Geology Reference
In-Depth Information
Table 15.1
Example of modelling studies on the impacts of climate change on soil erosion.
Temporal scale
Spatial scale
Climate change scenario
Geographical region
Reference
Continuous
Slope
Downscaling
South America (Amazon river basin)
Favis-Mortlock & Guerra (1999)
Europe
Mantel
et al
. (2003)
US
Pruski & Nearing (2002b)
US (Midwest)
O'Neal
et al
. (2005)
US (Oklahoma)
Zhang & Nearing (2005)
China (Yellow river basin)
Zhang & Liu (2005)
Hypothetical
US
Pruski & Nearing (2002a)
Catchment
Downscaling
Europe (Finland)
Bouraoui
et al
. (2004)*
Europe (Britain)
Lane
et al
. (2007)
Europe (Denmark)
Thodsen
et al
. (2008)
Hypothetical
US
Istanbulluoglu & Bras (2006)
US (Iowa and Texas)
Chaplot (2007)
Europe (Portugal)
Nunes
et al
. (2008)
China (Yangtze river basin)
Zhu
et al
. (2008)**
Event-based
Slope
Downscaling
Europe (Germany)
Michael
et al
. (2005)
Catchment
Downscaling
Europe (Portugal)
Nunes (2007)
Hypothetical
US (Arizona) and Europe (Belgium)
Nearing
et al
. (2005)
Europe (Portugal)
Nunes (2007)
*Climate in the late 20th century, with variability removed.
**Empirical model using Artificial Neural Networks (ANN).
hydrology and soil erosion in most models (Favis-
Mortlock
et al
., 2001) are similar enough to allow
for a comparative analysis, grouping similar mod-
els into more general categories. These categories
can be matched to a particular approach to cli-
mate change impact assessment, and can be a
useful guide when devising modelling strategies
for other studies.
Table 15.1 summarizes a number of soil ero-
sion studies reviewed in this chapter, grouped
according to temporal scale, spatial scale, and cli-
mate change scenarios. Almost all studies used
models based on a conceptual description of water
and sediment sources and sinks, also called proc-
ess-based models. The terms used for each group
follow the model reviews by Aksoy and Kavvas
(2005) for the first two categories, and Xu and
Singh (2004) for the third. Temporal and spatial
scales in the Table refer to the model extent (the
period or area of simulation encompassed by the
model) rather than the model resolution (the level
of discretization with which time or space are
represented). The categories used in the table can
be described as follows:
●
Temporal scale
: Modelling studies can be
divided into (i) continuous, if the model is applied
to consecutive rainfall events occurring during a
season or longer period; and (ii) event-based, if the
model is applied to a single rainfall event. The
processes governing the long-term temporal vari-
ability of hydrological and erosion processes are
quite different from those operating within an
extreme event (Imeson & Lavee, 1998; Favis-
Mortlock
et al
., 2001), which has led to a struc-
tural distinction in soil erosion models. Models
which operate continuously usually incorporate
some sort of vegetation modelling component as
well as long-term hydrological processes such as
evapotranspiration and subsurface runoff, while
in models operating for single events, these
parameters are considered to be constant or negli-
gible (Morgan & Quinton, 2001) This scale differ-
ence means that continuous models usually do
not simulate at the within-event scale, as the
