Jozsef (Joe) Szilagyi

Jozsef (Joe) Szilagyi

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Title Research Hydrologist
Address 625 Hardin Hall
3310 Holdrege Street
Lincoln NE
Phone 402-472-9667 & 402-472-3471
FAX 402-472-2946
Vitae Download file
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Joe Szilagyi is a research hydrologist and professor in the School of Natural Resources. He is associated with SNR's water faculty and has been at UNL since 1997.

His main research interests include the interaction of surface water and groundwater, hydrological forecasting, regional-to-continental-scale analysis of the hydrologic cycle, and the effect of climate change on it. One of his current research projects involves estimating watershed-to-continental-scale evapotranspiration (ET) by standard meteorological measurements and 1-km resolution Moderate Resolution Imaging Spectroradiometer (MODIS) daytime land surface temperature data. Recent research involving estimating riparian ET from diurnal changes in the stream-flow rate and in the groundwater level are important to the state and nation. His work helps citizens, agricultural producers and decision makers understand how groundwater and surface water communicate with each other, and how ET is distributed in space over the watershed, which helps in local and catchment-scale water management tasks and irrigation-impact studies.

He also has an example of his work in regional ET estimation with CREMAP in this website site's data section.

Drought Year (2002)

The distribution of ET over the Elkhorn watershed in a drought (2002) year.

Wet Year (2007)

The distribution of ET over the Elkhorn watershed in a wet (2007) year.

The distribution of ET over the Elkhorn watershed in a drought (2002) and in a wet (2007) year. Note how the rangelands of the Sand Hills in the western part of the watershed become much drier in a drought year than the rest, mostly irrigated soybean and corn, of the catchment. Click on images to enlarge.

Selected Publications

Crago, R., Qualls, R., Szilagyi, J., Huntington, J. (2017). Reply to comment by Ma and Zhang on ‘Rescaling the complementary relationship for land surface evaporation'. Water Resources Research, 53, 2. Online
Szilagyi, J. (2017). On the Clark Unit Hydrograph Model of HEC-HMS. Periodica Polytechnica Civil Engineering, 62(1), 277-279. Online
Szilagyi, J., Crago, R., Qualls, R. J., 2017. A calibration-free formulation of the complementary relationship of evaporation for continental-scale hydrology, Journal of Geophysical Research-Atmospheres, 122, doi:10.1002/2016JD025611. Online
Ma, N., Szilagyi, J., Niu, G.-Y., Zhang, Y., Zhang, T., Wang, B., Wu, Y. 2016. Evaporation variability of Nam Co Lake in the Tibetan Plateau and its role in recent rapid lake expansion. Journal of Hydrology. 537:27-35. Online
Szilagyi, J. 2016. Recent trends in land surface evapotranspiration across the contiguous United States. Journal of Hydrology and Environment Research, 4, 33-40. Online
Szilagyi, J., Crago, R., Qualls, R. 2016. Testing the generalized complementary relationship of evaporation with continental-scale long-term water-balance data. Journal of Hydrology, 540:914-922. Online
Wang, T., Franz, T., Yue, W., Szilagyi, J., Zlotnik, V., You, J., Shulski, M., Young, A. 2016. Feasibility analysis of using inverse modeling for estimating natural groundwater recharge from a large-scale soil moisture monitoring network. Journal of Hydrology. 533: 250-265. Online
Ma, N., Zhang, Y., Szilagyi, J., Guo, Y., Zhai, J., Gao, H., 2015. Evaluating the complementary relationship of evapotranspiration in the alpine steppe of the Tibetan Plateau, Water Resources Research. 51: 1069-1083. Online
Ma, N., Zhang, Y., Xu, C-Y., Szilagyi, J., 2015. Modeling actual evapotranspiration with routine meteorological variables in the data scarce region of the Tibetan Plateau: comparisons and implications, Journal of Geophysical Research Biogeosciences, 120, 1-20, Online
Szilagyi, J. (2015). Comment on “Revised coefficients for Priestley-Taylor and Makkink-Hansen equations for estimating daily reference evapotranspiration” by N.C. Cristea, S.K. Kampf, and S. J. Burges, published in Journal of Hydrologic Engineering, 18(10), 1289-1300. Journal of Hydrology and Environment Research, 3(1), 67-70.
Szilagyi, J. (2015). Water balance validation of a temperature dependent parameter value of the Priestley-Taylor equation of evapotranspiration. Journal of Hydrology and Environment Research, 3(1), 1-5.
Szilagyi, J. 2015. Complementary-relationship-based 30 year normals (1981–2010) of monthly latent heat fluxes across the contiguous United States. Water Resour. Res., 51, 9367– 9377, doi:10.1002/2015WR017693. Online
Szilagyi, J., 2015. Complementary-relationship-based 30-year normals (1981-2010) of monthly latent heat fluxes across the contiguous United States, Water Resources Research, 51: 9367-9377. Online
Gates, J. B., Steele, G. V., Nasta, P., Szilagyi, J., 2014. Lithologic influences on groundwater recharge through incised glacial till from profile to regional scales: Evidence from glaciated Nebraska, Water Resources Research, 50, 1-16,
Rossman, N. R., Zlotnik, V. A., Rowe, C. M., Szilagyi, J., 2014. Vadose zone lag time and potential 21st century climate change effects on spatially distributed groundwater recharge rates in the semi-arid Nebraska Sand Hills, Journal of Hydrology, 519, 656-669. Online
Szilagyi, J. (2014). MODIS-aided water-balance investigations in the Republican River basin, USA. Periodica Polytechnica-Civil Engineering, 58(1), 33-46. Online
Szilagyi, J. (2014). Testing the rationale behind an assumed linear relationship between evapotranspiration and land surface temperature. Journal of Hydrologic Engineering. 20.
Szilagyi, J., 2014. Temperature corrections in the Priestley-Taylor equation of evaporation, Journal of Hydrology, 519, 455-464. Online
Szilagyi, J., Laurinyecz, P. (2014). Accounting for back-water effects in flow routing by the Discrete Linear Cascade Model. Journal of Hydrologic Engineering, 19(1), 69-77. Online
Szilagyi, J., Parlange, M. B., Katul, G. G. (2014). Assessment of the Priestley-Taylor parameter value from ERA-Interim global reanalysis data. Journal of Hydrology and Environment Research, 2(1), 1-7.
Szilagyi, J., Schepers, A., 2014. Coupled heat and vapor transport: the thermostat effect of a freely evaporating land surface, Geophysical Research Letters, 41(2), 435-441. Online
Gribovszki, Z., Kalicz, P., Szilagyi, J. (2013). Does the accuracy of fine-scale water level measurements by vented pressure transducers permit for evapotranspiration estimation? Journal of Hydrology, 488, 166-169. Online
McMahon, T., Peel, M., Szilagyi, J. (2013). Comment on the application of the Szilagyi–Jozsa advection–aridity model for estimating actual terrestrial evapotranspiration in “Estimating actual, potential, reference crop and pan evaporation using standard meteorological data: a pragmatic synthesis” by McMahon et al. (2013). Hydrology and Earth System Sciences, 17, 4865-4867.
Szilagyi J., Jozsa, J. 2013. MODIS-aided statewide net groundwater-recharge estimation in Nebraska, Ground Water, 51(5), 735-744, Online
Szilagyi J., Zlotnik, V., Jozsa, J. 2013. Net recharge versus depth to groundwater relationship in the Platte River Valley of Nebraska, USA, Ground Water, 51(6), 945-951 Online
Szilagyi, J. (2013). Application of MODIS-based evapotranspiration rates in runoff modeling: a case study in Nebraska, USA. Open Journal of Modern Hydrology, 3, 172-178.
Szilagyi, J. (2012). Comment on ’Assessing interannual variability of evapotranspiration at the catchment scale using satellite-based evapotranspiration data sets’ by Cheng et al. Water Resources Research, 48.
Szilagyi, J., Kovacs, A., Jozsa, J. (2012). Estimation of spatially distributed mean annual recharge rates in the Danube-Tisza interfluvial region of Hungary. Journal of Hydrology and Hydromechanics, 60, 64-72.
Huntington, J., Szilagyi, J., Tyler, S., Pohll, G., 2011. Evaluating the Complementary Relationship for estimating evapotranspiration from arid shrublands, Water Resources Research, 47. Online
Szilagyi, J., Jozsa, J., 2009. An evaporation estimation method based on the 2-D turbulent heat and vapor transport equations, Journal of Geophysical Research-Atmospheres, 114: D06101, doi:10.1029/2008JD010772. Online
Szilagyi, J., Jozsa, J., 2009. Complementary relationship of evaporation and the mean annual water-energy balance, Water Resources Research, 45, W09201, doi:10.1029/2009WR008129. Online
Szilagyi, J. 2005. Discrete state-space approximation of the continuous Kalinin-Milyukov-Nash cascade of noninterger storage elements. Journal of Hydrology. 328(1-2):132-140.
Szilagyi, J., Harvey, F. E., Ayers, J. F., 2003 (RS-307). Regional Estimation of Base Recharge to Ground Water Using Water Balance and a Base-flow Index. Ground Water 41:504-513. Online
Szilagyi, J. 2002. Comment on "The hydrology and hydrometeorology of extreme floods in the Great Plains of Eastern Nebraska" by Y. Zhang, J.A. Smith, and M.L. Baeck. Advances in Water Resources. 25(6):701-702.
Szilagyi, J. 2002. Vegetation indices to aid areal evapotranspiration estimations. Journal of Hydrologic Engineering. 7(5):368-372. Online
Szilagyi, J., Harvey, F. E., Ayers, J. F. 2002. Mapping Recharge to Groundwater in Nebraska and Mapping Base Recharge to Groundwater in Nebraska. Map. No Scale. Lincoln: Conservation and Survey Division, University of Nebraska. Print.
Szilagyi, J., Harvey, F.E., Ayers, J.F. 2002. Regional Estimation of Base Recharge to Ground Water Using Water Balance and a Base-Flow Index. Ground Water. 41(4):504-513.
Szilagyi, J., Parlange, M.B., Pats, J.A., Graczyk, T.K. 2002. Sensitivity of watershed runoff under humid conditions to potential climate variations. Journal of Environmental Engineering. 128(7):635-642.
Parlange, J.Y., Stagnitti, F., Heilig, A., Szilagyi, J., Parlange, M.B., Steenhuis, T. S., Hogarth, W.L., Barry, D.A., Li, L. 2001. Sudden drawdown and drainage of a horizontal aquifer. Water Resources Research. 37(8):2097-2101. Online
Summerside, S.E. Ponte, M., Dreeszen, V.H., Hartung, S.L., Khisty, M.J., Szilagyi, J. 2001 Update and Revision of Regional 1x2 Degree Water-Table Configuration Maps for the State of Nebraska. Conservation & Survey Division, University of Nebraska - Lincoln
Summerside, S.E., Szilagyi, J. 2001. Configuration of Water Table, Circa 1995 (Valentine). Map. [1:250,000]. Configuration of Water Table, Circa 1995 Series. Lincoln: Conservation and Survey Division, University of Nebraska. Print.
Szilagyi, J. 2001. Identifying the cause of declining flows in the Republican River, USA. Journal of Water Resources Planning and Management. 127(4):244-253. Online
Szilagyi, J. 2001. Modeled areal evaporation trends over the conterminous United States. Journal of Irrigation and Drainage Engineering. 127(4):196-200.
Szilagyi, J. 2001. On Bouchet's complementary hypothesis. Journal of Hydrology. 146:155-158. Online
Szilagyi, J., Katul, G.G., Parlange, M.B. 2001. Evapotranspiration intensifies over the conterminous United States. Journal of Water Resources Planning and Management. 127(6):354-362. Online
Szilagyi, J. 2000. Can a vegetation index be indicative of areal transpiration? Ecological Modeling. 127:65-79.
Szilagyi, J. 1999. On the Use of Semi-Logarithmic Plots for Baseflow Separation. Ground Water 37(5):3. Online
Szilagyi, J., M.B. Parlange 1999. A Geomorphology-based Semi-distributed Watershed Model. Advances in Water Resources 23(0):9. Online
Szilagyi, J., M.B. Parlange 1999. Defining Watershed-scale Evaporation Using a Normalized Difference Vegetation Index. Journal of the American Water Resources Association 35(5):11. Online
Szilagyi, J., D.C. Rundquist, D.C, Gosselin, and Parlange, M.B. 1998. NDVI Relationship to Monthly Evaporation. Geophysical Research Letters 25(10):1753-1756. Online
Szilagyi, J., D.C. Rundquist, D.C. Gosselin, and M.B. Parlange 1998. NDVI relationship to monthly evaporation. Geophysical Research Letters. 25:1753-1756. Online
Szilagyi, J., M.B. Parlange, J.D. Albertson. 1998. Recession Flow Analysis for Aquifer Parameter Determination. Water Resources Research 34(7):7. Online
Szilagyi, J., M.B. Parlange. 1998. Baseflow Separation Based on Analytical Solutions of the Boussinesq Equation. Journal of Hydrology 204(0):10.

Educational Background

  • MS - Eotvos University, Hungary, Meteorology (1989)
  • MS - University of New Hampshire, Hydrology (1994)
  • PhD - University of California-Davis, Hydrologic Sciences (1997)

SNR Program Area(s)

  • Environmental Science

Affiliations (index)

Professional Organizations

  • American Geophysical Union
    • member Since 1995
  • European Geophysical Union
    • Member 2003

Notable Websites

Areas of Interest

  • Linear systems in hydrology
  • Hydrological forecasting
  • Flow routing
  • Evaporation/ET
  • Watershed hydrology
  • Stream-aquifer interactions.
  • Freshwater
  • Surface and Groundwater

Currently this page only displays grants that were awarded on 1/1/2009 to the present. If a grant was awarded prior to 1/1/2009 and is still active, it will not be displayed on this page.

There no Grants found for this selection.

Graduate Program(s)

Master of Science in Natural Resource Sciences

Doctor of Philosophy in Natural Resource Sciences