Groundwater quality management is one of the most important issues in many arid and semi-arid regions, including Iran.Nitrate (NO3-) is one of the most common anions contaminating groundwater. This study aimed to range nitrateconcentrations in water resources in Bahabad plain in Yazd province. To evaluate the nitrate data in this descriptive study,260 nitrate samples from 13 wells in Bahabad we...

Drought monitoring is a fundamental component of drought risk management. It is normally performed usingvarious drought indices that are effectively continuous functions of rainfall and other hydrometeorological variables.In many instances, drought indices are used for monitoring purposes. Geostatistical methods allow the interpolationof spatially referenced data and the prediction of values fo...

Geostatistics and geographic information system (GIS) were performed to characterize the spatial variability of soil water characteristics in western semiarid area of Heilongjiang Province and delineate the spatial distributions of the variables. On the basis of data source spatial distribution and professional knowledge, the study site was divided into four irrigation management zones. Then st...

In geostatistics, one of the crucial problems is the choice of the covariance function. In this paper we show how to improve the cross-validation criterion, traditionally used for evaluating the /t of a covariance function, in the case of unequally spaced data. c © 2001 Elsevier Science B.V. All rights reserved

Interpolating scattered data points is a problem of wide ranging interest. One of the most popular interpolation methods in geostatistics is ordinary kriging. The price for its statistical optimality is that the estimator is computationally very expensive. We demonstrate the space and time efficiency and accuracy of approximating ordinary kriging through the use of covariance tapering combined ...

A method for 3D modeling and interpretation of log properties from complex seismic attributes (obtained from 3D post stack seismic data) is developed by integrating Principal Component Analysis and Local Linear Modeling. Complex seismic attributes have non-linear relationships with petrophysical properties of rocks. These complicated relationships can be approximated using statistical methods. ...

Interpolation of spatial data is a very general mathematical problem with various applications. In geostatistics, it is assumed that the underlying structure of the data is a stochastic process which leads to an interpolation procedure known as kriging. This method is mathematically equivalent to kernel interpolation, a method used in numerical analysis for the same problem, but derived under c...

The development of geostatistics has been mostly accomplished by application-oriented engineers in the past 20 years. The focus on concrete applications gave birth to many algorithms and computer programs designed to address different issues, such as estimating or simulating a variable while possibly accounting for secondary information such as seismic data, or integrating geological and geomet...