WMO (World Meteorological Organization) has released its first annual State of Global Water Resources Report 2021. The aim of this annual report is to support monitoring and management of global freshwater resources in an era of growing demand and limited supplies.
Overview of The Report:
The report gives an overview of river flow, as well as major floods and droughts. It provides insights into hotspots for changes in freshwater storage and highlights the crucial role and vulnerability of the cryosphere (snow and ice).
The report shows how large areas of the globe recorded drier than normal conditions in 2021 – a year in which precipitation patterns were influenced by climate change and a La Niña event. The area with below-average streamflow was approximately two times larger than the above-average area, in comparison to the 30-year hydrological average.
Focus Of The Report: 3 Key Areas:
- Streamflow, the volume of water flowing through a river channel at any given time.
- Terrestrial water storage (TWS) — all water on the land surface and in the sub-surface.
- The cryosphere (frozen water).
What Has Been Said:
“The impacts of climate change are often felt through water — more intense and frequent droughts, more extreme flooding, more erratic seasonal rainfall and accelerated melting of glaciers — with cascading effects on economies, ecosystems and all aspects of our daily lives. And yet, there is insufficient understanding of changes in the distribution, quantity, and quality of freshwater resources,” said WMO Secretary-General Prof. Petteri Taalas.
“The State of Global Water Resources report aims to fill that knowledge gap and provide a concise overview of water availability in different parts of the world. This will inform climate adaptation and mitigation investments as well as the United Nations campaign to provide universal access in the next five years to early warnings of hazards such as floods and droughts,” said Prof. Taalas.
An Alarming Situation:
Currently, 3.6 billion people face inadequate access to water at least a month per year and this is expected to increase to more than 5 billion by 2050. Between 2001 and 2018, UN-Water reported that 74% of all natural disasters were water-related. The recent UN climate change conference, COP27, urged governments to further integrate water into adaptation efforts, the first-time water has been referenced in a COP outcome document in recognition of its critical importance.
Key findings of the Report: Across the Globe: Streamflow:
- The area with below-average streamflow is two times larger than the above-average area when compared with the 30-year hydrological average.
- The areas having below-average streamflow are:-
- South America’s Rio de la Plata area, where drought has remained persistent since 2019
- South and South-East Amazon
- River basins like the Colorado, Missouri and Mississippi in North America.
- In 2021, rivers in Africa like Niger, Volta, Nile and Congo experienced less than normal discharge. Similarly, rivers in several parts of Russia, West Siberia and Central Asia also experienced lower-than-average discharge during the same period.
- Places that experienced above-normal river discharges are several North American basins, the North Amazon and Southern Africa (Zambezi and Orange), Northern India and China (Amur river basin).
- Around one-third of the areas that were analysed was in line with the 30-year average.
- Major flood events occurred in China, north India, western Europe and countries affected by Tropical cyclones like Mozambique, the Philippines and Indonesia.
- Countries like Ethiopia, Kenya and Somalia have experienced several consecutive years of below-average rainfall, leading to the occurrence of regional drought in these places.
Condition Of Surface Water: Terrestrial water:
- In 2021, places like the US’ west coast, central part of South America and Patagonia, North Africa and Madagascar, Central Asia and the Middle East, Pakistan and North India had below-normal terrestrial water storage (when compared with the average from 2002-2020).
- It was above-normal in central Africa, northern part of South America (specifically the Amazon basin) and the northern part of China.
- In the long term, several places are expected to experience a negative trend in terrestrial water storage. These include Rio Sao Francisco basin in Brazil, Patagonia, the Ganges and Indus headwaters and the south-western US.
- Places like Great Lakes Region, the Niger Basin, East African Rift and North Amazon basin are expected to record positive trend in terrestrial water storage.
- However, the negative trends are stronger than the positive ones. Excessive exploitation of groundwater resources for irrigation purposes are expected to worsen the negative trend.
- The cryosphere (places where glaciers, snow cover, ice caps and permafrost are present) is the largest natural reservoir of freshwater in the world.
- Changes to cryosphere water resources affect food security, human health and ecosystem, leading to significant impact on economic and social developments. These changes can also cause river inundation and flash floods because of glacier lake outbursts.
- Due to the rising atmospheric temperatures, the annual glacier run-off will increase until reaching the point called “peak water”, after which run-off declines.
- The long-term projections of the changes in glacier run-off and the timing of peak water are important inputs for making long-term decisions required to improve the climate adaptation capabilities.
- The future assessments by the WMO’s State of Global Water Resources will provide incentive to regularly assess the changes in the cryosphere and changes in the availability of water resources at basin and regional levels.