They measured how much water was flowing in the rivers

#measured #water #flowing #rivers

A NASA with the help of the a research result, in which the water flow of the world’s rivers was measured, more precisely than ever before. The data so far were based on a 1974 UN database, re-estimated every year, but without new measurements. Since then, however, many new water measuring stations have been established, and we have much more accurate rainfall data.

The survey also revealed where these waters are used particularly intensively: the watersheds of the Colorado River in North America, the Amazon River in South America, and the Orange River in Africa are particularly under pressure.

Water flow of rivers – gray color indicates where the water flow is negative, that is, human activity raises more than what enters the rivers through precipitation.

Source: Nature Geoscience

We have to manage our planet’s fresh water resources well, because we need a lot of water, and in many places people are already getting too little of it. In the course of the research, the data of the individual water flow measurements were supplemented with computer modeling, on approximately 3 million specific sections of the world’s rivers.

Although surveys of river discharge (that is, how much water flows into the oceans) have long been carried out, estimates of the total amount of water stored in rivers have been highly uncertain. Cédric David, a participant in the research, said that this is like spending from our account without knowing how much money is on it: “We don’t know how much water we have, and population growth and climate change will further complicate the situation.”

The Colorado River is one of our negative flow waters.

Source: NASA

According to calculations, there was an average of 2,246 cubic kilometers of water at any given moment in all the rivers of our planet between 1980 and 2009. This is 0.006 percent of the world’s total fresh water supply, nearly 1,200 times the total water volume of Lake Balaton.

Despite the fact that the share of rivers in fresh water is so small, these waters have been vital to us since the dawn of humanity. Just think about the fact that the great ancient civilizations were born in river valleys.

During the research, data from the SWOT water level measuring satellite launched in December 2022 was also taken into account.

Most of the water is found in the Amazon basin, 850 cubic kilometers, and the most water flows into the ocean from the same place, 6789 cubic kilometers every year.

An average of 37,411 cubic kilometers of water reaches the oceans every year from all the world’s rivers.

There are also quite a few river sections that, due to water use, release less water than they received. These data, referred to as negative water yield, testify to where human water consumption is greatest.