Aquifer parameter identification and interpretation with different analytical methods

Aquifer tests yield estimations of hydrogeological parameters through suitable analytical models from field data recorded as drawdown variations by time or distance. In practice, most often a single model iK adopted with a set of assumptions, and unfortunately, field data deviations from the model type curves are not considered in interpretations . This is a rather mechanistic approach which implies assumptions that the aquifer is geologically homogeneous and isotropic . Stich an approach cannot be true because within the aquifer test area there may appear heterogeneities and anisotropics which hinder the application of a single model. It is, therefore, necessaryto try several availablemodels for the saris aq uifer test data, in orderto extractpossible variabilities in hydrogeological parameters . Such an extensive Study can only he done when there is a set of aquifer test data with main and obsen-ation wells at different distances and directions . This paper presents an analysis of an aquifer test in a thick alluvial valley in Pakistan . The aquifer consists of extremely heterogeneous sediments. Ditferent approaches including [tie Theis, Jacob, Hantush, and Singh analytical models . are used to analyse the drawdown data from several observation wells . Abstract