March 22 is World Water Day, an international day of observance that grew out of the 1992 United Nations Conference on Environment and Development (UNCED) in Rio de Janeiro.
The focus of World Water Day this year will be "Water and Climate Change". The importance of strengthening water security and establishing access to a sustainable water supply in the face of changing climate conditions worldwide will be highlighted. The observance will also raise public awareness about the many ways shifting atmospheric and oceanic conditions are reshaping the global hydrologic cycle.
Increasing sustainable access to safe drinking water is a key objective of the U.S Government Global Water Strategy and The United States Agency for International Development’s (USAID) Water and Development Plan. In support of the water strategy, USAID seeks to provide 15 million people with sustainable access to drinking water services by 2022.
Water is the medium through which many of the impacts of climate change are felt by society. The science is clear, climate change is increasing the variability of the water cycle. Over the last decade, floods, storms, heatwaves, droughts and other weather-related events have caused more than 90% of disasters. Events are expected to increase in frequency and intensity because of climate change.
Action plans to address climate change need to be integrated across different sectors and coordinated across borders. And they must have one thing in common: safe and sustainable water management.
Water and Climate Change in South Africa
Water is the primary medium through which climate change will impact people, ecosystems and economies.
Climate change impacts on water in South Africa could exacerbate existing water-related challenges and create new ones related to climate variability, extreme weather events and changing rainfall seasonality. This would affect a wide range of economic sectors and livelihoods and impact on the development of infrastructure into the future, including water quality-related issues.
According to the Fourth Assessment Report (AR4) of the Intergovernmental Panel on Climate Change (IPCC), this is no longer a potential threat but a conclusive inevitable reality. Rainfall is generally expected to become more variable; floods are expected to become more common; droughts are expected to be more intense and last longer, and sea-levels are expected to rise.
Potential demand for water is expected to increase with economic growth, increased urbanisation, higher standards of living, and population growth. Because of the critical importance of water in the South African economy the country has a sophisticated water resources planning capacity, founded
on a good understanding of the country’s variable rainfall. This planning capacity will be a key capability for adaptation planning under ongoing and future climate change.
Effects of Climate Change on Water Resources
| Climate Change | Effect | Impact |
| CO2 enrichment | Increased photosynthesis; reduced transpiration | Increased water use efficiency |
| Increased temperatures | Faster plant growth, increased transpiration. Increased evaporation from lakes and reservoirs, reduced runoff and reduced groundwater recharge, higher demand for water for irrigation, bathing and cooling | Changes in water yields, higher stress water in delivery systems during peak loads |
| Rise in sea level | Land loss, saline intrusion into coastal aquifers, movement of salt-front estuaries affecting freshwater abstraction points | Reduced water quality in coastal areas, reduced groundwater abstraction |
| Change in seasonal precipitation | Change in soil moisture, change in river runoff and groundwater recharge | Changes in projected yields of reservoir systems, changes in water quality |
| Change in spatial patterns of temperature and precipitation | Shift in basin hydrology (Surplus and deficit regions) |
Changes in infrastructure to supply water |
| Change in variability of precipitation (Daily and inter-annual) |
Changes in water stress between rainfall events, changes in peak runoff | Increased requirement for storage of water supply systems |
| Changes in drought hazard | Changes in seasonal water stress or off season water replenishment | Altered risk water resources |
| Change in flood hazard | Change in risk in flood plain, change in area affected | Altered risk water resources, change in reservoir operations |
Source: Center for International Climate and Environmental Climate Change in Africa - Issues and Challenges in Agriculture and Water for Sustainable Development Report.
For countries like South Africa, that have not achieved water security, climate change will make it very difficult. As for countries that have achieved water security, it may prove more difficult to sustain in the future. In other words, all countries of the world - whether they are water secured or not - are likely to be faced with new challenges that they have not anticipated before.
World Water Day Poster 1 2020 (3.13 MB)
