Resumen

Anthropic activities, topographic characteristics of the land and climatic changes, variations in water sources which generate social, environmental and economic problems in the department of Tolima. In this work the morphometric characteristics of the Cay microbasin will be analyzed, using the Arcgis 10.5 software; Bathymetric survey was carried out 2 km upstream from the mouth of the creek to identify the heights of the banks and the depths of the riverbed, calculate the maximum flows for return periods of 25, 50, 100 and 200 years, using the Method of Soil Conservation Service of the United States (SCS) which was validated with the HEC-HMS software, this information was processed in the Hec-Ras program, which simulates the flow of flows along the riverbed. Finally, using the Hec-GeoRas tool, the flood zones of the Cay microbasin were determined. In order to analyze the hydrographic behavior and the flood risk assessment, with the support of the methodological guide of the risk, the established parameters can be specified and the degree of vulnerability of the residents adjacent to the channel can be determined. 60% of the study area has sinuous sections, which allows sediments to accumulate in its meanders, generating flood oscillations from 0 to 4 meters, with the return periods of 100 and 200 years having the greatest area extension flooding and with problems with it to determine that the inhabitants are at a medium or high level of risk in the face of this phenomenon.