Uploaded on 2018-02-16 by Maria Lampe

Picture 1: The picture shows how the water level in our lake can rise and fall (= flow) and how additional land can be used when the water level is low (= stock). (I was only able to upload 1 picture) Picture 2 (birds): In autumn many migratory birds gather together to fly towards the south (= flow) which leads to a change in stock. Picture 3 (children playing): Whenever new children are born there is a flow which changes the stock but at the same time others pass away which also changes the stock.