integrated rainwater harvesting and management systems for sustainable development in semi-arid...
TRANSCRIPT
Integrated Rainwater Harvesting and Management System: Adaptive
Research, Development and Promotion in Kenya
Presented by: Stephen Ngigi
GHARP/KRA Secretariat/MDG Centre for East & Southern Africa
Problem Analysis: Poor Water Management
The problem is being aggravated by climate change, BUT it addressed by improved agricultural (rain)water management => blue revolution is a prerequisite for smallholder farmers-led green revolution in Africa
Inappropriate agricultural water
management
Low agricultural production
Food insecurityPoverty
Poverty trap
Hydro-climatic Challenges: Water Scarcity
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273 279 285 291 297 303 309 315 321 327 333 339 345 351 357 363 4 10 16 22 28
Day of the year
Rai
nfal
l, SI
R, E
T cro
p (m
m d
ay-1
)
Rainfall
SIR
ETcrop
ODS
ISDS
Crop growing period (90 days)
Rainy season
Crop water stress related to climate change: Poor rainfall partitioning, intra-seasonal dry spells & short growing period
Farmers’ Interventions and Challenges
High water losses: High Seepage and Evaporation
Simple on-farm water storage ponds: irregular shapes, steep side slopes, siltation, physical and health risks
Ew
Graduated staff gauge
1
n
Qr
r
h
P
Qi
Kitchen garden
Qp
( )pwir QAEQPAQt
V −−−+= )(d
d
Research: Quantifying of water losses
Seepage and evaporation losses account for 30-60%
Past Attempts to Reduce water losses
High investment costs: Need for cost-effective interventions
Seepage losses: Lining with either concrete, masonry, UV-resistance plastic
Evaporation losses: Roofing with iron sheets, thatch, vegetation e.g. non-flowering passion fruit
Cost-effective and Sustainable Interventions
Reducing surface area, different roofing material, and plastic lining
Development of Water Efficient Drip irrigation Systems
Improved Rainwater Harvesting and Management
Efficient water use technology: Shifting from hand-watering to drip irrigation
Increasing water storage and reliability: Reducing water losses and health risks
Scaling up
RHM Systems are appropriate for SAE of SSA. Scaling up interventions have been going on in Kenya, and transfer of technology to the GHA is underway