Location: Range Management ResearchTitle: Observed changes to the hydrologic cycle in multiple sub watersheds: a regional study for the upper Rio Grande
|IFTEKHARUL ISLAM, KHANDAKER - New Mexico State University|
|DUBOIS, DAVID - New Mexico State University|
|BROWN, CHRISTOPHER - New Mexico State University|
Submitted to: Western Snow Conference Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 2/1/2021
Publication Date: 4/15/2021
Citation: Iftekharul Islam, K., Elias, E.H., James, D.K., Dubois, D.W., Brown, C.P. 2021. Observed changes to the hydrologic cycle in multiple sub watersheds: a regional study for the upper Rio Grande. Western Snow Conference Proceedings.
Technical Abstract: Since the middle of the 20th century, peak snowpack in the Upper Rio Grande basin has been decreasing and mean temperatures increasing. Warming influences measured snowpack characteristics such as snow cover, snow depth, and Snow Water Equivalent (SWE), which can affect runoff quantity and timing in snowmelt-runoff-dominated river systems of the region. Here we explore measured components of the hydrologic cycle in multiple sub-watersheds to examine mechanisms contributing to runoff over the past 40 years. We investigate observed relationships between watershed factors affecting streamflow as foundational to understanding the importance specific variables in a warming climate and the resulting impact on streamflow. By studying a number of prospective factors such as precipitation, temperature, albedo, soil moisture, SWE, snow cover, snow depth and sublimation, we identified important variables that affect runoff volume in different sub-watersheds, and we observed seasonal changes in variable importance. For each sub-watershed, we conducted analyses at two different temporal scales (monthly and annual base flow/runoff periods) and employed two different analysis strategies: 1) Pearson correlation analysis and 2) Linear regression with multimodel inference based on the second-order Akaike’s information criterion (AICc). We found that the variables influencing naturalized streamflow change not only by month or season, but also by watershed and mountain range. The study links variables fundamental to streamflow generation with sub-watershed water balances, leading to a variety of local water management implications. This research explores important parameters, which are the main drivers in changing surface water supplies that serve both the needs of society and a range of ecosystem services in the Upper Rio Grande (URG) basin.