Acamel has a hump to store water so it can survive in its desert environment. which kind of adaptation is this?

This kind of adaptation is called STRUCTURAL ADAPTATION.
There are three types of adaptation, which are: behavioral adaptation, physiological adaptation and structural adaptation. A living organism is said to possess a structural adaptation if it has an organ in its body which helps it to survive harsh conditions. The hump on the camel's back is an example of structural adaptation which helps it to survive in the desert.