فصلنامه جغرافیا و پایداری محیط
پیاپی 33 (زمستان 1398)

One of the most interesting landforms in the Sabalan massif landscape is the 12 Kilometers caldera-shaped circular fault. The fault has affected landforms, including catchments and associated alluvial fans. The purpose of this study was to analyze the role of Sabalan Caldera in the evolution of river basins and associated alluvial fans in the northern slopes. Morphotectonic indices including Stream Gradient Index (SL), Mountain-Front Sinuosity (SMF), Valley-Floor Width to Height Ratio (VF) and Transverse Topographic Symmetry Factor (T) were used in the present study. Besides, Topographic maps 1:25000, Geological maps 1:100000, Digital Elevation Model (Dem) with resolution of 20 meters, Landsat satellite image with resolution of 30 meters, Geographic Information System (GIS), Excel, Arch Hydro10 and Envi 4.8 as research tools, have been used to provide the quantitative and qualitative analyses of morphotectonic indices. Moreover, field observations and geomorphologic evidence have been used to verify greater confidence in the results. The findings from the calculation of morphotectonic indices and field observations, also geomorphologic evidence showed that the caldera range are still tectonically active. Moreover, the drainage network map obtained from the digital elevation model, revealed that the caldera collapse has changed the pattern of the drainage networks from the radial to the central state and then to the dendritic state. Likewise, this process has increased not only the area of the catchments but also the power flow of the rivers. As a result, the rivers using a loose formation of Lahar have incised fan systems and left behind the abandoned terraces and old fans.

Heavy daily rainfall occurs when it exceeds the region's long-term average and becomes an extreme event or climate hazard. The aim of this study is to provide the synoptic and statistical analysis of the most intense daily precipitation in western Iran during a period from 1996 to 2017. To achieve this aim, Precipitation days with a maximum of 70 mm or more were specified and arranged according to the season. Finally, the most intense rainfall events of each season were selected for the analysis. Based on results, the main area of heavy rainfall is located on western slopes of Zagros, including Ilam and Marivan. In winter, the expansion of the Mediterranean system to the western Iran with accompaniment the Red Sea humidity has been recognized as an essential factor for heavy rainfall. In the spring, the formation of a Mediterranean cyclone on the Caspian Sea and the northwest of Iran has caused heavy rainfall. The most intense extreme rainfall of all times have been observed in October and autumn, due to the convergence of the Mediterranean and Sudanese systems and the establishment of a cut-off low over the eastern Mediterranean at the middle level of the atmosphere. The deployment of high-temperature air mass on the Persian Gulf and humidity advection from the southern seas and the Mediterranean have strengthened the system. The Jet stream in the atmosphere's mid-level played an important role in enhancing the convergence of winds and the low-pressure pattern of the Earth's surface. Because, the flow of warm air ascend from the Earth's surface toward the middle of the atmosphere has been out of the area rapidly. Therefore, hot and humid wind currents are absorbed more rapidly towards the low pressure center adjacent to the Earth's surface and with the release of latent heat, the air ascend to higher levels of the atmosphere. Extended Abstract 1-Introduction Precipitation is one of the most important climatic parameters in any geographical area. The Precipitation enhances surface and groundwater levels providing soil moisture through Influence into the soil. This climate parameter in mountainous areas such as Zagros in western Iran has wide variations. Diversity of topography is one of the factors leading to these changes. Altitude, aspect of slopes, differences in sun exposure, distance and proximity to water sources such as seas and latitude are the most important factors in the complexity of the relationship between topography and precipitation. There is a direct relationship between precipitation and the activity of precipitation systems in western Iran. The Mediterranean systems are transmitting cold air higher latitudes and Mediterranean Sea humidity to the Zagros Mountains. The expansion of the Mediterranean trough in the middle level of the atmosphere toward low geographical latitudes activates the humid low pressure system on Sudan and the Red Sea. The Sudanese system extends over Iran through the movement of the northward or northeastward Mediterranean trough making precipitation. The humidity of the Sudanese low-pressure system is supplied by the Red Sea, the Arabian Sea, and the northern Indian Ocean. Sometimes, the energy and humidity of these systems is so high that it causes very heavy rainfall over the Zagros Mountains in western Iran during one day. 2-Materials and Methods In this study, daily rainfall data of 22 western synoptic stations of Iran were processed for the period 1996 to 2017. Besides, sea level pressure, atmospheric geopotential height, U-Wind, V-Wind, specific humidity and air temperature data were used for mapping and synoptic analysis. Having checked the rainfall days, maximum daily rainfall of 70 mm or more was considered as a quantitative criterion. According to this criterion, 30 cases of precipitation over 70 mm daily were identified. The most severe of these precipitation were analyzed and studied as the examples of extreme rainfall. These were the February 3, 2006 (162 mm), the April 13, 1996 (131 mm), and the October 29, 2015 (282 mm). The combinatorial maps of atmospheric parameters including sea level pressure, geopotential height, specific humidity, U-Wind and V-Wind and air temperature for levels of 850 and 500 hPa have been analyzed in order to identify the synoptic circulation patterns that cause extreme precipitation events. The composite maps displayed the arrangement of synoptic patterns on a geographical coordinates including latitudes of 10 to 50 degrees north and longitudes 20 to 70 degrees east with a spatial resolution of 2.5 to 2.5 geographical degrees. 3-Results and Discussion In the cold season of the year whenever the Siberian high-pressure system withdraws from the western parts of Iran, conditions are provided for the establishment of a Mediterranean low-pressure system at sea level. In higher levels of the atmosphere, the Mediterranean trough advances toward Sudan and the Red Sea, resulting in the convergence of western and southern winds.  Extreme specific humidity, severe pressure decreasing, air vorticity increasing, velocity increasing of upward motions, and temperature conflict over the area are logical reasons for the formation of heavy rainfall in western Zagros slopes such as Ilam and Marivan. The air that ascends to higher levels, consumes significant amounts of latent heat to ascend the air, and condenses water vapor in a wide surface. Whatever the humidity content of the system increases, the air column consumes more energy through releasing the latent heat to ascend to higher levels. Increasing the height of the water vapor density contributes to the growth of more cumulus clouds such as cumulonimbus, and the cloud height increases from base to peak. The main cause of the extreme winter precipitation was the expansion of the Mediterranean trough over western Iran, the humidity of the Red Sea and the strong convergence of the southern and western winds. In the case of extreme spring precipitation, the role of the Mediterranean system and the humidity feeding of this system through the Caspian Sea and the Red Sea have been the cause of heavy rainfall. The main reason for heavy rainfall event on the region in autumn season has been the expansion of the Mediterranean cyclone and its integration with the Sudanese low pressure system and the warm and humidity air convection from the lower latitudes. 4-Conclusion Based on results, the main area of heavy rainfall is located on western slopes of Zagros, including Ilam and Marivan. In winter, the expansion of the Mediterranean system to the western Iran with accompaniment the Red Sea humidity has been recognized as an essential factor for heavy rainfall. In the spring, the formation of a Mediterranean cyclone on the Caspian Sea and northwest of Iran has caused heavy rainfall. The most intense extreme rainfall of all times have been observed in October and autumn, due to the convergence of the Mediterranean and Sudanese systems and the establishment of a cut-off low over the eastern Mediterranean at the middle level of the atmosphere. The deployment of high-temperature air mass on the Persian Gulf and humidity advection from the southern seas and the Mediterranean have strengthened the system. The Jet stream in the atmosphere's mid-level played an important role in enhancing the convergence of winds and the low-pressure pattern of the Earth's surface. Because, the flow of warm air that has ascend from the Earth's surface toward the middle of the atmosphere has been out of the area rapidly. Therefore, hot and humid wind currents are absorbed more rapidly towards the low pressure center adjacent to the Earth's surface and with the release of latent heat, the air ascends to higher levels of the atmosphere.

Affected by the change of land-use pattern, soil pollution has become an important environmental issue in developed and developing countries.  Heavy element pollution, as a kind of soil pollutant, is really dangerous due to their high toxicity and persistence in the environment. In the current study, the extent of pollution to heavy elements in downstream area of southern waste landfill of Kermanshah city was investigated. In this research, 208 soil samples (from 0 to 20 cm depth), were collected with 50 meters distances systematically from downstream area of waste landfill. The spatial pattern of variables was investigated through calculating experimental variograms and fitted models using geostatistics.  The mean concentrations of Fe, Mn, Cu and Zn in downstream area of waste landfill are 4077, 943, 41.8 and 102 mgkg−1 respectively. The spherical model was recognized as the best model to describe the spatial variability of total heavy metals. Total content of Fe, Mn, Cu and Zn showed a strong spatial dependence. According to the ordinary kriging maps, the total concentration of elements in the central parts of the study area is less than the other parts. This is probably due to the lower slope of the central region and consequently the lower infiltration. The concentration of elements in the southeastern towards the northeast High slope of the area is the result of the adjacency to the waste landfill and also the higher steepness in this part. The findings indicated a long-term progressive trend soil pollution, thus it is necessary to halt latex infiltration either towards the soil or vertically ground water. The results showed a long-term progressive trend in soil pollution. Considering population growth, waste production rate, distance from the city center, and other factors determining the location of landfill, it is suggested to reconsider positioning waste landfill scientifically. Furthermore, some services such as waste separation in the source, waste recycling in the source, and composting would be inevitable.

Roads, as the main artificial linear structures in any landscape, have an important role in the vulnerability of natural ecosystems and their sustainability. The purpose of this research is to introduce a systematic method for ecological vulnerability assessment to be used in road site selection and environmental impact assessment procedure. Five steps of the vulnerability assessment are involved in this study; like determining the indices of vulnerability dimensions, calculating and mapping the indices, standardization of the indices, determining the vulnerability index and analysis of local variability. Lorestan province was selected as the case study due to its ecological properties and the presence of important road network to transfer goods and passengers. Indices like infrastructure fragmentation index, fractal dimension, residential neighborhood index, road traffic noise, erosion, topographic position index, and landscape connectivity index and dominance degree have been applied to quantify sensitivity, exposure and adaptive capacity as major components of the vulnerability. The findings show that the highest tension of road events is on the woodland habitat in 157270 ha. Besides, the regions with a high degree of sensitivity cover 28/1% (795132 ha) of the total study area. Wetland and temperate grassland habitats have the least adaptive capacity. Furthermore, the vulnerability classes in very low, low, moderate, high, and very high cover 2/5%, 52%, 42/1%, 3/1% and 0/3% of the total study area respectively. Therefore, approximately half of the province has the vulnerability degree in over average. This study showed the importance of the ecological vulnerability evaluation in environmental impact studies of development projects.

 

Earthquake is one of the most important and destructive natural disasters that can disrupt the business process and cause a long interruption affecting the livelihoods and income of the survivors. The purpose of this study was to investigate and identify not only the ways in which small businesses are restored and damaged but also their effective factors after the earthquake of 2017 in Kermanshah. The research is a kind of qualitative type based on grounded theory. The study population consisted of the owners of damaged and destroyed urban and rural businesses as well as government officials in Kermanshah province; earthquake-prone areas. The sampling method was a theoretical one using targeted and snowball techniques. Accordingly, 56 interviews were conducted with urban and rural business owners and government officials. Data were collected using semi-structured interviews and thematic analysis using Strauss and Corbin strategy. Long-term researcher engagement methods, triangulation method and member control technique were used in order to evaluate the validity of the research. The reliability of the study was calculated using Holsti's formula which was 82%. Inductive Content Analysis Results of Interview Data, Through Three Open, Axial, and Selective Coding Procedures, to Identify and summarize factors affecting small business sustainability after the earthquake crisis based on grounded theory, including 263 Codes, 52 concepts and 14 subcategories, with the axial category included. Based on the findings of the study, the primacy or synchronization of the reconstruction of damaged and demolished businesses with other aspects of post-crisis reconstruction could provide the basis for the livelihoods of the survivors to continue.                   

Depletion of groundwater is one of the main challenges in Iran especially in the arid and semi-arid lands. The aim of this study is to identify the factors that affect the reduction of groundwater levels and provide a water police strategy for a better management and groundwater monitoring in Sorkheh city of Semnan province. The statistical population in the quantitative part of the research includes villagers living in Iij, Jouin and Sufi Abad. The sample size was determined 160 using Cochran's formula, and factor analyses were used for the data. In the qualitative section of the councils, the regional water company and village administrators were used to analyze the data, the design of mental mapping and content analysis. According to the factor analysis results, water police factor can determine 87.4 of variance compared with other factors which had a high influence on the finding. Based on the results of multi-criteria analysis, the most important reason for the reduction of groundwater aquifers in these villages is the overexploitation and drilling of unauthorized wells. Besides, farm cultivation with high water need can increase water consumption causing stress on the water resources in the study area. According to the conducted survey, the water police can be considered as an approach to monitor and control unconventional exploitation of groundwater resources. On the other hand, to achieve this goal knowledge and preparing the necessary equipment can play a key role in this section. Thus, it needs necessary plans to establish it in the related organization.
   

The lack of precise planning to improve the physical-spatial structure of cities brings a lack of relaxation and quality of life for citizens as governments and urban planners today seek to improve living in urban areas against this heterogeneity .The present study investigates the physical-spatial structural improvement and its impact on the mental and psychological environment of Kermanshah people. Library document and original references related to the subject under study were used to gather background and theoretical background of the study subject. Besides, a survey questionnaire was used to assess the attitudes and opinions of research experts. After the opinion polls were edited, various opinions were categorized and analyzed. Fuzzy Vikor model and linear regression analysis path analysis were used to analyze the research data. The results show that the indicators of impact of public transport circuits, the effect of organizing environmental and urban publicity elements, the effect of refining, organizing and beautifying public landscapes, and the readability of visual milestones and urban signs are the fuzziest coefficients. They have a strong role in promoting the mental and psychological health of urban people in the area. Moreover, the findings of statistical analysis and path analysis model show that there is a positive and significant relationship between independent variables (age, sex, marital status, education, occupation, income, length of residence) and dependent variable (feeling of peace of mind). The overall results indicated that there was a significant relationship among the indicators, but there was no significant relationship between the duration of residence, in one hand, and age and mental and psychological well-being, on the other hand.