Project Number: 5362-13610-010-00
Project Type: Appropriated

Start Date: Jan 14, 2012
End Date: Jan 13, 2017

Objective:
1) Evaluate the impact of landscape change on fluxes of energy, water and CO2 for Great Basin rangeland ecosystems. 2) Quantify soil-water plant growth relationships and complex terrain effects on soil temperature and moisture using the Reynolds Creek Experimental Watershed as a model system. 3) Expand integrated snow hydrology modeling to larger scales, coupling to belowground processes, including wind effects on precipitation input, and helping to incorporate snow-related processes into ARS watershed and management simulation models (e.g., SWAT, AnnAgNPS, KINEROS, AgES, AGWA, RHEM, ISNOBAL, PIHM, etc).

Approach:
This project is motivated by the following two interconnected aspects of water resources in the western U.S.: 1) water resources and covarying biological resources are concentrated in snow dominated mountainous terrain in which critical processes vary dramatically over short distances; and 2) climate change is affecting hydrologic processes, particularly snow accumulation and melt, in ways that may drastically alter water supply and land management. There are three objectives, two of which focus on field measurement and modeling of critical processes using the Reynolds Creek Experimental Watershed facilities and infrastructure. Those two objectives provide fundamental verification and evaluation data for the third, modeling objective. In the first objective, we combine innovative application of eddy covariance in mountainous terrain with intensive measurement and modeling to evaluate the impacts of ongoing landscape (vegetation) change on the net ecosystem flux of water and CO2. In the second objective, we measure soil water and temperature, along with important climatic parameters, and simulate the water balance and plant production across the rain/snow transition elevation. The third objective focuses on integrated hydrologic modeling to assess the impact of climate warming and landscape change on the seasonal snow cover, soil moisture, groundwater recharge, evaporation and streamflow in mountainous terrain. Model development includes upscaling process models from research to management scales and extending the modeled features to improve management models. The second and third objectives include multi-location research projects in which hydrologic trends at Reynolds Creek are analyzed and compared in a broader, nationwide context. Replacing 5362-13610-008-00D (02/12)