What+are+the+elements+of+this+environment?

=** Relief **= Tectonic processes have created mountains and steep hills. Glaciation has created the U-shaped main Rakaia Valley and many glacial landforms can be seen. Freeze-thaw has created scree slopes. Fluvial processes have created single thread steams in V-shaped valleys with inter-locking spurs (fluvial erosion), and alluvial fans (fluvial deposition) where the streams/rivers enter the main U-shpaed valley - and the stream velocity decreases. There are numerous river landforms and features resulting from fluvial processes. The drainage network reflects the relief with single thread streams being short and steep - their water running quickly to meet the main Rakaia (which is also has several larger contributing rivers e.g. the Wilberforce River) The main Rakaia River is eroding into the fluvioglacial sediments left after the last glaciation and has created river terraces and cliffs, it is extensively braided and has extensive deposition near the mouth of the river (due to the large load being carried) =** Climate **= Precipitation shows a marked pattern - increases with higher relief due to orographic rainfall. High altitudes cause cooler temperatures and there are areas of permanent snow cover (which feed the remanant glaciers) and also periglacial areas. Snowmelt in Spring affects river discharge. NW is the prevailing wind and is a fohn wind. High altitudes have freeze-thaw process. Vegetation patterns reflect altitude - little vegetation or none at high altitudes. =** Soils **= Mostly thin mountain soils. Easliy eroded - on slope and high precipitation. River flats have recent soils. = **Geology** = Sedimentary rocks - soft mudstones and sandstones - which have been folded and faulted by tectonic processes and are easily eroded by freeze-thaw and fluvial processes. = **Vegetation** = Sparse alpine vegetation. Some introduced/improved areas for agriculture.

return to start