Dear student,

Surface water is generally found on the surface of the earth such as in a river, lake or other low levels surfaces. Rain water is important source of surface water.

It is called as soft water due the presence of very less mineral content.

Groundwater is water the contained in or by a sub surface layer of soil or rock. I t commonly contains less contamination because the rock tends to act as a filter to remove some contaminants.

Due to very high content of mineral content it is hard water. Ground water is filtered and even used for drink. Surface water is used to wash clothes etc. Also surface water is a good sources to grow plantation.  The important factor for degradation of water is cutting of trees . Also soil erosion is also an important factor for water degradation.