Splitting streamflow: understanding the contributions of snow and ice in Canterbury headwaters

Brian Mason Scientific and Technical Trust
2022-2024

Team

Shelley MacDonell and Zane Shadbolt

The Problem 

In the Canterbury headwaters, the main contributors to streamflow include precipitation, seasonal snow, and ice bodies (such as glaciers and rock glaciers). The relative contributions are likely to vary both spatially and temporally, depending largely on precipitation timing and quantities. Whilst seemingly intuitive, there is currently limited understanding of the relationships between these hydrological units in the Canterbury context, and how they vary through time. This study aims to evaluate the temporal variability of hydrological inputs to an alpine headwater catchment using a combination of natural tracers (water isotopes) and mixing models to provide a baseline for understanding both hydrological connectivity and response to meteorological and geographic variability.

Research Goals 

The main aim of this project is to evaluate the temporal variability of hydrological inputs to alpine headwaters. To achieve this, we will instrument a small catchment in the Arthurs Pass region to use as a model system, in which we will make observations over the course of a year. We know from previous work in other mountain regions, it is important to take high frequency samples (daily) over at least a one-year period to understand baseline variability. We envisage that this study will be used as a platform to understanding hydrological processes in the area, as well as for informing future modelling work aimed at understanding catchment response to climate and landuse change.