Key Environmental and Economic Concepts Explained

Environmental Definitions

Here are some fundamental environmental definitions:

Aquifer

An aquifer is an underground water reservoir. Aquifers form when precipitation water filters through the ground, finds a waterproof layer, and accumulates on it. Their waters can be discharged through rivers and springs or directly into the sea.

Acid Rain

Acid rain is precipitation with a higher degree of acidity than normal. It occurs when emissions of sulfur and nitrogen mix with water vapor in the air and become diluted solutions of sulfuric acid and nitric acid, which then fall to the Earth's surface as rain. It causes changes in vegetation, soil, water, and buildings.

The Ozone Layer

The ozone layer lies between 15 and 55 km in height and filters ultraviolet radiation from the sun. The decrease in its thickness is mainly due to the chlorine contained in CFCs (chlorofluorocarbons), which are used in aerosol sprays and refrigerants. Chlorine reacts with ozone and converts it into normal oxygen. This problem affects plant, animal, and human life, in the latter case, increasing the incidence of skin cancer and cataracts. The ozone layer thickness over Spain has fallen by 8%.

The Greenhouse Effect

The greenhouse effect is caused by the emission of gases, primarily carbon dioxide, into the atmosphere. These gases allow sunlight to enter but, once it reaches Earth, they retain it and prevent it from escaping into outer space, acting just like the glass in a greenhouse. An increase in greenhouse gas emissions causes a greater amount of heat to be retained. The main consequences are a global increase in the Earth's temperature and climate change, leading to phenomena such as droughts and large floods.

Land and Economic Systems

Understanding key concepts in land management and economics:

Land Tenure Systems

The land tenure system refers to the degree of control over land. Tenure is direct when the farm owner and the businessman are the same person. In Spain, 79.6% of ownership is direct, especially on small properties. Tenure is indirect when the owner transfers the land use to another person in exchange for a percentage of the crop – known as sharecropping – or by paying a rent – known as a lease. Today, sharecropping has declined markedly.

Land Consolidation

Land consolidation, which began in 1952, continues today. Since 1985, it has been transferred to autonomous communities. It aims to decrease smallholding by giving each owner a single parcel or a few equivalent parcels in terms of land and crop types to what they had before, and also providing plots with access to roads. At each end, a minimum unit of cultivation is fixed, below which there can be no new lot, and it is not allowed to divide the resulting parcels below the set minimum unit.

Fisheries

Fisheries are places for setting or throwing nets. The problem with fisheries is the depletion of national fisheries and fishing restrictions in both national and international waters.

Balance of Payments

The balance of payments is a document that records a country's economic transactions with the outside world over a period of time. It records income and expenditure for each operation, from which a positive or negative balance (surplus or deficit) arises.