On the relationship between the shape of the hydrograph and the topography of a basin using a physical model

Abstract

This work intended to establish the main relations between the topographic characteristics of the basin and the main parameters, like total runoff volume, peak flow, time to peak and base time, that determine the shape of the unit hydrograph measured at the outlet of the river basin; in order to remove the subjectivity found in traditional synthetic methods and the trial and error setting of the main parameters of the unit hydrograph. The work was developed through physical experimentation of the rainfall-runoff process using observed information of different watersheds of Chiapas, Mexico as reference. The experiments were carried out on a state of the art semi-automatic runoff simulator which was designed and built especifically for this project. The results were analyzed and models were obtained to prove the hypothesis that a unit hydrograph can be completely deter- mined based only on topographic information of the watershed under study.