Water Resources: Uses, Management, and Conservation
Water Balance
Water balance: Rain = surface runoff + evaporation + underground runoff. In a lamb, regional inputs and outputs are always balanced.
Basin
A basin is an area of land where water and sediments drain into a common riverbed. It is a natural formation with magnificent hydrogeological, physical, chemical, and biological properties that make up various common elements (climate, etc.). It is formed by many water currents and increases the water below.
It starts in small streams, to rivers, and streams drain into large rivers that bring water to the sea.
The water that falls as precipitation in the basin can exit in three ways:
- Evapotranspiration
- Drainage outlets
- Underground drainage
Lysimeter
A lysimeter is a recipient full of earth that has a hole at the bottom. If watered, it can measure the quantity of water that leaves underneath, that stays stored in the earth, and that evaporates.
Water Uses
Consumptive Uses
Consumptive uses refer to the reduction of water quality or quantity (water supply is over 70% in Catalonia, intended for irrigation, and 30% is underground water, which is used for urban supply and industrial purposes).
Non-Consumptive Uses
Non-consumptive uses do not involve a reduction in water quantity or quality.
Domestic or Urban Uses
Drinking water consumption average in urban and industrial areas is 250 liters/person/day. For domestic uses, it is 126 liters/person/day.
Mineral Water
Mineral water contains a minimum ion content in solution. Its characteristics are the result of the soil type that constitutes the aquifer. It is captured in wells and galleries. It requires bottling plants equipped with modern technology to maintain its quality intact.
Industrial Uses
- Coolant: Absorbs heat through different mechanisms.
- Cleaning agent: Eliminates impurities from vehicles, acting through dissolution, emulsion, and displacement of dirt. Chemical action is performed on the environment.
- Transport: Transports heat and many different materials.
- Feedstock: Used in the manufacture of chemicals, detergents, and foods such as soft drinks. It requires high purity.
- Other uses: Hydraulic devices, materials cut with water pressure, etc.
Agricultural Uses
The quantity of water used depends on the type of crops and the irrigation system used.
Water as an Energy Source
20% of the world’s electricity is obtained from the water harvesting cycle, specifically the potential energy that impels water from the mountains to the sea. The first apparatuses were wheels, which extracted water from rivers to feed irrigation canals. The Romans were the first to convert hydraulic energy into mechanical energy for grinding grain using watermills. At the end of the 19th century, the dynamo allowed the conversion of energy into electricity from turbines. Electricity cannot be stored in large quantities, but water can be stored in dams. Dams in reservoirs accumulate water’s potential energy. When their doors are open, this energy is released and drives turbines connected to the dynamo. However, they have negative consequences, such as high construction costs and economic performance that is not guaranteed. Water is also used for 2% of tidal energy, but few companies are dedicated to it.
Water Management
Of the 3% of the planet’s total continental water, only 1.1% corresponds to flowing water. Flowing water amounts to some 9,000 km3, and its distribution is not uniform or regular.
Problems
- Dry regions are easily contaminated.
- Abusive consumption where it is scarce.
- Lack of purification.
- Constant increase in water demand on a global scale.
Solutions
- Search for new resources.
- Improve the efficiency of current resources.
Research on New Water Resources
Construction of New Dams
The construction of dams along the river course can regulate the flow, control floods, generate energy, and store water during dry periods.
Water Desalination
Desalination makes saltwater drinkable, but it is very expensive. Distillation involves using a heat source to evaporate the water, which then condenses without salts. However, it is not suitable for drinking because it lacks almost all salts. Membrane technology, or reverse osmosis, is based on the use of a pressure pump to overcome the osmotic pressure of salt and achieve water filtration and separation. It is very energy-intensive and expensive.
Recycling Used Water
This involves a kind of cycle to return water to the tank from which it was extracted. It can be used for irrigation, sports facilities, etc.
Water Transfers
This involves exporting water from a surplus basin to a deficit basin. However, it entails many problems.
Improving Management of Existing Resources
We need to change from supply management (researching new resources) to demand management (studying consumptive uses and applying water-saving objectives in end uses).
General Measures
- Networks and distribution channels should reduce water losses, which can be very high.
- Reforestation of basin headwaters to prevent erosion and promote water infiltration.
- Application of pricing policies that favor reduced consumption and penalize waste.
- Installation of water-saving equipment.
Saving in Agriculture
- Changes in irrigation systems.
- Repair or lining of canals.
- Rethinking the type of crop.
- Reconsidering the need for new irrigation.
Action on Urban Consumption
- Choose technological innovation with the introduction of plumbing elements and appliances with low water consumption.
- Saving measures: do not run the washing machine if it is not full.
- Avoid leaks.
- Maintain xerophytic gardens in urban landscapes and private gardens with native species.
- Water gardens in the evening.
- Reuse or regenerate treated urban water.
Measures for Industrial Consumption
- Recycle water in cooling circuits and production processes.
- Purified water can be reused.
- Install devices to prevent leaks.