Determinación del perfil térmico de embalses de riego mediante el empleo del modelo DYRESM

Abstract

Models based on the resolution of the energy balance of irrigation water reservoirs can provide useful information about the magnitude and time-evolution of evaporation losses, E. The existence of a thermal gradient (stratification) can influence the rate of losses. To investigate this issue, we compared evaporation estimates given by a multilayer model (DYRESM) which is able to simulate the vertical temperature profile within the reservoir, to a single-layer model assuming no thermal stratification. The comparison was carried out under the climate conditions of Campo de Cartagena (South Eastern Spain), for a 10 m depth reservoir. The multi-layer model indicated a slight thermal stratification, the maximum temperature difference between the surface and the bottom of the reservoir being about 1ºC. The stratification does not significantly affect the estimates of E given by both models. From a practical point of view, it could be concluded that a single-layer model is adequate for calculating the evaporation losses from irrigation reservoirs.