1. Effects of high and low population densities

2. Areas with high population densities can be seriously polluted with lack of water, services and open spaces. Areas with low population densities can have land abandoned, high immigration rates and low marriage rates.

4. India has close to one billion people living in its country. Calcutta is one of India’s most densily populated cities with over 15 million people living in the city. Poor migrants that come from other parts of Inida live in slums around the edge of the city called shanty towns or bustees. Problems that people in Calcutta face are overcrowding, lack of open space, lack of clean water and pollution

8. Overcrowding The population density in Calcutta is 35000 per square km, this make calcutta one of the most densily popullated cities in the world. This overcrowding results in overcrowded homes been made of loose material and more than half a million people having no homes at all.

12. Lack of open space This overcrowding also results means there is very little open space in the city, unlike modern cities like Dublin and London. All space in the city is taken up by houses or bustees.

16. Clean water With the city expanding up along the Hooghly river for 50 km the river gets easily polluted. Only rich people can afford the technology for filtering water. The rest of the popullation use dirty river water which results in diseases.

18. Pollution The bustees and slums of calcutta have many types of pollution with sewage and other waste in open drains which floods during the monsoon season. There is also a large amount of garbage the litter that pile up with nobody employed to move it.

21. Hong kong Hong kong located in the south of china is another city affected by overcrowding. It is rich compared to Calcutta but some of its inhabitants are still poor. It is one hundred times more densely populated than Ireland. Kong kong suffers the same problems as Calcutta such as overcrowding, lack of open space, lack of clean water and pollution.

25. Overcrowding Becasue of the severe population density many peopl live in shanty towns or poor apartments. The city has expanded upwards as well as outwards to meet the rising population. The city is so overcrowded that schools run a 16 hours system with students having a choice of coming in the morings or the evenings.

30. Lack of open space In mainland Hong Kong space is at a premium. On the fringes on the city there is more space with new housing estates being developed. Space is so scarce in the city itself that industries are building on polders which is land that is reclaimed from the sea.

33. Clean water Becasue Hong Kong is a modern city there is a clean supply of water, but the beaches and sea are full of industrial waste and sewage making it impossible to go swimming. This problems was highlighted in the olympics where any sailors who fell into the sea quickly fell sick

34. Pollution Air pollution in Hong Kong is immediately evident from the constant fog that hangs over the city. This smog is a result of traffic pollution. There is also a high level of noise and visual pollution with ugly high rise buildings.

38. Low population density With low population densities, where areas are under populated there is often a very low marriage rate, political and economic isolation and abandoment of agricultural land. Examples of areas with low population densities are the West of Ireland, and Mali in Africa.

41. Isolates ares have few jobs, third level college or leisure facilities This results in many people migrating to cities With these young people gone there are fewer marriages This results in a falling birth rate Which means a fall in the population Low marriage rates in the west of Ireland

43. Abondement of Land With this decline in population and the migration of young people, there are less and less people to farm the land which becomes abandonded. With the older generation left to farm the land by themselves the EU give grants and pensions to Elderly farmers who turn their land into forestry.

50. Political and Economic Isolation Becasue of the lack of population there is a lack of representation, with the west of Ireland having fewer TD’s than the east of Ireland. Economically the west suffers also with a lack of infrastructure such as roads and services. Because of its location on the west coast of Ireland it is in fact isolated from Irelands political and economic hub which is Dublin, its surrounding counties and other main cities.

52. Mali Mali is a landlocked country in West Africa with a populaiton density of 10 people per square km. The reasons for this are to do with the lack of precipitation, the Sahara Desert and desertification which leads to drought and famine, making it one of the worlds poorest countries.

55. Marriage Rates As in Ireland many young people migrate to the country’s main cities for jobs. Due to Mali’s traditions it is mostly young males who migrate which leaves a surplus of females in the countryside, this reduces marriage rates and reduces the population

56. Abondonment of Agricultural land Due to severs drought and desertification most of the rural population has been forced to abondon its land with thousands of acers been destroyed by the desert and entire animal herds being wiped out. These people flee to the main cities of Mali in searh of employment, health care and better educational services.

57. Population migration

60. Political and economic isolation Mali was once a colony of France, becasue of the lack of population and the fact that the population is scattered mean the road and communication networks is poorly developed, making it hard to sustain a vibrant economy. Also becasue the country is landlocked this makes it very hard to attract a foreign market