Uploaded on 2015-06-05 by Guillaume05

![enter image description here][1] ![enter image description here][2] [1]: https://edxuploads.s3.amazonaws.com/14335284093241573.png [2]: https://edxuploads.s3.amazonaws.com/14335287411389176.jpg 1. Stocks and flows: (a) Water (b) Energy (Electricity and Gas) (c) Waste (d) Commuters 2. Models (a) Water: could be represented as an input/output type of model. - Input: clean, drinkable water delivered by the city - Stock: There is not much stock, except in pipes within the residence and the pool :-) - Output: can be multiple: water consumed by people (in cooking, drinking) will be ultimately evaporated or eliminated in waste water, water used for gardening and finally waste water going to sewage facilities. (b) Energy: - Input: electricity and gas from external providers converted in heat, light, etc... no flow out or stock. (c) Waste: - Stock: within the residence, waste is collected in big containers - Flows: from the residents to the containers and from the containers out of the residence when full. (d) Commuters: - Flows: in and out the residence mostly by car, few by shuttle or bike - Stocks: at night parking lots are full of commuters' cars 3. Evolution (a) Water: rain water could be collected, reducing the amount of clean water used for common gardens/lawns (b) Energy: electricity could be produced on site, from wind and solar panels, resulting in a flow within and out of the residence when more energy than necessary is produced. (c) Waste: part could be recycled on site in compost bins (stock), reducing outgoing flow and garbage collect cost. (d) Commuters: more shuttles / public transport options could be offered to reduce traffic at peak hour (and pollution)