An analysis of Gonabad City physical growth using Entropy and Holdern Model

Industrial revolution has had disadvantages despite its numerous advantages in all areas of human societies. One of the main problems our city planning is faced with these days which is caused by inappropriate special structure is the uncontrolled expansion and growth of cities. Urban sprawl growth is not limited to large cities but it has happened to small cities and middle cities as well. An example of such cities is Gonabad city and has had uncontrollably expansion throughout its life. The method of research in this study is an analytic-comparative and Shanon and Holdern entropy models are used together with ARC GIS software for preparing the maps and then the city growth pattern of Gonabad is analyzed at the end. The results that have been achieved from Shannon’s Entropy model, shows that physical development of Gonabad city have been reduce during the last ten years. Though this development has been irregular and uncompressed. Applying Holden’s model about Gonabad shows that during the years 1956-2006 around 51% of physical development has been a growth in population and 49% has been the horizontal and sprawl growth of the city that caused a reduction in population gross density and an increase in gross urban land per person.