|  | Much has changed since this 1940 photo of Johannesburg | |
Social development and space
The last 50 years have seen a tremendous movement of people away from country areas to towns and cities, as societies have become more industrial and less rural. Industrial growth benefits society by providing jobs, improving standards of living and providing the goods needed by developing societies. The move to towns and cities often increases the possibility of obtaining a job, an education and basic health care.
These developments can be beneficial both for individuals and for societies – providing that industrial development and the growth in towns and cities is sustainable. It should not put at risk the environment in which we live or destroy the resources on which we depend.
In the past this huge influx of people to urban areas and industrial development have often led to shanty towns and settlements springing up, sometimes in areas unsuitable for housing or factories, due to the risk of landslides, flooding or subsidence.
These hurriedly built unplanned new settlements place a tremendous strain on infrastructure and already over-stretched facilities and resources. The end result can be overcrowding, poor housing, poor sanitation, a lack of clean drinking water and industrial pollution.
| | Satellite image of Johannesburg | |
How satellite data can help
Very little escapes the all-seeing eye of Earth observation satellites. Day and night, regardless of weather conditions, satellites keep watch over the Earth. The data they transmit has many uses, including providing town planners with the information they need to try and control the spread of urban settlements and provide the facilities needed to make new settlements liveable. Satellites can even be used to provide people living in remote areas with access to education.
Data from ESA’s ERS-2 and Envisat satellites can trace and quantify pollution from industry and traffic; identify houses, roads and other infrastructure in danger of flooding; detect subsidence of as little as 1 mm a year in towns and cities; discover water resources and leakages; and check on possible pollution of the rivers and lakes that supply urban populations with water.
Meteosat provides information on climate and can provide early warning of floods and drought. It can also be used to help develop early warning systems for diseases such as malaria, which can easily spread in crowded urban areas. Once the new Meteosat satellite MSG is launched in August, even more comprehensive and frequent data will become available. All these measures can help planners to make our towns and cities liveable and restrict damage to the environment.
Last update: 29 September 2004 | 
