On the Theoretical Equation Showing the Relationship between the Water. table Death and its Corresponding Area for a Given Period

1, Introduction For practical purposes we often need to know the water-table depth for a given area for a given period. From an isobath map, we obtained the distribution curve showing the relationship between the water-table depth and its corresponding area. Applying the log-normal-probability-distribution equation, we obtained the theoretical equation to estimate the relation stated above. 2. Theory There is an isobath map consisting of n-class water-table depth, Di, D2, ... D, and the whole study area A. The relationship between the n-class water-table depth and its corresponding areas, al, a2, , a,„ are defined in Eq. (1).