Freshwater represents a crucial sort for human development, for nature and for ecosystem services. This graphic compares freshwater supplies in cubic metres per capita, per river basin in 1995 with a projection of freshwater supplies for the same areas in 2025. The graphic shows which areas were experiencing water stress, which were experiencing water scarcity and which had sufficient quantities of freshwater in 1995, and shows projections for th...

Freshwater represents a crucial sort for human development, for nature and for ecosystem services. This graphic compares freshwater supplies in cubic metres per capita, per river basin in 1995 with a projection of freshwater supplies for the same areas in 2025. The graphic shows which areas were experiencing water stress, which were experiencing water scarcity and which had sufficient quantities of freshwater in 1995, and shows projections for th...

This graphic shows the availability of freshwater through average river flows and groundwater recharge, in cubic metres per capita per year, at the national level in the year 2000. The graphic highlights the countries with the least freshwater resources (Egypt and the United Arab Emirates) and those with the most (Suriname and Iceland).

This graphic shows the availability of freshwater through average river flows and groundwater recharge, in cubic metres per capita per year, at the national level in the year 2000. The graphic highlights the countries with the least freshwater resources (Egypt and the United Arab Emirates) and those with the most (Suriname and Iceland).

A comparison of the major watersheds between the two decades showed that Northern Europe and North America had lower phosphate concentrations, while the Ganges and Brahmaputra watersheds in South Central Asia had higher concentrations. Nutrient control programmes in municipal and agricultural activities may be key factors in the observed reductions in phosphate concentrations.

A comparison of the major watersheds between the two decades showed that Northern Europe and North America had lower phosphate concentrations, while the Ganges and Brahmaputra watersheds in South Central Asia had higher concentrations. Nutrient control programmes in municipal and agricultural activities may be key factors in the observed reductions in phosphate concentrations.

The water cycle consists of precipitation, evaporation, evapotranspiration and runoff. This graphic explains the global water cycle, showing how nearly 577 000 km3 of water circulates through the cycle each year. A table of estimated residence times of the world's water shows the estimated times that water resources exist as biospheric water; atmospheric water; river channels; swamps; lakes and reservoirs; soil moisture; ice caps and glaciers; oc...

The water cycle consists of precipitation, evaporation, evapotranspiration and runoff. This graphic explains the global water cycle, showing how nearly 577 000 km3 of water circulates through the cycle each year. A table of estimated residence times of the world's water shows the estimated times that water resources exist as biospheric water; atmospheric water; river channels; swamps; lakes and reservoirs; soil moisture; ice caps and glaciers; oc...

This map shows the locations of 13 major river basins in Africa: the Senegal, Volta, Niger, Lake Chad, Nile, Lake Turkana, Juba Shibeli, Ogooue, Congo, Zambezi, Okavango, Limpopo and Orange river basins.

This map shows the locations of 13 major river basins in Africa: the Senegal, Volta, Niger, Lake Chad, Nile, Lake Turkana, Juba Shibeli, Ogooue, Congo, Zambezi, Okavango, Limpopo and Orange river basins.

This graphic shows the average bicarbonate concentrations, in milligrams per litre, at major river mouths for the time periods 1976 to 1990 and 1991 to 2000. The graphic also shows the changes in average bicarbonate levels between these two time periods. Bicarbonate is an indication of the alkalinity in the rivers which reflects the geology (rock, minerals, sand) and increases the buffering capacity, but can also increase the risk of eutrophicati...

This graphic shows the average bicarbonate concentrations, in milligrams per litre, at major river mouths for the time periods 1976 to 1990 and 1991 to 2000. The graphic also shows the changes in average bicarbonate levels between these two time periods. Bicarbonate is an indication of the alkalinity in the rivers which reflects the geology (rock, minerals, sand) and increases the buffering capacity, but can also increase the risk of eutrophicati...

The Mesopotamian marshlands in the Tigris and Euphrates river basins were devastated by damming and river channelisation during the late 1980s. This graphic illustrates the decline in the area's marshlands by comparing the locations of its marshlands and lakes in 1973 and in 2000. The graphic shows the locations of permanent and seasonal marshes; permanent, shallow and seasonal lakes and mud flats or temporary marshes. The graphic for the year 20...

The Mesopotamian marshlands in the Tigris and Euphrates river basins were devastated by damming and river channelisation during the late 1980s. This graphic illustrates the decline in the area's marshlands by comparing the locations of its marshlands and lakes in 1973 and in 2000. The graphic shows the locations of permanent and seasonal marshes; permanent, shallow and seasonal lakes and mud flats or temporary marshes. The graphic for the year 20...

River runoff is cyclical in nature, with alternating cycles of wet and dry years. Significant deviations from average values differ in duration and magnitude. For example, 1940-44, 1965-68 and 1977-79 are clearly low periods in terms of total runoff from the world's rivers. During these periods, the runoff was estimated at 1 600-2 900 km3 below the average value. By contrast, 1926-27, 1949-52 and 1973-75 saw much greater levels of river runoff (S...

River runoff is cyclical in nature, with alternating cycles of wet and dry years. Significant deviations from average values differ in duration and magnitude. For example, 1940-44, 1965-68 and 1977-79 are clearly low periods in terms of total runoff from the world's rivers. During these periods, the runoff was estimated at 1 600-2 900 km3 below the average value. By contrast, 1926-27, 1949-52 and 1973-75 saw much greater levels of river runoff (S...

River runoff represents the accumlated water, from preciptation and meltwater, that feeds into rivers that feeds into seas. The estimated annual figures in this graphic is what volume of water that ends up in the World Ocean. Factors influencing this volume is primarily the area that drains (e.g. area of continent), precipitation and evaporation. Tropical regions typically exhibit greater river runoff volumes. The Amazon carries 15% of all the wa...

River runoff represents the accumlated water, from preciptation and meltwater, that feeds into rivers that feeds into seas. The estimated annual figures in this graphic is what volume of water that ends up in the World Ocean. Factors influencing this volume is primarily the area that drains (e.g. area of continent), precipitation and evaporation. Tropical regions typically exhibit greater river runoff volumes. The Amazon carries 15% of all the wa...

This graphic shows the number of new dams that were under construction in 1998. It also indicates the areas which are most affected by river channel fragmentation and flow regulation. River fragmentation is defined as the interruption of a river's natural flow by dams, inter-basin transfers or water withdrawal, and is an indicator of the degree to which rivers have been modified by human activity.

This graphic shows the number of new dams that were under construction in 1998. It also indicates the areas which are most affected by river channel fragmentation and flow regulation. River fragmentation is defined as the interruption of a river's natural flow by dams, inter-basin transfers or water withdrawal, and is an indicator of the degree to which rivers have been modified by human activity.