The diagram compares two methods for protecting homes in different situations which are at significant risk of flooding.
In general, the key difference between the illustrations is that they reveal about stopbank and without. By contrast, how to contribute to the demonstration or not for defending a house in the trouble of flooding near the river. In this case, the solution for those at-risk homes is using stilt on the ground.
It is apparent from the first demonstration that the stopbank is used to prevent the homes from stopping river water. The stopbank is on the small mount and near the river that it is effectible to barrer from flooding. Using this method is useful as only need to build near the river above 100-year flood level.
On the other hand, it is also noteworthy that there is no stopbank. Such as no stopbank, so that the houses will be destroyed by water and not any protection. In this case, the solution is called ‘ freeboard’ in that it is to build the stilts under the house, and this method lets homes become higher until 300mm, which means higher than 100-year flood level that can effectively barrier the flooding by river.