Effective analysis on the human habitat in Tehran Based on DPSIR

Nowadays, the importance of urban environments as the main settlements for people is growing increasingly. High population density in urban areas has led to environmental degradation, therefore special attention must be paid to habitat quality in these areas. Today, Tehran is the largest and densest human settlement on Iran plateau, which has been established in one of the best natural and climatic conditions of Iran plateau. It seems that over two hundred years, environmental, natural and geographical conditions as well as ecosystems around the city have been changed in such a way that that not only it cannot be considered the city as an integral part of its surrounding ecosystems, but also even providing human biological needs and social demands has been faced to many problems. DPSIR approach, which starts with a chain of causal linkages of "driving forces" (cause) through "pressure" (i.e. pollutants) on logical "status" (physical, chemical, and biological) and "effects", eventually leads to "responses" (strategies) in ecosystems (structure and function).DPSIR was developed from model PSR model via Europe Environment Agency (EEA).This model was the most comprehensive model used in the preparation of environmental status reports (SoE). This model can be used via an applied approach as a tool to develop action and management plans. This study aimed to identify the cause and effect chains, analyze the environment of human habitats in Tehran city using driving force, effect, status, pressure and response model. This was performed as an analytical descriptive study based on DPSIR model using library studies and statistical analysis in 2013. The framework (DPSIR) used in this study which was among from causal-effect models, was the driving force of most of human factors which led to an environmental problem or issue. These factors were normally associated with socio-economic development, requiring the use of environmental resources. Excessive use of resources has led to laying pressure on the environment, consequently changing the situation of environmental parameters. These changes led to adverse effects on human and ecosystem well-being, and there is a need to offer appropriate responses by from the community to resolve these changes. This study was a part of the second environmental situation report on Tehran city, in which the various components of the human habitat component in Tehran city were analyzed using the DPSIR model. Using this conceptual framework, appropriate responses in terms of model components were presented. Then, using this framework, appropriate responses in terms of model components were presented. To achieve a quantitative approach for the analysis of causal-effect factors affecting the human habitat characteristics of Tehran, quantitative indicators were determined for each of the model components (DPSIR).To determine these parameters, literature review was applied and all indicators in the other metropolises habitats as well as similar documents were evaluated, then appropriate indicators were selected for each model component. The results of investigating the habitat components in Tehran city in form of driving force, effect, status, pressure and response (DPSIR model) showed that the most important development feature of Tehran city in recent times can be described as "rapid urbanization", as the development of the city over the last half century has not followed any discipline and in this viewpoint the city is regarded as an exception among the metropolises of the world. Accordingly, this can be considered as the root and driving forces of almost all environmental issues of the city. Under the direct influence of the driving force of rapid urbanization, pressure on ecological resources and natural resources of Tehran city and its surroundings is high due to the high volume of urban travels and increasing waste and runoff production and so on. But the main driving force of rapid urbanization is reflected in housing and construction, major land uses, situation of worn-out areas, transportation condition, green space, urban centers for leisure and public health. So for all variables assessed in this regard, despite having relatively positive trends, the situation is not very appropriate compared to the ideal standard. Also the most important effects of desirable and undesirable conditions of the major components of a habitat were reflected in two form of pollutions and public health. The main effect of pollutions in Tehran city is air pollution, followed by water pollution, vision and perspective pollution, and noise pollution. In public health, mortality and general health indicators reflect the impact of adverse environmental conditions of city on citizens. The response is adopted measures to reform the system, usually acts in the form of rules and control measures. Adopted responses were made in form of three parts including adopted policies and strategies, activities and studies then required policies and strategies were presented for reform. Population establishment and working centers establishment as well as activities associated with frame work indiscipline(in the absence of effective regulations)were among the most effective indicators as the driving force of habitat in Tehran city. Among the most important responses in the form of adopted policies and strategies are: the preparation and publication of the first report on environmental situation in Tehran, approval and delivering the structural strategic comprehensive plan of Tehran city in 2008, approval of the detailed plan for Tehran city in 2009 and commitment to preparing practical plan of Tehran Municipality, preparing the report on environment status of Tehran, preparing the atlas of Tehran, study plan of organizing gardens and green spaces in Tehran, implementing several measures in response to increasing urban journeys to promote public transportation. Despite the measures taken as responses, investigation and analysis carried out in the form of human habitat DPSIR model in Tehran suggests that the responses are lack of efficiency and effectiveness because of not focusing on the driving forces. Therefore, environmental managers and planners in Tehran city need to focus on driving forces by revising their policies and plans in order to mitigate environmental issues.