The Effect of Cracks and Geo-Morphology on Evaporation from Clay Soils.

Crack development in soils and the associated potential for higher evaporation rates are pertinent to many agricultural and engineering applications. Many researchers have attempted to model crack formation though none have succeeded to comprehensively capture it. Chertkov's model uses only two independent parameters to model crack development. This research sought to verify Chertkov's model, as well as to analyze the coupled effect of crack growth and evaporation. A clay drying test was carried out where crack development was tracked using a laser scanner, as well as by pixel analysis of surface photographs. The drying test has shown that crack surfaces contributed at most to 6% of total evaporation before de-saturation and up to 63.4% after de-saturation. Results have also shown that Chertkov's model could model crack growth, though with unrealistic parameter values. In contradiction to Chertkov's assumption, the fractographic analysis showed that plastic strains appeared to be important.