Integrated rainwater harvesting and management systems for sustainable development in semi-arid...

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

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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