Comprehensive regional rainfall frequency analysis for the 14 basins of the South Florida Water Management District.  This study is a simple but comprehensive presentation of frequency statistics defined in several forms for each of the 14 basins to aid planners, engineers, scientists and water managers with critical rainfall statistics.

Used 145 rainfall stations with continuous records to provide frequency evaluation and spatial characterization of rainfall in Central and South Florida. Point frequency analysis performed at all available sites has identified 2-parameter Gamma probability density function to be the best model for monthly rainfall frequency. Estimated rainfall frequency estimates are used to provide spatial maps.  Experimental variograms were computed and theoretical variograms were fitted and subsequent Kriging was applied to produce frequency and variance maps.   The results show that the existing rain gage network is inadequate to resolve rainfall variation in the wet season compared to the dry season.

A point frequency analysis of daily rainfall maxima for central and south Florida was performed on a uniform grid of 2 miles by 2 miles resolution. All available gaging stations throughout the study region were used to estimate the time series of annual maxima for each grid cell universal Kriging.  The 2-parameter lognormal probability distribution was found to be universally suitable distribution to represent rainfall maxima for 1-day, 3-day, and 5-day durations corresponding to return periods: 2, 5, 10, 25, 50, and 100 years. A preliminary quality control procedure was performed to ensure that the new methodology produced a reasonable estimate of the storms with the three different durations and for the various return periods. The procedure involved cross verification of the estimated rainfall against frequency analysis of the rainfall at 69 gaging stations. The resulting dataset of the three rainfall durations and the various return periods have been used for event simulations in hydrologic modeling.

A subsurface characterization tool for alluvium deposit aquifer in complex parts of Salt Lake and Ogden Valley Reservoirs for the Division of Water Rights, DWR, state of Utah, UT.  The tool uses innovative kernel estimator and nonhomogeneous Markov chain to provide the probability that a particular area has high or low conductivity using borehole data.  The tool provides alternative to Indicator Kriging when the environment is nonstationary.  Soils are classified through a binary indicator system defined as 0 for low and as 1 for a high conductivity soil. The tool has helped water and environmental managers to identify preferential pathways of contaminant transport from Sharon steel chemical site to nearby water supply wells.

Using a total of 860 stations of daily rainfall data spread throughout central and South Florida with discontinuous records from 1914 to 2005; the objective is to prepare one standard rainfall input file for all distributed and lumped parameter hydrologic and ecologic models for that area. Tasks for this study ranged from Double Mass Curve Analysis and Custer Analysis to Principal Components Analysis and Variogram Analysis.  We used innovative Triangular Irregular Network along with local pixel partition for a smoother spatial characterization of daily rainfall.

This 3 day intensive course in Geostatistics teaches the student the basics of variogram analysis, Kriging of several types, Co-Kriging.  This is a hands-on interactive course with real life application to rainfall and other environmental data.

The iModel©, an inverse modeling tool, reverses the process of traditional (direct) models by estimating system’s required input to achieve a system’s desired response.  The iModel© consists of a group of superfast utility units that can represent individual wetland/reservoir hydrologic and environmental system dynamics in infinitesimal time compared to the traditional models (Ali 2009). It employs two primary stochastic optimization engines (Genetic Algorithm and Pattern Search). Such a utility guides an efficient utilization of the available water for a better flow delivery (quantity and timing) to ENP and WCA3B to achieve desirable environmental benefits while maintaining flood control and water supply requirements. This solution can be in the form of time series for planning purposes and operational protocol for real time operations.