Hi, I'm Jensen Morgan. We're going to talk about some great concepts in environmental science. Today's topic is water availability. So let's get started.
Today we're going to talk about water supply and demand, water shortages, and different ways to address water supply problems. Water supply on Earth is finite. And as demand grows, it is out-distancing supply, creating water conflict.
Demand is being increased by three main causes-- population growth, increasing use of water for technology and industry, and increasing water wasting behaviors and practices. As I mentioned before, the amount of total usable water is fixed. And while it can be recycled through the hydrological cycle, we are using and faster than it can replenish itself.
On top of that, we are decreasing presently available freshwater with pollution, biological contaminants, and receding glaciers, which are producing less and less fresh water as they melt into the ocean. Population growth is also increasing the demand for water. However, it isn't proportional.
Currently, human water use is increasing at double the rate of our population growth. Many major aquifers where we get much of our freshwater are dramatically shrinking. An example of this is the Ogallala aquifer in the mid Western United States.
Water is being withdrawn much faster than it can be recharged. The map shows that the darker red, yellow, and orange patches indicate where the aquifer has been decreasing. Ogallala supports almost 5.5 million hectares of agricultural land, or about one-third of the groundwater used for irrigation in the United States, while also providing for at least 2.3 million people's drinking water. Since 1940, the water table in that area has declined around 300 feet.
Let's take a moment to look at this chart here. It breaks down the demand of water into its various uses. Globally, agriculture accounts for 70% of fresh water taken from streams and rivers. Industry utilizes 19% of all fresh water available, and households use the remaining 11%.
Around the world, many people cannot afford or even access clean drinking water. At least one billion people don't have access to it. At least one-fifth of the world's population lives in a location with physical scarcity of safe drinking water.
Not unlike food, water shortages are ofttimes a result of distribution problems. Other causes can generally be a dry climate, periodic drought, or over-population exceeding local water supply. California is a prime example of this problem, suffering from all three in 2014, when a 1,200-year drought struck and put numerous towns and cities in water shortages. Many farmers lost large portions of their crop, which impacted the rest of the United States, because California provides a large portion of the country's food.
Another example of water shortage is the one currently going on in India's capital, New Delhi. New Delhi's per capita availability of fresh water is greater than that of Paris. Yet Delhi cannot always provide reliable freshwater. This is primarily a distribution issue, as Delhi's poor distribution network results in a lot of unaccounted-for water.
There are strategies to improve water supply and demand issues, policies that restrict aquifer depletion can improve supply by conserving it. Improving water quality and preserving the health of aquatic ecosystems can protect the supply we do have from further contamination. Broad watershed management can conservatively and fairly distribute water across various sectors to provide adequate water while preserving enough for future use, by making agreements between groups and regions on how best to share water resources. Decreasing government subsidies and water will increase its cost and lead to decreased consumption. And educational campaigns for water conservation can reduce overall demand.
Now let's have a recap. Today we talked about water supply and demand, as well as what increases or decreases each. We talked about water shortages and what causes them. And finally, we talked about solutions to water supply issues.
Well, that's all for this tutorial. I look forward to seeing you next time. Bye.