Erosion in recreational areas is often triggered by vegetation removal as a result of activities like
walking, horse-riding, camping, motor vehicle use, mountain bike riding, and development of visitor
facilities. Sandy soils in two geomorphic settings were investigated for potential differences in erosion
patterns and conservation practices. On a coastal sand dune (100% coarse sand) leading to a popular
beach, fencing provided regulated access via rill-eroded, 2 m-wide paths over slopes ranging from 6.5
to 10 degrees and slope lengths from 35 to 45 m. Conservation measures on back-dune paths included
repeated spreading of off-site silt/clay-based fill and/or road metal, later replaced by concreting. On the
seaward-facing paths where potential erosion rates were estimated to be >10 times those on adjacent
vegetated areas, a below-surface board-and-chain system was replaced on some paths by low
maintenance solid-surface plastic pavers. In a second area, relic cliff-top dunes were traversed by a 26-
km walking track with non-vegetated and unfenced pathway segments 1-3 m wide. Soil texture of the
cliff-top dune was dominated by coarse sands (coarse:fine:silt of 91:9:<1 in the study area) which were
eroded by wind, water and mass downslope transfer from walkers' footfalls. Despite gentle slopes (<5
degrees), combined erosion processes resulted in hollowing of pathways below adjacent surfaces to
depths of up to 40 cm. Where path surfaces became uncomfortable for walkers, or deep gullies
developed, visitors widened paths by trampling adjacent vegetation. This study found that costly
installations on eroded pathways are feasible for well-frequented, beach-fringing dunes, but not for
lengthy walking tracks with long gentle slopes extending for kilometres; and erosion patterns and
conservation measures on sandy soils differ in contrasting geomorphic and recreational environments.
Erosion in recreational areas is often triggered by vegetation removal as a result of activities like
walking, horse-riding, camping, motor vehicle use, mountain bike riding, and development of visitor
facilities. Sandy soils in two geomorphic settings were investigated for potential differences in erosion
patterns and conservation practices. On a coastal sand dune (100% coarse sand) leading to a popular
beach, fencing provided regulated access via rill-eroded, 2 m-wide paths over slopes ranging from 6.5
to 10 degrees and slope lengths from 35 to 45 m. Conservation measures on back-dune paths included
repeated spreading of off-site silt/clay-based fill and/or road metal, later replaced by concreting. On the
seaward-facing paths where potential erosion rates were estimated to be >10 times those on adjacent
vegetated areas, a below-surface board-and-chain system was replaced on some paths by low
maintenance solid-surface plastic pavers. In a second area, relic cliff-top dunes were traversed by a 26-
km walking track with non-vegetated and unfenced pathway segments 1-3 m wide. Soil texture of the
cliff-top dune was dominated by coarse sands (coarse:fine:silt of 91:9:<1 in the study area) which were
eroded by wind, water and mass downslope transfer from walkers' footfalls. Despite gentle slopes (<5
degrees), combined erosion processes resulted in hollowing of pathways below adjacent surfaces to
depths of up to 40 cm. Where path surfaces became uncomfortable for walkers, or deep gullies
developed, visitors widened paths by trampling adjacent vegetation. This study found that costly
installations on eroded pathways are feasible for well-frequented, beach-fringing dunes, but not for
lengthy walking tracks with long gentle slopes extending for kilometres; and erosion patterns and
conservation measures on sandy soils differ in contrasting geomorphic and recreational environments.
Primary Language | English |
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Journal Section | Articles |
Authors | |
Publication Date | January 31, 2015 |
Published in Issue | Year 2015 Special Issue |