Simulación de la hidrología de la cuenca Humboldt del volcán Antisana

Abstract

In this project, the simulation of the hydrology of the Humboldt catchment is presented, without considering the catchment’s glacier area. For this purpose, the physical model: DHSVM was used in order to estimate the streamflow, particularly the baseflow under conditions of precipitation variability. The geographic information used was one Digital Elevation Model (DEM), land cover maps, soil type, soil thickness and a drainage network map with one spatial resolution of 20x20 meters. In addition, precipitation data, temperature, relative humidity, wind speed and solar radiation, measured by one meteorological station and a network of 5 rain gauges were used. The model was calibrated over a 5 months period (August-December 2010) at hourly time step testing the sensitive parameters: hydraulic conductivity, exponential decrease of lateral hydraulic conductivity and the precipitation and temperature lapse rates. The model performance was assessed using the Nash-Sutcliffe (NS) criterion calculated between simulated and the observed streamflow series at Humboldt gaging station (4010 m.a.s.l). As a calibration result, an optimum range for each parameter was determined, allowing to obtain values of NS>0.3 with NS=0.59 as maximum and relative error in the discharged volume of 1.18%. The model was validated during the January 2005- May 2008 period and under two scenarios of precipitation variability of ±10% of change in precipitation, showing that the baseflow responds to the precipitation variability and contributes with a volume between 71 and 86% to the overall Humboldt catchment streamflow in dry and wet seasons respectively.