Dendrochronology in Northern Utah: Modeling Sensitivity and Reconstructing Logan River Flows

Author

Eric B. Allen, Utah State University

Date of Award:

5-2013

Document Type:

Thesis

Degree Name:

Master of Science (MS)

Department:

Geosciences

Department name when degree awarded

Geology

Committee Chair(s)

Tammy M. Rittenour

Committee

Tammy M. Rittenour

Committee

Roger Kjelgren

Committee

Matthew F. Baker

Abstract

The population centers in northern Utah are highly dependent upon snowpack for drinking water, irrigation, and hydropower. When the snowpack melts in the spring and early summer, it feeds streams draining the Wasatch, Bear River, and Uinta Mountains. The rivers are diverted and dammed to deliver water to the greater Salt Lake metropolitan area. In order to properly allocate this water, managers need to know how much water normally flows in the rivers and the frequency and magnitude of wet and dry periods to expect. However, climate patterns in the region are not well understood and records of streamflows are too short to discern climate cycles that can be several decades long. Tree-ring records can be used to reconstruct past streamflow beyond the instrumental record and provides information on natural variability in the region. Dendrochronology is the use of tree rings to reconstruct past events such as climate. Trees limited by moisture will grow a thicker annual ring in wet years compared to dry years. Tree-ring records can also be used to reconstruct streamflow due to the relationship between precipitation and streamflow. This study uses dendrochronology to reconstruct streamflows of the Logan River in northern Utah. This involved collecting three Douglas-fir, one limber pine and two Rocky Mountain juniper chronologies in the Bear River Range of northern Utah. Combined with existing tree-ring chronologies, streamflow reconstructions of the Logan River were created: one using only within basin chronologies, one using all considered chronologies and one from chronologies which were older than the year 1500. The reconstructions using older and regional chronologies were the most accurate and show that the Logan River had more extreme and variable flows than in the instrumental period. These chronologies will be used by regional water managers when allocating water resources and planning for potential future extremes.

Checksum

9092fee699d7a5cc5e7b9d667ab37d40

Recommended Citation

Allen, Eric B., "Dendrochronology in Northern Utah: Modeling Sensitivity and Reconstructing Logan River Flows" (2013). All Graduate Theses and Dissertations, Spring 1920 to Summer 2023. 1716.
https://digitalcommons.usu.edu/etd/1716