Environmental Issues and Urban Development Explained
Environmental Issues and Their Impact
Air Pollution
Air pollution originates from industrial emissions. Its consequences include:
- Global warming due to increased CO2 and other gases.
- Thinning of the ozone layer due to CFCs.
- Air pollution in cities from traffic and industrial activities.
Water Exploitation and Pollution
The exploitation of water results from excessive consumption.
- Freshwater pollution is caused by untreated discharges from agricultural and urban activities.
- Oceans and seas are polluted by oil spills and ships.
Deforestation
Deforestation is due to burning or logging of forests, resulting in:
- A massive increase in carbon dioxide emissions.
- Decreased humidity.
Erosion
Erosion is caused by deforestation and unsustainable agricultural practices, which deplete the soil.
Contamination
Contamination results from chemicals dumped by agriculture and industry, leading to toxic products.
Biodiversity Loss
Biodiversity, the variety of living species, is threatened by:
Causes: habitat alteration, overexploitation of resources, and poaching.
Result: dangerous simplification of ecosystems.
Impact of Farming and Energy Activities
Farming practices lead to contaminated water and soil, and overuse of groundwater and surface water.
Energy activities emit harmful substances.
Urban Activities and Their Consequences
Urban activities cause pollution, generate noise, and pollute water.
- Air pollution affects large cities and areas near industrial zones.
- Alteration of soil occurs through erosion and desertification.
- Production of waste is an increasing problem affecting all regions, due to steady growth in consumption.
Environmental Policy and Protection
Environmental policy defines the guidelines for environmental management.
Protection of natural areas is achieved through the establishment of protected natural areas.
Prevention is implemented through the requirement of prior environmental impact studies for projects.
Environmental standards impose concrete measures to reduce pollution.
Quantitative and Qualitative Criteria
Quantitative criteria: based on figures.
Qualitative criteria: such as cities and villages that meet certain characteristics, including physical attributes.
Urban Development Through History
Early Cities
Pro-America cities: arose in Mesopotamia along the Tigris and Euphrates rivers approximately 7000 years ago. Shortly after, cities emerged on the banks of the Nile and Indus rivers.
Classical Era
Classical Era: During the first millennium BC, towns spread through the Mediterranean thanks to Greek colonization and the Roman Empire.
Middle Ages
Middle Ages: European Christian cities re-emerged from the 11th century, thanks to booming trade, and Muslim cities also reached remarkable development.
Modern Age
Modern Age: In the 15th and 16th centuries, geographical discoveries led to urbanization spreading through Africa and America.
Recent Urban Growth
Developed countries: Urban growth increased from the late 18th century through the crisis of 1975.
Underdeveloped countries: Urban growth began in the early to mid-20th century.
Urban Planning Concepts
Key Elements
- Emplacement: The space on which the city sits.
- Situation: The position of the city in relation to the surrounding areas.
- Plane: A set consisting of built-up areas of the city and free spaces, houses, monuments, streets.
- Plot: The arrangement of buildings within the city; open weave where buildings are separated by free spaces, and locked together.
- Edification: Single or low altitude, where single-family homes are located, or collectively.
Urban Areas
- Urban center: The area where the main commercial and business activities of the city are concentrated.
- Periphery: Areas built more recently.
Metropolitan Classifications
- National metropolis: Exceeds 3,000,000 inhabitants.
- Regional metropolis: Between 500,000 and 1,500,000 inhabitants.
- Subregional metropolis: 250,000 to 500,000 inhabitants.
Town Sizes
- Medium-sized towns: 50,000 to 250,000 inhabitants.
- Small towns: 10,000 and 50,000 inhabitants.
Historical Aspects
Emplacements: The preferred locations were on hills and along roads.
Old Town: The urbanized part of the city from its origins to 19th-century industrialization.