ABSTRACT
Traditionally, groundwater flow and transport problems are modeled as deterministic processes. In a deterministic process, all parameters in the model are assumed to be certain and known to a precision. But this is hardly true in real-world problems. Many elements of the model, such as the hydrological input, hydrogeological properties, extraction rate, etc., are random, uncertain, or unknown. For example, the aquifer hydraulic conductivity may have too rapid a spatial variation to be sampled in detail. The hydrological events cannot be controlled and thus are unpredictable. The lack of aquifer information due to the high cost of exploration also plays an important role in the uncertainty of modeling. The issues of randomness in groundwater, and the resulting uncertainty in modeling, should be closely examined.
