Date(s) - 11/10/2016
7:00 pm - 8:30 pm
Our speaker is Dr Ian Fuller, Associate Professor in Physical Geography at Massey University.
The Manawatu River is unique in New Zealand, being the only river to cross the ranges that divide east from west, which it does through the Manawatu Gorge. The catchment drains a diverse range of landscape terrains, including hard greywacke, and softer limestones, mudstones and sandstones.
This diversity of terrains is reflected in a diversity of channel types within the catchment, as well as a range of erosion sources that contribute sediment to the river. The river is characterised not only by a diversity of channel forms, but also a propensity for channel change. In turn, these natural tendencies to adjust its position have been modified by human activity, which has changed river channels in the catchment both directly by deliberate intervention and indirectly through land-use change. This talk will introduce the Manawatu from a geomorphological (landscape) perspective and consider both the tendency for natural channel change, as well as changes in response to human activity. We will also see that we can use the evidence preserved in old channel courses to reconstruct past river behaviour and floods, which helps inform our understanding of river change in the future. This understanding is essential to live with the Manawatu River successfully and sustainably.