2010 Annual Report 1a.Objectives (from AD-416) 1) Conduct detailed field experiments to quantify how fluxes of water and energy control snow accumulation and melt, and affect soil moisture, streamflow, and water supplies in western watersheds. 2) Develop methodology for detailed characterization of terrain and canopy structure over mountainous regions using high resolution LiDAR data. 3) Develop improved coupling of surface and below-ground models for spatial simulation of snowmelt, runoff, soil temperature and moisture, and streamflow. 4) Develop methodology for generating cold-season runoff distributions to improve RUSLE erosion predictions in agricultural regions dominated by winter snow and frozen soil. 5) Test and validate new instrumentation, databases, and model interfaces for use by the NRCS and other action agencies and potential users. 1b.Approach (from AD-416) (1) Five Eddy Co-variance systems will be deployed across a range of landscape and vegetation types to measure atmospheric fluxes over vegetation and snow. Within and above canopy radiation exchange, simulated by the SHAW model, will be tested using solar and long-wave radiation data collected for a variety of plant canopies (wheat, soybean, maize, and forest). ETRS integrated flux measurement systems will be established to accurately measure fluxes from the bedrock to the atmosphere. (2) LiDAR data will be acquired over a large area of southwestern Idaho, including RCEW, the Boise Front, and the Juniper Impact area of the Owyhee Mts. A voxel-based canopy model will be developed to estimate canopy transmissivity to direct and diffuse solar radiation and thermal radiation enhancement due to canopy emissivity and heating effects. The simulations will be validated against detailed sub-canopy radiation and canopy temperature measurements completed as part of Objective 1. (3)a. Detailed models of snow deposition, redistribution and melt, including adjustments for canopy effects will be scaled from plots the relatively small Reynolds Mountain, Upper Sheep Creek and Johnston Draw catchments and then scaled to the much larger Tollgate sub-basin. b. A spatially distributed soil water model will be used to simulate streamflow generation and plant water use for two water years for which extensive data have been collected. c. The hydrologic effects of fire will be evaluated at the Upper Sheep Creek catchment comparing historical, pre-fire data and validated modeling to and measured data and simulations following prescribed fire. (4) The SHAW model will be modified as necessary to accurately simulate frozen soil runoff. The model will then be applied for a series of climate and crop/residue cover scenarios to generate a distribution of runoff events to assess the influence of crop/residue cover on cold-season runoff to be incorporated in the RUSLE erosion model. (5) A state-of-the-art hydrological relational database that enhances user data accessibility will be developed and populated, the ISNOBAL snow accumulation and melt program will be incorporated into the NRCS OMS modeling system, and there will be continued work on snow water equivalent and soil water content measuring devises in cooperation with the NRCS.Replaces 5362-13610-006-00D (1/07). 3.Progress Report This project is based on experimental research, including instrument development, primarily in the field, and simulation of hydrologic processes. In terms of field research, this year we initiated new projects while maintaining numerous ongoing studies. Ongoing field studies include: monitoring post fire effects at the Breaks and Upper Sheep Creek fire sites, measurement of sap flux and soil water dynamics at Reynolds Mountain aspen site, measurement of CO2 and water vapor flux with eddy covariance at Upper Sheep Creek and Reynolds Mountain, and continued snow survey of different experimental sites. Northwest Watershed Research Center (NWRC) now has publications describing fluxes in mountainous terrain both during the winter and the growing season. NWRC has just completed the field research measuring vegetation production at sites, Reynolds Creek and Marble Creek in California. In terms of field instrumentation, NWRC installed 800 meters of fiber optic cable for soil spatially and temporally continuous measurement of soil temperature under a variety of environments at one site (Upper Sheep Creek) and have just begun the preliminary work to start a second, more extensive site (Johnston Draw). The data NWRC is collecting at Reynolds Creek are unique in terms of duration and range of conditions covered. This year NWRC has made considerable progress towards the goal of including updated and more extensive data in the National Science Foundation (NSF) sponsored Hydrologic Information System (HIS). NWRC has also analyzed soil water data between 1977 to present and have compiled a snow modeling data set from the data rich Reynolds Mountain for use in snow model testing. Hydrologic models, developed by NWRC have expanded considerably in application. The Simultaneous Heat and Water (SHAW) model applied to such problems related to permafrost infiltration and crop growth and was linked to the larger-scale Isnobal snow model. Two other major developments for Isnobal are the application to much larger scales, going from the Reynolds Mountain watershed to the Dobson Creek watershed, which represent more than a thirty fold increase in areal extent and a step towards working with even larger watersheds. The second major development is linking the Isnobal with the Penn State Integrated Hydrologic Model (PIHM), which allows for direct connection between simulated snow dynamics and resultant streamflow, which is really what most people are interested in. The field and simulation work we are doing was in collaboration with the University of Idaho, University of Saskatchewan, University of Reading, Penn State University, Utah State University, the Bureau of Land Management and the Natural Resource Conservation Service with the help of several local ranchers. 4.Accomplishments 1. SURFACE ENERGY, WATER, AND CARBON FLUXES QUANITIFIED FOR MOUNTAINOUS VEGETATION COMMUNITIES. Understanding the role of vegetation communities in modulating energy, water and carbon fluxes is critical to quantifying the variability in energy, carbon, and water balances across landscapes. ARS scientists at the Northwest Watershed Research Center in Boise, Idaho illustrated the influence of vegetation and site conditions on surface energy, water and carbon fluxes in mountainous headwaters catchments and demonstrate the utility of eddy covariance systems in quantifying the water balance of these complex mountainous watersheds. Scientists can capitalize upon these results to better describe and model these ecosystems and their response to climate change. 2. EFFECT OF CLIMATE CHANGE ON INTERMOUNTAIN HYDROLOGY. Increasing temperatures, declining snowpacks and earlier streamflow in snow fed streams have been linked in a variety of studies in the Western United States, but all those studies suffer from the fact that the different observations are from different locations, so that the linkage is always somewhat indirect. ARS scientists at the Northwest Watershed Research Center in Boise, Idaho analyzed forty-five years of air temperature, snow, precipitation and streamflow data measured at the same location, the Reynolds Creek Experimental Watershed. They demonstrated that, over the period of record, average air temperature has increased about 2 C, snow disappears more than a month earlier at lower elevations, and total annual precipitation has remained constant while streamflow occurs earlier in the season. This kind of information has major implications for reservoir management in the west, where the vast majority of agriculture is irrigated, because it demonstrates that current management approaches, which are based on the historic record, are inadequate. Review Publications Flerchinger, G.N., Xiao, W., Sauer, T.J., Yu, Q. 2009. Simulation of Within-Canopy Radiation Exchange. NJAS-Wageningen Journal of Life Sciences. 57:5-15. Weiss, A., Flerchinger, G.N., Mcmaster, G.S., Wang, E., White, J.W., Yin, X., Struik, P.C., Wienk, J.F. 2009. Recent Advances in Crop Growth Modeling, NJAS Wageningen Journal of Life Sciences, 57:3. Reba, M.L., Link, T.E., Marks, D.G., Pomeroy, J. 2009. An Assessment of Corrections for Eddy Covariance Measured Turbulent Fluxes Over Snow in Mountain Environments. Water Resources Research, 45, W00D38, doi:10.1029/2008WR007045. Kelleners, T.J., Chandler, D.G., Mcnamara, J.P., Gribb, M.M., Seyfried, M.S. 2009. Modeling the water and energy balance of vegetated areas with snow accumulation. Vadose Zone Journal, 8:1013-1030. Pomeroy, J., D. Marks, T. Link, C. Ellis, J. Hardy, A. Rowlands and R. Granger, 2009, The Impact of Coniferous Forest Temperature on Incoming Longwave Radiation to Melting Snow, Hydrological Processes, 23(1-2):2513-2525, doi: 10.1002/hyp.7325. Wang, H., Flerchinger, G.N., Lemke, R., Brandt, K., Goddard, T., Sprout, C. 2010. Improving SHAW Long-Term Soil Moisture Prediction for Continuous Wheat Rotations, Alberta, Canada. Canadian Journal of Soil Science, 90:37-53. Zhang, Y., S.K. Carey, W.L. Quinton, J.R. Janowicz, J.W. Pomeroy, and G.N. Flerchinger. 2010. Comparison of Algorithms and Parameterisations for Infiltration into Organic-Covered Permafrost Soils. Hydrology and Earth System Sciences, 14:729-750. Flerchinger, G.N., D. Marks, M.L. Reba, Q. Yu, and M.S. Seyfried. 2010. Surface Fluxes and Water Balance of Spatially Varying Vegetation within a Small Mountainous Headwater Catchment. Hydrology and Earth System Sciences. 14:965-978. Li, R., H. Shi, T. Akae, Y. Zhang, X. Zhang, G.N. Flerchinger. 2010. Scheme of Water Saving Irrigation in Autumn Based on SHAW Model in Inner Mongolia Hetao Irrigation District. Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering. 26(2):31-36. (Paper written in Chinese with English abstract). Sun, H., Y. Shen, Q. Yu, G. Flerchinger, Y. Zhang, C. Liu, X. Zhang. 2010. Effect of Precipitation Change on Water Balance and WUE of the Winter Wheat ––Summer Maize Rotation in the North China Plain. Agricultural Water Management, 97(8):1139-1145. Nayak, A., Marks, D.G., Chandler, D., Seyfried, M.S. 2010. Long-Term Snow, Climate and Streamflow Trends from at the Reynolds Creek Experimental Watershed, Owyhee Mountains, Idaho, United States. Water Resources Research,46, W06519, doi: 10.1029/2008WR007525. Logsdon, S.D., Green, T.R., Seyfried, M.S., Evett, S.R., Bonta, J.V. 2010. Hydra Probe and Twelve-wire Probe Comparisons in Fluids and Soil Cores. Soil Science Society of America Journal. 74:5-12.