2012年-世界发展银行全球_The_Future_of_Water_in_African_Cities___Why_Waste_Water__Urban_Access_to_Water_Supply_and_Sanitation_in_Sub-Saharan_Africa_Background_Report_38页_2mb

报告摘要

Summary of "The Future of Water in African Cities"

Core Content

This document provides an analysis of urban access to water supply and sanitation in Sub-Saharan Africa, focusing on the challenges and trends since the late 90s. It highlights the impact of rapid urbanization on the availability and quality of water and sanitation services, and discusses the institutional and operational performance of service providers in the region.

Main Purpose

The main purpose of the paper is to:

Explain the patterns of access to improved water supply and sanitation in urban areas of Sub-Saharan Africa since the late 90s.
Analyze the performance of service providers in the case of improved water supply.
Explore the institutional context of the water supply and sanitation sectors.

Key Definitions

Water Supply Sources

Improved water supply sources:
- Piped water (household connection inside dwelling, plot, or yard).
- Public taps (water points accessible to the public).
Unimproved water supply sources:
- Wells and boreholes (unprotected or protected).
- Vendors (water delivered by tanker-truck or carts).
- Surface water (rivers, dams, lakes, etc.).

Sanitation Facilities

Improved sanitation:
- Flush toilets, septic tanks, and improved latrines (e.g., ventilated improved pit latrines).
Unimproved sanitation:
- Traditional latrines (without slab or platform).
- Open defecation.
- Shared sanitation facilities between two or more households.

Data Sources

Data is primarily sourced from the Africa Infrastructure Country Diagnostic (AICD) database.
Additional data includes:
- Household surveys.
- Demographic and health surveys.
- World Health Organization (WHO) and UNICEF's Joint Monitoring Programme (JMP).
Data is available for 36 countries in Sub-Saharan Africa, representing 99% of the urban population in 2009.
Some countries (e.g., Burundi, Cape Verde, Comoros) were excluded due to lack of data.

Urbanization Trends

Current Trends

Sub-Saharan Africa is the second least urbanized region in the world after South Asia.
In 2009, 37% of the population lived in urban areas, with 310 million people.
The region's urban population growth rate is 3.9% per year, higher than the global average of 1.8%.

Projected Trends

By 2050, Sub-Saharan Africa's population is expected to more than double, reaching 1.7 billion.
The region will account for 30% of global population growth between 2010 and 2030, and 53% between 2030 and 2050.
Urbanization will transition from incipient to intermediate, and eventually to advanced stages.
By 2050, it is projected that 60% of the population will live in urban areas, compared to 69% globally.

Country Clustering

Countries are classified based on their urban population growth rate into three clusters:

Low urbanizing: <3% per year (e.g., Botswana, South Africa).
Medium urbanizing: 3-4% per year (e.g., Cameroon, Ghana).
High urbanizing: >4% per year (e.g., Angola, Uganda).

Key Differences

High urbanizing countries have the lowest level of urbanization (32%) and the highest GDP growth (6.7% per year).
Low urbanizing countries have the highest level of urbanization (53%) and the lowest GDP growth (2.4% per year).

Access to Water Supply

Improved water access has slightly increased from 67% in the late 90s to 69% in the late 2000s.
Piped water access increased from 37% to 41%.
Public taps access declined from 30% to 28%.
Unimproved sources (wells, vendors, surface water) have seen increased reliance.

Access to Sanitation

Sanitation access has also slightly increased, but the focus is on improved sanitation.
High urbanizing countries face greater challenges in expanding sanitation services due to lower urbanization levels and higher population growth.

Service Provider Performance

Operational Performance

Non-revenue water (water lost due to leaks, theft, or inefficiencies) remains a major issue.
Low billing collection and overstaffing hinder service providers' ability to maintain continuity and water consumption per capita.

Financial Performance

Cost recovery is low, with tariff structures often favoring the wealthiest households.
Collection ratio is low, further straining financial sustainability.

Institutional Framework

The institutional framework for water and sanitation is incomplete.
Political interference and lack of effective regulation are significant challenges.
Public-private partnerships (PPPs) are often inefficient or not well implemented.
Reforms are necessary to improve service delivery and financial sustainability.

Challenges for Future Expansion

Increasing water demand due to urban population growth.
Rehabilitating and expanding existing infrastructure.
Reducing operational and financial inefficiencies.
Furthering institutional reforms.
Raising financial resources (both local and external).
Climate change poses additional risks to water supply and sanitation systems.

Conclusion

Service providers in Sub-Saharan Africa are struggling to meet the demands of urban population growth. The institutional framework is not yet mature, and financial and operational inefficiencies persist. To ensure sustainable access to water and sanitation, the region must address these challenges through reforms, better regulation, effective governance, and increased financial resources. The high urbanizing countries, in particular, will face the most significant challenges due to their rapid growth and low urbanization levels.

Key Figures and Tables

Figure 1: Share of urban versus rural population by region (2009).
Figure 2: Sub-Saharan urban population growth.
Figure 3: Correlation between urban population growth rate and urbanization level.
Figure 4: Population projections for Sub-Saharan Africa and the world.
Figure 5: Urban population growth rate by country clusters.
Figure 6: Urban access to improved water supply.
Table 1: Water supply ladder.
Table 2: Sanitation ladder.
Table 3: Classification of countries by urban population growth rate.
Table 4: Characteristics of country clusters.
Table 5: Urban access to water supply by technology.