Geology Reference
In-Depth Information
Table 1.2
Issues covered by the erosion modelling applications in the Handbook, together with their spatial
and temporal scales.
Field/hillslope
(100-10,000 m
2
)
Small catchment
(1-500 ha)
Medium catchment
(500 ha to 1500 km
2
)
Plot (1-100 m
2
)
Regional
Agriculture
10 (SP)
5 (E)
9 (MA SP R)
15 (A MA)
15 (A MA)
11 (MA)
8 (MA SP)
12 (E)
13 (MA)
15 (A MA)
15 (A MA)
Forestry
10 (SP)
16 (D A RP)
16 (D A RP)
Construction
8 (MA SP)
Mine waste
18 (SP LE)
Land-use change
14 (MM MA SP)
14 (MM MA SP)
9 (MA SP R)
12 (E)
14 (MM MA SP)
Climate change
14 (MM MA R)
14 (MM MA SP)
9 (MA SP R)
15 (A MA)
15 (A MA)
15 (A MA)
14 (MM MA SP)
15 (A MA)
Numbers in each cell refer to the chapter, and the letters indicate the temporal scale of model outputs in the applications described (E, event;
D, daily; MM, mean monthly; A, annual; MA, mean annual; SP, set period of time; R, return period; LE, long-term landform evolution).
conservation practices at four different locations
on tropical steeplands, one in China, one in
Malaysia and two in Thailand.
The evaluation of sediment yield from a small
catchment in a highly erodible area is the focus
of Chapter 12, based on a case study on the loess
plateau of China. Chapter 13 addresses a problem
at a very different scale, namely the transfer of
sediment from individual fields to watercourses
in southwest England. Chapter 14 returns to the
catchment scale, using a model to examine the
impacts of land use and climate change on ero-
sion and sediment yield in small river basins
where hillslope erosion, river channel and bank
erosion and landslides are all important compo-
nents of sediment production. Chapter 15 is also
concerned with assessing the impacts of climate
change, but this time over a range of spatial and
temporal scales from hillslope to regional and
continental. There is no single model that can
apply to all situations, and several models are
reviewed. Chapter 16 looks at the risk of erosion
in forested areas in Montana, US, following dis-
turbance either by timber harvesting or wildfire.
Chapter 17 discusses the potential of the Internet
as both a source of data and a vehicle for operat-
ing erosion models to address problems of envi-
ronmental management. Chapter 18 examines
the role of longer-term landscape evolution mod-
els (LEMs) for designing hillslope landscapes to
encapsulate and contain mining waste. Chapter
19 reviews the question of modelling gully
erosion. Although there is no specific gully ero-
sion model that can be recommended, various
approaches that a user can adopt are described.
The Handbook ends with a review of the state-
of-art of erosion modelling, as illustrated by the
case studies, and discusses the developments that
users can expect in the near future. These include
the inclusion of more models within geospatial
frameworks, associated improvements to model-
ling across different scales, and the increasing use
of web-based approaches and risk-based applica-
tions. It is hoped that, by combining a general
review of the principles of erosion modelling with
examples of model applications across a range of
management issues, the Handbook will enable
potential users to employ models in a more
informed way. Hopefully, managers, decision-
makers and policy-makers within the erosion
