Podcasts & Webinars

Webinar Chat Q&A Follow-Up:

Q1: What precipitation trends, if any, are you seeing during the winter months at your ARS site over time (from 1970s to present)?

A: In the Goodrich et al. 2008 paper non-summer (excludes July, Aug., Sept.) total for 1956 to 2006 are plotted but a specific trend test is not made. The plots exhibit high interannual variability. More on winter rain in the Osborn et al., 1979 paper (it is spatially much more uniform than summer ppt.) 
           Goodrich, D.C., Unkrich, C.L., Keefer, T.O., Nichols, M.H., Stone, J.J., Levick, L., Scott, R.L. 2008. Event to multidecadal persistence in rainfall and runoff in southeast Arizona. Water Resour. Res., 44, W05S14. 
           Osborn, H.B., Koehler, R.B., Simanton, J.R. 1979. Winter precipitation on a southeastern Arizona rangeland watershed. Hydrology and Water Resour. in Arizona and the Southwest, Office of Arid Land Studies, Univ. of Ariz., Tucson 9:15-50

Q2: What research might there be addressing how these increasing intensity of precipitation events effects recharge rates in water tables?

A: There is little to no recharge in upland (non-channelized non-concentrated) in hot arid and semi-arid valleys (Goodrich et al, 2004 and Walvoord references below). To the extent that increased rainfall intensities increase runoff there may be an increase in recharge from the ephemeral channels. Trends in runoff from the Walnut Gulch Experimental watershed are discussed in more detail in Goodrich et al., 2008
           Goodrich, D.C., Williams, D.G., Unkrich, C.L., Hogan, J.F., Scott, R.L., Hultine, K.R., Pool, D., Coes, A.L., Miller, S. 2004. Comparison of methods to estimate ephemeral channel recharge, Walnut Gulch, San Pedro River Basin, Arizona. In: Groundwater Recharge in a Desert Environment: The Southwestern United States, J.F. Hogan, F.M. Phillips and B.R. Scanlon (eds.), Water Science and Applications Series, Vol. 9, American Geophysical Union, Washington, DC, pp. 77-99.
           Goodrich, D.C., Unkrich, C.L., Keefer, T.O., Nichols, M.H., Stone, J.J., Levick, L., Scott, R.L. 2008. Event to multidecadal persistence in rainfall and runoff in southeast Arizona. Water Resour. Res., 44, W05S14. 
           Walvoord, M., A unifying conceptual model of water, vapor and solute movement in deep arid vadose zones, Ph.D. thesis, New Mexico Institute of Mining and Technology, 2002. 
           Walvoord, M., F.M. Phillips, S.W. Tyler, and P.C. Hartsough, Deep arid system hydrodynamics, Part 2: Application to paleohydrologic reconstruction using vadose-zone profiles from the Northern Mojave Desert, Water Resour. Res., 38, 1291, doi:10.1029/2001WR000925, 2002.

Q3: Do you have any experimental watersheds records or datasets across Texas and Oklahoma? Farming practices records or Climate parameters like P in these regions?

A: There are ARS Experimental Watersheds in Texas and OK. 
For more information of the ARS watersheds and where to obtain data from them see the two Goodrich et al. references below. Note that the ARS LTAR (Long-Term Agro-ecosystem Research) Network is organizing the data from the ARS experimental watershed in a more easily accessible form in the USDA Ag Data Commons.  Go to the data tap at the top of: https://ltar.ars.usda.gov/
           Goodrich, D.C., Heilman, P., Anderson, M.C., Baffaut, C., Bonta, J.V., Bosch, D.D., Bryant, R.B., Cosh, M.H., Endale, D.M., Havens, S.C., Hedrick, A., Kleinman, P.J., Langendoen, E.J., Marks, D.G., Rigby Jr., J.R., Schomberg, H.H., Starks, P.J., Steiner, J., Strickland, T.C., Veith, T. L. 2020. The USDA-ARS experimental watershed network evolution, lessons learned, societal benefits, and moving forward. Water Resources Research 57(2): e2019WR026473.
           Goodrich, D.C., Bosch, D., Bryant, R., Cosh, M.H., Endale, D., Veith, T., Kleinman, P., Langendoen, E., McCarty, G., Pierson, F., Schonbetg, H., Smith, D., Starks, P., Strickland, T., Tsegaye, T., Awada, T., Swain, H., Derner, J., Bestelmeyer, B., Schmer, M., Baker, J., Carlson, B., Huggins, D., Aqrchera, D., Armendariz, G.A. 2022. Long term agroecosystem research experimental watershed network. Hydrological Processes. 36(6). Article e14534.