Hydrological modelling

Hydrologic models are simplified, conceptual representations of a part of the hydrologic cycle. They are primarily used for hydrologic prediction and for understanding hydrologic processes. Two major types of hydrologic models can be distinguished:

Recent research in hydrologic modelling tries to have a more global approach to the understanding of the behaviour of hydrologic systems to make better predictions and to face the major challenges in water resources management

Groundwater models are computer models of groundwater flow systems, and are used by hydrogeologists. Groundwater models are employed to simulate and predict aquifer conditions.

These models use an empirical method to convert rainfall volume into runoff volume. An example is the Curve Number method.
The runoff curve number (also called a curve number or simply CN) is an empirical parameter used in hydrology for predicting direct runoff or infiltration from rainfall excess. It can be used with a unit hydrograph to derive the runoff rate from the direct runoff by convolution.

These models describe rainfall-runoff relations using the concept of a (non)linear reservoir. Examples include: Vflo.

These models describe the flow and routing of water once it has entered a river/stream system and the transport of dissolved or suspended material and debris in a river/stream. Examples include MIKE 11, MOHID, WAFLEX and DSSAM.

Distributed hydrological models are grid-cell based and take into account the spatial variability of meteorological input and other inputs like terrain, soils, vegetation and land use. In distributed hydrological models runoff generated in a grid cell is transported downstream through a grid cell to grid cell network using the local drain direction of each grid cell. Examples of distributed hydrological models are PCR-GLOBWB, DHSVM, HL-RDHM and the glacio-hydrological SPHY model

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