Form and function relationships revealed by long-term research in a semiarid mountain catchment

Authors: MCNAMARA, JAMES - Boise State University; BENNER, SHAWN - Boise State University; POULOS, MICHAEL - Boise State University; PIERCE, JENNIFER - Boise State University; CHANDLER, DAVID - Syracuse University; KORMOS, PATRICK - National Weather Service; MARSHALL, HANS-PETER - Boise State University; FLORES, ALEJANDRO - Boise State University; Seyfried, Mark; GLENN, NANCY - Boise State University; AISHLIN, PAMELLA - Boise State University

Submitted to: Water Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/26/2017
Publication Date: 12/22/2017
Citation: Mcnamara, J., Benner, S., Poulos, M., Pierce, J., Chandler, D., Kormos, P., Marshall, H., Flores, A., Seyfried, M.S., Glenn, N., Aishlin, P. 2017. Form and function relationships revealed by long-term research in a semiarid mountain catchment. WIREs Water 2018. 5:e1267. doi: 10.1002/wat2.1267.
DOI: https://doi.org/10.1002/wat2.1267

Interpretive Summary: The Dry Creek Experimental Watershed was established 15 years ago and is presented as an example of the benefits of long-term research sites for the advancement of hydrologic science. It has been maintained by Boise State University and been used as a research site by numerous institutions. Some of the results related to how topography, hydrology and vegetation are related. For example, it has been shown that: north-facing hillslopes have steeper slope angles, thicker soil mantles, finer soil texture, and higher water holding capacities than their south-facing counterparts. This trend is modulated by elevation and vegetation; higher elevation sites, where aspect differences in vegetation are less evident, exhibit less distinct hydrologic properties. The storage of water first as snow, then as soil moisture determines how upland ecosystems survive the seasonal and persistent water stress that happens each year, and sustains streamflow throughout the year. They conclude that researchers working in DCEW have brought meaning to this place by living and learning in it. This sense of place is a core characteristic of all great long-term hydrologic field sites where generations of researchers pass through, each enriched by, and building on, the cumulative knowledge of those who came before.

Technical Abstract: Fifteen years of cumulative research in the Dry Creek Experimental Watershed in southwest Idaho, USA, has revealed relationships between catchment form and function that would not have been possible through independent short-term projects alone. The impacts of aspect and elevation on incident energy and water, coupled with climate seasonality, have produced tightly connected landform properties and hydrologic processes. North-facing hillslopes have steeper slope angles, thicker soil mantles, finer soil texture, and higher water holding capacities than their south-facing counterparts. This trend is modulated by elevation and vegetation; higher elevation sites, where aspect differences in vegetation are less evident, exhibit less distinct hydrologic properties. The storage of water first as snow, then as soil moisture determines how upland ecosystems survive the seasonal and persistent water stress that happens each year, and sustains streamflow throughout the year. The cumulative body of local knowledge has improved general understanding of catchment science, serves as a resource for conceptual and numerical evaluation of process-based models, and for data-driven hydrologic education.