Rogalus M.J.,McLane Environmental LLC. |
Ogden F.L.,University of Wyoming
World Environmental and Water Resources Congress 2011: Bearing Knowledge for Sustainability - Proceedings of the 2011 World Environmental and Water Resources Congress | Year: 2011
Statistical analyses were performed on five years of WSR-88D weather radar-rainfall estimates that were produced for the Global-Continental scale International Project (GCIP) over the entire Mississippi River basin covering the period 1996-2000. The GCIP data were adjusted using an altered Z-R relation to improve performance at the time scale of individual storms. The accuracy of radar-rainfall estimates were analyzed considering a number of factors including: number of overlapping radar(s), distance from nearest radar to gage, elevation of the gage, and the geographic location of the radar. Additionally, estimation of the bias between radar and gage-rainfall in areas without gages was assessed. Results show that the dominant factor affecting the accuracy of radar rainfall estimates is the number of overlapping radars, and the estimation of the bias in radar pixels without gage data can be approximated with a non-overlapping gage with varying levels of accuracy. © 2011 ASCE.
Rogalus III M.J.,McLane Environmental LLC. |
Ogden F.L.,University of Wyoming
Journal of Hydrologic Engineering | Year: 2013
Statistical analyses were performed using five years (1996-2000) of Weather Surveillance Radar-1988 Doppler (WSR-88D) weather-radar rainfall estimates that were produced for the Global-Continental Scale International Project over the entire Mississippi River basin. The project radar rainfall estimates were adjusted using a Z-R relation optimized to improve performance at the time scale of individual storms. The accuracy of radar-rainfall estimates were analyzed during the warm season considering a number of factors, including number of overlapping radars, distance from gauge to nearest radar, gauge elevation, and the geographic location of the radar. Results were used to identify optimal radar-rainfall estimation areas (ORREAs) within the Mississippi River basin with high correlation between storm-total radar and rain gauge rainfall. Additionally, estimation of the bias between storm-total radar-rainfall and rain gauge rainfall accumulations in areas without gauges was assessed to identify the appropriateness of applying bias adjustments derived from gauge data at points away from those rain gauges. © 2013 American Society of Civil Engineers.
Hunt R.J.,McLane Environmental LLC. |
Luchette J.,McLane Environmental LLC. |
Schreuder W.A.,Principia Mathematica |
Rumbaugh J.O.,Environmental Simulations Inc. |
And 4 more authors.
Ground Water | Year: 2010
Groundwater models can be improved by introduction of additional parameter flexibility and simultaneous use of soft-knowledge. However, these sophisticated approaches have high computational requirements. Cloud computing provides unprecedented access to computing power via the Internet to facilitate the use of these techniques. A modeler can create, launch, and terminate " virtual" computers as needed, paying by the hour, and save machine images for future use. Such cost-effective and flexible computing power empowers groundwater modelers to routinely perform model calibration and uncertainty analysis in ways not previously possible. Journal compilation © 2010 National Ground Water Association.
Fitts C.R.,McLane Environmental LLC. |
Godwin J.,University of Southern Maine |
Feiner K.,University of Southern Maine |
Mclane C.,University of Southern Maine |
Mullendore S.,McLane Environmental LLC.
Groundwater | Year: 2015
This paper presents the analytic element modeling approach implemented in the software AnAqSim for simulating steady groundwater flow with a sharp fresh-salt interface in multilayer (three-dimensional) aquifer systems. Compared with numerical methods for variable-density interface modeling, this approach allows quick model construction and can yield useful guidance about the three-dimensional configuration of an interface even at a large scale. The approach employs subdomains and multiple layers as outlined by Fitts (2010) with the addition of discharge potentials for shallow interface flow (Strack 1989). The following simplifying assumptions are made: steady flow, a sharp interface between fresh- and salt water, static salt water, and no resistance to vertical flow and hydrostatic heads within each fresh water layer. A key component of this approach is a transition to a thin fixed minimum fresh water thickness mode when the fresh water thickness approaches zero. This allows the solution to converge and determine the steady interface position without a long transient simulation. The approach is checked against the widely used numerical codes SEAWAT and SWI/MODFLOW and a hypothetical application of the method to a coastal wellfield is presented. © 2014, National Ground Water Association.