Priorización de microcuencas tributarias del río chico – manabí, ecuador, basada en la susceptibilidad a las crecidas

Abstract

The susceptibility of the physical environment to the occurrence of floods in the micro basin system of the Chico river is largely conditioned by the characteristics of the hilly relief, as well as by the effects of anthropogenic modifications related to drastic changes in land use and the elimination of primary natural cover (forests); In view of these considerations, the purpose of this research is to prioritize the system of tributary micro watersheds of the Chico river hydrographic system (Manabí province, Ecuador) based on their susceptibility to floods, by integrating hydrological, geomorphological and land cover and use criteria. The work methodology was based on: (a) determination of the magnitudes of the hydrological response parameters of the micro basins in the study area, (b) measurements and calculations of the morphometric parameters of the micro basins and their drainage networks, (c) generation of thematic maps for geoprocessing and spatial analysis of flood susceptibility, (d) analysis of current land cover and land use conditions on the surface of the study area, (e) prioritization of the Chico River tributary micro basin system according to flood susceptibility, and (f) preparation of the final flood susceptibility map. The relationship between the hydrological and morphometric parameters of the micro basins became evident, since the latter condition the hydrological responses of these units. The quantified areas of land use and land cover showed that most of the surface area of the micro watershed system is occupied by native forests, crops from different periods of time and pastures. The final prioritization based on combined parameters of hydrological, morphometric and land use and cover responses determined that only 7 of the 38 micro watersheds have a low level of susceptibility, while 15 micro watersheds have a medium level of susceptibility and 16 micro watersheds have a high susceptibility to floods.