| 1
Model identification |
Soil
Erosion Network - Model |
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1.1
Model name |
WEPP
- Water and Wind Erosion |
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1.2
Most recent version |
95.0 |
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1.3
Date of release |
January
1995 |
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| 2
Water erosion and Wind Erosion |
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| 3
Contact person |
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|
3.1
Name |
Mark
Nearing |
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3.2
Address |
1196
Soil Building,
Purdue U, W Lafayette IN
47907-1196,
USA |
|
3.3
Tel |
+1
317 494 8683 |
|
3.4
Fax |
+1
317 494 5948 |
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3.5
Email |
nearing@ecn.purdue.edu |
|
| 4
Model Author(s) |
Nearing,
Flanagan, Nicks, Laflen, Gilley, Weltz, Alberts, Young, Foster,
Savabi, Rawls, Lane, Stone |
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| 5
Model components |
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5.1
Water erosion: |
Entirely
new and validated on >2000 plot years |
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5.2
Wind erosion: |
No |
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5.3
Hydrology: |
Green
Ampt Infiltration. Kinematic Wave Routing |
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5.4
Site/topography: |
Complex
Topography, multiple land use |
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5.5
Plant growth: |
Epic
variant |
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5.6
Management: |
Extensive
data required. Tilage dates - harvest dates - etc. |
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5.7
Soil: |
Basic
information required |
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5.8
Chemistry: |
No |
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5.9
Weather: |
CLIGEN
or measured input |
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| 6
Model characteristics |
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6.1
Spatial |
Field
or small watershed |
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6.1.1
Class of area: |
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|
6.1.2
Flow routing system: |
Channels
and hillslopes (maybe run separately) |
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6.1.3
Minimum area: |
1
x 1 m |
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6.1.4
Maximum area: |
640
to ha |
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6.2.
Temporal |
Single
storm or multi-year |
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6.2.1
Timestep: |
Daily |
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6.2.2
Single or multiple event? |
Both |
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|
6.2.3
Maximum simulation duration: |
None
recommended. No computational limits |
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| 7
Model's representation of processes |
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7.1
Water erosion processes |
Erodibility
from est. egs. |
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|
7.1.1
Interrill: |
Ki
Ig Sf Cf 6f. Intensity
rainfall g = runoff. |
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|
7.1.2
Rill: |
Shear
stress model/Yalin Transport |
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7.1.3
Gully: |
Ephemeral
channels only. No classical gullies |
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7.1.4
Streambank: |
No |
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7.1.5
Deposition: |
Yes
and sediment sorting |
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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: |
Penman
or Hargraves+ |
|
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7.3.2
Runoff: |
Kinematic
Wave |
|
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7.3.3
Infiltration |
Green
Ampt |
|
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7.3.4
Subsurface flow: |
Yes |
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7.3.5
Return flow |
Yes |
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7.4
Plant processes: |
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7.4.1
Light interception and photsynthesis: |
EPIC
derived |
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7.4.2
Dry matter and residue |
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7.4.3
Root growth: |
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7.4.4
Pests: |
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7.4.5
CO2 sensitivity: |
Yes
- in-house version |
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7.5
Soil: |
Tillage,
consolidation, freeze/thaw |
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7.5.1
Crust development |
Yes
- rainfall energy calculated |
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7.5.2
Aggregate properties |
Yes
- Foster/Young/Niebling method |
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7.6
Chemistry: |
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7.6.1
Nutrients: |
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7.6.2
Carbon |
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7.6.3
Pesticides |
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7.6.4
Other contaminants |
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7.7
Weather: |
CLIGEN
or measured data |
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7.8
Other: |
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|
| 8
Input Data (* = Mandatory) |
|
8.1
Weather: |
Daily
precipitation*, maximum minimum temperature*, sola radiation*,
dewpoint* wind |
|
8.2
Soil: |
Texture,
CEC, rocks, erodibility (est. equations provided) |
|
8.3
Hydrology: |
Computed
internally |
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8.4
Plant cover: |
Computed
internally |
|
8.5
Soil surface cover: |
Computed
internally |
|
8.6
Management: |
Plant
parameters, tillage parameters, plant and harvest dates |
|
8.7
Topography/site characteristics: = |
Slope
at points along profile |
|
8.8
Micro-topography: |
Internally
calculated |
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8.9
Other |
Irrigation,
if active channel information |
|
| 9
Output data |
Daily
runoff, peak runoff, soil loss, detachment, deposition, sediment
yield, change in erodibility, infiltribility - also annual values
crop yield (there are literally hundreds of output variables) |
|
| 10
Programming language |
FORTRAN/C |
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| 11
Computer requirements |
386
W/Coprocessor or better |
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| 12
Documentation |
|
12.1
Scientific documentation: |
On-line
Internet access to all documentation is coming |
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12.2
User's guide: |
Currently
on-line |
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12.3
Technical documentation: |
Soon
on-line |
|
| 13
Availability |
From
Internet or by request |
| 14
Other Relevant Information |
This
model represents the work of several USDA-ARS scientists spanning
a 10-year period. It has been well-tested in hillslope applications
and works very well. Watershed applications have not been as
well validated. We are currently modifying the program to study
the effect of CO2 and temperature change on hydrologic
and erosion processes. |
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