Simple model for daily evaporation from fallow tilled soil under spring conditions in a temperate climate.

Abstract

A simple parametric model is presented to estimate daily evaporation from fallow tilled soil under spring conditions in a temperate climate. In this model, cumulative actual evaporation during a drying cycle is directly proportional to the square root of cumulative potential evaporation. The model contains only one soil parameter. Evidence from a literature study indicates that this model is an improvement on models proposed previously in which cumulative actual evaporation is related to the square root of time. The model was used to calculate evaporation from fallow loamy sand in the Netherlands in spring and summer. A literature study showed that evaporation characteristics of sieved soils as determined in the laboratory are not valid for field soils. Therefore the single evaporation parameter was determined by a quick and cheap microlysimeter technique. In a limited field test, measured and predicted cumulative evaporation in periods of 5, 8 and 34 days were found to correspond reasonably well. The evaporation model together with a simple soil water flow model were found to describe quite well moisture profiles in field soil under a range of conditions. (Abstract retrieved from CAB Abstracts by CABI’s permission)