Climate change is drying up major rivers: study
* More water rivers are losing rather than winning, even with the melting of ice
* The flow decreases while increasing the needs
WASHINGTON (Reuters) – Rivers of some of the most densely populated regions of the world are losing water, often due to climate change, announced on Tuesday a team of scientists.
Among the affected rivers are the Yellow River in northern China, the Ganges in India, the Niger in West Africa and the Colorado in the southwestern United States.
When you add the effects of dams, irrigation and other uses for water, these changes may threaten the future deliveries of food and water, identified by experts in the Journal of Climate of the Meteorological Society United States.
A low flow rate increases the pressure on freshwater resources in large parts of the world, especially with increased water demand as population grows, he said in a statement aigu Dai, National Center for Atmospheric Research (NCAR, its acronym in English) of Boulder, Colorado, who led the study.
As the fresh water a vital resource, the downward trends are a big concern, he added.
Dai's team consulted the records of water level in 925 major rivers between 1948 and 2004 and found significant changes in about one third of the major rivers of the world.
The rivers flow with a decreased exceeded those that had increased by a ratio of 2.5 to 1, said.
For example, fresh water that receives the Pacific Ocean was reduced by about 6 percent, or 526 cubic kilometers, equivalent to around volume of water flowing into the Mississippi River for years.
The annual flow of rivers to the Indian Ocean fell about 3 percent – or 140 cubic kilometers – during those 56 years.
The Columbia River, in northwestern United States, has lost about 14 percent of its volume in this period, largely due to a reduction in rainfall and increased water consumption in the west, the team said Dai.
However, the Mississippi River has a 22 per cent more water due to increased rainfall in the Midwestern U.S. since 1948, said.
Also, the annual contribution from the melted ice in the Arctic has increased about 10 percent, some 460 cubic kilometers.
In addition, there are indications that the rapid warming from #39 and 70 caused an earlier spring, which advances the melting of snow and the associated maximum flow in the western United States and New England, and a break early in the rivers of ice in Arctic Russia and many Canadian rivers, wrote the researchers.
As climate change will inevitably continue in the coming decades is likely to see major impacts on many rivers and water resources with which the society, said NCAR scientist Kevin Trenberth, who worked in the studio.