Environmental Engineering Reference
In-Depth Information
other human activities, including surface mining and activities at construction sites (RULSE;
Renard et al . 1997, Ofi ce for Surface Mining 1998). The structure of the original USLE
remains unchanged, but the estimation of the i ve factors has been rei ned to characterize the
special site conditions resulting from mining, construction and reclamation activities.
RUSLE is a very powerful tool that can be used to estimate soil loss under a wide vari-
ety of site-specii c conditions. The equation can include the full spectrum of land mani-
pulation, including rock cover, mulches, random surface roughness, effects of mechanical
equipment on soil roughness, terraces and vegetation types. Its successful application is
directly related to the experience of the model user in estimating site-specii c empirical
control factors as model input data.
RUSLE originated in the USA. The extensive i eld data that are available to guide the selec-
tion of the empirical factors apply to weather and soil conditions in the USA, but not necessarily
to other areas. Model users outside the USA are rarely able to rely on a similar set of support-
ing data; erroneously they often transfer US based data blindly to their host region. However,
some countries have generated their own set of empirical input data. In Australia, for example,
the SOILOSS model, while based on RUSLE, specii cally rel ects Australian weather and soil
conditions (Rosewell 2005). More often than not, however, experienced professional judgement
is needed to allow the empirical factors to provide adequate predictive value.
It is also important to recognize that water erosion related to Earth moving activities
such as mining often depends on small-scale local features that escape generic assessment
methods ( Figure 20.3 ). The degree to which erosion will occur is directly related to applied
management efforts and installed sediment retention measures. In these circumstances,
estimating water erosion will remain qualitative, in the form of an expert opinion.
Empirical equations, however, provide useful estimates of erosion on various surface
covers for mine waste placements. As with any quantitative approach, estimates should
be used in conjunction with engineering judgement. Empirical equations are particularly
Model users outside the USA are
rarely able to rely on a similar set
of supporting data; erroneously
they often transfer US based data
blindly to their host region.
As with any quantitative
approach, estimates should
be used in conjunction with
engineering judgement.
FIGURE 20.3
Localized Water Erosion Illustrated
(a) Gully erosion along a site access road.
(b) Multiple catch dams constructed across
steep gully to stabilize debris from limestone
mine. (Sirmour area, Lesser Himalayas, Himachal
Pradesh, India)
 
 
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