Distributed hydrological models rely on a spatial discretization composed of homogeneous units representing different areas within the catchment. Hydrological Response Units (HRUs) typically form the basis of such a discretization. HRUs are generally obtained by intersecting raster or vector layers of land uses, soil types, geology and sub-catchments. Polylines maps representing ditches and riv...

The parameterization of crop coefficients (kc) is critical for determining a water balance. We used satellite-based and literature-based methods to derive kc values for a distributed hydrologic model. We evaluated the impact of different kc parametrization methods on the water balance and simulated hydrologic response at the basin and sub-basin scale. The hydrological model SPHY was calibrated ...

Rainfall-runoff relationships in semi-arid environments are highly non-linear due to the spatial and temporal variability of precipitation and watershed antecedent soil moisture conditions. Specifically within dryland regions, precipitation is often short in duration, limited in spatial extent, and characterized by high intensities. When combined with seasonal periods of elevated basin wetness,...

Streamflow estimates are substantially important as fresh water shortages increase in arid and semi-arid regions where evapotranspiration (ET) is a significant contribution to the water balance. In this regard, evapotranspiration data can be assimilated into a distributed hydrological model (SWAT, Soil and Water Assessment Tool) for improving streamflow estimates. The SWAT model has been widely...

Continuous hydrologic models account for the soil moisture balance in the catchment over a long-term period. Different hydrologic physical processes such as: interception, surface depression storage, infiltration, soil storage, percolation, and groundwater storage should be considered in continuous hydrologic modeling. In this paper, the Hydrologic Modeling System (HMS) model was used for conti...

The prediction uncertainty of a hydrologic model is closely related to model formulation and the uncertainties in model parameters and inputs. Currently, the foremost challenges concern not only whether hydrologic model outputs match observations, but also whether or not model predictions are meaningful and useful in the contexts of land use and climate change. The latter is difficult to determ...