Sustainable intensification of small-scale agriculture in the upper Blue Nile Basin: Multi-criteria optimization of rainwater management strategies

Sustainable intensification of small-scale agriculture in the upper Blue

Nile Basin: Multi-criteria optimization of rainwater

management strategies

Kindie GetnetInternational Water Management Institute (IWMI), East Africa & Nile Basin

Office, Addis Ababa, Ethiopia

Nile Basin Development Challenge (NBDC) Science Workshop

Addis Ababa, Ethiopia, 9–10 July 2013

Water for a food-secure worldWater for a food-secure world

IntroductionA broad consensus on the importance of rainwater management (RWM) to improve system productivity and livelihood resilience in rainfed agriculture

Choosing the appropriate RWM strategy can be contentious

The need for ex-ante analysis and evaluation to make informed decisions

Water for a food-secure worldWater for a food-secure world

The research questionWhat are the consequences of alternative RWM strategies, compared to the business as usual scenario?

Evaluation criteria (indicators)?•Net farm income (economic benefit) •Employment opportunities (social benefit)•Runoff and sediment (environmental benefit)

How is the analysis made?

A decision support tool with multi-criteria optimization

Sustainability

Interactions (understanding spatial and temporal trade-offs and synergies)

ECOSAUT for economic, social, and environmental evaluation of RWMs

Basic Data

Crop Crop Crop1 9 172 10 18 Area (Ha)3 11 19 7.9

4 12 Pastures 1 8.8

5 13 Pastures 2 3.9

6 14 Pastures 3 20.7

7 15 Forest 18 16 Forest 2

Period1 2 3 4 5 6 7 8 9 10 11 12 1 2 1 2 31 2 3 1 2 1 2 3

1 crop 1 crop 8 crop 14 forest 1 forest 2 pasture 1

2 crop 2 crop 9 crop 15 forest 1 forest 2 pasture 1

3 crop 3 crop 10 crop 16 forest 1 forest 2 pasture 1

4 crop 4 crop 11 crop 17 forest 1 forest 2 pasture 1

5 crop 5 crop 12 crop 18 forest 1 forest 2 pasture 1

6 crop 3 crop 13 crop 19 forest 1 forest 2 pasture 1

7 crop 6 crop 8 crop 14 forest 1 forest 2 pasture 1

8 crop 2 crop 9 crop 15 forest 1 forest 2 pasture 1

9 crop 7 crop 9 crop 16 forest 1 forest 2 pasture 1

10 crop 1 crop 12 crop 17 forest 1 forest 2 pasture 1

(enter the name of the crop or land use of interest , e.g., potato, cereal, quinoa, tree, grass, alfalfa, etc)

Description Description

Zone 1

DescriptionBWPPeTFBe WBeB STBeWBFPPe

WBBePT WTBeB NMTBPW LocationAvailable Land

Crops in Rotation

WBPBeT WBT

BTBeWP BWTP WTBeSPeP

BPeTFPWBe WBeBT Grazing

TBBeWP TBPS Eucalyptus

Location in watershed ->

BPTPeWBe NMSBFTPBe

Zone 2

TotalZone 3

WBTBeP WNMBeT T1T4 (degraded forest/shrub land)

Rotation Trees Forages

What is evaluated?

Quantitative characterization of Meja micro-watershed in the Upper Blue Nile

70 sample plots in the HRU (upper, middle, lower zone)

Geo-referenced spatial and temporal data on:Production (crop, livestock, forest, pasture) Employment (labor use)Runoff and sediment

• ECOSAUT populated and preliminary analysis made

Water for a food-secure worldWater for a food-secure world

Results (business as usual scenario)

Optimization made possible over the entire HRU considered (20ha)

Model results mimic reality

Baseline scenario generates a net farm income of US$404,790 over 10 years (2011-2021)

Water for a food-secure worldWater for a food-secure world

Agriculture will remain major source of farm income and employment

Farm income positively trending but not significantly drifting

• System productivity stagnant• Given rapid population growth, declining per capita farm

income?• Poverty reduction role of agriculture not dependable?

Negative externalities associated with farm income growth (soil erosion)

• Trade-off between farm income growth and land resource• Is the farming system sustainable?

Land the most limiting resource for farm income growth and labor the most abundant

Water for a food-secure worldWater for a food-secure world

Next activitiesHow will a change in land use and resource management practices change farm income, poverty, and soil erosion?

– Develop land use and resource management scenarios

– Assess consequences at HRU scale

– Extrapolate basin-wide impact

Water for a food-secure worldWater for a food-secure world

Challenges

• Lack of crop-specific sediment and run off data

• Need for concretized and quantified scenarios and strategies

• How to extrapolate impacts to a basin scale