Geology Reference
In-Depth Information
13
Kriging for Estimating
Hydrogeological Parameters
Shakeel Ahmed and K. Devi
Indo-French Centre for Groundwater Research
National Geophysical Research Institute, Hyderabad-500007, India
INTRODUCTION
Geostatistics based on the theory of regionalized variables has found more
and more applications in the field of groundwater hydrology. Now geostatistics
has found applications in almost all domains of hydrogeology from parameter
estimation to predictive modelling including the most important one: data
network designing. Geostatistical estimation variance reduction, cross-
validation techniques etc. are a few procedures that could study adequacy of
a given monitoring network and could evolve an optimal monitoring network
with some given constraints. The advantage of the geostatistical estimation
technique is that the variance of the estimation error could be calculated at
any point without having the actual measurement on that point (well). Thus
the benefits to be accrued from an additional measurement could be studied
prior to its measurement. Monitoring through an optimal network can reduce
the amount of data required while providing the desired accuracy and a few
simple procedures have been developed for a geostatistical optimization of
the monitoring network in this study.
A number of geostatistical estimators have been developed and depending
on the nature of the parameter, objectives of the result on precision etc. a
particular method is applied. In this article development of the basic estimation
method i.e. Ordinary Kringing as well as Universal Kriging; from the Kriging
family are described in detail and remarks on them have been discussed.
BRIEF DESCRIPTION OF THE THEORY OF ESTIMATION
The kriging technique was originally developed by Matheron (1965, 1971)
to estimate regionalized variable such as the grade of an ore body at known
location in space, given a set of observed data. Its application to groundwater
