Application of modelling techniques in a groundwater nitrate pollution problem

An aquifer system, located in the Chalkidiki peninsula, Greece, has been studied during the last five years. High nitrate concentrations were found, not only in many shallow irrigation wells but also in deeper boreholes. The ongoing studies include in-situ hydrogeological investigations, groundwater sampling and chemical analyses, as well as desk work, enhanced by the application of several modelling approaches. The aim of the paper is to prove the worth of the simultaneous use of various models in tackling a nonpoint contamination problem for which physical, chemical and biochemical phenomena occur within a complex hydrogeological environment. By utilising all available field data in the best possible way, statistical, geostatistical and numerical simulation models are employed to study the areal and temporal variations of nitrate concentrations, together with the flow and solute transport processes. The results of the study show the usefulness of different modelling approaches in assessing, predicting, and managing groundwater nitrate pollution.