每个人都有足够的水资源吗?

As the global population grows, so does the need for water. The Worldwatch Institute says increased demands for food, energy and industry, along with climate change, could lead to water scarcity in some places. The warning comes on World Water Day, March 22.

Worldwatch says billions of people are already facing some kind of water scarcity or shortage. Spokesperson Supriya Kumar said that it’s only expected to get worse as the population increases.

“Over 1.2 billion are basically living in areas of physical water scarcity. And almost 1.6 billion face economic water shortage. And these are really extreme numbers. And as our population continues to grow there’s just going to be more problems. And we’re going to really have to face drastic measures in order to make sure the people have access to water.”

There are several types of water scarcity. The first is called “physical.”

“Physical water scarcity really just means that there’s not enough actual water to meet all demands. Water is not distributed evenly. Areas in the Middle East, in northern China, in northwestern India – very arid regions – where there’s just not enough water. And so there’s just not physical availability,” said Kumar.

And then there’s economic water scarcity.

“Economic water scarcity refers to just the lack of investment in water programs and water capacity. And that’s something seen in large parts of Africa, where there’s actually physical water available, but just not enough investment made to make sure that water is available and accessible to the people that live in that region,” she said.

Kumar said that action to relieve these problems can be taken on the local, national and regional levels.

“In terms of the local level,” she said, “we could put more investment into water harvesting – into better methods of reusing water that’s wasted -- treating it to be reused for agriculture or for other industries.”

On the national level, the Worldwatch Institute recommends that governments develop better water policies, which could include fewer or revised agricultural subsidies.

“For example, in India, a lot of farmers have subsidies that provide them with the use of electricity for 24 hours without any fees. And so, that leads them to pump water constantly, which is really depleting the ground water,” she said.

Worldwatch says, globally, 70 percent of what’s called “water withdrawals” is for agriculture; 19 percent for industry and 11 percent for municipal demands. Some of the countries with very high withdrawals include India, China and the United States.

Many water sources are not confined within a particular country’s borders. Rivers and lakes are often used by several nations and therefore regional agreements would be needed on water use.

Climate change – with its rising global temperatures – has a direct effect on water scarcity, said Kumar, especially when it comes to rainfall.

“The changes in the rainfall patterns seriously affect some of the sectors, especially agriculture, for example. In India, a lot of farmers are unable to prepare for what crops they’re going to grow because they’re just not sure of the amount of rainfall they’re going to receive and when they’re going to receive that rainfall. And that’s the large effect that climate change is having.”

Kumar said that uncertainty about rainfall can directly affect food security.

What’s more, the Worldwatch Institute expects that in the Mediterranean basin and the semi-arid areas of the Americas, Australia and southern Africa, there will be reductions in river runoff. It also expects aquifers – underground water saturated rock – to take much longer to recharge. In Asia, large areas of irrigated land could be adversely affected by changes in water runoff patterns.

Also, highly populated delta regions could be affected by reduced fresh water runoff, rising sea levels and greater salinity.

The Worldwatch Institute’s concerns about water scarcity can found in its online Vital Signs reports.