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Evaluation of Flooding below Gadar Catchments based on Morphometric Parameters and Statistical Correlation
2020
Yamani, Mojtaba | Abbasi, Mousa
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.
Mostrar más [+] Menos [-]The Spatial Correlation Analysis of Population Changes With the Intensity of Tehran’s Environmental Vulnerability Changes in the Last Decade
2020
Rezaei Rad, Hadi | Akbarian, Zahra
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.
Mostrar más [+] Menos [-]Assessing the Agricultural Land Use Potential in National Lands Using Spatial Planning Approach: The Case Study of Chalancholan Basin, East of Lorestan Province
2020
Sharafi, Siyamack | Noorollahi, Darioush
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.
Mostrar más [+] Menos [-]The Typology of the Spatial Pattern and the Suggestion the Possible Future Scenarios of Possible Urban Systems for the Development of Future Urban System of Alborz Province
2020
Sharifzadegan, M. Hossein | Khalili, Bita
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.
Mostrar más [+] Menos [-]Evaluating Groundwater Pollution Potential to Select the Optimal Landfill Site in Karun County
2020
Safaeepour, Masoud | Babaei, Ali Akbar | Abiyat, Mahmud | Abiyat, Mohammad
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.
Mostrar más [+] Menos [-]Spatial Configuration, Environmental Quality, and Residentials` Density Perception in Settlements (Case Study: Beheshti Town of Hamadan)
2019
Hatami, Yaser | Zakerhaghighi, Kianoush
Researchers believe that population density is defined as the estimation of the amount of population and their activities. Put it differently, it is equivalent of spatial congestion. This concept is measured based on some environmental indexes. Also, it is closely related to the environment`s design style and culture and environmental indexes. Thus, the environment has a substantial influence on the perception of density which is assessed as spatial configuration. As a result, the environment has a great impact on density perception, which we consider as a spatial configuration. Configuration, in other words, is a set of relationships between spaces that exist in a particular situation in time and affect the perception of density by citizens and environmental quality. In this regard, the present study was conducted with the aim of using condensation tools in urban planning and trying to create a favorable environment for the residents of Shahid Beheshti residential town of Hamadan. The type of research is applied and its method is descriptive. The information is collected through observation and questionnaire adjusted with the Likert spectrum. The statistical population of the study in Beheshti town of Hamedan is 7652 people, and the sample size is 366 people using Cochran formula. Data analysis was also performed through Spatial Distance Index (SOI) calculations and one-way ANOVA and multiple regression (HMR) tests. Finally, it was found that the lower the spatial distance index (SOI), the more enclosed and compact space, the lower the environmental quality, and the higher the SOI, the higher the openness and extent, and ultimately the higher the environmental quality. As a result, the present study has presented a conceptual framework for planning and designing standard and appropriate spatial configuration of urban space with respect to the level of citizens' perception to improve the quality of the urban environment.
Mostrar más [+] Menos [-]Planning the Natural Context of Ecological Networks (A Case Study of Urban Landscape of Karaj)
2019
Hassani, Sholeh | Barghjelveh, Shahindokht
The qualitative study of the urbanization process indicates that inappropriate development has caused a great deal of damage to the urban landscape structure. The problem solving tool is planning the ecological networks as matter and energy pathways. Planning natural elements of the structure, including green and open spots and corridors, will guide the researcher toward achieving research goals such as the conservation and restoration of natural resources and the improvement of cybernetic forces to enhance performance sustainability, structural equilibrium, and habitat variability. The methodological model of research in the Karaj metropolis identified flexible elements to strengthen ecological processes. Then, adopting the ecological-sociological approach and forming the urban habitat network, it was applied for sustainability. GIS software was used to map and digitize the data, RS to capture satellite images, and FRAGSTATE 4.2 to analyze the metrics changes in the years 2008 and 2018. The results of Bayer spot changes were -7.98% for CA, +5.79% for NP, and -1.5% for Cohesion, while residential spot changes were -24.15% for CA, +26.16% for NP, -3.96% for Cohesion, and green-space spot changes were -38.8% for CA, +275.5% for NP increase, and -34.0% for Cohesion. These indicated increased discontinuity, decreased natural bedding connectivity, and decreased ecological performance along with its adverse effect on social structure. Thus, using a nature-based planning, we can witness the network dynamics of natural/man-made communication/isolation networks over time, and by establishing a holistic, bio-ethical culture, we can overcome social vacuum. This way, Karaj can move in the excellent sustainable development path.
Mostrar más [+] Menos [-]An Investigation and Analysis of the Effect of Urmia Lake Water Level Reduction on the Development Levels of Surrounding Counties
2019
Mohammadi Hamidi, Somayeh | Nazmfar, Hossein | Yazdani, Mohammadi Hassan | Rezayan Ghyeh Bashi, Ahad
The discussion of environmental change is currently one of the most important challenges which the international community faces. This issue comprises one of the most extensive scientific, economic, social, and even political debates at different global levels. Severe and sustained droughts have threatened many parts of the globe at different times and have led to rapid and profound changes at the economic and social development levels. The Middle East, especially Iran, has been no exception in this regard. The drying up of water resources, including lakes, is a prominent feature of these changes that has caused problems for the surrounding habitats. The purpose of this study is to evaluate the status of development indicators in 22 cities in Urmia Lake catchment area. In recent decades, water level has decreased significantly and drought level has increased in this lake. This study is an applied research project in terms of purpose and a descriptive-analytical one in terms of methodology. Data and information were collected from sources and documents of the Census Bureau for the years 2006 and 2016. Also, Vikor method and Moran's spatial autocorrelation index in Arc Gis software were used for the data analysis. The results of the statistical calculations showed that the development levels in the catchment area have transformed dramatically over the last 10 years, from the cluster distribution of 2006 to the dispersed distribution pattern of 2016. Moreover, the employment rate has declined and the unemployment rate has increased.Comparing the various statistics, one can clearly see the negative effects of the Lake water level decline on catchment area counties over the last 10 years. The gradual decline in the Lake water level (followed by a decrease in the employment rate and an increase in the unemployment rate) is the main reason for the imbalance in the development of the region.
Mostrar más [+] Menos [-]The Spatial Impact of Socio-Economic Structure of Rural Areas on Groundwater Resources Drawdown (Case Study: Rural Settlements of Lordegan)
2019
Taghipoor Javi, Ali | Seidaiy, Seyed Eskandar | Barimani, Faramarz
As the most essential element of life, water has long been regarded as an indicator of development because it is inextricably linked to the sustainability of human societies, especially the socio-economic function of rural settlements. The main purpose of this study is to explain and root out the causes of groundwater resource draw-down in relation to the socio-economic structure of rural areas. The main issue is that as population growth and demand have increased (to meet the needs of rural communities), excessive exploitation and pressure on groundwater resources have been on the rise. The research data were collected through document analysis and field study. Next, the longitudinal statistics of 40 observational wells (1984-2014) were combined with quantitative observations and interviews with subject matter experts. These were then analyzed through descriptive-analytical methods using inferential statistics and GIS software. Research findings show that the implementation of land reform program, the increase of number of farmers, deep well drilling, the development of irrigated area, and the change of production method had a relationship with unnecessary exploitation and draw-dawn in groundwater level in the research area. The result of the study illustrates the fact that as the population has increased threefold in the living space of the plains, the farms have been fragmented, and numerous deep wells have been drilled, the groundwater level in the aquifer has drawdown to -22 m.
Mostrar más [+] Menos [-]Analysis of the Spatial Interaction between the Iranian Southern Ports and the Regional Hinterland Cities
2018
Dadashpoor, Hashem | Arasteh, Mojtaba
Ports in most parts of the world play a great role in creating integrity between the prosperous of the regions and balancing the supply chain (production, distribution, and consumption). This article is to analyze the spatial interaction between the southern ports of Iran and local-regional hinterlands and explain the role of ports in shaping the spatial structure. For this purpose, a network analysis of commodity flows method is used in 1996, 2006 and 2015. The findings indicate that southern Iran's ports are often the importer of consumer goods in the populated centers, located in regional hinterlands, and, at best, have exported energy sources and raw materials. While urban centers, located in local hinterlands, do not play an effective role in the production and delivery of goods to ports, they are often dependent on the regional center (Shiraz) to meet their consumption needs. It revealed that although the process of spatial inequality has been moving towards greater balance over the past two decades, the development of medium-sized ports and local nodes in the contiguous hinterlands and forelands has led to a balanced monocentric spatial structure in this region.
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