targeting interventions to reduce catchment sedimentation sub watershed in the white volta basin
DESCRIPTION
by F. Kizito, E. Obuobie, J.P. Venot, C. Le Page and W. Daré Presented at the Final Volta Basin Development Challenge Science Workshop, September 2013TRANSCRIPT
A Partner of
Targeting interventions to reduce catchment sedimentation: The case of a sub-watershed in the
White Volta Basin
Kizito F., Obuobie, E., Venot J.P., Le Page C., and Daré W
Andes • Ganges • Limpopo • Mekong • Nile • Volta
Presentation outline1. Key message2. Background and Purpose3. Methodology4. Findings5. Lessons 6. Recommendations
Andes • Ganges • Limpopo • Mekong • Nile • Volta
Key message
- Study illustrates the relevance of distributed erosion models to target erosion control measures
- Illustrates the use of vegetative buffer strips to reduce erosion rates by 10-20%
- Importance of community involvement
Andes • Ganges • Limpopo • Mekong • Nile • Volta
Background and Purpose
- Study area lies in the White Volta Basin - Coverage of sub-basin is about 2,400
sq.km- Major issues relate to climate variability,
poor soil functions, and reduced storage capacity of reservoirs
- Intervention: landscape management to reduce erosion and sedimentation
Andes • Ganges • Limpopo • Mekong • Nile • Volta
Background
%
%
%
_ _
_
_
_
_
___
__ __ ___ _
__ __ ___ __
___ __ ___ __ ___ _ ___ ___ _ __ _ _ __ __ __ __ ___ __ _____
_
#*
#*
5
5
5
5
55
5
5
5
5Nangodi on Red Volta
Yarugu on White Volta
BANSI BAWKU
TILLI
BIDURI
BINABA
TIMONDE
KOSANABA
WIDENABA
NAFKULIGA
ZONGOYIRI
0°0'0"
0°0'0"
11°0'0"N 11°0'0"N
±0 7 14 21 283.5
Kilometers
V4 Watershed
5 V4 Communities
White Volta Basin Boundary
_ Small reservoirs
#* Flow Stations
Rivers
Andes • Ganges • Limpopo • Mekong • Nile • Volta
Methodology
Hydrological modeling
GEOSFM
Wet season Dry season
Participatory methods
Andes • Ganges • Limpopo • Mekong • Nile • Volta
Findings
Andes • Ganges • Limpopo • Mekong • Nile • Volta
Findings
19681970
19721974
19761978
19801982
19841986
19881990
19921994
19961998
20002002
20090.00
100.00
200.00
300.00
400.00
500.00
600.00 0
200
400
600
800
1000
1200
1400
1600
Rainfall Confidence band Observed Flow Simulated Flow
Disc
harg
e (m
3/s)
Rain
fall
(mm
)
Andes • Ganges • Limpopo • Mekong • Nile • Volta
Findings
Major contribution: Upstream catchments
Andes • Ganges • Limpopo • Mekong • Nile • Volta
Findings
- NE portion is most vulnerable- Highly linked to landscape
attributes
Andes • Ganges • Limpopo • Mekong • Nile • Volta
Findings
- With vegetative buffers in place- Erosion reduction by up to 15%
Andes • Ganges • Limpopo • Mekong • Nile • Volta
Recommendations
- Explore linkage with V1 on scaling out interventions
- Targeted interventions are context specific dependent on the biophysical characteristics as well as social dimensions
- Intervention need to consider associated environmental consequences, use of ecosystem based approaches would be appropriate