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Evaluation Cooperation GroupOctober 25, 2013Washington, D.C.

AARON ZAZUETA Chief Evaluation Officer

Use of Remote Sensing for Triangulation in Impact Evaluations

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The objective was to assess GEF contributions to environmental change in

specific sites in the South China SeaThis analysis was part of a larger regional evaluation.Task at the site level was to determine:• what environmental changes have occurred,

and• to what extent GEF has contributed to these

changes.27 sample sites, of which GEF supported 18 through coastal habitat management.Of these, 6 sites included mangroves

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3 Steps to Assess GEF Impact on Mangrove Protection

1. Determine what the mangrove conditions were before and after GEF intervention.

2. Establish causality. 3. Discount rival hypothesis

(counterfactual analysis).

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Remote Sensing is One of Many Tools

• Faced data gaps and data reliability issues.

• GEF EO triangulated evidence using various methods to measure change:– Site visits and interviews– Documents and historical review – National and regional databases– Remote Sensing Analysis• Images found for 4 out of the 6 sites

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Did GEF help improve mangrove cover in Trat, Thailand?

1990 – 28.35 ha 2000 – 38.25 ha

2006 – 59.22 ha

Remote Sensing shows increasing mangrove cover before GEF support.

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Mangroves improved, but did GEF help?

Remote sensing: Mangrove cover increasing over time, even before GEF support.Document and historical reviews: Policy changes across the region were slowing down the decline.National and regional databases:Mangrove cover declined throughout the region, although at a decreasing rate.Site visits and interviews: Local engagement and national economic conditions drove successful activities 10 years before GEF intervention. GEF support enabled cooperation between communities in conflict to achieve protection of a greater area of mangroves.CONCLUSION: GEF support did not result in increasing mangrove cover per se, but sustained and increased the momentum of community and government support for mangrove protection that otherwise might have eroded.

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Did GEF help improve mangrove cover in Fangchengghang, China?

Increase in mangrove cover according to remote sensing was lower than that reported through interviews.

2009 – 1525.1 ha

1999 – 1435.2 ha1990 – 1046.3 ha

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Mangroves improved, but did GEF help?Remote sensing: Mangrove cover increasing during GEF support.Document and historical reviews: Long trend of degradation due to conversion of mangroves to shrimp ponds; collection of marine benthos within the mangrove forests; grazing of buffaloes on mangrove seedlings; and erosion. National and regional databases:Mangrove cover declined throughout the region, although at a decreasing rate.Site visits and interviews: The GEF approach focused on building local partipation in protection, eco-friendly utilization, and cross-sectoral planning and management. 70% of mangrove cover increase was due to natural regeneration from better protection, 30% due to plantings.CONCLUSION: GEF support strengthened management capacity.

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Did GEF help improve mangrove cover in Peam Krasop, Cambodia?

There is progressive decrease in mangrove cover, even during GEF intervention.

1990 – 11524 ha 2006 – 11230 ha

2009 – 10086 ha

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Mangroves worsened, what was GEF’s role?

Remote sensing: There is progressive decrease in mangrove cover even during GEF intervention.Document and historical reviews: Cessation of political conflict in the early 1990’s to have caused population growth and exploitation of mangrove resources in Cambodia. National and regional databases:Mangrove cover has declined in the country, at an increasing rate.Site visits and interviews: Mangrove areas have been cleared for charcoal production, and converted to agricultural purposes, but law enforcement starting to improve.CONCLUSION:GEF-supported activities were not sufficiently effective in reducing the larger pressures on this resource base.

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ConclusionRemote sensing:• Filled in data gaps on before/after• Verified reports by projects

Used in combination with other sources of information

An important limitation: cloud cover.

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Thank you

ops5@thegef.orgwww.gefeo.org