Abstract:
Geotextiles are reported to be highly effective and economically viable erosion control products. The objective
of this study was to test this hypothesis by determining the extent of differences in erosion-related variables
between bare soils and mine tailings and those covered with palm mats, via rainfall simulation. Erosion parameters
studied included runoff (RO), sediment load in the runoff (SL), percentage of stable aggregates (SA), final
infiltration rate (FI) and inter-rill erodibility (Ki). Thirty samples, representative of South African soils and mine
tailings, were investigated. The soils varied considerably with respect to their textural, chemical and mineralogical
properties in line with soil taxonomy, annual precipitation and geological substrate. Tailing sample selection
was based on the dominant type of mine. Erosion parameters varied greatly within, but to a much lower extent
between, the two different types of material. Several significant correlations were obtained. Sediment load had
the best correlation with kaolinite content and with fine sand content, while for runoff, the best correlation was
with organic carbon content. When the samples were covered with palm mats, final infiltration rate, stable aggregate
and inter-rill erodibility values were similar to those of bare materials and the amount of runoff was slightly
higher. Sediment load, however, was reduced by 65%. These results document the suitability of palm geotextiles
for soil conservation.
