| 1
CONTACT PERSON |
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1.1
Name |
Dr.
Simon Lorentz |
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1.2
Address |
Department
of Agricultural Engineering,
University of Natal, Box X01,
Scottsville, 3209, South Africa. |
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1.3
Tel |
+27
331 260 5701 |
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1.4
Fax |
+27
331 260 5818 |
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1.5
E-mail |
lorentz@aqua.ccwr.ac.za |
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1.6
List other researchers involved: |
Professor
Roland Schulze |
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| 2
WATER EROSION |
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2.1
mm2 - cm2: |
Dynamics
of soil aggregation |
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2.2
m2: |
soil
surface dynamics: physical degradation (surface sealing, crusting)
and its impact on surface roughness, infiltration and runoff,
dependence of soil erodibility on water content; biological
processes; bioessays of root densities in grassland soils/maize/cassava
above ground biomass, buried biomass. |
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2.3
100m2 - 10 000 m2: |
interrill
and rill erosion: monitoring only; (ephemeral) gully erosion:
monitoring only (specifically monitoring one gully in sugar
cane estate). |
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2.4
small catchments (< 100 ha): |
gully
erosion: monitoring only; sediment budgets: monitoring 1 - 2
ha catchments. |
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2.6
other scale or processes investigated: |
Nested
catchment monitoring proposed in Umzindusi Valley. |
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| 3
WIND EROSION |
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| 4
MASS MOVEMENTS |
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| 5
TILLAGE EROSION |
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Plot
studies. Maize, Sorghum (sugar cane main catchments + plots).
Cultivated
forest with different preparation : pitting - ripping - ridging.
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| 6
TEMPORAL SCALE OF EXPERIMENTS |
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Most
experimental data is daily. Event based experimentation is break
point. Catchment sediment sampling is flow based. |
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| 7
DESCRIPTION OF EROSION FACTORS STUDIED |
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7.1
Climate: |
- EI30;
rainfall vd EI30 monthly correlation studies.
- Daily
rainfall.
- Temperature
and Radiation, wind.
- Evaporation
potential.
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|
7.2
Topography: |
- Slopes.
- Aspect.
- Shape
of slope.
- Convergence
of flow.
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7.3
Soils: |
- Physical
and erosion mass yield.
- Hydraulic
properties tested and/or extracted from surveys.
- Soil
water status monitoring.
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7.4
Vegetation: |
- Cover
and type.
- RUSLE
parameters.
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7.5
Management: |
- Forestry
preparation methods.
- Sugar
cane terracing
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7.6
Others: |
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| 8
FIELD EXPERIMENTS Description of the field site and
of the type of experiments and equipment involved for each of
the erosion processes being studied: |
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8.1
Erosion process: |
(1)
1-2 ha monitoring of sediment yield, sugar cane fields.
(2) RUSLE plots, including different vegetation preparations,
w/c monitoring. |
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8.2
Location (town, state, country): |
(1)
Stanger, KwaZulu Natal, South Africa.
(2) Throughout Kwazulu, Natal, South Africa. |
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8.3
Equipment involved: |
(1)
Sediment sampling; automatic and turbidity meter. Weather station.
Runoff flumes infiltration characteristics testing (disc and
double ring infiltrometer
(2) USLE plot, with sediment sampling tanks. Weather station.
Neutron probe soil water monitoring in USLE plots.
(3) Automatic flow related sampling in stream and fertility. |
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8.4
Remarks: |
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| 9
LABORATORY EXPERIMENTS Description of the laboratory
and the type of experiments and equipment involved for each
of the erosion processes studied: |
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Soils
retention and hydraulic characteristics. Soils textures and
density. Turbidity meter development and testing. |
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| 10
REMARKS |
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| 11
LIST RELEVANT PUBLICATIONS |
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|
Kienzle
and Lorentz (1993). Production of a soil erodibility map for
the Henley Dam Catchment, Natal using a GIS approach. In: Lorentz
et al. 6th South African National Hydrology Symposium
XII Proceedings.
Howe and
Lorentz (1995). Sediment yield modelling in the Henley catchment.
South African Agricultural Engineering Journal (in press).
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