Dr. Victor Miguel Ponce's significant research accomplishments are in the fields of unsteady flow in open channels, overland flow, flood routing, dam-breach flood wave propagation, drought characterization, hydroclimatology, and groundwater sustainability. In 1977, he published, with [the late] D. B. Simons, a paper in which he solved, for the first time, the Saint Venant equations using linear stability theory. This enabled the description of the whole spectrum of unsteady flow phenomena, from kinematic to dynamic waves. For this work, the authors were awarded the [National] ASCE Karl E. Hilgard Hydraulics Prize in 1979.

The dimensionless relative wave celerity across the dimensionless
wavenumber spectrum in unsteady open-channel flow.

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The following year, Dr. Ponce published a paper in which he used his 1977 findings to establish, for the first time, limits for the applicability of kinematic and diffusion models of unsteady flow in open channels. This work has been widely quoted in the literature. Also in this year, he published a paper, with [the late] V. Yevjevich, in which he improved the Muskingum-Cunge method of flood routing by extending it to the nonlinear domain.

The criterion for applicability of the diffusion wave model.

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The diffusion wave model has been at the center of Dr. Ponce's research for many years. In 1986, he published a paper in which he applied, for the first time, the diffusion wave model to the overland flow problem. In this work, he developed the routing coefficient C3 applicable to the lateral-inflow term. This concept was later adopted by the HEC-1 (in 1990) and HEC-HMS (in 1998) models of the U.S. Army Corps of Engineers. In 1989, Dr. Ponce's extensive research and teaching experience led to the publication of the textbook entitled Engineering Hydrology, Principles and Practices (Prentice Hall). This book is used as a reference by hydrologic engineers all over the world. In addition, the book has the most comprehensive online resources available anywhere.

The C3 routing coefficient in diffusion-wave overland flow modeling.

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In 1990, Dr. Ponce published the first comprehensive review of baseflow augmentation by streambank storage. Since then, this work has become required reading for those involved in baseflow recovery and stream/watershed restoration, and in the nascent field of ecohydrology. A showcase project on baseflow augmentation is represented by Camp Creek, in Eastern Oregon, which has continued to recover after appropriate fencing limited creek grazing (http://campcreek.sdsu.edu).

Camp Creek under recovery, as seen in May 2004.

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In 1991, Dr. Ponce published a paper in which he expressed, for the first time, the hydraulic diffusivity as a function of the Vedernikov number, extending the work of Dooge and his collaborators to the realm of dynamic waves. In the same year, he reviewed the concept of kinematic wave in a comprehensive paper entitled "The kinematic wave controversy." This paper has been widely quoted in the literature. In 1995, he published two papers, with A. V. Shetty, in which he coupled L'vovich's water balance additive model with the SCS rainfall-runoff model, leading to a conceptual model to predict runoff and baseflow coefficients for basin yield applications.

The dynamic hydraulic diffusivity as a function of the Vedernikov number.

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In 1996, Dr. Ponce teamed up with Dr. Pete Hawkins, from the University of Arizona, to publish a comprehensive review paper on the SCS runoff curve number. This paper is required reading for professionals wishing to take an in-depth look at the methodology developed by [the late] Vic Mockus and his associates in the 1950s. In the same year, Dr. Ponce managed to get Vic out of his self-imposed isolation, and interviewed him prior to writing the closure of his paper. This is the only time when Vic spoke on the record about the widely used methodology.

The water balance coefficients across
the climatic spectrum.

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In 1997, Dr. Ponce published a paper in which he extended Budyko's hydroclimatological model of the hydrologic cycle. The introduction, for the first time, of the water-vapor discharge coefficient and moisture-recycling coefficient, including their variation across the climatic spectrum, allowed an improved understanding of the hydrologic cycle across the climatic spectrum, from superarid to superhumid regions. In 2000, he published a paper in which he developed, for the first time, a conceptual framework for drought characterization across the climatic spectrum. This work enabled the definition of intensity-duration-frequency relations for droughts.

The conceptual model of drought characterization
across the climatic spectrum.

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In 2003, Dr. Ponce published a theoretical paper in which he showed, for the first time, that flooding resulting from dam breaching will reach the same stage at a certain distance downstream, regardless of the magnitude of the breach hydrograph. This "ultimate distance" is shown to be a function of the channel hydraulics. Given that dam-breach failures remain a possibility around the world, the findings of this paper are of significant practical value.

The dimensionless flood-wave propagation following
a postulated dam-breach failure.

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Dr. Ponce's continued commitment to international hydraulic and hydrologic research spans almost four decades, beginning in 1976 with his work on the meandering patterns of the Link Canals of the Indus Basin, Pakistan. In 1979, he developed an upland routing model for the Upper Paraguay river, in Mato Grosso, Brazil. Several years later, in 1995, this experience uniquely qualified him to undertake the hydrologic impact study of the proposed Parana-Paraguay waterway. In 1986, he developed a routing model for water management in the São Francisco river, in Brazil, and in 1989, a sediment routing model for the Pirai river, in Santa Cruz de la Sierra, Eastern Bolivia. In 1992, he performed catchment routing studies on the Malaprabha river, in Karnataka, South India. In the past few years, he has performed extensive research on several streams in Baja California, including Alamar, El Barbon and Tecate. In 2008 and 2009, Dr. Ponce completed hydrologic and environmental studies for the La Leche river flood control project, in northern Peru.

Digitally enhanced image of the Campo landfill-Tierra del Sol site.

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In 2006, Dr. Ponce completed a white paper on groundwater utilization and sustainability and a study of the hydrologic impact of the proposed Campo landfill on the hydrology of the Tierra del Sol watershed, in San Diego County. In 2007, he completed a white paper entitled Sustainable yield of ground water, which led to The facts about groundwater sustainability and Who owns the groundwater? In 2010, he completed Comments to the Draft Supplemental EIS for the proposed Campo landfill. In 2012, he completed the Thompson Creek groundwater sustainability study, which pioneered the evaluation of groundwater sustainability beyond the conventional hydrogeologic perspective. In 2013, he completed a study of the cumulative impacts of water resources of large-scale energy projects in Boulevard, San Diego County, California.

Geometric model of a groundwater reservoir.

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In 2008, Dr. Ponce implemented the first online version of USBR's Modified Einstein Procedure for the computation of total sediment load. This is the only sediment transport method that computes both bed material and wash load, and both measured and unmeasured sediment loads, by individual size fractions. The online program is open to the world at-large.

U.S. DH-48 depth-integrated suspended wading-type sediment sampler.

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In 2009, Dr. Ponce introduced the concept of Pubs + Cals, which consists of online publications featuring online calculations, i.e., publications where calculations can be made as the article is being read. Eightteen (18) Pubs+Calcs have been posted to date.

The Apple iMac, the Visualab's media development workstation.

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In 2009, Dr. Ponce inaugurated the domain all.sdsu.edu, which features online videos for diverse applications, including teaching, research, and service. The videos, three-hundred and ten (310), open to the world at-large, run on a media server (ion), which is hosted by the Visualab. To enhance accessibility by a global audience, the Visualab videos are also posted on YouTube.

To this date, Dr. Ponce and his associates have developed three-hundred and thirty-nine (339) online computer programs for a variety of hydraulic and hydrologic applications, including closed-conduit flow, open-channel flow, water-surface profiles, evapotranspiration, routing, sediment transport, and water quality. The most computationally intensive of these programs, Online DO Sag Analysis, performs about 30 million computations in a few seconds, and runs on three (3) mirrored data servers. These programs, open to the world at-large, are available at http://onlinecalc.sdsu.edu.

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The Visualab's HP Proliant D385 G7 server

The Visualab's SPARC T4-1 public server (pon ≡ ponce)

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