Estimating subsurface drain spacing considering evaporation from bare soil

✍ Scribed by Mahmoud Abdel-Fattah; Abdullah Bazaraa; Mohamed Bakr

• Book ID: 102282395
• Publisher: John Wiley and Sons
• Year: 2005
• Tongue: English
• Weight: 278 KB
• Volume: 54
• Category: Article
• ISSN: 1531-0353
• DOI: 10.1002/ird.204

✦ Synopsis

The unsteady movement of the groundwater table in an equally spaced subsurface drainage system was studied to estimate lateral drain spacing, taking evaporation from bare soil into consideration. A physical model was installed in the field and exposed to atmospheric conditions to evaluate the effect of evaporation from the soil surface on the recession of the groundwater table in different soil types. The applied soil types were clay, silty clay loam and sand. In addition, a well-known drain discharge equation was combined with a general evaporation equation and a new formula for unsteady movement of the groundwater table was deduced. The deduced equation was used to determine the subsurface drain spacing, taking evaporation into consideration in the design process. The results showed that taking evaporation into account in the design of subsurface drain spacing leads to wider drain spacing (24, 74 and 23% for clay, silty clay loam and sand soils, respectively).