Determination of the Performance of Different Envelope Materials Used in Subsurface Drainage Systems under Laboratory Conditions Using a Sand Tank Model

Project no. 30762 · Status: Kapanmış (Yayın bekleniyor) · 2023

Summary

Efficient subsurface drainage in agricultural production areas reduces yield losses by controlling excess water and salinity in the root zone. In this study, the technical performance of different envelope materials used around subsurface drains was comparatively evaluated under controlled laboratory conditions. Conventional pore-filtration materials (sand–gravel and geotextile) were assessed together with Hydroluis-type materials, which operate based on buoyancy-driven filtration and were tested with two different lateral inlet clearances (8 mm and 4 mm). Experiments were conducted in a sand tank model using five treatments: control without envelope, sand–gravel envelope, geotextile-wrapped drain, Hydroluis (8 mm lateral clearance), and Hydroluis (4 mm lateral clearance). For each treatment, drain discharge, entrance resistance, sediment accumulation, and unit cost were analyzed. The results showed that Hydroluis (8 mm) and geotextile were classified within the “normal” range in terms of drainage performance, and Hydroluis (8 mm) also reached the “good” performance class. The Hydroluis material modified to have a 4 mm lateral clearance achieved the lowest entrance resistance, indicating the highest hydraulic efficiency. Differences in entrance resistance among treatments were statistically significant (p < 0.05). Sediment accumulation was lowest in the sand–gravel configuration and highest in the Hydroluis (4 mm) configuration. Cost assessment indicated that Hydroluis was the most economical envelope material on a per-unit-length basis. These findings indicate that, in sandy soils, Hydroluis with an 8 mm lateral inlet clearance is a technically viable alternative to geotextile. However, further narrowing of the lateral inlet clearance to 4 mm negatively affected sediment control and is expected to increase long-term clogging risk.

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