| Summary: | Saline conditions govern soil behavior during evaporation, thereby affecting the water budget in semi-arid regions. This research examined the effects of saline pore fluid on soil behavior during evaporation. The results indicated volumetric reductions of about 5% for silty sand and about 15% for lean clay. The evaporative flux for silty sand decreased from 26 mg/m<sup>2</sup>∙s to 22 mg/m<sup>2</sup>∙s in <i>Stage</i><i>II</i>, remained at a constant flux in <i>Stage</i><i>III</i>, and decreased to 13 mg/m<sup>2</sup>∙s in <i>Stage</i><i>IV</i>. The air entry and residual suction values were found to be 5 kPa and 100 kPa, respectively, and the total suction of about 5000 kPa merged with matric suction near the <i>Stage II</i>/<i>Stage III</i> boundary. The swell–shrink curve (SSC) was J-shaped with the only void ratio decrease in <i>Stage II</i>. In contrast, the evaporative flux for lean clay decreased from 30 mg/m<sup>2</sup>∙s to 15 mg/m<sup>2</sup>∙s in <i>Stage</i><i>II</i>, to 10 mg/m<sup>2</sup>∙s in <i>Stage</i><i>III</i>, and then to 5 mg/m<sup>2</sup>∙s in <i>Stage</i><i>IV</i>. The air entry and residual suction values were 5 kPa and 2000 kPa, respectively, and the total suction during <i>Stage II</i> and <i>Stage III</i> ranged from 1000 kPa to 6000 kPa, with an average value of 3500 kPa. The SSC showed a major void ratio decrease in <i>Stage II</i>, marginal decrease in <i>Stage III</i>, and no decrease in <i>Stage IV</i>. Under high demand, the evaporative flux for silty sand was constant at 180 mg/m<sup>2</sup>∙s in <i>Stage</i><i>III</i> and decreased to 50 mg/m<sup>2</sup>∙s in <i>Stage IV</i>, whereas it decreased for the lean clay from 230 mg/m<sup>2</sup>∙s to 145 mg/m<sup>2</sup>∙s in <i>S</i><i>tage</i><i>II</i>, to 95 mg/m<sup>2</sup>∙s in <i>Stage</i><i>III</i>, and then to 25 mg/m<sup>2</sup>∙s in <i>Stage</i><i>IV</i>. For both soils, the total water loss was found to be six times higher than that under low demand.
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