CSS 210 Lecture 7: Watermovements in soil (7).txt
Document Summary
There are energy forces associated with water molecules and the mineral particle surfaces that cause water to move in soils. Water that is moved as aresult of elevation differences is called gravitational water and generally does not remain in soils for long periods of time unless the downward movement is inhibited by an impermeable layer. The forces responsible for the movement of water are associated with the electromagnetic charge of the water molecules and gravity. A water molecule has a neutral charge, one oxygen atom with a charge of 2 and two hydrogen atoms each with a charge of +1. Due to the nonlinear arrangement of the hydrogen atoms, one end ofthe water molecule is positive and the other is negative. Since water molecules have an asymmetric structure with positive and negative poles, they are dipolar. This dipolar property accounts for water being attracted to cations, anions, andthe charged surfaces of soil particles.