Assessing the Performance of Several Rainfall Interpolation Methods as Evaluated by a Conceptual Hydrological Model

The objective of this study was to assess the performance of several rainfall interpolation methods as evaluated by a conceptual hydrological model. To this purpose, the upper Toro River catchment (43.15 km²) located in Costa Rica was selected as case study. Deterministic and geostatistical interpolation methods were selected to generate time-series of daily and hourly average rainfall over a period of 10 years (2001-2010). These time-series were used as inputs for the HBV-TEC hydrological model and were individually calibrated against observed streamflow data. Based on model results, the performance of the deterministic methods can be said to be comparable to that of the geostatistical methods at daily time-steps. However, at hourly time-steps, deterministic methods considerably outperformed geostatistical methods.