The layer of earth at the top of the ground ; holds the rain water and is suitable for farming . Supporting the rain water at this level is ground water which is saltier and heavier thus remaining below the fresh water . Holding the ground water from sinking deeper in to the Earth is a layer of oily coal , then shale , then ground oil , then gas . The problem with taking these layers of semi-impermeable oil away is that the ground water then sinks away deeper in to the earth , leaving the soil deprived of fresh water . There is evidence of this in the Sahara desert which is dunes of dry earth at high elevation. The crude oil production in the Middle Eastern countries may have contributed to this.
Comments
Post a Comment