An Analysis of Polarization Effects of Offices Site-selection on Overlapped Areas of City Service Zones (case study: Rasht city)

Polarization of land use in cities plays a significant role in the importance of the different city zoning. Administrative land uses can be identified as the effective uses in cities. Such land uses attempt to get located in expensive parts of cities from the very beginning step, but after locating they would turn into a factor to attract other Organizations. In addition, each one of key service organizations in cities attempt to do city zoning based on special standards which, in many cases, are overlapping and may cause some problems. Present research paper is determined to scrutinize the polarization of land uses in city and also the importance of overlapped areas of five organizations involved in developmental and management issues of Rasht (departments of power, gas, water and water waste, telecommunication and municipality). It is based on the importance of their organization applying their documentary and survey studies. Therefore, the required databases in GIS environment was created. Moreover, current situation of different city zoning  was drawn and analyzed. After that, overlapped areas were identified and the available layer of  administrative centers were provided using statistical block data of 2011. The data were compared with the layer of  administrative overlapped zones. AHP method was used to rate the bureaus in overlapped zones. Besides, polarization of land uses was performed using Entropy model and ArcGIS software. The findings indicate that the centers of state government-governance, management of bank branches and justice department are considered to be more significant than other administrative centers. Furthermore, zones of 2, 3, 10, 17 and 35 have the most accumulated offices among other overlapped centers. Also, service land uses and municipality have the highest focus and state government-governance, while justice department and roads and urban development have the least focus among other administrative centers.
Extended Abstract
1-Introduction:
Urban land, as an essential factor of the establishment of cities, plays a special role in land-use planning and it is highly valuable due to the exceptionally exclusive and limited supply. It is so effective that can lead to create important polarized spaces in the urban spatial structure. To the extent that an ecological dealing occurs in achieving these spaces between individuals and different organizations in cities. Polarization of land use in cities plays a significant role in the importance of the different city zoning. Administrative land uses can be identified as effective uses in cities. Such land uses attempt to get located in expensive parts of cities from the very beginning step, but they would turn into a factor to attract other organizations after locating. In addition, each of key service organizations in cities attempt to city zoning based on special standards that in many cases they are overlapping and may cause some problems. Present research paper is determined to scrutinize the polarization of land uses in city and also the importance of overlapped areas of five organizations which is involved in developmental and management issues of Rasht (departments of power, gas, water and water waste, telecommunication and municipality) based on the importance of their Organization by using their documentary and survey studies.
 
2- Materials and Methods:
This research is a kind of descriptive-analytical study whose results will be applied.  At first, related data of studied organizations were collected by using documentary method at first, then the required databases in GIS environment was created and current situation of different city zoning was drawn and analyzed. In the following, overlapped areas were identified by using overlay tools. Then, available layer of administrative centers, as one of significant land uses, was provided by using statistical block data of 2011. Administrative centers in Rasht were classified into 9 groups based on service type they offer. They were compared to the layer of administrative overlapped zones. Then the rate of bureaus in overlapped zones was determined using ideas of experts and professors of urban planning and management in questionnaires of even comparisons. Finally they were weighted using AHP method in Expert Choice environment. In the following, city clustering of administrative centers and entropy model was sued. to clarify and compare the polarization and focus of administrative land uses in the spatial structure.
3- Results and discussion:
The results indicate that there are 35 overlapped areas among all organizations covering the entire city. The highest value of the overlapped areas belong to a shared area of departments, including 2^nd sub-region of the water and sewage, 1^st sub-region the gas, 5^th zone of the municipality, 2^nd district of the power department and 4^th sub-region of the telecom center. Besides, the lowest one consists of an overlapped area of 3^nd sub-region of the water and sewage, 2^st sub-region the gas, 3^th zone of the municipality, 1^st district of the power department and sub-region of the telecom center. The findings show that the centers of state government-governance, management of bank branches and justice department are considered to be more significant than other administrative centers. By surveying calculated weights, it was revealed that the zones of 2, 3, 10, 17 and 35 have the highest weight among other overlapped centers. In entropy method, the administrative centers in Rasht were studied in 35 interference areas. The entropy index of all administrative centers of Rasht (9 clusters of administrative land uses) are less than the calculated “In”, indicating the trend of all to focus and polarization in the city. Among these, service land uses and municipality have the most focus, while state government-governance, justice department and roads and urban development have the least focus (decentralized) among other administrative centers.
4- Conclusion:
Since spatial disharmony of urban service zones cause problems for citizens and other administrative centers, it is necessary to identify important areas of cities in order to set priorities addressing these issue. The findings reveal that the centers of state government-governance, management of bank branches and justice department are considered to be more significant than other administrative centers and zones of 2, 3, 10, 17 and 35 have the most accumulated offices among other overlapped centers. Also service land uses and municipality have the most focus. In contrast, state government-governance, justice department and roads and urban development have the least focus among other administrative centers. This suggests the importance and necessity of proper distribution of administrative centers in cities.