Computation of changes in the run-off regimen of the Lake Santa Ana watershed (Zacatecas, Mexico).

This study describes the application of a water run-off model for Lake Santa Ana, Mexico, developed through the combined application of two simulation models: the Watershed Modelling System (WMS) and the Hydrologic Modelling System (HEC-HMS). The WMS was used to estimate the geometric parameters of the hydrographic basin from a digital elevation model and geographical information describing the location of the hydraulic infrastructure developed in the basin in recent years. The HEC-HMS was used to estimate the run-off hydrographs, by using historical rainfall data and calibrating the model with the observed hydrometric data. The lake bathymetry was taken into account in order to estimate the lake's water balance. Recent observations indicate that anthropogenic activities have modified the natural run-off features of the lake basin. The magnitude of these modifications was estimated by linking the WMS and HEC-HMS models. Application of these linked tools allowed the successful estimation of the modified basin limits and hydraulic behaviour of Lake Santa Ana. [ABSTRACT FROM AUTHOR]