Cute Young Brunette Girl Wearing Necklace On The Sandy Shore Posing With A Colorful Scarf

Porosity is the volume of void space in the sand. It is the volume of water needed to saturate a given weight of dry sand. Most sands have a porosity of about 30 to 40 % of the total volume. The finer a sand the greater its porosity. Permeability is the rate of flow or drainage of water through the sand. Fine sands have lower permeabilities due to their smaller pore sizes. Penetrability is related to particle size and porosity. It can be important to the macrofauna. All species must be able to burrow into the substratum. To determine the penetrability, the proportion of clay and silt and the water content are very important.
The two basic beach types are dissipative and reflective. Together with the intermediate types, there are six major microtidal beach types. The reflective type occurs when conditions are calm and/or the sediment is coarse. There is no surf zone and waves flow upon the beach. It reflects a major part of the incoming wave. When bigger waves cut back a beach and spread out its sediments to form a surf zone, the reflective beaches create a series of intermediate types. When wave action is strong and/or sediment particle size is fine, the dissipative beach type is created. This type has a flat and maximally eroded beach. The sediments are stored in a broad surf zone that may have multiple sandbanks parallel to the beach. The intermediate types are characterized by high temporal variability, sand storage both on the beach and in the surf zone and sandbanks and troughs.
Beach types can also be based on the degree of exposure. This ranges from very sheltered over sheltered and exposed to very exposed.