Metropolitan City is a general term for city together with their suburbs with a population of more than 10 million people.

International trade has three very important aspects.

(i) Volume of Trade- The actual tonnage of goods traded makes up the volume. However, services traded cannot be measured in tonnage. Therefore, the total value of goods and services traded is considered to be the volume of trade.

(ii) Composition of Trade- The nature of goods and services imported and exported by countries have undergone changes during the last century. Trade of primary products was dominant in the beginning of the last century.

(iii) Direction of Trade- Historically, the developing countries of the present used to export valuable goods and artefacts, etc., which were exported to European countries. During the nineteenth century there was a reversal in the direction of trade.

Examples of human imprints are:

(i) Health resorts on highlands.

(ii) Fields, orchards and pastures in plains and rolling hills.

(iii) Ports on the coasts.

The examples:

(i) This canal had been constructed in 1869 in Egypt between Port Said in the north and Port Suez in the south linking the Mediterranean Sea and the Red Sea.

(ii) It gives Europe a new gateway to the Indian Ocean and reduces direct sea-route distance between Liverpool and Colombo compared to the Cape of Good Hope route.

(iii)It is a sea-level canal without locks which is about 160 km and 11 to 15 m deep. About 100 ships travel daily and each ship takes 10-12 hours to cross this canal.

Density of population is expressed as number of persons per unit area.

(i) Availability of water- It is the most important factor for life. So, people prefer to live in areas where fresh water is easily available.

(ii) Landforms- People prefer living on flat plains and gentle slopes. This is because such areas are favourable for the production of crops and to build roads and industries.

(iii) Climate- An extreme climate such as very hot or cold deserts are uncomfortable for human habitation. Areas with a comfortable climate, where there is not much seasonal variation attract more people.

(iv) Soil –Fertile soils are important for agricultural and allied activities. Therefore, areas which have fertile loamy soils have more people living on them as these can support intensive agriculture.