Geology Reference
In-Depth Information
16
Governing Equations of
Groundwater Flow and Aquifer
Modelling Using Finite
Difference Method
Shazrah Owais, S. Atal and P.D. Sreedevi
Indo-French Centre for Groundwater Research
National Geophysical Research Institute, Hyderabad-500007, India
INTRODUCTION
Groundwater, the term used for water occurring below the ground surface,
is an important constituent of hydrological cycle and is the major source of
water supply in various sectors. Due to over exploitation, mainly because of
high population growth rates and extensive agricultural uses, there has been
a growing concern about the water resources. For groundwater assessment
and management it is essential to have a thorough understanding of complex
processes viz., physical, chemical and/or biological occurring in the system.
To understand these complexities groundwater model plays an important
role. Groundwater models are simplified, conceptual representations of a
part of the hydrologic cycle. They are primarily used for hydrologic prediction
and for understanding hydrologic processes. During the last few decades
there has been continuous improvement in the development of groundwater
models. In the beginning groundwater models concentrated mainly on the
flow behaviour in groudwater system while recent attempts are made to have
full check on the water quality problem and to simulate the contaminant
migration in groundwater. Now-a-days models range from simple two-
dimensional analytical groundwater flow models to complex three-dimensional
numerical groundwater flow and solute transport models.
DARCY'S LAW
More than a century ago, French Engineer Henry Darcy investigated the
flow of water through a horizontal bed of sand to be used for filtration. In
