Population viability analysis (PVA) is a powerful method for evaluating the probability of extinction in the face of variation, in contrast to traditional models such as the Leslie matrix that are strictly deterministic.  The influence of multiple types of variation can be examined with PVA, including differences in the values of population parameters, such as initial population sizes and birth or death rates, and differences in the way those parameters vary, including binomial or random distributions and bootstrapping of observed values.  The PVA extension to ArcView allows one to create life tables based on overall population parameters or utilize a fully populated life table to conduct multiple population simulations.   The program was designed as part of a tool kit for an individual based spatially explicit modeling toolkit to be used in ArcView.  As the PVA module is self contained and the modeling toolkit is still early in its development we have decided to release it as a separate extension.  Please use caution in interpreting the results of this program.  Individual routines have been tested against the same models in spreadsheet designs and other programs, but this PVA extension allows one to combine multiple complex simulations in ways that have not yet been thoroughly tested.

This extension, which is described in detail in the Fjord Oceanography Monitoring Handbook, was specially created for the Glacier Bay oceanography project, but is designed to be used with any oceanographic data set.  The program allows 3- and 4-D analysis and display of volumetric and time series oceanographic data.  It is the only tool available at the current time that allows integration of full-cast oceanographic data into a GIS system.  It has a special module for processing Sea-bird CTD data from the raw text form into a 3-D hierarchical spatial data set.  In addition, there are multiple tools for functions such as calculating photic depth, integrating chlorophyll-a, processing weather data, exporting and importing, aggregation, summarizing, etc.