عنوان مقاله [English]
Today, in most of the cities of the world, its necessary to prepare the urban land use plans, in order to make a balance and interaction to develop the different parts of the city. Relying on urban planning knowledge, such plans are made for a certain period of time. The time period set for development plans, sometimes causes challenge during the implementation. The main reasons of challenges are subjects that were not mentioned or have been omitted because of the large scale of the plan. An important part of spatial development plan is the way of encountering these challenges. Some of these challenges are caused the need to change approved plans, spatially about land use change. As Land use plan is the operational aspect of urban planning, it has become the concentrate of urban planners in the world. In this case, the changes in official documents for land uses, is a challenging point. The feasibility of plans is a strategic point. Most of professions in urban development claimed that it is necessary to change some land uses because of rapid spatial evolutions. The mechanism of land use change is an important task. In the case of Iran, there are many institutional problems that cause formal and informal changes in land uses. It seems that urban development plans in Iran are not well-defined to cope with uncertainties for change. in this case, this article is considering the different experiments for land use change mechanisms in two kind of countries, developed (Britain and United states) and under developed (India and Turkey) ones. Therefore, the main objective of this paper is studying the system of urban management in different countries to recognize the mechanism of land use change after improvement of development plans. Also the comparative study of the process of such changes in studied countries is the other objective of this paper. Method of data collection was library research while qualitative and comparative analyses were used to organize the topic. This study could step ahead in order to update the land use planning system, proper process of making change in it and use the true methods of planning used in Iran and other parts of the world. In all cases, the land use change occurred in two situations: first the changes of formal documents and second the changes that the stakeholders demand for them. In the UK, there are categories (classes) for land uses, and the change from one class to another one needs permission. In the U.S there is a flexible manner in land use plans with the help of variances. These facilities for land use change are in the processes of land use planning in India. There are two proposed land uses, one is the main land use and the other is the secondary land use. The second land uses make the plan flexible for change. The final decision maker is not the local government, but the main national state. In Turkey, the change in land use would be occurred after the amendments of main urban land use plan. The main ministry in national scale is responsible for monitoring the changes in land use plans. In Iran, the changes would happen if the stakeholders demand for it. This article clarifies that the changes in proposal land uses are inevitable, so the processes for managing them is the strategic point. In the final step, the principals of land use change mechanisms derived from the successful land use planning systems, are analyzed in Iran regarding the experts, professional actors and decision makers’ viewpoints. By applying the Delphi method, the main actors who has significant role in land use changes in Iran were defined. The analysis shows that market leaders play an important role in land use changes. On the other hand the opportunities and constraints of applying the principals improving land use change mechanisms were defined and evaluated by the professionals. The results show that the importance of hierarchy of national to local order is as well as the flexibility of land use plans to consider inevitable changes. The results show that for the principal of stakeholder’s participation, the uncertainties of regulative systems is the main constrain and the role of strategic planning with emphasize on the performance of plans is the main opportunity. For the principal of environmental considerations, the local organizations, NGOs and new approaches in land use planning which emphasize on ecological aspects of urban activities are the main opportunities in Iran and as well as the previous principal, the lack of regulative mechanisms to perform environmental considerations is the main constrain.