Geology Reference
In-Depth Information
Rainfall
Interception
Depression storage
Dynamic, distributed
erosion and deposition
Vegetation
information
Stemflow
Leaf drainage
Throughfall
Sediment
concentration
Splash detachment
Microtopographical
information
Net rainfall
Infiltration model
Runoff
Flow erosion/
deposition
Hydraulic model
Input parameters
Topographical
information
Model components
Transport capacity
Model outputs
Soil information
Fig. 5.2
Flow chart of the European Soil Erosion Model (from Quinton, 1997).
and its routing through the virtual landscape.
This routing relies upon solving the dynamic
mass balance equation (equation 18, Table 5.2)
numerically, and allows the volume of water and
concentration of sediment passing any given
point in the landscape at any given time through
the storm to be derived. Individual processes are
represented by a series of algorithms (Table 5.2).
These processes are linked together as repre-
sented in the model flow chart (Fig. 5.2). Rain
falling on the plant canopy is split into through-
fall, storage and leaf drainage. The drainage term
is split between stemflow and leaf-fall. The
kinetic energy of the throughfall and the leaf fall
are calculated separately. The kinetic energy is
then used to calculate the splash detachment.
Water falling on the soil surface infiltrates into
the soil at a rate calculated using the Smith-
Parlange equation (equation 5, Table 5.2). The
water that does not infiltrate is stored in
depressions on the soil surface; once these are
filled to capacity they can over-top and runoff is
routed over the surface using the kinematic wave
equation. The moving water may erode the soil
surface, carry sediment and deposit it. These
processes are modelled as a continuous exchange
of material between the flow and the surface
through both erosion and deposition (equation
16, Table 5.2), with the transport capacity of the
flow described as the point of balance between
two continuously interacting processes.
EUROSEM also has the capability to simulate
flow and erosion processes in concentrated flow
paths, such as rills. However, such flow paths
need to be predefined for each planar element: the
model cannot generate rills. The processes which
are active in the flow paths and in the areas
between them are controlled by the properties of
those areas: there is no artificial distinction
between inter-rill and rill areas, and these terms
