Structural surveys of groundwater areas provide information on the geological structure and hydrogeology of groundwater areas. The surveys are based on a rock surface model of the surveyed area, created by using data from gravity measurements and drill core samples.
GTK has conducted structural surveys on important groundwater and esker areas since the 1990s in cooperation with environmental centres, municipalities, cities and waterworks. The results are utilised in, for example, protection of groundwater, increasing the efficiency of water supply, specifying new water supply sources, investigating the deterioration of groundwater, and as background material for land use planning.
Creating a reliable 3D model of the flow of water and substances requires collecting and analysing geological mapping data. GTK compares the material and the objectives of modelling and draws up a concept of the hydrological structures and conditions of the groundwater body. Based on this, a suitable modelling method will be chosen.
Knowledge of geochemical processes is needed when evaluating the influence of soil and bedrock on the quality of groundwater. The surveys of soil and bedrock structure and quality help to locate new water supply sources. Sustainable use of groundwater bodies requires the integration of different forms of land use. Geological data is crucial when assessing the suitability of different forms of land use on esker and groundwater areas.
The different isotopic composition of natural surface water and groundwater is utilised when studying the interaction of surface and groundwater. Interaction can affect water quality. Isotopes are utilised in both the absorption of artificial and natural groundwater. GTK has studied the ratio of natural groundwater and absorbed surface water, and the area of impact of surface water as well as water flow routes in groundwater bodies.