Uploaded on 2020-05-12 by Sepehr Semsar

There are some stocks and flows such as water, energy, food ,people and... in my city. People is known as stock in cities, but it also may causes some changes gradually. Areas of the city, for example, which have been inhabited for a long time by generations of people from similar backgrounds, could be called to represent a stock of people. The flow of people is characterized by those who newly came into the city from the outside and by those who leave the city or die in the city. Water is another example of stock and flow. Last year, heavy rains in north of iran cause flooded and destroyed many of the river banks, and also in suburb of my city, Tehran, it also causes River flood and unfortunately it leads to some life and financial losses. Conversely, years ago, weather conditions dried up large parts of Lake "Urmia", with many endangered species. Energy can be another instance of stack and flow …. As a consequence, Spatial Network Model and planning cause better understand flow patterns will allowing to have better frame a strategy to tackle different challenges or information and models may help prevent problems.