The Yellow Creek alluvial fan dynamics and impact to tourism infrastructure in the Fox Valley
Thesis DisciplineEnvironmental Sciences
Degree GrantorUniversity of Canterbury
Degree NameMaster of Science
Alluvial fans are dynamic depositional landforms that are susceptible to abrupt changes influenced by fluctuations in sediment supplies. In paraglacial environments alluvial fans display accelerated aggradation due to the extraordinary influxes of sediment into the system following glacier retreat. This thesis examines how a paraglacial alluvial fan in the Fox Valley has evolved over time, and assess the impact of fan dynamics on tourism infrastructure as well as probabilities of walking track closures. The study area is a significant tourism destination for the West Coast of New Zealand, with the Franz Josef and Fox Glaciers attracting 400,000 visitors to the area each year. Structure from motion (SfM), aerial imagery analysis, experimental physical modelling, binary regression statistics and chronological investigations using a Schmidt hammer, have all been incorporated into the methodology of this research.
The findings of this research identified that between 2015-2017, there had been a mean elevation change of 1.94 m (+/- 30 cm) across Yellow fan, signifying a significant amount of aggradation that impacted the walking track locality. Noticeable changes on other fans within the valley displayed a similar aggrading trend, which has influenced the locality of the active Fox River channel, and has consequently increased the vulnerably of potential damage to infrastructure. The research also indicated that there is a 17.7% chance the glacier walking track could be closed on any given day linking track closure to rainfall events. Overall the significance of this research provides insight into the relationship between the dynamic paraglacial processes within the Fox Valley and impacts on tourism infrastructure.