Photo of Alfonso Mejia

Alfonso Mejia

Associate Professor


  • Civil and Environmental Engineering

215B Sackett Building


Personal or Departmental Website

Research Areas:

Water Resources Engineering

Interest Areas:

Hydrology, floods and droughts, hydrometeorology, urban-water systems, water resources sustainability, ecohydrology




  • BS, Civil and Environmental Engineering, University of Maryland, 1999
  • MS, Civil and Environmental Engineering, Colorado State University, 2006
  • Ph D, Civil and Environmental Engineering, University of Maryland, 2009


Book, Chapters

  • Y Guo, P Daeryong, A Mejia, J Gironas and L Roesner, 2017, Urban Hydrology: Probabilistic Models for Urban Stormwater Management, Chapter 9 in Probability Distribution Functions in Hydrology (ASCE monograph)
  • A Mejia, T. Jovanovic and S. Pavlovic, 2016, Orinoco River Basin, Chapter 95 in Handbook of Applied Hydrology, McGraw-Hill, New York, NY, pp. 95.1-95.5

Journal Articles

  • X. Yang, S. Sharma, R. Siddique, S. Greybush and A Mejia, 2017, "Postprocessing of GEFS reforecasts over the U.S. middle Atlantic region", Monthly Weather Review, 145, (5), pp. 1641–1658
  • C Ahams, Willa Paterson, S Garcia, R Rushforth, B Ruddell and A Mejia, 2017, "Water footprint of 65 mid- to large-sized U.S. cities and their metropolitan areas", Journal of the American Water Resources Association
  • H. Kreibich, T. Krueger, A. Van Loon, A. Mejia, J. Liu, H. McMillan and A. Castellarin, 2017, "Scientific debate of Panta Rhei research – how to advance our knowledge of changes in hydrology and society?", Hydrological Sciences Journal, 62, (3), pp. 331-333
  • S. Sharma, R. Siddique, N. Balderas, Jose D Fuentes, Seann Reed, Peter Ahnert, Robert Shedd, Brian Astifan, Reggina Cabrera, Arlene Laing, Mark Klein and A Mejia, 2017, "Eastern U.S. verification of precipitation forecasts", Weather and Forecasting, 32, (1), pp. 117–139
  • R. Siddique and A. Mejia, 2017, "Ensemble streamflow forecasting across the U.S. middle Atlantic region", Journal of Hydrometeorology, 18, (7), pp. 1905–1928
  • P. Sanzana, J. Gironas, I Braud, F Branger, F Rodriguez, X Vargas, N Hitschfeld, J F Munoz, S Vicuna, Alfonso Mejia and S Jankowfsky, 2017, "A GIS-based urban and peri-urban landscape representation toolbox for hydrological distributed modeling", Environmental Modeling and Software, 91, pp. 168–185
  • T. Jovanovic, S. García, H. Gall and A. Mejia, 2016, "Complexity as a streamflow metric of hydrologic alteration", Stochastic Environmental Research and Risk Assessment, pp. 1-13
  • H McMillan, A Montanari, C Cudennec, H Savenije, H Kreibich, T Krueger, J Liu, A Mejia, Anne Van Loon, H Aksoy, G Di Baldassarre, Y Huang, D Mazvimavi, M Rogger, B Sivakumar, T Bibikova, A Castellarin, Y Chen, D Finger, A Gelfan, D M Hannah, A Y Hoekstra, H Li, S Maskey, T Mathevet, A Mijic, A Pedrozo-Acuna, M J Polo, V Rosales, P Smith, A Viglione, V Srinivasan, E Toth, R van Nooyen and J Xia, 2016, "Panta Rhei 2013-2015: Global perspectives on hydrology, society and change", Hydrological Sciences Journal, 61, (7), pp. 1174-1191
  • S Pavlovic, S Perica, M. St Laurent and A Mejia, 2016, "Intercomparison of selected fixed area areal reduction factor methods", Journal of Hydrology, 537, pp. 419-430
  • T. Jovanovic, A. Mejia, H. Gall and J. Gironas, 2016, "Effect of urbanization on the long-term persistence of streamflow records", Physica A: Statistical Mechanics and its Applications, 447, pp. 208–221
  • W. Paterson, R. Rushforth, B. L Ruddell, M. Konar, I C Ahams, J. Gironas, A. Mijic and A. Mejia, 2015, "Water footprint of cities: A review and suggestions for future research", Sustainability, 7, (7), pp. 8461-8490
  • A Mejia, F Rossel, J Gironas and T Jovanovic, 2015, "Anthropogenic controls from urban growth on flow regimes", Advances in Water Resources, 84, pp. 125-135
  • R. Siddique, A. Mejia, J. Brown, S. Reed and P. Ahnert, 2015, "Verification of precipitation forecasts from two numerical weather prediction models in the middle Atlantic region of the USA: A precursory analysis to hydrologic forecasting", Journal of Hydrology, 529, (3), pp. 1390–1406
  • A Mejia, E Daly, F Rossel, T Jovanovic and J Gironas, 2014, "A stochastic model of streamflow for urbanized basins", Water Resources Research, 50, (3), pp. 1984–2001
  • F J Rossel, J Gironas, F Mejia, F Rodriguez and A Rinaldo, 2014, "Spatial characterization of catchment dispersion mechanisms in an urban context", Advances in Water Resources, 74, pp. 290-301
  • A I Mejia, 2013, "Assessment of hydrologic controls on the applicability of routing methods", Journal of Hydrologic Engineering, 18, (8), pp. 948-957
  • A I Mejia, 2013, "Scaling of the network instantaneous response function from basin geomorphology and hydraulic geometry", Journal of Hydrologic Engineering, 18, (12), pp. 1786-1789
  • A I Mejia and S M Reed, 2011, "Evaluating the effects of simplified routing and parameterized cross section shapes with a coupled distributed hydrologic and hydraulic model", Journal of Hydrology, 409, (1-2), pp. 512-524
  • A I Mejia and S M Reed, 2011, "Role of channel and floodplain cross-section geometry in the basin response", Water Resources Research, 47, (9), pp. 1-15
  • A I Mejia and G E Moglen, 2010, "Impact of the spatial distribution of imperviousness on the hydrologic response of an urbanizing basin", Hydrological Processes, 24, (23), pp. 3359–3373
  • A I Mejia and G E Moglen, 2010, "Spatial distribution of imperviousness and the space-time variability of rainfall, runoff generation, and routing", Water Resources Research, 46, (7), pp. 1-14
  • A I Mejia and G E Moglen, 2009, "Spatial patterns of urban development from optimization of flood peaks and imperviousness-based measures", Journal of Hydrologic Engineering, 14, (4), pp. 416-424
  • A I Mejia and J D Niemann, 2008, "Identification and characterization of dendritic, parallel, pinnate, trellis, and rectangular drainage networks based on deviations from planform self-similarity", Journal of Geophysical Research, 113, (F2), pp. 1-21

Research Projects

Honors and Awards


Service to Penn State:

Service to External Organizations:




The Penn State Civil and Environmental Engineering Department, established in 1881, is internationally recognized for excellence in the preparation of undergraduate and graduate engineers through the integration of education, research, and leadership.

Department of Civil & Environmental Engineering

212 Sackett Building

The Pennsylvania State University

University Park, PA 16802-1408

Phone: 814-863-3084