Sensitivity analysis to determine variations in evapotranspiration is much important considering a known variation in one of climatic variables. In this study, sensitivity of evapotranspiration from Penmann-Mantith, Penmann-Kimberly (1996), Penman-Kimberly (1972) and Penmann (1984)  and Hargrivs (1985) approaches to three climatic variations (maximum temperature, wind speed, solar radiation) wa...

The knowledge of evapotranspiration is of great interest in many applications such as assessing irrigation water use. In this paper, a methodology is presented to estimate evapotranspiration using the surface energy balance model S-SEBI (Simplified Surface Energy Balance Index) and the evaporative fraction. The method is applicable under the assumptions of constant atmospheric conditions and su...

BIOME-BGC is a general ecosystem model designed to simulate hydrologic and biogeochemical processes across multiple scales. The objectives of this investigation were to compare BIOME-BGC estimates of hydrologic processes with observed data for different boreal forest stands and investigate factors that control simulated water fluxes. Model results explained 62 and 98% of the respective variance...

Evapotranspiration (ET) is the movement and transfer (i.e., flux) of water as a liquid at the Earth’s surface to the atmosphere as a gas. ET is a combination of open water evaporation and plant transpiration ( , which is the Sublimation transition of solid water (i.e., ice, snow) to vapor due to low atmospheric pressure (i.e., high altitude), dry air and high sunlight, is generally considered s...

Available energy (often expressed in terms of potential evaporation) and precipitation largely determine annual evapotranspiration and runoff rates in a region. The ratio of annual potential evaporation to precipitation, referred to as the aridity index by Budyko, has been shown to describe the evaporation ratio (the ratio of annual evapotranspiration to precipitation) of catchments from a rang...

Parameterization of physically based and distributed hydrological models for mesoscale catchments remains challenging because the commonly available data base is insufficient for calibration. In this paper, we parameterize a mesoscale catchment for the distributed model HydroGeoSphere by transferring evapotranspiration parameters calibrated at a highly-equipped headwater catchment in addition t...

Representation of the hydrological interaction between the land surface and the atmosphere requires considerable improvement, particularly for predicting evapotranspiration feedbacks for use in models of the general circulation (GCMs) of the atmosphere. The predictive model developed here attempts to use a water balance approach that extracts information from the masses of catchment-scale time ...

A study was carried out in central Italy into the evapotranspiration from linseed (Linum usitatissimum L.). In particular, the objectives were to (a) evaluate the accuracy of daily evapotranspiration estimates from partially incomplete Bowen ratio data; (b) measure seasonal evapotranspiration from linseed; (c) test the FAO 56 method for estimating crop coefficients for linseed and (d) calculate...

Usually the energy balance equation is used to estimate evapotranspiration. To calculating the potential evapotranspiration for long periods of time (more than a day), soil heat flux is assumed equal to zero. But in a catchment, the energy balance equation should be in terms of actual evapotranspiration is less than the potential. In this state, the amount of soil heat flux is not equal to zero...