A geographic database (GDB) for the San Miguel river basin has been built by integrating data from multiple sources for analysis and graphical representation of diverse physiographic features and hydroclimate phenomena such as rainfall, temperature, soil-evaporation and topography, among others. This database allowed us to combine digital maps and images along with thematic information and spatially- referenced vector data. Moreover, further geographical referencing and validating processes enabled us to accurately represent continuous data through discrete data structures which fit the mathematical models used in representing the physical phenomena at the study site. In this paper we discuss some significant progress on models generated for the analysis of existing records for a season with measurable rainfall at the San Miguel river basin during the period from June 1st to September 30th of 2005.