• The WHO/UNICEF 2000 Assessment statistics for sanitation for 43 of Africa’s large cities showed that 19% of the population remains unserved. Among these populations, only 18% have toilets connected to sewers, a very low proportion as confirmed by an analysis of the Demographic and Health Surveys suggesting that a mere 25% of Africa’s urban population has access to toilets connected to sewers.

This conclusion is also supported by statistics on the proportion of households with sewer connections in the largest city in each African nation. In most of these cities, less than 10% of the population has sewer connections while in many, including Abidjan (Cte dIvoire), Addis Ababa (Ethiopia), Asmara (Eritrea), Brazzaville (Congo), Cotonou (Benin), Kinshasa (Congo), Libreville (Gabon), Moroni (Comoros), NDjamena (Republic Of Chad), Ouagadougou (Burkina Faso), and less than 2% have connections. Read more

• Annual rainfall varies from 25 mm in the Sahara desert, in the north, to over 1,500 mm in the south.
• Sudan is so vast (about 2,000 km from north to south and 1,800 km from east to west) that it lies in multiple climatic zones. In the north, where the Sahara extends into much of the country, the climate is arid, while the south is influenced by a tropical wet-and-dry climate. This variation directly affects rainfall: a rainy season runs from April to October in southern Sudan, but the rainy period gradually diminishes in length towards the north, and rainfall is scarce in the far north.
• In addition to geographic and seasonal variability in rainfall distribution, there are indications of a decreasing trend in the amount of rainfall in the last 30 years, with the dry zone increasingly extending towards the south.
• Almost 80% of the country falls in the basin of the Nile River and its two main tributaries: the White Nile, originating in the equatorial lake region (shared by Burundi, Kenya, Rwanda, Uganda, the United Republic of Tanzania and Zaire), and the Blue Nile, which rises in the Ethiopian highlands. The two join at Khartoum to form the Nile, which flows northwards through Egypt to the Mediterranean Sea.  Read more

• Extending over 3.1 million km2, La Plata River basin is the second largest river system in South America and the fifth largest in the world. Shared by Argentina, Bolivia, Brazil, Paraguay and Uruguay, it covers about one-fifth of South America. With over 100 million inhabitants, close to 50 big cities and 75 large dams, La Plata River basin is at the core of the region’s socio-economic activities, which generate around 70% of the per capita GDP of the five basin countries.
• With its extensive geographic coverage, La Plata River basin is highly variable topographically, ranging from 4,000 metre high mountains in north-western Argentina and southern Bolivia to almost sea level southern plains in Argentina and Uruguay. Rainfall similarly varies, from less than 700 mm per year in the western Bolivian highlands to more than 1,800 mm per year along the Brazilian coast in the east. Read more

• The capital, Seoul, one of the world’s largest cities, is located in the Han River basin. The population of the basin, now 41% of the national total, almost tripled between 1966 and 2005, from about 7 million to almost 20 million. Nevertheless, urban areas account for just 1% of the basin. Forests make up 78%, cultivated areas 16%, and grasslands and water bodies 5%. The Han River basin is considered the heart of South Korea.
• Annual renewable water resources in the Han River basin are estimated at 16 billion m3. As of 2003, 8.5 billion m3 of this amount was actually in use.
• Owing to the high rate of urbanization, the household sector – which accounts for 2.8 billion m3 (33% of overall consumption) – is the number one source of consumption, followed by agriculture (1.6 billion m3 or 19%) and industry (0.8 billion m3 or 9%). The remaining 3.3 billion m3 is allocated for environmental purposes. Read more