab, South Rudbar, and Manojan are located in the zone with high vulnerability. In general, about 95% of Kerman province is in the medium, high, and very high vulnerability category.
4- Conclusion
Nowadays, due to the effects of dust storms on human societies, many researches have been conducted on dust storms in different parts of the world. The research carried out by (Pouyan et al., 2018) showed that the cities of Regan, Fahraj, Bam, South Kerman, and Qalaganj were identified as dust sources and Menasha fine particles with high and very high class. On the other hand, the wind causes the movement of dust and leaves its effects on the neighboring cities. Therefore, it is in line with the present research. Therefore, there is a need for more planning and studies of decision-makers in the field of reducing the effects of dust in Kerman province.
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