2016年-世界发展银行全球_Promoting_Green_Urban_Development_in_African_Cities___Dar_Es_Salaam_Tanzania_Urban_Environmental_Profile_82页_12mb

Summary of "Promoting Green Urban Development in African Cities: Urban Environmental Profile for Dar es Salaam, Tanzania"

Core Content

The document "Promoting Green Urban Development in African Cities: Urban Environmental Profile for Dar es Salaam, Tanzania" is a comprehensive analysis of the environmental challenges and opportunities facing Dar es Salaam, a rapidly urbanizing city in Tanzania. It is part of a World Bank initiative aimed at promoting sustainable urban development by enhancing the relationship between urbanization, environmental assets, and ecosystem services.

Main Objectives

• To assess the current state of environmental assets in Dar es Salaam.
• To identify the key drivers of environmental vulnerability and degradation.
• To examine the institutional challenges that hinder effective environmental management.
• To provide a resource for municipal officials and stakeholders to inform sustainable urban development.

Key Findings

Urbanization and Environmental Degradation

• Dar es Salaam has experienced unprecedented urbanization over the past three decades, growing at 5% or more annually, making it the fastest-growing city in East Africa.
• The city's population is projected to exceed 7 million by 2025, with 80% of residential land occupied by informal settlements.
• Informal settlements are the main driver of ecosystem loss, due to lack of infrastructure, poor planning, and limited access to basic services.
• Urban sprawl has led to intensive densification in existing areas and radial expansion along major roads, increasing traffic congestion and infrastructure costs.

Environmental Assets

• Terrestrial ecosystems: Forest reserves have declined by over 30% in 30 years due to urban expansion, encroachment, and charcoal use.
• Aquatic ecosystems: The Msimbazi River is the most polluted and degraded of the four major rivers, receiving untreated industrial waste, effluent, and leachates from solid waste dumps.
• Coastal and marine ecosystems: Beach erosion and intense mangrove harvesting (1990–2000) have degraded coastal systems. However, mangrove recovery is observed in Kinondoni due to conservation efforts.
• Air quality: Many indicators exceed WHO limits, with charcoal use and motor vehicle emissions being major contributors. Inland areas suffer from high pollution levels.

Drivers of Environmental Vulnerability

• Informal settlements lack basic services and contribute to pollution and land degradation.
• Charcoal use for household fuel has increased due to its affordability, leading to deforestation and soil erosion.
• Solid waste is a significant issue, with 60% of waste not collected due to lack of equipment, inadequate funding, and limited access to some areas.
• Water extraction from limited groundwater sources is accelerating saltwater intrusion and aquifer depletion.
• Stormwater runoff exceeds the capacity of the city’s drainage system, which is poorly maintained and only covers the central city.
• Industrial effluent and untreated wastewater contribute to water pollution and ecosystem degradation.

Institutional Challenges

• Fragmented institutions are involved in environmental management, with multiple legal frameworks and overlapping responsibilities.
• Weak enforcement of environmental laws and limited access control to natural resources.
• Inadequate organizational capacity, including lack of effective systems, fiscal decentralization, and insufficient human resources.
• Limited baseline data and environmental inventory, which hinders comprehensive planning and policy development.
• Institutional mapping shows a complex network of stakeholders, including municipal bodies, national ministries, international organizations, and NGOs.

Conclusion

The city's rapid and unplanned growth has led to significant environmental degradation, including pollution of water bodies, loss of biodiversity, and air quality deterioration. Informal settlements and overexploitation of natural resources are key contributors to these issues. Institutional fragmentation and lack of coordination further complicate the management of environmental assets. The document emphasizes the need for strategic action to protect and conserve the remaining environmental assets, and to promote sustainable and inclusive urban development through effective policies, better planning, and improved institutional coordination.