ZONAL ESTIMATION AND INTERPOLATION AS SIMULTANEOUS APPROACHES IN THE CASE OF SMALL INPUT DATA SET (ŠANDROVAC FIELD, NORTHERN CROATIA)

Abstract

The Bjelovar Subdepression area in Northern Croatia was analysed, especially the Šandrovac Field that is located in the northern part of the subdepression. In this example, e-log depth marker Z’, i.e. the Pannonian and Pontian boundary, was used as an input data. The data were statistically analysed for the entire subdepression from 497 data readings from the regular grid with cell size of 1x1 km that covers the existing palaeostructural map. Then is selected 18 well data within the Šandrovac Field where e-log markers are recognised (an example of a small number of data). They are also read directly for given structural map and mapped using one of the declustering methods known as Thiessen polygon method or Kriging. It is concluded when the mapping includes small number of data, and consequently local uncertainties, the subsurface mapping need to be done on both ways and maps compared.

Keywords

• point data
• Thiessen polygons
• declustering
• Kriging
• Bjelovar Subdepression