areas of expertise, Dr. Victor Miguel Ponce, hydrology, hydrologic engineering



  • Hydraulic design of open channels

    2016:   The inherently stable channel with online computation.

    The inherently stable channel is reviewed, elucidated, and calculated online. The asymptotic neutrally stable Froude number for the inherently stable channel is Fns. Theoretically, such a channel will become neutrally stable when the Froude number reaches infinity. Since the latter is a physical impossibility, this requirement effectively guarantees that the inherently stable channel will always remain well below the threshold of instability, regardless of flow discharge, thus completely eliminating the possibility of roll wave formation.

    Inherently stable channel

    Cunge portraits

  • Online numerical hydraulics

    2016:   Muskingum-Cunge amplitude and phase portraits with online computation.

    A comprehensive review of the amplitude and phase portraits of the Muskingum-Cunge method of flood routing is accomplished. Expressions for the amplitude and phase convergence ratios R1 and R2, respectively, are developed as a function of: (a) spatial resolution L/Δx; (b) Courant number C; and (c) weighting factor X. It is concluded that the Muskingum-Cunge routing model is a good representation of the physical prototype, provided: (1) the spatial resolution is sufficiently high, (2) the Courant number is close to 1, and (3) the weighting factor is high enough, better if in the range 0.3 ≤ X ≤ 0.5. Two online calculators of the convergence ratios are developed and tested.

  • Field research in ecohydrology

    2016:   The Linear Oasis:  Ecohydrology of Red Shank.

    The presence of soil moisture gradients in otherwise similar patches of ground has been documented by measurements in the community of Tierra del Sol, in southeast San Diego County, California. These gradients may be explained by leakage from the underlying fractured rock aquifer. In all probability, leakage proceeds along planes of fracture, with a clear linear tendency. The red shank species (Adenostoma sparsifolium) has morphological and other phenological traits which strongly suggest adaptability to shallow, more or less permanent, substrate moisture. This fact explains the substantial differences between the two lone congeners: (a) red shank, which presents itself with taller specimens in the immediate vicinity of the fractures, and (b) chamise (Adenostoma fasciculatum), which is known to colonize much drier patches of ground. Thus, the rationale for the linear oasis, which owes its existence to groundwater exfiltration along linear paths. The oasis is able to sustain an arborescent shrub such as red shank, whose water affinities lie loosely in between those of the xerophytes and the mesophytes.

    Impact of Soitec Solar projects

    Upper Paraguay River at Porto Murtinho, Brazil

  • Ecohydroclimatology

    2014:   Ecohydroclimatological research: The case for geomorphology.

    In Nature, everything is related. The Earth's crust and its environment, including climate, water, soils, nutrients, flora and fauna interact with each other in time and space in endless and demonstrably self-perpetuating ways. In the meantime, humans have endeavored to explore Nature by dividing it into convenient fields. This approach has given way to several natural sciences, among them, geology, geomorphology, climatology, hydrology, and ecology. Over the past two centuries, the development of scientific fields has produced a wealth of knowledge. This knowledge has been forthcoming, but it has been at the expense of the holistic view.

  • Sustainability of groundwater

    2013:   Impact of Soitec Solar projects on Boulevard and surrounding communities, San Diego County, California.

    The planned industrial-scale development of solar energy in Boulevard and surrounding communities is likely to permanently change the essentially rural character of these East San Diego County communities. While the negative impacts of energy development will be felt locally, its benefits will accrue somewhere else, very likely in distant urban settings. Boulevard has an arid climate, with limited precipitation, an avowed scarcity of surface water, and often highly destructive floodwaters. Over the years, the lack of reliable surface water has forced local people to rely on groundwater for their survival.

    Impact of Soitec Solar projects

    Upper Paraguay River at Porto Murtinho, Brazil

  • Flood hydrology

    2013:   Comparison of two types of Clark unit hydrograph.

    Clark's original unit hydrograph and Ponce's somewhat improved version are explained and compared. Clark's procedure routes, through a linear reservoir, a discrete unit-runoff hyetograph, while Ponce's procedure routes a continuous unit hydrograph. Since the unit hydrograph has a longer time base than the unit-runoff hyetograph, Ponce's procedure provides a somewhat smaller peak discharge and a longer time lag than Clark's. The difference, however, does not appear to be substantial.

    Shu'luuk Wind Project: Comments - Water Issues

  • Sustainability of groundwater

    2013:   Shu'luuk Wind Project: Comments - Water Issues.

    The proposed project involves the construction, installation and operation of 54 to 85 wind turbines to generate electricity, with the actual number to depend on the alternative selected. The use of water in the region is likely to change substantially when industrial-scale projects start to share the already scarce resource.

  • Sustainability of groundwater

    2012:   Thompson Creek groundwater sustainability study.

    The groundwater resources of Thompson Creek, in Poway, California, are limited and not readily replenishable. Existing hand-dug wells indicate that the water table was higher, i.e., much closer to the surface, prior to the extensive groundwater development of the past 15 to 20 years. Aquifer depletion amounts to as much as 280 feet in certain areas.

    Sustainability of groundwater

    Environmental impact assessment

  • Environmental impact assessment

    2010:   Comments to Campo Landfill DSEIS.

    The siting of the proposed Campo landfill: (a) on top of a fractured rock aquifer of uncertain characterization, (b) on the headwaters of Lower Campo Creek, (c) within close reach of the groundwater, and (d) in a region subject to strong earthquakes, poses a high risk of contamination of groundwater, of difficult and costly mitigation.

    Flood hydrology

  • Flood hydrology

    2009:   Cascade and convolution.

    The methods of cascade of linear reservoirs and unit hydrograph convolution are shown to be one and the same when the cascade parameters are used to calculate the unit hydrograph of the convolution.

    Water quality

  • Water quality

    2008:   Online DO sag analysis.

    Minimum dissolved oxygen concentration and its location along a given stream, in response to an input effluent biochemical oxygen demand and a ratio of effluent discharge to stream discharge.

    River mechanics

  • River mechanics

    2008:   The Lane relation revisited.

    A dimensionless formulation of the Lane relation of fluvial hydraulics. The new criteria enables improved assessment of aggradation and degradation.

  • Sediment transport

    2008:   Total sediment discharge by the Modified Einstein Procedure.

    Online calculation of Modified Einstein Procedure (1955). This online script will accept sediment data input and calculate total sediment load, including measured and unmeasured load, and bed material and wash load.


  • Groundwater hydrology

    2007:   Sustainable yield of ground water.

    Assessment of groundwater potential from a hydrologic perspective. Criteria is developed to determine sustainable yield as a fraction of mean annual recharge.