Uploaded on 2016-04-28 by VNBM

**1. Density** ![][1] As Washington DC is a hub for many government agencies and companies, every day a tremendous amount of people flows in and out of the city disturbing the density of both the city and its suburbs. More than 400 000 people either drive, carpool, or use public transportation to come to their workplace from outside the city every work day. At the scale of a city that counts only 600 000 residents, this flow has a major impact on the infrastructure, the economy and the livability: traffic jam, predominance of office space in many neighborhoods, « floating » businesses that come and go like the « food truck » phenomenon… Also, a bad management of the metro system brings a lot of troubles to the flow of commuters that lose a significant time stuck in trains. Last but not least, a flow of tourism coming from further away also defines the occupancy of some areas of the city: National Mall, Chinatown... All those movement of population increase the price of real estate and redefine the social and economic aspect of the DC area. **2. Food** ![][2] As most big cities, there is no agriculture or farming within the city, neither food processing industry. Hence food needs to flow in the city on a daily basis in its final « product » form to supply the retailers and their customers. The food outlet -the grocery stores- also have a direct impact on the location of residential areas and entail a shifting, a movement in the stock of density that generates another form of flow: at a more local scale, people move to get closer to commercial areas or spend their day in one or another "food corridor" **3. Energy** ![][3] Although mostly invisble, the energy flow is every where. Each post lamp, AC unit, gaz station is a reminder that the city needs fuel too. Although natural gas comes from far away in the USA, energy is also produced and stock within th district. For instance, the U.S. Department of Energy’s Forrestal headquarters building boasts one of the biggest solar panel installation in the city that generates about 230,000 kilowatt-hours of electricity per year. Maybe one day, this stock of energy is actually going to be big enough to flow out and spread inside the city. [1]: https://edxuploads.s3.amazonaws.com/14618858827567286.jpg [2]: https://edxuploads.s3.amazonaws.com/14618859069702744.jpg [3]: https://edxuploads.s3.amazonaws.com/14618859727312273.jpg