Nye metoder for prøvepumpning af boringer og grundvandsreservoirer

Abstract

The purpose of this paper is to introduce the practical application of selected quantitative and analytical methods for testing wells and evaluation of aquifers to engineers and geologists within the field of groundwater hydrology in the Nordic countries. This abstract, a list of symbols and units and text of figures and tables in English may possibly provide understanding of the used formulas and methods for readers not familiar with Danish.

The increasing demand for ground water and the need for optimal utilization of aquifers accelerate the use of quantitative methods for predictions of available quantities of ground water and aquifer response on withdrawal.

The first part of this paper gives a short introduction into the developed theory for analysing drawdown data from pumping tests and a number of selected formulas in their developed form for determining the hydraulic properties of wells (B, C and n), aquifers, (T and S) and confining bed (P'). Selected hydrogeological terms are defined. The procedure of pumping and the frequency of waterlevel observations in space and time is briefly mentioned both for step-drawdown test and pumping test with constant capacity.

Formulas for adjustments of drawdown- and recovery data for barometric efficiency and decrease of saturated thickness are described. Examples of logarithmic and semilogarithmic plots of data are given together with type curves for leaky artesian and watertable conditions.

Principles and formulas for prediction of the future drawdown in pumped wells and aquifers are outlined.

The second part of the paper gives the practical application of the selected analytical methods and formulas. Illustrative examples with actual field data collected by the Hydrogeological Department, Geological Survey of Denmark, are presented for each method discussed. Basic data as well drawdown as recovery from 4 pumping tests and their numerical and graphical analysis a represented in 27 figures and 16 tables.