Abstraction and Multiplicity as approaches to overcome uncertainty in modelling moisture transfer in soils. АБСТРАГИРОВАНИЕ И КОМПЛЕКСИРОВАНИЕ КАК ПОДХОДЫ К ПРЕОДОЛЕНИЮ НЕОПРЕДЕЛЕННОСТИ МНОЖЕСТВЕННОСТИ МОДЕЛЕЙ ВЛАГОПЕРЕНОСА В ПОЧВЕ

Many conceptually models have been developed to simulate flow and transport in vadose zone. The objective of this work is to make an argument for using several models rather than looking for the best model. One method of using several conceptually models has been recently termed ‘model abstraction’. An example of the systematic model abstraction will be presented for the case of the infiltration in variably saturated soil under natural rainfall conditions when the complex original model gave inexplicable simulation results. Abstracting base modelled to more transparent process description with a simpler model and more robust parameter set without the loss in accuracy of simulating soil water fluxes as the key output. Another way to take advantage of the model multiplicity is to combine results obtained from several models using weights reflecting models’ performance. This approach called multimodeling is appropriate for the case of using several pedotransfer functions to simulate flow and transport in unsaturated zone. An example of multimodeling for the case of the infiltration in variably saturated soil under natural rainfall conditions will be presented.