| 1
Model identification |
Soil
Erosion Network - Model |
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|
|
1.1
Model name |
MEDRUSH
-Water ersosion |
|
1.2
Most recent version |
0.1 |
|
1.3
Date of release |
Still
under development, hopefully late 1995 |
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| 2
Water erosion |
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| 3
Contact person |
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3.1
Name |
Mike
Kirkby |
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3.2
Address |
School
of Geography, University of Leeds, Leeds LS2 9JT |
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3.3
Tel |
+44
113 233 3310 |
|
3.4
Fax |
+44
113 233 6758 |
|
3.5
Email |
mike@geog.leeds.ac.uk
|
|
| 4
Model Author(s) |
M
D McMahon, M J Kirkby, J B Thornes, J.C Bathurst F I Woodward |
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| 5
Model components |
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5.1
Water erosion: |
Water
and sediment routed over rough surface |
|
5.2
Wind erosion: |
- |
|
5.3
Hydrology: |
Infiltration
into rough surface, overland flow and network routing, lumped
soil based on modified TOPMODEL |
|
5.4
Site/topography: |
DEM |
|
5.5
Plant growth: |
Models
for uncultivated annuals, grass and shrubs |
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5.6
Management: |
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|
5.7
Soil: |
Dynamic
change with erosion in armour and composition |
|
5.8
Chemistry: |
Organic
soil component using C budget |
|
5.9
Weather: |
Automatic
Weather station data (5-15 minute) or generator from available
data or scenario |
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| 6
Model characteristics |
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6.1
Spatial |
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6.1.1
Class of area: |
Catchment |
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|
6.1.2
Flow routing system: |
Stream
network |
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|
6.1.3
Minimum area: |
Erosion
plot |
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|
6.1.4
Maximum area: |
5000
km2 |
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6.2.
Temporal |
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|
6.2.1
Timestep: |
Hourly |
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|
6.2.2
Single or multiple event? |
Multiple |
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|
6.2.3
Maximum simulation duration: |
100
years |
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| 7
Model's representation of processes |
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|
7.1
Water erosion processes |
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|
|
7.1.1
Interrill: |
Included
in spectrum of surface roughness |
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7.1.2
Rill: |
Ditto |
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7.1.3
Gully: |
Ditto |
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|
7.1.4
Streambank: |
Ditto
for rills and gullies. Major channel modelled via hydraulic
geometry and generated flood frequencies |
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|
7.1.5
Deposition: |
Included
in integrated sediment routing |
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7.2
Wind erosion processes: |
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|
7.2.1
Creep/surface roll: |
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7.2.2
Saltation: |
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7.2.3
Suspension |
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7.3
Hydrological processes: |
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7.3.1
Evaporation/transpiration: |
Modified
Penman, allowing for soil layers, plant stress etc. or simpler,
depending on data availability. At worst, from temperatures
or radiation! |
|
|
7.3.2
Runoff: |
Overland
flow routing over rough microtopography. Linearised network
routing, incorporating hillslope contributions |
|
|
7.3.3
Infiltration |
Spatially
variable using simplified single layer model, linked to TOPMODEL
subsurface flow component |
|
|
7.3.4
Subsurface flow: |
TOPMODEL |
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|
7.3.5
Return flow |
ditto |
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7.4
Plant processes: |
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7.4.1
Light interception and photsynthesis: |
Beer's
law |
|
|
7.4.2
Dry matter and residue |
Based
on photosynthesis and transpiration; leaf fall etc. |
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7.4.3
Root growth: |
Functional-group
based partition of net growth with stems |
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7.4.4
Pests: |
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7.4.5
CO2 sensitivity: |
Implicit
in water stress photosynthesis calculations |
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7.5
Soil: |
Single
layer, with rate of change parameters to allow for erosion and
organic matter |
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|
7.5.1
Crust development |
Not
modelled for stony soils |
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7.5.2
Aggregate properties |
- |
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7.6
Chemistry: |
Only
for carbon |
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7.6.1
Nutrients: |
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|
7.6.2
Carbon |
Used
in logging organic soil accumulation, mixing decomposition |
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7.6.3
Pesticides |
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7.6.4
Other contaminants |
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|
7.7
Weather: |
Stochastic
generator used for future scenarios |
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7.8
Other: |
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|
| 8
Input Data (* = Mandatory) |
|
8.1
Weather: |
Hourly
(or stochastic generator) for Precipitation*, temperature, net
radiation, humidity, wind speed (AWS data) - enough to generate
evapotranspiration * |
|
8.2
Soil: |
Grain
size* including stoniness*, and rates of change with depth |
|
8.3
Hydrology: |
Infiltration
curves* |
|
8.4
Plant cover: |
%
shrub, grass*, annuals* and bare*, with detail as available |
|
8.5
Soil surface cover: |
Surface
stoniness*, vegetation crown cover by functional; type |
|
8.6
Management: |
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|
8.7
Topography/site characteristics: = |
DEM*,
and some of land use, lithology, soil type etc. |
|
8.8
Micro-topography: |
RMS
roughness related to gradient, lithology and land use |
|
8.9
Other |
Physiological
characteristics of dominant plants in each functional group |
|
| 9
Output data |
Runoff,
soil moisture profiles, sediment transport and net erosion/deposition
for subcatchments (of 1-20 km2), integrated over
selected time intervals. Vegetation and organic soil biomass,
surface roughness and armour characteristics over time. Generalised
within sub-catchments |
|
| 10
Programming language |
C++ |
|
| 11
Computer requirements |
HP/Sun
work-station or equivalent |
|
| 12
Documentation |
|
12.1
Scientific documentation: |
Interim
project reports only to data-available from author |
|
12.2
User's guide: |
Not
yet available |
|
12.3
Technical documentation: |
Not
yet available |
|
| 13
Availability |
Not
yet available |
| 14
Other Relevant Information |
Currently
still undergoing development |
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