Location: Northwest Watershed Research Center
2024 Annual Report
Objectives
Objective 1) Develop improved snowmelt and streamflow forecasting tools.
Sub-objective 1A) Improve spatial representation of precipitation and solar radiation as snow model forcing data.
Sub-objective 1B) Develop and improve model linkages between spatially distributed snowmelt and streamflow generation.
Objective 2) Quantify and predict terrestrial ecosystem carbon dynamics, including rangeland productivity, soil respiration, carbon flux, and carbon sequestration in response to water availability and climate variability.
Sub-objective 2A) Identify and model linkages between climate variability, water availability, and primary productivity.
Sub-objective 2B) Improve understanding of soil carbon dynamics related to soil carbon sequestration.
Objective 3) Develop long-term observational data sets for climate, hydrology, vegetation, soils, geophysics, and water quality to make inferences about function, long-term productivity and sustainability of rangeland ecosystems that can be widely used in local, regional, and national models and in collaboration with the LTAR network.
Sub-objective 3A) Maintain and enhance long-term observational infrastructure for climate, hydrology, vegetation, soils, geophysics, and water quality in support of network wide LTAR collaborations and research community at large.
Sub-objective 3B) Quantify climate change effects on hydrology and the past, present, and future sustainability of rangeland ecosystems using the long-term dataset from RCEW.
Approach
Objective 1 builds on the snowmelt and streamflow forecasting advancements made with the iSnobal model during the last five-year project cycle that enabled near real-time snowmelt forecasting in support of operational water supply forecasting and water management. We will take a four-pronged approach to further improve operational streamflow forecasting: 1) We will take advantage of recent advances in estimating precipitation patterns and snow depth over mountainous areas from airplane overflights; 2) We will use satellite observations of solar reflectance, snow cover, and cloud cover to better estimate the solar energy absorbed by the snow; 3) We will develop approaches to estimate streamflow from simulated snowmelt using historical relationships between measured streamflow and simulated snow melt; and 4) We will couple the iSnobal model with an existing model that routes snowmelt water to the stream. In Objective 2, we will combine field observations and modeling tools to better understand and predict water and carbon dynamics in semi-arid rangeland ecosystems. Tools for quantifying and modeling vegetation productivity and carbon storage of sagebrush ecosystems will be developed, providing a better understanding of vegetation productivity and soil carbon sequestration in water-limited ecosystems. Research will capitalize on the network of research sites along an elevation/climate gradient within the Reynolds Creek Experimental Watershed (RCEW). Measurements include CO2 uptake and emission from plants and soil, weather observations, soil temperature/water/CO2 profiles, chambers that measure soil CO2 emission, etc. Annual vegetation surveys and cameras that track plant growth/phenology are available at three of the sites. Using the natural gradient in climate and productivity across the research sites presents a unique opportunity to study factors regulating carbon fluxes and productivity and observe changes in ecosystem function as climate and ecohydrological properties shift. Data will be used to test and improve existing models that simulate management and climate on vegetation productivity and carbon storage within the soil. In Objective 3, we will expand the scientific infrastructure of the RCEW to: 1) quantify offsite transfer of water and carbon in streams and groundwater; 2) measure changes in productivity and carbon cycling as sagebrush ecosystems transition to invasive annual grasses; and 3) support collaborations both within USDA-ARS, especially with the Long-Term Agroecosystem Research (LTAR) network, and with our University collaborators. We also take advantage of our long-term record to document ecohydrological change that has occurred in the past 60 years on the RCEW. Approaches that will be pursued if initial methods are unsuccessful include: 1) using alternative satellite products if the data from the aging MODIS satellite proves problematic, 2) using existing inhouse computational infrastructure if the coupled snowmelt-streamflow model does not lend itself to a High-Performance Cluster, 3) using a different model (UNSATCHEM) if soil inorganic process are significant and cannot be easily implemented into the SHAW model.
Progress Report
This report documents progress for project 2052-13610-015-000D, titled, “Ecohydrology of Sustainable Mountainous Rangeland Ecosystems”, which started in January 2022.
In support of Objective 1, a manuscript is in revision on catchment-scale hydrologic model calibration using electromagnetic induction surveys; a paper was resubmitted on snow water equivalent variability in the Tuolumne Basin; and a paper was published on improvements to solar radiation parameterization in the iSnobal model. A headwater stream gaging station that was lost to a fire in 2023 was replaced and instrumented for the 2024 water year. A master's student was selected as part of an ongoing agreement with Boise State University to assist model application.
For Objective 2, manuscripts have been submitted or are under revision on the following topics: modeling evapotranspiration and gross primary production of sagebrush ecosystems; landcover controls on ground freezing and groundwater recharge in permafrost; and coupling remote sensing and process modeling for simulation rangeland carbon dynamics. Preliminary analysis was conducted to evaluate soil respiration algorithms and parameter uncertainty.
Supporting Objective 3, manuscripts have been submitted on stream and ground water quality within the Reynolds Creek Experimental Watershed and the Great Basin Long-Term Agroecosystem Research (LTAR) Comment Experiment. The 40-year hydroclimate dataset of the Reynolds Creek Experimental Watershed was updated, quality controlled and distributed to a 10-m grid. Phenology camera, eddy covariance, and meteorological data have been submitted to colleagues within the LTAR network for papers on carbon cycling on grazed rangelands and a synthesis of the carbon dynamics and vegetation phenology across LTAR sites. The Johnston Draw prescribed burn was successfully completed in October 2023, and data were/are being collected in support of collaborative projects with colleagues at Idaho State University, Boise State University, University of Texas, El Paso, and Oregon State University. Snowmelt modeling strategies were developed in the Johnston Draw for pre- and post-burn conditions.
Accomplishments
Review Publications
Bonnell, R., McGrath, D., Hedrick, A., Trujillo, E., Meehan, T., Williams, K., Marshall, H., Sexstone, G., Fulton, J., Ronayne, M., Fassnacht, S., Webb, R., Hale, K. 2023. Snowpack relative permittivity and density derived from near-coincident lidar and ground-penetrating radar. Hydrological Processes. 37(10). Article e14996. https://doi.org/10.1002/hyp.14996.
Clark, P., Woodruff, C.D., Hedrick, A., Hardegree, S.P., Flerchinger, G.N. 2024. The LTAR Grazing Land Common Experiment at the Great Basin. Journal of Environmental Quality. 53(6):861-868. https://doi.org/10.1002/jeq2.20617.
Feng, S., Chen, J., Jones, S., Flerchinger, G.N., Dyck, M., Filipovic, V., Hu, Y., Si, B., Lv, J., Wu, Q., He, H. 2024. Miscellaneous methods for determination of unfrozen water content in frozen soils. Journal of Hydrology. 631. Article 130802. https://doi.org/10.1016/j.jhydrol.2024.130802.
Hardegree, S.P., Richards, C.M., Sheley, R.L., Reeves, P.A., Jones, T.A., Walters, C.T., Schantz, M.C., Flerchinger, G.N. 2024. Virtual reciprocal garden assessment of germination syndromes for Elymus elymoides ssp. brevifolius and Elymus multisetus. Rangeland Ecology and Management. 96:1-11. https://doi.org/10.1016/j.rama.2024.04.013.
Schlegel, M., Souza, J., Warix, S., MacNeille, R., Murray, E., Radke, A., Godsey, S., Seyfried, M., Finney, B., Flerchinger, G.N., Lohse, K. 2023. Seasonality and evaporation of water resources in Reynolds Creek Experimental Watershed and Critical Zone Observatory, Southwestern Idaho, USA. Vadose Zone Journal. 22(6). Article e20278. https://doi.org/10.1002/vzj2.20278.
Warix, S., Godsey, S., Flerchinger, G.N., Havens, S.C., Lohse, K., Bottenberg, H.C., Chu, X., Hale, R., Seyfried, M.S. 2023. Evapotranspiration and groundwater inputs control the timing of diel cycling of stream drying during low-flow periods. Frontiers in Water. 5. Article 1279838. https://doi.org/10.3389/frwa.2023.1279838.