Sea Level Rise in Zanzibar

Causes:

• Global warming leads to the melting of polar ice caps and thermal expansion of seawater.
• Zanzibar’s coastal elevation is generally low, making it more sensitive to small increases in sea level.

Observed and Projected Trends:

• Historical data shows a rise of approximately 2–4 mm/year, consistent with global averages.
• Projections suggest sea levels could rise by up to 1 meter by 2100 if global emissions are not curtailed.

Impacts:

• Flooding of coastal areas: Especially during high tides and storm surges.
• Salinization of freshwater: Intrusion of saltwater into coastal aquifers and agricultural land.
• Damage to infrastructure: Roads, buildings, and ports are at risk.
• Displacement of communities: Especially in low-lying areas like Stone Town and Nungwi.

Coastal Erosion in Zanzibar

Causes:

• Natural processes: Wave action, currents, and tides.
• Human activities: Sand mining, deforestation of mangroves, and construction close to shorelines.
• Sea level rise: Accelerates erosion by allowing waves to reach further inland.

Affected Areas:

• Nungwi and Kendwa (North Unguja): Erosion affects beaches and tourism facilities.
• Jambiani, Paje, Bwejuu, Michamvi (East Coast beaches): Particularly vulnerable due to high energy waves and coral reef degradation.
• Stone Town (West Unguja): Some historic sites face coastal degradation.

Consequences:

• Loss of beaches: Impacts tourism, a major economic sector.
• Threats to biodiversity: Especially marine habitats like coral reefs and mangroves.
• Damage to livelihoods: Fishers and farmers face declining productivity.

Mitigation and Adaptation Strategies

Government and NGO Initiatives:

• Coastal zone management: Establishing setbacks for construction.
• Mangrove reforestation: Natural buffer against erosion and storm surges.
• Beach nourishment and sea walls: Short-term erosion control.
• Community education and resilience-building.

Policy Frameworks:

• Zanzibar is aligned with Tanzania’s National Adaptation Programmes of Action (NAPA).
• Participation in international climate resilience programs, such as those funded by the UNDP and the Green Climate Fund.