Agricultural Water Use

Agricultural Water Use

The images of seemingly endless crop fields of the American Midwest and the lush San Joaquin Valley of central California are powerful symbols of the agricultural might of the United States. In the past century, the United States has become the greatest producer of food in the world.

Water has always been a vital part of agriculture. Just like humans, crops need water to survive and grow. The process where dry land or crops are supplied with water is called irrigation. A century ago, the relatively small fields of a local farmer in many areas of the United States could receive enough moisture from rainwater, along with water that could be diverted from local streams, rivers, and lakes.

The growth of huge corporate farms that are thousands of acres in size has taken the need for water to another scale. For these operations, water needs to be trucked in, pumped up from underground, and obtained from surface water (freshwater located on the surface) sources in large quantities.

Aquaculture

Aquaculture

Aquaculture is the farming of animals or plants under controlled conditions in aquatic environments. Aquaculture usually refers to growing animals and plants in fresh or brackish water (water that has a salt content between that of freshwater and that of ocean water). Mariculture indicates the farming of animals and plants in ocean waters. (Marine means seawater.)

Just as on land, aquaculture and mariculture farmers try to control the environmental factors surrounding their crops in order to make them grow quickly and in good health. Some of the factors that aquaculture and mariculture farmers manipulate are the diet of their animals, the nutrients provided to their plants, the reproductive cycles of both animals and plants, and the chemistry and physical properties of the water where the farms are located.

They also try to develop methods to minimize diseases in their crops, to keep their crops safe from predators (animals that hunt them for food), and to reduce the pollution produced by their crops.

Commercial and Industrial Uses of Water

Waterpark

Besides being vital for human survival, water is also necessary in commerce and in industry. Commercial operations are those that generally do not manufacture a product, but provide a service, such as hospitals, restaurants, and schools. Industry usually involves manufacturing a product.

In industry, water helps keep machinery needed for the making of products running smoothly and efficiently. Water can also be a vital part of the product, such as in sports drinks or soft drinks. In the United States, the total amount of fresh and salt water used every day by industry is nearly 410 billion gallons.

To illustrate such a huge number, think of that amount of water in terms of weight. A gallon of water weighs a little over 8 pounds (3.6 kilograms). The daily water usage in the United States totals almost 3.5 trillion pounds (1.6 trillion kilograms), about the same as 200 million 200-pound (90.7 kilogram) people!

Economic Uses of Groundwater

Groundwater in Burkina Faso, Africa

Groundwater is one of humans’ most valuable natural resources. Groundwater is the water contained in the rock and soil layers beneath Earth’s surface, and it makes up most of Earth's supply of fresh, liquid water. (The oceans and ice in the North and South Poles contain 99% of Earth's total water supply. Groundwater accounts for almost all of the remaining 1%.)

Throughout history, humans have settled in areas with plentiful and pure groundwater, and have fought to own and protect wells and springs. Today, human water needs in many arid (dry) or heavily populated regions far exceed surface water supplies. Earth’s rapidly-growing human population is becoming increasingly reliant on groundwater.

Groundwater fills wells and city water supplies. Ground-water irrigates (waters) crops, feeds livestock, and produces farm-raised fish. Groundwater is used to cool nuclear reactors that generate electricity, mix concrete, and manufacture millions of consumer products. In short, groundwater plays a vital role in almost every facet of people’s lives, from drinking water, foods, and products people buy to roads and the buildings in which people live and work.

Minerals and Mining

Traditional gold mining

Minerals are defined as naturally occurring solids found in the earth that are composed of matter other than plants or animals. Ore is a naturally occurring source of minerals, such as a rock. A mineral can be composed from one element, such as diamond, which contains only carbon, or several elements, such as quartz, which contains silicon and oxygen. An element is a substance that cannot be divided by ordinary chemical means.

Even ice is considered a mineral. Minerals are found everywhere on Earth, from the bottom of the ocean to the highest mountains. Mineral deposits are frequently located underground, and thus they must be mined. South Africa and Russia hold the largest amount of minerals in the world. Minerals are vital to people’s lives, and many of these minerals are critical to countries’ industries and economies.

The United States is relatively poor in critical minerals, including platinum, cobalt, and gold, but there are sand deposits of titanium ore in Florida and the Pacific Northwest. In the central United States, minerals that contain lead and gallium (used in computer chips) are abundant, and iron ore is found in the states near the Great Lakes. Most of the diamonds are mined in Africa, as is gold, although gold is found in many other locations as well.

Municipal Water Use

Drinking tap water

Many people live in municipalities (cities, towns, and villages with services such as water treatment, police, and fire department). One benefit of living in a municipality is that potable water (water safe to drink) is usually available at any time by turning on the tap. Part of the responsibility of citizens and municipal officials however, is to manage and protect the local water supply.

If municipal water becomes contaminated, the result can be far-reaching and rapid. Bacteria and viruses in water can spread throughout the underground reservoir of water (the aquifer) or throughout the miles of pipelines that carries water to houses in towns and cities. As well, non-living pollutants such as oil, gasoline and sediment can spread contaminate water.

The results of such contamination can be disastrous. In the summer of 2000, the municipal water supply of Walkerton, a town in the Canadian province of Ontario, became contaminated with a certain type of bacteria called Escherichia coli (or E. coli for short). This type of E. coli caused a serious illness in over a thousand people who drank the town water, and killed seven people.

Petroleum Exploration and Recovery

Oil rig - Petroleum exploration

Petroleum, also called crude oil, is a thick, yellowish black substance that contains a mixture of solid, liquid, and gaseous chemicals called hydrocarbons. Since its discovery as an energy source in the mid-1800s, petroleum has become one of humans’ most valuable natural resources. Petroleum is arguably the single-most important product in the modern global economy.

Hydrocarbons separated (refined) from crude oil provide fuels and products that affect every facet of life in industrialized nations like the United States. Natural gas and propane are gaseous hydrocarbons that are used to heat homes and fuel stoves. Natural gas actually exists as a gas in underground reservoirs (underground rock formations containing oil or natural gas) and is not refined from crude oil, but it is still considered a petroleum product.

The liquid portion of petroleum becomes such essential products as home heating oil, automobile gasoline, lubricating oil for engines and machinery, and fuel for electrical power plants. Asphalt road surfaces, lubricating oils for machinery, and furniture wax are all composed of semi-solid hydrocarbons. Petroleum products are the building blocks of plastics. The hydrocarbon gas ethylene is even used to help ripen fruits and vegetables!

Residential Water Use

Residential Water Use

In the United States, approximately 408 billion gallons (1,544 billion liters) of water are used every day! While power production and irrigation (watering crops) consume the majority of water usage, public and self-supply water systems produce 47 billion gallons (178 billion liters) a day for residential users and businesses.

Residential water use includes both indoor and outdoor household water usage. Water is used indoors for showering, flushing toilets, washing clothes, washing dishes, drinking, and cooking. Outdoor water usage includes washing the car, and watering the lawn, pools, and plants.

Public and private water

Nearly 85% of residential water users in the United States receive their water from public supply water systems. A public supply water system is a government facility or private company that collects water from a natural source such as a lake, river, or the ground.

Salt

Natural sea salt

Common table salt is a compound. A compound is a chemical substance in which two or more elements are joined together. An element is a substance that cannot be broken down into a simpler substance. Elements, either alone or joined together as compounds, make up every object. The elements sodium and chlorine join together to make table salt.

Sodium is represented by the symbol "Na," and chlorine is represented by the symbol "Cl." Because one atom (smallest unit that has all the chemical and physical characteristics of an element) of sodium joins with one atom of chlorine, table salt is represented by the symbol "NaCl."

The need for salt

All animals, including humans, require salt. Salt is needed to regulate many bodily functions including maintaining a regular heart rhythm, blood pressure, and fluid balance in the body. Additionally, salt is required for nerve cells to communicate efficiently, and for regulating the electrical charges moving into and out of cells during processes such as muscle contraction.

Shipping on Freshwater Waterways

Ancient Egyptian boat replica

For thousands of years humans have used freshwater waterways to ship food, building materials, and goods between regions. A freshwater waterway is any low-salt body of water, such as a river, lake, or man-made canal on which ships may travel. The need for freshwater for drinking and irrigation (watering crops) led most early civilizations to develop along rivers.

Shipping on freshwater waterways continues to be a reliable and important way to transport goods. Shipping goods over waterways is slower than other forms of shipping, yet it is less expensive and allows larger loads of cargo. Therefore many heavy raw materials such as coal, oil, timber, food products, and metal are often shipped over water. Many modern cities are still located along rivers and lakes.

Shipping in ancient Egypt

The ancient Egyptians (3000 b.c.e.-30 c.e.) depended upon the Nile River for their survival. The Nile River was the only source of drinking water for most Egyptians. Its yearly floods deposited silt (fine particles smaller than sand) that fertilized Egyptians crops. The Egyptians also used the Nile as their main highway, connecting Upper Egypt in the south with Lower Egypt in the north.

Shipping on the Oceans

Cargo ship on the ocean

Throughout recorded history, humans have relied on the oceans to ship goods quickly and efficiently. Historically, shipping on the oceans had several advantages over shipping over land. Shipping over land required moving bulky and heavy goods over mountains, across deserts, or through forests.

The location of roads often dictated where goods could be shipped. Before vehicles, land travelers also had to carry enough food and water to keep their pack animals alive, adding to the weight of their loads.

Two thousand years ago, the power of the Roman Empire was founded on the economic benefit that Rome gained from its control of trade on the Mediterranean Sea. Most of Rome’s empire lay on the shores of the Mediterranean Sea, which served as a highway for the trade of wine, food, timber, spices, and other valuable materials.

Surface and Groundwater Use

Surface water - Lake Wanaka, New Zealand

Surface water is the water that lies on the surface naturally as streams, rivers, marshes, lagoons, ponds, and lakes. Surface water can also be collected and stored in containers that have been built especially for that purpose. These containers are called reservoirs. Fresh water also collects in areas of soil and rock underground. This is groundwater.

Rain falling from the sky and snow melting in the springtime can flow downhill to gather in stream or riverbeds. From there, the water flows to a lake or ocean. In other locations, the rain or melted snow is soaked up by the soil and makes its way further down into the ground because of gravity (the force of attraction between all masses in the universe).

Uses of surface and groundwater

Surface water tends to be used by humans more often than groundwater. This is because it is much easier to obtain surface water. Inserting a pipe or tube into the water and then pumping out the water is all that is needed. Sometimes, if the surface water source is located on a hillside, the water flows through the pipeline because of gravity.

Tourism on the Oceans

Tourism on the Oceans

Human interest in the sea fuels a multi-billion dollar a year ocean tourism industry. Ocean tourism refers to pleasure travel in which the sea is the primary focus of activities. Ocean tourism comes in many forms including cruises, ecotourism, and fishing expeditions.

Cruising the oceans

Cruises are one of the most popular forms of ocean tourism. In the late nineteenth and early twentieth century, cruise liners were needed to carry passengers across the oceans. Many of these cruise ships—including the ill-fated Titanic, which sank in 1912 killing over 1,500 people—provided passengers a luxurious way to travel. Originally powered by steam-driven engines, most modern cruise ships use diesel fuel to power their engines.

While cruise ships were needed for Atlantic Ocean crossings, by the mid-twentieth century, air travel made ocean crossings cheaper and faster. An airplane can cross the Atlantic in several hours instead of the one week required by most cruise ships. Cruise lines could no longer promote their services as providing a means of travel to and from vacation. (A cruise line is a company that owns one or more cruise ships.)

Transportation on the Oceans

Transportation on the Oceans

For thousands of years, oceans provided one of the fastest and most valuable forms of transportation. By 3200 b.c.e., Egyptian ships made of reeds (tall, woody grass) used sails to travel along the coast of northern Africa. Over the centuries, ocean-going ships became larger and faster.

Around 1000 b.c.e. the Vikings explored the coast of Canada in sailboats. Spanish ships explored the Americas in the fifteenth and sixteenth centuries. British tall ships carried settlers to the Americas, Asia, Australia, and Africa in the sixteenth through nineteenth centuries.

Until the mid-twentieth century, ships were the only mode of transportation for ocean crossings. The rise of air transportation after 1930 reduced the role of ocean-going vessels in transportation. Airplanes provided a quicker and often cheaper way to move people great distances, which caused the types of vessels and purposes of ocean transportation to change.

Whaling

Whaling

Whaling, which is the hunting and killing of whales, is an activity that dates back centuries. Native people like the Macah, Nootka, and Coastal Salish of the Pacific Northwest are known to have hunted whales nearly 2,000 years ago. Whaling became popular with Europeans when they colonized North America in the late 1600s.

By 1672, whaling parties were organized off of Cape Cod in Massachusetts and off of Long Island in New York. However, by the early 1700s, the number of whales that close to shore had already begun to decline, so larger ships called sloops were developed that could capture whales farther off shore.

In the late 1800s, whaling had become a thriving commercial industry. Two of the most commonly hunted whales were the right whale and the sperm whale. The right whale was so named because it was the "right" whale to catch.