EFFECTS OF SPATIAL PATTERNS OF PRECIPITATION ON THE HYDROLOGIC RESPONSE. AN EVALUATION WITH OBSERVED DATA IN A TROPICAL RIVER BASIN FOR HYDROPOWER PURPOSES

In this paper we assess the influence of the spatial patterns of precipitation in a tropical basin, with simultaneous data of precipitation and discharge at the basin outlet. Indexes of spatial pattern of precipitation developed for higher latitudes in non-tropical regions were validate in this study. Also, we correlated these indexes with the hydrologic response. We implemented a hydrological model distributed at event scale, calibrated and spatially and temporally validated with real events. Some patterns of spatial distribution of precipitation were identified through of indexes of ‘Spatial Moments’ of precipitation. We generated synthetic storms following this pattern of spatial distribution and evaluated the response of the basin using the hydrological model with these storms as rainfall input. Results allowed to identify the storm types, according to their spatial distribution, for which the response of the basin is more critical in terms of peak discharge time and duration. Patterns of precipitation distribution identified in basin, show a preponderance of unimodal rainfall located downstream of the basin's centroid, which is related to the most critical responses. This result allows us to conclude that in the lower area of the basin, the density of the precipitation station network must be increased, in such a way that these events can be identified and involved in the hydrological models, in order to improve the prediction of maximum floods.