Determination of evaporative flux from water and soil surfaces

Abstract

The Canadian Prairies has the highest water demand-to-availability ratio in Canada. The region is characterized by a scarcity of water resources because evaporation generally exceed precipitation. Evaporation is a complex phenomenon based on interactions between meteorological and physiological factors. The purpose of this research was to accurately determine evaporative flux from water and soil surfaces. The main research contributions of this research are summarized as follows: (i) a Bench-scale Atmospheric Simulator (BAS/BAS2) was developed to control artificially generated parameters for short time periods; (ii) a Controlled Photogrammetry System (CPS) using Structure-from-Motion (SfM) technology was developed for accurate and non-destructive measurement of dimensional changes during evaporation; (iii) high-quality evaporation datasets were developed for calibration of devices, validation of prediction equations and evaluation of theoretical frameworks; (iv) predictive models for evaporation from water were evaluated to select appropriate empirical equations for predicting potential evaporative flux from water; and (v) a theoretical framework for evaporation from soils was developed to correlate with soil behavior (water retention and soil shrinkage) for both fresh water and saline water. The findings of this research are useful for developing methods to minimize evaporation and for helping with devising water use policy.