Abstract
Hydrological distributed modeling is a key point for a comprehensive
assessment of the feedback between the dynamics of the hydrological
cycle, climate conditions, and land use. Such modeling results are
markedly relevant in the fields of water resources management. Here
TopModel (TOPography based hydrological MODEL) is employed for the
hydrological modeling of an area in the Middle Magdalena Valley (MMV), a
tropical basin located in Colombia. This study is located in the
intertropical convergence zone and is characterized by special
meteorological conditions, with fast water fluxes over the year. It has
been subject to significant land use changes, as a result of intense
economic activities, i.e., agriculture, energy and oil & gas
production. The model employees a record of 12 years of: • Daily
precipitation database from observed gauges • Daily evapotranspiration
database from temperature data • Streamflow database as observed data
from calibration Calibration is performed using data from 2000 to 2008,
and validation is performed with data from 2009 to 2012. The
Nash-Sutcliffe coefficient is used to assess the robustness of our
calibration process.(values of this metric being 0.62 and 0.53,
respectively for model calibration and validation). The results reveal
high water storage capacity in the soil, and a marked subsurface runoff,
consistent with the characteristics of the soil types in the regions.
The calibrated model provides relevant indications about recharge in the
region, which is important to quantify the interaction between surface
water and groundwater, especially during the dry season, which is more
relevant in climate-change and climate-variability scenarios.