(i) The various parts of the hydrological cycle are inter-related by the exchange of water. Water is a resource which cycles between atmosphere, land and water bodies. This cyclical nature is prompted by evaporation and condensation, followed by precipitation.

Water from the oceans enters the atmosphere through evaporation, and causes precipitation over land. This recharges our rivers, ground water systems and glaciers. The glaciers, in turn melt, and supply water to the perennial rivers.

(ii) The temperature distribution of oceans is influenced by many factors:

• Latitude: As we move away from the equator, the temperature of oceans decreases. This is because the direct rays of the sun do not reach those areas.

• Presence of Land: The oceans receive greater heat in the northern hemisphere, due to their extensive contact with the landmass

• Wind systems: Two competing wind systems exist. The winds that blow from the land drive the warm water away from the coast, and bring up cold water from below. But the onshore winds drive the warm water towards the coastal areas.

• Ocean Currents: Warm currents like Gulf Stream raise the temperature of the ocean water in colder areas, whereas cold currents like the Labrador Current reduce the temperature of water in warmer, equatorial areas.