Imputing missing data using grey system theory and the biplot method to forecast groundwater levels and yields

Groundwater management is one of today’s important tasks. It has become necessary to seek out increasingly reliable methods conserve groundwater resources. Dependable forecasting the amounts that can be abstracted in a sustainable manner requires longterm monitoring regime (rate abstraction and levels). Monitoring source for town Bečej, Serbia had been disrupted multiple years. The objective paper assess possibility reinterpreting missing data or, other words, reconstruct operation its effect on levels. At Bečej source, withdrawn from three water-bearing strata comprised fine- coarse-grained sands. Historic are used between 1st October 1980 May 2010. monitored parameters total yield piezometric head at seven observation wells 14 pumping wells. A reconstruction methodology was developed, which included use an autoregressive (AR) model, grey model (GM), biplot method. applied fill gaps during considered period. also describes criteria evaluating accuracy AR GM, proposed approach yielded satisfactory results deemed useful data, as well historic not necessarily associated with sources, but control protection systems, hydrometeorological, hydrological similar uses.