Special Issue INTERNATIONAL JOURNAL OF HUMANITIES AND March 2016 CULTURAL STUDIES ISSN 2356-5926 Seismic hazard zoning of Hamadan Town for urban development by using remote sensing and GIS Mohammad Ahmadi Department of Urban Planning, College of Arts and Architecture, Hamedan Branch, Islamic Azad University, Hamedan, Iran [email protected] Mohammad Rahmani Faculty Member, Department of Urban Planning, College of Arts and Architecture, Hamedan Branch, Islamic Azad University, Hamedan, Iran Corresponding Author: [email protected] Abstract In the nature of Iran, earthquake is known as the most destructive factors threatening the human life. Historical reviews showed that sometimes, large areas of Iran had been destroyed by the natural disaster and many casualties and financial damages had been left. Lack of proper application of the techniques to deal with the earthquake, has put the country at the risk of acute vulnerability. In this study, it is tried to do the zoning of urban development based on the earthquake hazard through fuzzy logic model by considering the indicators such as accessibility, slope, aspect, geology and distance from fault lines and the use of remote sensing and GIS. The satellite images (2015) were used in this study, studied area was classified to 7 classes (developed lands, brown lands, irrigation lands, agriculture lands, rocky land, urban green spaces and the lands related to cultural heritage) in term of land cover. To define the fuzzy membership pf variables, linear function was used with respect to the linear nature of the variables (0 to 1). Comparison in the multivariate regression model showed that the linear regression with the correlation coefficient of 0.97 between the dependent variable (zoning of urban development) and independent variables (slope, aspect, accessibility, geology and distance from fault lines) had the best coefficient for doing the zoning of urban development. The results showed that in recent years, Hamadan Town has been further developed to the north and northeast. Its development to the south was limited due to the mountains. The north and northeast parts of the city are the best places for the development of Hamadan Town in the coming years due to the lower altitudes and lower slopes. Keywords: town, remote sensing, GIS, urban development, earthquake, zoning. http://www.ijhcs.com/index.php/ijhcs/index Page 983 Special Issue INTERNATIONAL JOURNAL OF HUMANITIES AND March 2016 CULTURAL STUDIES ISSN 2356-5926 Introduction: Town as a settlement system needs to be planned in a way that its inner potential capabilities will be actualized and also, the spatial organization of its land uses will be balanced and well- proportioned to continue its life and improve it qualitatively and quantitatively. Urban system like other systems can continue its dynamic life in the context of a desired plan in normal circumstances, but, the occurrence of crisis and unforeseen conditions would mean the entropy in the life of this system (J.d.Kartez, 1987, p.489). In the critical conditions, complex natural systems adapt themselves with them and pass them, while, the simple systems are disrupted and damaged. Adaptiveness with critical conditions can be internal or external. Socio-economic development has direct relationships with spatial-local organization and structure that, in turn, needs proper urban planning and thus, it is clear that urban planning with regard to the earthquake varies in terms of the socio-economic development level of the countries (Ibid.p.487). The direct and immediate risk of earthquake to human life is due to the danger of earthquake that threatens the built environment. So, the vulnerability of the built environment largely make the immediately vulnerability of human life conditional. In terms of socio-economic development, retrofitting the built environment; along with balanced distribution of individuals and activities in space in a manner that is proportional to the vulnerability and risk probability, provides the best conditions to minimize the damages and casualties. On the other hand, such situation means to reduce the losses and material damages to achieve such a level of development that the above conditions are fulfilled. Those measures must be taken in the context of urban planning that make the system flexible as much as possible and reduce its vulnerability (UNDRO: 1991.p.95). The basic mechanisms which are in the ground and cause the earthquake, have been not yet understood fully and different theories have been proposed that are contradicting each other. But, it is obvious that the causes of the earthquake are closely related to the tectonic developments of the earth. So, sudden shakes and vibrations caused bythe tectonic developments of the earth are called earthquake (Hojjatollah, 1990: 65). One of the slope instability which causes many financial damages and casualties to the socioeconomic and environmental systems yearly is landslide. Currently, tens of landslides occur in different parts of the country yearly and threaten many residential areas, roads and facilities. The provinces of Gilan, Mazandaran, Ardabil, Fars, Chaharmahal and Bakhtiari, Kohgiluyeh and Boyer-Ahmad, Lorestan and Tehran are the most important areas of landslides in the country. High volume of damages and casualties caused by the landslides because of the development of human activities in recent years, makes the predication and control of this destructive phenomenon complicated and has put it as a priority in many countries. For this reason, how to evaluate the risk of landslide and different methods of evaluation have been studied in multiple researches. In most studies, landslide has been considered as the synonym of mass movements (Amirahmadi et al., 2010). http://www.ijhcs.com/index.php/ijhcs/index Page 984 Special Issue INTERNATIONAL JOURNAL OF HUMANITIES AND March 2016 CULTURAL STUDIES ISSN 2356-5926 Theoretical basics: Factor affecting the development of the city: Natural factors: The topography, as the restriction, sometimes stop or limit the development of the city. For example, because of the mountains on both sides, the city will expand along the way or the river in the linearly. Sometimes, it provides useful natural conditions for varied urban developments with impressive landscapes, especially for residential area (Rahnamaei, 1991: 75). The heights of 900 to 1200 m, and in some conditions up to 1500m according to the average height of Iran plateau and their geographical positions, are the best places for locating the cities in Iran (Nazarian, 2000: 118). Economic factors: Economic activities are the causer of employment and attract a lot of people to these centers. So, it can be said that the economy of a city is an effective factor for the development of lands. Studying on the economy of the city will have very basic and important practical use in analyzing and reviewing land-use planning (Shieh, 2010: 195). The development of the city is closely related to the employment, income and how this income earned in town, as far as the experts are concerned, these are more important than other factors in the emergence and development and prosperity of the cities (Rahmani, 2013:35). In the past and also, in recent centuries, locating the centers of government in the cities such as Isfahan, Qazvin, Shiraz, Mashhad, Tehran and other major cities has followed the rule and many of these centers have been located in the surrounding and lowlands of Khozestan plains, the coast of Caspian sea and foothill plains adjacent to the mountains (Ghafari Gilandeh, 2001:2) Social factors: Social characteristics are the social status of the different neighborhoods of the city. Cultural, living, residential, behavioral, ethnic, racial, religious characteristics and other causes are the measures to evaluate the segregation of the different groups living in the town and create social stratification that in municipal decision, it determines the limitation of the activities and how to deal with them. Also, the development of the city is closely related to the urban population growth and in this relationship, natural increase of urban population, the rate of net migration to town, transfer of the rural population construction to town and construction of urban population are more important factors. Also, immigration, as one of the political, economic and social reasons which, in turn, has a major impact on creating new socioeconomic structures, plays an important role in the physical development of the cities (Khalili Iraqi, 1987:1-6). Political factors: The roles of governments and their political and economic decisions, depending on whether the political and social affairs are centralized or not, have different external effects. Under capitalism, the role of governments has not been significant in the development of the cities but, http://www.ijhcs.com/index.php/ijhcs/index Page 985 Special Issue INTERNATIONAL JOURNAL OF HUMANITIES AND March 2016 CULTURAL STUDIES ISSN 2356-5926 in the planned economy, they have the most important role. They determine the economic policies and use the capital through determined ways. Thus, they prevent the development of large cities. In poor areas, they pay more salaries and prioritize the development of small and medium cities and investing in them (Shakuie, 2006: 339). Definition of earthquake: The basic mechanisms which are in the ground and cause the earthquake, have been not yet understood fully and different theories have been proposed that are contradicting each other. But, it is obvious that the causes of the earthquake are closely related to the tectonic developments of the earth. So, sudden shakes and vibrations caused by the tectonic developments of the earth are called earthquake (Hojjatollah, 1990: 65). The earthquake is intense moves and vibrations of the part of the Earth’s crust with all materials and structures on it due to the moves of folds, volcano and/or stresses of the Earth’s crust (Biroudian, 2006). Literature review: National Research Council of Italy performed the seismic hazard zoning in a study by the use of Geographical Information System (GIS).