A method for measuring erosive flow velocity with simulated rill

• Published in: Geoderma Vol. 232-234; pp. 556 - 562
• Main Authors: Dong, Yuequn, Zhuang, Xiaohui, Lei, Tingwu, Yin, Zhe, Ma, Yuying
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.11.2014; Elsevier
• Subjects: Agronomy. Soil science and plant productions; Biological and medical sciences; Computer simulation; Earth sciences; Earth, ocean, space; Exact sciences and technology; Flow rate; Flow velocity; Fluid flow; Fundamental and applied biological sciences. Psychology; Hydrodynamics; Pulse Boundary Model; Sandpaper; Shallow water flow; Simulated rill; Slope gradients; Soils; Surficial geology; Transport processes; Velocity; Water flow; Pulse Boundary Model; Shallow water flow; Sandpaper; Simulated rill; Velocity; experimental studies; digital simulation; measurement sensor; Water flow; slopes; electrolytes; Shallow water; Water erosion(soil); new methods; Computerized processing; discharge; soils; Tracer technique; solutes; testing; hydrodynamics; rills; Flow velocity; Hydraulic equipment; Measurement method; soil erosion; Comparative study
• ISSN: 0016-7061; 1872-6259
• DOI: 10.1016/j.geoderma.2014.06.014

The water flow velocity along an eroding rill is of interests for understanding rill erosion hydrodynamics. Soil erosion makes the measurement of flow velocity highly variable. In this paper, a new method is suggested to simulate rills so as to make controllable and efficient measurements of erosive velocity of rill flow. A series of comparative flume experiments were conducted to verify the method by measuring the shallow water flow velocity, along both the simulated and real rills, by using a computerized electrolyte tracer method. The experiments involved three flow rates (12, 24 and 48L/min) and three slope gradients (5°, 10° and 15°). Five sensors were used to trace the solute transport processes at 30, 60, 90, 120 and 150cm from the location where the salt solute was injected into the water flow. Flow velocities under simulated rill and real conditions were computed by fitting the measured solute transport processes with its analytic solution. The results showed that under different flow rates and slope gradients, velocities along the simulated rill agreed very well with those along the real rill. This demonstrates that the simulated rill well simulates the real rill. This method will help further study of the hydrodynamics in eroding rill. •A rill was simulated by sand paper glued with soil particles.•Flow velocity was measured on simulated and actual rills by electrolyte tracer method.•The method was verified by the measured velocity along simulated and real rills.