Spatiotemporal evaluation of snowmelt water and snowpack isotopes (18O and 2H) and their application in subarctic catchment hydrology

Thesis event information

Date and time of the thesis defence

Place of the thesis defence

Tellus Backstage, Linnanmaa, University of Oulu

Topic of the dissertation

Spatiotemporal evaluation of snowmelt water and snowpack isotopes (18O and 2H) and their application in subarctic catchment hydrology

Doctoral candidate

M.Sc. Kashif Noor

Faculty and unit

University of Oulu Graduate School, Faculty of Technology, Water, Energy and Environmental Engineering

Subject of study

Water and Environmental Engineering

Opponent

Professor Daniele Penna, University of Florence

Custos

Associate Professor Pertti Ala-aho, University of Oulu

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Studying snowmelt processes using stable water isotopes

Snow is characteristic of the north and is important for understanding how water moves through the environment in cold regions, especially when it comes to streams, rivers, lakes and water supplies, and even for generating power. In this research, we looked closely at how snow melts using stable water isotopes (δ18O and δ2H). These isotopes act like unique tags, helping us understand the processes occurring in the snow. They reveal how the snow behaves when it melts and moves through the catchment, such as a forest, and they are vital in quantifying the proportion of meltwater when it mixes with water from streams, rivers, and lakes.

We conducted our study in the Pallas research area. We found out that during spring, when the snow starts melting, the isotope values in the snow change more compared to in the winter. Also, these isotope values change more over time than in different places. The results showed that the rate of snow melt, and other meteorological factors affect the isotope values in the melting water. We also investigated different ways to collect snow samples and mathematical methods to determine how much of the water in streams comes from melting snow. We suggest the best way to collect this information is to use special equipment in the field, for example, a snowmelt lysimeter. If that is not possible, then taking bulk snow samples during melting may provide closer estimates of meltwater fractions in the stream water.

This research enhanced our understanding of how snow contributes to the water cycle in northern regions. Knowing how snow melts and tracking it with isotopes (δ18O and δ2H) are key tools for conducting such studies. This knowledge is particularly important in cold regions, as it helps us understand how much snow meltwater ends up in streams during spring. The results offer new insights and tools for forecasting spring flood and assessing water availability.
Last updated: 23.1.2024