One of the main challenges in the energy transmission arena (especially the natural gas transmission) in Iran is the optimal demarcation of operational boundaries in order to cover the whole land. In other words, over time and due to the changes in the consumption level and the facilities installed in the related areas, the boundaries defined as the operational areas have lost their optimal response potential, and there have appeared challenges such as more difficult access, increased volume and importance of transmission, etc. Therefore, it is necessary to define and demarcate new boundaries based on these changes. As a result, this article addressed the optimal model for the demarcation of natural gas transmission operational areas using spatial allocation method. Spatial allocation method is an instrument for maximum optimization and high access in various algorithms. The spatial allocation methods that are usually used for positioning stations and work facilities are a great instrument for planning the public services. In this study, in line with using comparative studies and external experiences, instruments such as interview (for the determination of indices), statistical tests in GIS, weighing methods, etc., were used. According to the obtained results, the number of yards and areas should be fixed, but the boundaries of the operational natural gas transmission areas and yards should be mobilized maximally to match the defined scenario so that maximum optimization is achieved.

In recent decades, dust storms have intensified due to climate changes, including drought and human interventions. In addition to removing soil particles, dust brings storms bring about severe economic, social, and health problems. Due to its strategic conditions – including its status as an industrial and agricultural hub and the province hosting more than 29 million Iranian and international pilgrims, especially during the seasons and months with specific holidays – should be prioritized in the examination of dust storm frequency. The purpose of this study was to examine and track the frequency of dust storms and analyze the effect of climactic changes on them through the investigation of drought trend as well as the trend of changes in the land surface coverage percentage during the statistical analysis period. The results of counting the dust codes showed that dust storms with local origin had the highest frequency. According to the monthly analysis, Sarakhs and Mashhad stations had the most dust phenomena, with the most dusty days in the study area during summer and spring seasons, especially June and July months. The results of regression analysis of drought index and the monthly local dusty days indicated the existence of a significant, positive relationship between dust increase and drought intensity in Mashhad and Sarakhs stations during the statistical period of 27 years at 99 percent confidence interval. Finally, in the light of the results obtained from the examination of the land surface changes, it is recommended that land use plans be used along with short-term methods of soil stabilization in order to reduce the economic damages and preserve people’s health against dust during busy months and seasons so as to achieve the goals of long-term methods.

Today, ecotourism is deemed a key industry and is granted a special position in the economic development of different countries. This industry has always faced risks in making decisions about selecting places with high ecotourism potential. Therefore, the purpose of this study was the assessment of ecotourism development capability in rural areas, with an emphasis on the environmental risk-taking in decision-making. In this study, 12 spatial criteria were used. Ordered weighted average (OWL), analytic network process (ANP), TOPSIS, and sensitivity analysis were used to assess the concept of decision-making risk, calculate the weight and importance of the criteria, rate the appropriate villages, and assess the modeling precision, respectively. The results showed that among the used criteria, the distance from the built lands and the distance from faults have the highest and lowest weight, respectively. With the increase and decrease in the risk-taking degree, the high potential class space increases and decreases, respectively, such that in the risk-taking degree of 0 or less, less than one percent and in the risk-taking degree of 1, thirty-five percent of all lands of the area fall in the “very high potential” class. The examination of the appropriate villages in the 0.5 risk-taking degree for ecotourism development showed that among all Mazandaran province villages, only 55 villages are in the “very high potential” class. Among these, Aali Kola with the relative distance of 0.8505 is the most capable village for ecotourism development. Finally, the results of sensitivity analysis revealed the adequate stability of the model results in various scenarios, i.e., the high reliability of the model results.

Several benefits that humans get from ecosystems are called ecosystem services. Carbon sequestration as an eco- regulation service is declining, due to the transformation and destruction of the earth used to recompense the burgeoning human needs for development. In the present study, a pilot landscape of hyrcanian forests, protected area in Jahannama was selected. By examining the land use / cover changes during 2001 to 2018, future condition of the land will be set to determine the carbon storage and carbon sequestration model in 2036. The amount of carbon in the four carbon storage sources including biomass, underground biomass, soil and organic matter along with IPCC reports facilities, field studies and sampling was extracted. Deterioration trend in forest lands and grassland with remarkable role in carbon sequestration was sharpened. The reduction trend will be predicted to reach as much as 40 per cent which will be equivalent to 400859 tons per land. With the same rate in land deterioration, a considerable decrease in ecosystem storage and carbon sequestration’ potentiality will be expected present study indicated that the integration of the concept of the ecosystem services in land planning discourse and land use management via the provision of spatial maps of ecosystem services on a regional scale, along with the rational development of human use, ecological hazards should be minimized, as a result better decision will be made in planning the land. It is also suggested that to enhance the quality of Jahannama ecosystem services in development plans and review within the protected boundaries and the principled management of land use within the protective boundaries.

Spatial imbalances and spatial inequalities exist at different levels, and the realization of spatial and social justice at these levels depends on eliminating these imbalances through spatial planning. Service organizations to clients and, most importantly, the Welfare Organization, may have a lot of data and figures from their clients, but in many cases, existing data does not have a spatial dimension, and they are purely descriptive. The main objective of this research is to analyses spatially clients covered by welfare in the scale of Mashhad, in both regional and neighborhood level. The statistics required for this study are collected from the Department of Welfare of Khorasan Razavi and Mashhad. The methods used for spatial analysis are the standard deviation elliptic index, regional and neighborhood demographic density, kernel density, basic graphic statistical methods including the nearest neighbor's index, spatial autocorrelation measurement models such as general Moran I and LISA. The results of this research, presented in various maps and diagrams, show that the welfare beneficiaries in the city of Mashhad have not been distributed equally and different regions and neighborhoods have a significant difference, with the highest number of clients in regions 2, 3 and 4, the city of Mashhad where tjeay are located in the north and northeastern parts of the city. Also, at the neighborhood level, Shahid Ghorbani, Northern Tabarsi, Derevey and Bahman neighborhoods include the most welfare-clients population. In a general analysis based on the kernel density analysis, it can be stated that four condensed nuclei and a subunit formed in the city of Mashhad. Also, the results of Moran indicator and others indicate that the spatial distribution pattern of welfare clients in Mashhad is quite clustered and in particular parts of Mashhad, which mainly coincide with the informal settlements of the city and the eastern and northern parts of the city are distributed in cluster form.

Prioritizing sub-basins in terms of flooding potential has an important impact on catchment management. The purpose of prioritizing flood basins below basins is to provide a model to reduce flood hazards and evaluate the role of sub basins in peak discharge hydrograph of outflow from basin. In this study, flood potentials of sub-basins were determined based on 12 morphometric parameters and prioritization of Gadar sub-basins based on combined morphometric analysis method and statistical correlation. Initially, values ​​of 12 morphometric parameters and index (Cv) were calculated and sub-basins were zoned for flood potential. Then, the relationship between the parameters and the effect weight of each were analyzed using Kendall's blend correlation and weighted sum analysis (WSA). Finally, Sub-Basin Prioritization Index (SWPI) was calculated based on WLS method for each sub-basin. In order to validate the results, past destructive flood location data in the Gadar catchment were used. The results showed that in the flood potential method based on 12 morphometric parameters calculated under Sheikhan tea and Sufian tea basins with high flood potential, sub-spring source basin with medium potential and Godard tea basins and Nalivan creek basins have They have little potential for flooding. In fact, 33.83% of Gadar basin area has high risk potential, 14.28% has moderate risk potential and 51.88% has low risk potential. The results of morphometric parameters and statistical correlation showed that sub-basins of Sheikh tea and Sufian tea with 24.1 and 21.10 priority sub-basins were identified respectively. Comparison of the results of the two methods with the morphometric and geomorphologic conditions of the sub-basins shows that the results obtained by relying on 12 morphometric parameters are more in line with the geomorphic conditions of the basin.

Compared to other cities, metropolises are exposed to the more vulnerabilities derived from environmental disasters because of their population, and the vulnerability of most of them is even increasing. The assessment of vulnerability, especially in specific intervals, generates new foundations for better urban planning and management. Additionally, the concept of the term “vulnerability” has been emphasized in the context of studying the relationship between natural-human interconnected systems, and consequently, in urban ecology. On the other side, population movements in different districts of big cities always follow different models. Therefore, the main purpose of this research is to identify the spatial connection of population changes of the districts of Tehran metropolis with the changes in environmental vulnerability intensity in the last decade. The methodology of the research included the assessment of vulnerability in three layers, namely the damages stemming from natural disasters, urban structure, and environment in the last decade in Tehran. In addition, the vulnerability has been measured in accordance with the census statistics of population changes in 22 districts of Tehran in the recent decade. The results of the research modeling show that the southern area of the city has had the highest increase in vulnerability during the last decade, and so, it has had the highest reduction of the population, too. Nonetheless, the district 18, which is located in the west zone of the city, has faced an increase in population despite its increased vulnerability. Moreover, the northeastern area of the city has faced increased vulnerability as well as a sharp increase in population during the last decade. These changes can challenge this part of the city because of possible future crises. Finally, the reduction of vulnerability along with the increase in urban population has happened in the northwestern area. To keep this vulnerability low, the acceptable capacity of the population in this part of the city (especially district 22) should be taken into account.

Due to the growing importance of environmental problems and increasing human interventions in natural environments, it is necessary to use spatial planning and sustainable development approach in order to conserve natural resources and move along with the land and its productive capacity. The rough topography of Lorestan Province has caused a large part of its lands to be recognized as national lands due to their steep slope and the necessity of preventing the destruction of natural resources. However, there some activities such as agriculture, industry, tourism, etc., which are possible if certain conditions and criteria are met. Regarding the dependence of the region's economy on agriculture and the increase in unemployment, these lands can be used to develop agricultural activities based on their environmental potentials using spatial planning approach. The purpose of this applied study was to determine the potential of national lands of Chalancholan basin in the east of Lorestan Province for the development of agricultural activities. We used tools and data such as topographic maps, geological maps, climate data, pedology, hydrology, and Arc GIS software to determine national lands with agricultural potential based on the guidelines and standards of the Forests, Range, and Watershed Management Organization of Iran, taking into account the local conditions. To this end, first, the land units (geomorphology) were determined and then, the allowable land uses were specified in each of the homogeneous environmental unit. Next, different variables were used to assess the suitability of national lands for agricultural land uses. The study results showed that national lands under study are more suitable for dryland agriculture compared to irrigated agriculture and horticulture, the reason of which is poor pedogenesis‎ due to geological characteristics of the region and limited water resources. The study results indicate that the lands located in the plains and alluvial sediments are more suitable for irrigated agriculture and horticulture, while the lands surrounding the plains are more suitable for drayland agriculture.

Population distribution, economic functions, as well as the status and role of cities in the urban system change and evolve through their interaction with other cities over time. This change in the organization of the urban system is not a static one,   but rather it is a context-dependent issue. Alborz province has experienced highly rapid changes in the urban system that have led to the emergence of severe imbalances in the urban system, increasing population and functional concentration in its metropolitan area compared to other cities and the marginalization of other cities of the province in the urban system. The typology of urban system in Alborz province that aims at describing the spatial pattern in which the cities of this urban system are organized and proposing the possible scenarios for the future spatial pattern of this urban system are the subjects of this article. This issue has been pursued through the analysis of the morphological and functional spatial pattern of cities, the analysis of the grounds affecting the formation of the urban system, and for the examination of the possible futures for the urban system. This research had mainly a descriptive nature, relied on quantitative methods and spatial analyses, and emphasized both morphological and functional aspects. According to the findings, the main east-west corridor of the province is the most important factors in the spatial pattern of this province’s urban system. The urban system of the province might develop in future through three possible spatial scenarios. These scenarios include the corridor, polycentric, and monocentric development patterns. It seems that in the urban system of Alborz province despite the spatial concentration of the population and the majority of the provincial functions in Karaj metropolis, there are potentials for the realization of a more balanced development. The potential and tendency to the corridor development model around the east-west axis, which agrees with the natural, infrastructural, and economic structure of the region, is one of these tendencies that can create a demographic and functional balance in the urban system of the province and lead its cities to take various economic roles.

The increasing population growth along with human activities has led to the booming of waste production.  The selection of inappropriate landfill sites contributes to the increased potential of underground pollutions. The purpose of this study was to zone the underground water vulnerabilities of Karun County in Khuzestan Province to select the optimal landfill site, so that a site with the least vulnerability of aquifer would be selected for waste disposal. Two models were used to zone the aquifer pollution potential, namely GODS and SINTACS. After preparing the vulnerability maps of the two models in GIS software, the appropriateness levels of the sites for waste disposal were prioritized. The results of SINTACS model demonstrated the following vulnerability statistics: 455.22 hectares have no vulnerability potential, 780.84 hectares very low vulnerability, 3281.31 hectares low vulnerability, 12582.4 hectares low to medium vulnerability, 11169.9 hectares medium to high vulnerability, 9449.6 hecaters high vulnerability, 5844.15 hectares very high vulnerability, and 495.72 hectares totally at vulnerability risk. Moreover, in GODS model, nearly 215.576 hectares have negligible vulnerability, 560.544 hectares low vulnerability, 5169.08 hectares medium vulnerability, 37471.9 hectares high vulnerability, and 641.9 hectares very high vulnerability. In both models, the least vulnerable zones comprise a small part of the area (1.03 percent in SINTACS and 0.49 percent in GODS model). This level can be selected as the optimal landfill site (rank 1), while other zones are ranked lower due to their higher aquifer vulnerability levels.