Week 4a- Water

We all love being in water - a vital lifeforce for planet Earth.  Just as for land, water resources are part of a system which is interlinked.  This system is more commonly known as the hydrological cycle. The hydrological cycle may be affected by man's activities in all areas from the mountains through to the sea. A simplified version of this system is shown in the diagram and a more thorough cycle in provided on the next page..

In New Zealand, there are:

• Over 180,000 kilometres of rivers has been mapped in New Zealand
• The longest river in New Zealand is the Waikato River with a length of 425 kilometres.
• The largest river by volume is the Clutha River with a mean discharge of 533 cubic metres per second.
• Some of the rivers have wide flood plains and stop banks, such as the Rakaia River

In New Zealand, Lotic systems such as rivers are diverse ranging from glacial rivers and huge braided river systems to small urban streams.  These natural systems are vital for water resources, especially for agriculture as well as for recreational purposes.