Uploaded on 2014-12-07 by Ibrahimkmin

1- The most important stocks & flows that enter, staying in and leaving the city of Riyadh are: a) Water b) Fuel c) Steel 2- The water is brings to Riyadh city from three sources: rains, wells and by desalination of sea water. As an output of oil refining process, gasoline and diesel are transported to the city for vehicles and industrial uses. While iron enters as a raw material, that the city produce steel for local uses and for exports. 3- In future there will be some changes of kinds and amounts of these stock & flows because of the necessity of preservation of natural resources. Desalination will be the main source for water, solar energy will replace the fossil fuel and there will be new synthetic materials for constructions like carbon fibers and Teflon. [1]: https://edxuploads.s3.amazonaws.com/14179775394630512.jpg