The main goal of this study is to evaluate the potential of the FAO-56 dual technique for the estimation of regional evapotranspiration (ET) and its constituent components (crop transpiration and soil evaporation), for two classes of vegetation (olives trees and cereals) in the semi-arid region of the Kairouan plain in central Tunisia. The proposed approach combines the FAO-56 technique with re...

Soil moisture is an important control over atmospheric evolution, since it controls the partition of incoming radiation into latent and sensible heating. To accurately model these land surface fluxes, atmospheric models must ultimately have accurate soil moisture fields. Yet soil moisture is typically initialised indirectly in Numerical Weather Prediction (NWP) models, frequently resulting in u...

Data for water vapor adsorption and evaporation are presented for a bare soil (sandy loam, clay content 15%) in a southern Spanish olive grove. Water losses and gains were measured using eight high-precision minilysimeters, placed around an olive tree, which had been irrigated until the soil reached field capacity (!0.22 m m). They were subsequently left to dry for 10 days. A pair of lysimeters...

Abstract This paper presents the inclusion of the soil-vegetationatmosphere interactions in a proven conceptual model. This new scheme simulates the daily streamflows over small catchments by taking into account the average characteristics of the surface (soil and vegetation) for the calculation of actual evaporation and évapotranspiration. The model also simulates the daily evolution of soil m...

This paper describes the relationship of forest soil dryness and antecedent rainfall with suspended sediment (SS) yield due to extreme rainfall events and how this relationship affects the survival of forest plants. Several phenomena contribute to this relationship: increasing evaporation (amount of water vapour discharged from soil) due to increasing air temperature, decreasing moisture conten...

Papers published in Hydrology and Earth System Sciences Discussions are under open-access review for the journal Hydrology and Earth System Sciences Abstract Using two methods of eddy correlation system and evaporation pan to measure respectively the aerodynamic resistance over bare soil surface and maize field, this paper analyses the diurnal variation of the aerodynamic resistance and its rel...

This study presents an “Earth observation-based” method for estimating root zone storage capacity – a critical, yet uncertain parameter in hydrological and land surface modelling. By assuming that vegetation optimises its root zone storage capacity to bridge critical dry periods, we were able to use state-of-the-art satellite-based evaporation data computed with independent energy balance equat...

An important scaling consideration is introduced into the formulation of the complementary relationship (CR) of land surface evapotranspiration (ET) by specifying the maximum possible evaporation rate (Epmax) of a small water body (or wet patch) as a result of adiabatic drying from the prevailing near-neutral atmospheric conditions. In dimensionless form the CR therefore becomes yB= f( Epmax Ep...

Modeling of water vapor transport through a dry soil layer (DSL), typically formed in the top during seasons arid and semi-arid areas, is still problematic. Previous laboratory experiments controlled environments showed that only process DSL by Fick's law diffusion. However, field exhibited consistently higher evaporation rates than predicted diffusion flow only. Some proposed reasons for misma...