Hydrology has been almost taken over by mathematical modeling. However, natural systems are multidimensional and multiparametric, and to understand them real data—observations and measurements obtained in real study areas—are needed. The following are examples of the applied research approach:
The three spatial dimensions are surveyed via a large number of sampling and measuring points, e.g., springs, wells, drillings, geological surveys, and more.
The time dimension is addressed by investigation of the geological and hydrological dynamics of the system, e.g., by dating of the groundwater host rocks, by isotopic dating of the water itself, and on the small scale by seasonally repeated measurements.