Surface water and groundwater in the basin of the Gulp Creek - some major characteristics

Abstract

Within the framework of a training project for students from the Agricultural University in Wageningen. hydrogeological studies have been undertaken in the valley of the Gulp creek in the SE part of The Netherlands. This report deals with the chemical characteristics of natural surface and groundwater; the analytical data cover a 4-years period of sampling. The water composition is studied not only to determine the overall chemical character of the water the data of the water-analyses are primarily used as a tool to investigate the relation among basin geology and the groundwater and surface water regimes as a sequential dynamic unity. The water bearing sequence in the Gulp Basin is not homogeneous, but a multiple layer aquifer composed of a Mesozoic series of fine grained sands, silty clays and limestones overlying the Palaeozoic bedrock. Generally, the surface water and groundwater are of the calcium-bicarbonate type. Differences found for samples from wells are related to the geological formations. Surface water samples show seasonal variations of the dissolved solid species that are related to the varying contributions of base flow and subsurface flow to the total discharge; the period of drought in 1975 and 1976 is also reflected.