Estimation of daily soil moisture variation, surface runnof and infiltration, using HIDROSUELO computer model

Patricio Novoa O.1 y Patricio Sepúlveda N.2

A mathematical model refered to the universal water balance formula is presented to estimate the daily soil moisture variation, infiltration, runnoff and the eficiency of water acumulation caused by runnoff storage techniques. The model allowed to estimate with precision the annual variation of moisture contents of surface Horizon in a semiarid area, and allowed to measure the water recharge caused by contour furrows in the lower soil Horizon. Also the model estimated surface runnoff. The model had some restriction specially in estimating soil moisture during the desiccation period, in dry years. This limitation was caused by inactivation incrop coeficient estimations in years with small rainfall. This restriction was observed also in soil having thiny A Horizons soil, with little water retention capacity.

Keywords: contour furrows, rangeland evapotranspiration, runnoff simulation, water balance.
1 Corporación Nacional Forestal, VI Región, Casilla 447, Rancagua, Chile.
2 Oficina de Informática Corporación Nacional Forestal, VI Región. Casilla 447. Rancagua, Chile.