Instead of a conventional catchment area construction, for example, by using stream lines, here the catchment area will be determined by a transport calculation using the inverse flow.

One can imagine this process as a reverse flow, on which the transport of individual particles of water from the well is tracked back to the starting point.

The result is a concentration distribution of the incoming particles in the well, that match the probability of arrival.

With this process advection and dispersion / diffusion processes can be considered in the determination of catchment areas. Local heterogeneities, which are limited when using the traditional methods are represented.

Calculated 50-days-area in a cross section

Calculated 50-days-area (protection zone II)

• Considering advection and dispersion / diffusion processes in the determination of catchment areas
• Representing local heterogeneities, which can not or only partly be determined with the conventional methods of speed tracking
• Calculating the probabilities of the incoming particle in the well as concentration values
• Representing the arrival of a particle in the well as isoconcentration areas