Researchers at the University of South Wales, using data from 43,000 rainfall stations and 5,300 river monitoring sites across 160 countries, have found (2018) that water supplies worldwide are decreasing. Despite growing precipitation due to climate change, higher evaporation rates and dryer grounds that soak up more water leads to less water in rivers.
This study is in line with a study from 2009, that points out that world’s major rivers, amongst which the Yellow river in Northern China and the Ganges in India, are ‘drying up’. Causes are human activities such as dam building and diverting water for agriculture (that caused e.g. the Aral Sea to disappear) and climate change altering rainfall patterns and increasing evaporation rates. The only exceptions are rivers in the Arctic, the Brahmaputra in South Asia and the Yangtze in China. Very much likely because of additional melting of glaciers and ice sheets.
Experts predict that water levels of Euphrate and Tigris might drop 30-70% compared to end 20th century and speak about the “Fertile Crescent” disappearing altogether. Even notoriously wet places such as the United Kingdom are expecting severe water shortages by 2050s as summers get drier. The Colorado river has no longer enough water to go around.
Most of northern china suffers from acute water shortage (multicausal). In the past 25 years, 28,000 rivers and waterways have disappeared across the country. The iconic Yellow River, the second-longest in Asia, is now a tenth of what it was in the 1940s, and often fails to reach the sea. Former Chinese premier Wen Jiabao has warned the lack of water threatened the very survival of the Chinese nation itself.