Journal of Spatial Analysis

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Today urban livability reflects a powerful discourse in urban development and city design that is prevalent in urban planning literature suggests that there is an ideal relationship between the urban environment and the social life .On the one hand, the livability indicates the strong urban influence and attraction. On the other hand, the livability will further strengthen the urban connectivity and influence by attracting more investment, human and cultural resources. The livability of a city is closely related with a healthy and ecological city and sustainable urban development. This study aimed to measure the livability in the neighborhood of  region(2) of Sanandaj city and research methodology is descriptive-analytical.  A base map of the study area was prepared using Arc view Software. The region (2) is located in the central parts of the Sanandaj city.and the population of region is 239,965. The sample size was calculated using the formula Cochran. Therefore, 370 residents of neighborhood filled the questionnaire and expressed their viewpoint about the indicators of livability. A data collection method with respect to the merits of subject is Library and field method. The filled questionnaire by residents of different aspects of livability is measured. According to the Social features, facilities, geographic, economicfacilities and services available in the region , urban managers and experts have weighted the dimension and index of urban livability.The index of economic, social and environmental livability was calculated and  the sum of these three dimensions is considered as total livability.To assess the livability of neighborhoods, data from filled questionnaires by people have been analyzed by the software GIS, SPSS and Excel. Using hot spots, three indicators and total livability of each neighborhood displayed.The results of the analysis of economic indicators showed that the areas in  the western parts of the city  are hotter and more color spots, But in the East and South East areas neighborhoods, like Shahrdari, Sepahdegaran  have  in colder and less color spots. This actually shows the cluster distribution of economic indicators. Also the results of the analysis of social indicator showed that spatial distributon is cluster neighborhoods like Khosow Abad, Masnav, Chahar Divari, Mobarak Abad are in the hotter spots and neighborhood Adab, Varmaghani, Hassan Abad are in colder spots.The resualts for environmental indicator reveals  that spatial distribution is cluster. Mriginal neighborhoods are in colder spots and Nezam Mohandsi and Shardari town and Degaran allocated the lowest Z. In contrast neighborhood like Mobarak Abad and Khosrow Abad are in hotter spots. Analysis of hot spots for total livability implies that neighborhood in West area of city follow clusters of  hotter spots and the South East neighborhood follow colder spots. This can result in injustice in space services and  the lack of performance in order to improve the quality of the environment and quality of life in area, livability is defined as one of the aspects that could contribute to a high quality of living, because high quality of living will affect citizen's lifestyles, health condition and shows stability of the built environment. most researchers agree that livability refers to the environment from the perspective of the individual and also includes a subjective evaluation of the quality of the place so measurement of urban livability   for all places promote the perception of urban managers and planners and with such knowledge, the path will be open for practical, creative and futuristic management of the urban environment. In relation to the livability of neighborhoods to each other, spatial and non-spatial analysis shows that areas with different ratings are compared to each other. With respect to results of measurements of livability: centrally located neighborhood is more livable than their peripheral counterparts which may calculate that location has significant importance in the pattern of livability. Therefore spatial distribution of dimension and index of livability is not the same extent.The results showed that between main dimensions of neighborhood livability is not different. But in terms of spatial distribution, three dimensions are not equally distributed and it is cluster. Ranking based on total index indicate neighborhood of Khosrow Abad with score (3.279) is ranked at first and Sharif Abad with score (2.228)is ranked at last.

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 Investigation of the daily minimum visibility meteorological conditions using RVR data at IKA airport during 2013-2014
Hatami, J. ¹, Sabetghadam, S. ^2*, Ahmadi-Givi, F. ^3
1M.Sc. Student, Institute of Geophysics, University of Tehran
²Assistant Professor, Institute of Geophysics, University of Tehran
³Associate Professor, Institute of Geophysics, University of Tehran
 
Abstract
Atmospheric visibility is defined as the greatest distance at which an observer can see a black object viewed against the horizon sky, which is usually known as visual range. It shows the degree to which the atmosphere is transparent to visible light, therefore its impairment results from light scattering and absorption that can originate from natural or anthropogenic sources.  Visibility is an important atmospheric parameter in landing and takeoff of an aircraft. Reduced visibility due to snow, rain, fog, and haze is an important consideration in the landing and takeoff of aircraft. Visibility and the related quantity Runway Visible Range (RVR) are meteorological parameters that are crucial for the operations at an airport. The Runway Visible Range is defined as the range over which the pilot of an aircraft on the centre line of a runway can see the runway surface marking or lights delineating the runway or identifying its centre line. A large number of aviation accidents are happened cause many passengers to die. Today, safety is very important in aviation. In fact, it is a competitive factor among aviation companies. Measuring the exact visual range is one of the most important factors in flight security. According to the international standards, whenever the visual range is less than a certain threshold for runways, take-off and landing will not be authorized, and pilots will be ordered land on an alternative airport that costs airlines a lot of expenses.
   One of the methods in determining the runway visual range is to use instruments such as transmisometer and forward scaterometer to measure the amount of scattering and absorption of light by the atmosphere. A transmissometer measures the extinction of light over an atmospheric path between an emitter and a receiver and it  is directly related to the extinction. A forward scatter meter measures the amount of light scattered by a small measurement volume. RVR instruments usually locate at three places across each runway that is mandatory for operation in international airports.
    For the first time in Iran, data obtained from the RVR system from Imam Khomeini International Airport are applied in this study to examine the circumstances under which the runway visual range reached its minimum during two years 2013 and 2014. The high accuracy of these devices is a valuable factor for researchers to get more precise results. The data used include visibility range, temperature, dew point temperature, humidity, wind speed and wind direction, which are measured using the RVR system.  The main part of this study concentrates on fast decreases of RVR, meaning a decrease of visibility to below 1500 m which takes more than 10 minutes. Therefore some cases of RVR data have been investigated in more detail utilizing one-minute observations are presented. For these cases, some meteorological parameters are investigated before and after  this fast decrease of RVR occurred. These parameters as well as RVR are plot to find out what happened before and during each specific event.
    Results show that the critical low visibilities were mainly occurred in May and March and no cases of low visibility were seen between July to September. This can be due to the impact of more atmospheric systems and variable weather conditions in the relatively cold months. The highest visibilities were mostly occurred in July-September, due to the weakness of atmospheric systems and their less frequency of occurrences. Low visibility days were usually accompanied by dust, fog, mist and precipitation events.During 2013 and 2014, categorizing the weather events that may lead to the decrease of visibility to less than 1500 meter, shows that the 45 percent of the cases with the low visibilities caused by by dust, 35 percent by haze, 15 percent by fog and 5 percent caused by haze.
    For the critical cases, case studies show that the high relative humidity and the change of wind direction were also favored in the occurrence of low visual range. Case studies of the events suggest that these factors differ from one another based on how they are formed. After the fast decreases of RVR, the relative percentage of RVR events show an increasing in relative humidity especially during fog and precipitation.
 
Keywords: runway visual range, scattering and absorption of light, low visibility.
 
 

 

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A new Approach to Urban livability, Thermal Comfort as the Primitive Condition to enhance the livability: Case study, District 22 of Tehran.
 
 
Ahmad Porahmad: Professor of Urban Geography and Planning, University of Tehran
Hossain Hataminezhad: Professor of Urban Geography and Planning, University of Tehran
keramatollah Ziyari: Professor of Urban Geography and Planning, University of Tehran
Saeideh Alijani^*: PhD candidate of Urban Geography and Planning, University of Tehran
 
The concept of urban livability is defined as the quality of life and wellbeing of urban residents. That is the interaction of people, environment and built environment. The residents can achieve happy life and well-being only when the nature surrounding them is happy and healthy. According to the range of welfare concept there is a spectrum of quantitative indicators that directly measure (human body temperature, heart rate, air temperature, wind speed ...) and qualitative indicators such as quality of life, pleasure and joy. The comfort and ease of environment are in the middle of the spectrum, in other words, the intrinsic concept of ambient comfort is environment. The inadequacy of natural environment will affect both indicators in the spectrum and lead to citizens' dissatisfaction and decline in social welfare and threaten the health of humans. Living in a salty marsh or very dry hot climate is never happy and satisfied. Accordingly, many concepts such as living quality, living environment, and quality of place, quality of life and sustainability are often used interchangeably with livability).
         This research is trying to weight the natural environment at least equal to the other two components of the sustainable development triangle. Among the components of natural environment, climate is playing the most important and significant role. Urban climate affects all aspects of city including building interiors, city architecture and open spaces. Thermal comfort of open spaces promote the social life and interrelations of residents. Therefore, in order to promote the social relations and economic activities especial consideration should be paid to open spaces. Accordingly, two types of data were measured for calculating the thermal comfort in the district 22. Subjective and objective evaluations which present qualitative and quantitative data. Objective data includes micrometeorological measurements with mobile instruments. Subjective data evaluated actual sensation vote or perception vote of thermal comfort by people using the urban open spaces. To this goal, questionnaires were prepared and scattered through space users simultaneously with micrometeorological measurements. Subjective data evaluated perceptual sensation vote of thermal comfort by people using the urban open spaces in three hot days of August 2018. Nine points are selected for site measuring and field survey which are representative of two types of urban open spaces in this research:1) Urban park and 2) street. Four cardinal points were chosen adjacent to the Shohadaye Khalije Fars Lake inside the park located in sidewalk pathway around the Lake.  Other five points were selected in streets with different orientation and aspect ratio through the district. The physiologically equivalent temperature (PET), mean radiant temperature (Tmrt), sky view factor (SVF) and aspect ratio (H/W) are the most important indicators in this research which were calculated for evaluating comfort in the district.
      Results showed that urban open spaces in the district are discomfort and expose people to the extreme heat stress; over 40°C. This determines that, the natural environment especially around the Shohadaye Khalije Fars is not comfort. The questionnaire also indicated that people felt warm and dissatisfied.
        There is a high linear correlation between thermal comfort and mean radiant temperature and globe temperature. Therefore, it is concluded that thermal comfort in the district, is directly affected by urban areas.  Also in the streets with low SVF and high aspect ratio, PET were calculated more comfortable than other streets. Point 5 at Naghibzade street, confirmed the effect of urban geometry on thermal comfort. Otherwise, the lack of tremendous trees for creating shade is visible especially around the lake. The high linear correlation between Tmrt and SVF around the lake confirmed the openness of the area and the high amount of solar radiation. Therefore, planting more trees for creating the shade effect is necessary. 
        The perceptual analysis of thermal comfort indicated that by increasing of PET, people felt warmer. However, in a city like Tehran, people are more resistance to the heat stress. In addition, the characteristics of human body strongly depends on psychology and individual features and is a hard issue to predict. Otherwise, the people who felt warm were more than those felt slightly warm which indicates dissatisfaction of people. To be noticed that, thermal comfort of above 40 °C in summer is an alarm to urban planner and designers to rethink about climate consideration and global warming as a most important urban challenge in the district seriously. Besides, the consideration of thermal comfort and urban geometry should be imbedded into the comprehensive plan. This research proved that the climatic consideration for improving the quality of life and livability is important and urban designers and planners should rethink and review the comprehensive plan of Tehran to make a livable and sustainable city in the future.
Keywords: urban livability, climate comfort, sustainable development, urban sustainability, urban geometry, physiologically equivalent temperature, district 22 of Tehran.
 
 
 
 
 
 
 
 

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 Karst Geomorphology effects on the environmental hazard intrinsic vulnerability of groundwater resources (Case study: the Aleshtar and Nourabad basins)
 
Introduction
Karst is the result of the dissolution (physical and chemical) in carbonate (limestone and dolomite) and evaporate rocks. Karst developing is affected by climatological and geological factors. In the other words Karst landscapes and karst aquifers are formed by the dissolution of carbonate rocks by water rich in carbon dioxide waters. Karst aquifers include valuable freshwater resources, but are sometimes difficult to exploit and are almost always vulnerable to contamination, due to their specific hydrogeologic properties, therefore, karst aquifers require increased protection and application of specific hydrogeologic methods for their investigation. The groundwater protection in karst aquifer has a special importance, because the transit time for unsaturated and saturated zone is so quickly that the attenuation of the pollutant. Karst groundwater vulnerability mapping should form the basis for protection zoning and land use planning. A conceptual framework was devised for vulnerability mapping based on this European approach.
Social and economic life of cities such as Nourabad, Alashtar, and numerous rural societies is connected to the Gareen anticline springs. In this paper we used PaPRIKa method for vulnerability assessment in the Aleshtar and Nourabad basins.
 
Material and Methods
 The Gareen anticline in the Zagros Mountain range is located in the active deforming Zagros fold-thrust belt and Sanandaj-Sirjan zon. Alashtar and Nourabad karst aquifers are located in the north of Lorestan province. There are several thrust faults with northwest–southeast strike such as Gareen-Gamasiab and Gareen-Kahman Faults. Nourabad unit is composed mainly by gray limestone rocks, embedded marl limestone, recrystallized limestone and pyroclastic rocks. One of the most important features of the structural geology of the Alashtar unit, is abundance of the sedimentary rocks and scarcity of igneous rocks in this area. In other words In the Study basins the main geological formations incloud: Bakhtiarian conglomerate, carbonates of Sormeh, Taleh Zang, Pabdeh and Kashkan Formations.
The groundwater vulnerability assessment methods (PaPRIKa) applied at the test sites were designed specifically for karst aquifers. They are based on various types of information concerning the physical characteristics of the unsaturated and saturated zones, the aquifer structure and its hydrological behavior.
The PaPRIKa method takes into consideration criteria for both structure and functioning of the aquifer. Based on EPIK and RISK resource methods, PaPRIKa method was developed as a resource and source vulnerability mapping method, allowing assessing vulnerability with four criteria: Protection, Rock type, Infiltration and Karstification. The P map (Protection) considers the protection provided to the aquifers by layers above the aquifers: the S (soil texture, structure and thickness), Ca (permeability formations), the Uz (thickness, lithology and fracture degree of unsaturated zone) and E (Epikarst aquifer). Moreover, including the catchments of water losses where the vulnerability is higher. R map (Rock type) considers the lithology and the degree of fracturing of the sutured zone. I map (Infiltration) distinguishes concentrated from diffuse infiltration. Ka map (Karstification development) assesses the drainage capacity and the organization of the karst conduits network.
To  calculate  the vulnerability  index,  the  four  mentioned  maps(P. R. I. Ka)  have been  combined  using  the  following  equation coefficients (eq.1):
 
PaPRIKa Index= 0.2 P + 0.2 R + 0.4 I + 0.2 Ka                                        (1) eq
 
Due to the fact that karst geomorphology has a great impact on the quantitative and qualitative characteristics of water resources and the vulnerability assessment of these resources, fuzzy logic has been used to zonation of the Karst development in the Aleshtar and Nourabad basins.  In the fuzzy method used a gamma operator (eq.2):
µ _Combination= ((Fuzzy Algebraic Sum) (Fuzzy Algebraic Product)) ^1-γ                                                (2) eq                    
The vulnerability map for aquifers was prepared using the software Arc GIS_10.4.
 
Discussion and Results
In the Gareen Antarctic region, due to the availability of suitable Karstification, includes: Lithology, Active Tectonics, Mediterranean climate (with average rainfall of between 454-448 mm and average temperature of 13 C˚) features are formed by various forms of karst such as closed pits (Doline, Swallow Hole, Aven, Polyeh (Peljee), several types of Karrens, dissolution Cavities, small and large Caves and Springs. The most important karst features in this area including Dolines (Solutional, Collapse, Subsidence and Dropout) which are known the Karst Nival. Based on the Karst development zoning map by using the fuzzy logic, 15% of the study area has been developed. Due to the vulnerability based on PaPRIKa method, the Aleshtar and Nourabad basins divided into 5 categories. Resuls show that the vulnerability of the study area is mainly classified as High or Very High, due to the highly developed Epikarst, which minimizes the protective function of the unsaturated zone. There are many karst landforms such as dolines and Swallow Holes that are highly vulnerable.
 
Conclusions
The final evaluation of the vulnerability ground waters in the Aleshtar and Nourabad basins using the PaPRIKa method shows that the study area is divided into five vulnerable (very high, high, moderate, low and very low). So that areas with a very low, low and moderate vulnerability are 27.3%, 22.3% and 20.6% of the basin area respectively. Also that areas with a high and very high vulnerability are 17% and 12.8% of the study area cover, respectively. Due to the lack of soil and plant cover, heavy snowfall and the formation of Karst-Nival (including Dolines) highlands of the Gareen Anticline have a very high vulnerability potential. Validation of the results of the karstic aquifers vulnerability to Electrical Conductivity (EC) data and monthly discharge of springs shows that the Zaz and Ahangaran springs are in a high vulnerability zone. In the aquifer of this springs, Rapid reductions in EC are detected after each recharge period. Also in contrast Rapid increases in EC with reductions in recharge. This situation shows the High developed of this aquifers, as a result, the potential for vulnerability in these aquifers is high.
But in the springs of Niaz and Abdolhosseini in the Nourabad basin, the EC chart has not changed much compared to recharge. Therefore, the aquifer of these springs is less undeveloped or low developed and also less vulnerable.
 
Key Words: Gareen Anticline, Geomorphology, Karst, Lorestan, Pa
 
 

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