Figure 4.3: Oxygen-18 content of stream water along the main stem of large rivers

Note: Surveys of oxygen-18 along the main stem of large rivers, such as Darling, Amazon, Danube, Rio Grande and Mackenzie show the contribution and mixing of runoff sources to rivers, such as tributaries, irrigation water and wastewater. Isotopes also reflect impacts of climate and land use pattern changes on the water balance such as an evaporative enrichment of river water in arid regions. Source: IAEA, 2002.

Source: UNESCO  The United Nations World Water Development Report 2
Section 2: Changing Natural Systems,
Chapter 4, Part 1. Global Hydrology and Water Resources, p.124

Water Resources

Table 4.1: Precipitation distribution into surface water and groundwater components (by climate region)

Table 4.2: Selected large aquifer systems with non-renewables groundwater resources

Table 4.3: Water availability information by country (AQUASTAT, FAO 2005)

Table 4.4: Major principal sources and impacts of sedimentation

Table 4.5: Freshwater pollution sources, effects and constituents of concern

Table 4.6: Spatial and time scales within which pollution occurs and can be remediated

Table 4.7: Potential applications for reclaimed water

Figure 4.1: Global distribution of the world’s water

Figure 4.2: Schematic of the hydrologic cycle components in present-day setting

Figure 4.3: Oxygen-18 content of stream water along the main stem of large rivers

Figure 4.4: Variations in continental river runoff through most of the twentieth century (deviations from average values)

Figure 4.5: Typical hydrographs in accordance with climatic settings

Figure 4.6: Acid rain and its deposition processes

Figure 4.7: Five-year mean of the pH level in rainfall in the eastern regions of Canada and the US

Figure 4.8: Primary sources of groundwater pollution

Map 4.1

Map 4.2

Map 4.3: Groundwater abstraction rate as a percentage of mean recharge

Aral Sea