Effects of slope gradient on soil resistance to rill erosion under concentrated flow
Aqua Water Infrastructure, Ecosystems and Society, cilt.75, sa.5, ss.225-246, 2026 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 75 Sayı: 5
- Basım Tarihi: 2026
- Doi Numarası: 10.2166/aqua.2026.057
- Dergi Adı: Aqua Water Infrastructure, Ecosystems and Society
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
- Sayfa Sayıları: ss.225-246
- Anahtar Kelimeler: critical shear stress, erosion modelling, hydraulic parameters, mini-flume experiments, sediment detachment, soil texture
- Ankara Üniversitesi Adresli: Evet
Özet
Understanding the detachment process in small channels is essential for improving process-based erosion modelling. However, the reliability of rill parameters in the Water Erosion Prediction Project (WEPP) model across slopes and soil textures remains insufficiently evaluated. This study hypothesizes that slope and texture control rill detachment thresholds and that model predictions may be biased under saturated conditions. Mini-flume experiments were conducted using sandy loam and clay loam soils under saturated conditions to isolate slope and soil texture effects. Four slope gradients (3, 5, 7, and 10%) were tested, and detachment parameters were derived from runoff and sediment data. Results showed erodibility (Kr) was higher in clay loam, while critical shear stress (τcr) increased with slope in both soils. Slope exerted a statistically dominant control (Kr: F = 53.74; τcr: F = 41.77, p < 0.001), whereas soil texture played a secondary role. Kr decreased with slope (0.0199–0.0043 and 0.0639–0.0072 s m−1), while τcr increased (0.56–0.86 Pa and 0.45–0.90 Pa). WEPP predictions showed reasonable agreement for sandy loam but lower accuracy for clay loam. Although based on controlled mini-flume experiments with repacked soils that do not fully represent natural hillslope conditions, the results help refine rill detachment parameters and erosion thresholds.