Quantitative Sensitivity

The quantitative sensitivity is defined as the product of the groundwater residence time with the infiltration rate. When a water particle remains underground twice as long, it is twice as important for the water quality in an aquifer. The same applies to the infiltration rate. When twice as much infiltration occurs in one area as in another area (and the residence time is the same), the area is twice as important for the overall groundwater quality. The map therefore indicates which areas are important for the 'overall water quality', only taking into account conservative transport, and thus without taking degradation and retardation into account. Insight into the quantitative sensitivity is important, because the most important characteristic of groundwater systems is that the greater part remains shallow and short in the subsurface, and a very small part of an area largely determines the deeper water quality. The chart shows the quantitative sensitivity on a logarithmic scale. No data is yet available for the municipality of Vijfheerenlanden, which has been part of the province of Utrecht since 1 January 2019.