Uploaded on 2016-08-25 by Ryan Hare

In São Paulo, three major flows flows in the city are the flow of people heading in and out of the city center, the flow of water in the river Tiete, carrying the sewage out of the city, and the flow of food that arrives from other areas. All three creating a stock of its respective flow. Stocks and flows can easily be described as a bathtub that is being filled with water. While the plug is impeding the water of flowing away, a flow of water generates a stock (the water in the tub). But, if we decide to take out the plug, thus allowing the water to escape, we create another flow. During the early hours of a day, the people of the city of São Paulo migrate in mass from the outlying areas of the city to the city center. There they spend the day with their daily occupations. Coming the end of the day they migrate back to there homes, in the outlying areas, thus creating a system of stocks and flows. As the city is very densely populated, the amount of food necessary to feed to population is grand, and comes from all over the county and even from other countries, arriving in ships, trucks, trains, etc. And is stocked and sold in markets, supermarkets, etc. But after all of the food is consumed, waste is created and, unfortunately, the city of São Paulo has a very low percentage of its sewage treated and reused so most of the sewage is directly dumped into the river Tiete.