Several generalized frequency distributions have been employed in environmental and water engineering over the years. These distributions are quite versatile and can apply to frequency analysis of a wide variety of random variables, such as flood peaks, volume, duration, and inter-arrival time; extreme rainfall amount, duration, spatial coverage, and inter-arrival time; drought duration, severity, spatial extent, and inter-arrival time; wind speed, duration, direction, and spatial coverage; water quality parameters; and sediment concentration, discharge, and yield. However, because of their relatively complex form, these distributions have not become as popular as the simpler distributions. These distributions have at least three but usually more parameters, which have been estimated using the methods of moments, maximum likelihood, probability weighted moments, and L-moments. In some cases, entropy theory has been used to estimate parameters. This chapter provides a snapshot of the generalized distributions that will be discussed in this book. Moreover, a short discussion of the methods of parameter estimation, goodness-of-fit statistics, and confidence intervals is provided.

The lessons from the previous chapters are here applied to a very brief discussion of numerical techniques. First we show how to calculate the capacitance of three-dimensional structures; we then follow this with similar calculations of inductance. Both of these are well defined in the long wavelength approximation. We then describe how a full wave numerical solutions can be implemented using the popular method-of-moments. We follow this by discussing how to implement excitations or wave ports and how to implement boundary conditions between different dielectric layers.