Effectiveness of Geotextile Ropes in Slope Erosion Protection

Abstract

Paper deals with application of geotextile ropes in erosion protection of slope of gravel pit in Nieboczowy, Poland. For protection of the slope the segments formed from thick ropes were applied. The ropes with the diameter of 120 mm were produced by the Kemafil technology. Ropes were made from strips of stitch-bonded nonwoven produced from a mixture of recycled natural and synthetic fibres and strips of wool needle-punched nonwoven. The protected slope had the length of 4 to 6 m, slope inclination from 1:1 to 1:1.8 and total area of approximately 150 m² Generally, slope surface in protected section is without rills and gullies. This case also shows that vegetation is very good anti-erosion measure. Thanks ropes installed on the slope, favourable conditions for vegetation growth are created and maintained. Effectiveness of the ropes in slope erosion protection will be shown by the actual mean annual soil erosion rate E_A and potential mean annual soil erosion rate E_p for two cases: slope with the ropes and slope without the ropes. Values of E_a and E_p were calculated applying Universal Soil Loss Equation (USLE). Values of parameters of the USLE were determined based on rainfall records of 17 years, soils properties, slope geometrical parameters, cropping and management practices as so as erosion control practice on the site. The obtained value E_a = E_p = 0.71 (t ha⁻¹ year⁻¹) in slope part with ropes shows that there is no erosion in this part at present and also in future. The value of E_a = 15.68 (t ha⁻¹ year⁻¹) in slope part without ropes shows that there is strong erosion in this part at present. The value of E_p = 71.27 (t ha⁻¹ year⁻¹) in slope part without ropes also shows that there will be strong erosion in this part in future.