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SE Alaska GIS User Group

The Spatial Analysis Discussion Group (SADG) is a collection of people in Juneau who share an interest in GIS or other spatial analysis topics. SEALAB coordinates a monthly speaker for the group to give a presentation on work they have done that has a spatial component. Past topics have ranged from kriging methods to avalanche forecasting and technical levels vary considerably.

Talks are generally held on the first Tuesday of every month at 12:00 pm.

Note:  This spring's Spatial Analysis Discussion Group series will meet at the Downtown Public Library, Large Meeting Room.

If you would like to present or have your name added to the SADG email list please contact us.

Note:  This spring's Spatial Analysis Discussion Group series will meet at the Downtown Public Library, Large Meeting Room.

Spatial Analysis Discussion Group, Fall 2014

Location: Downtown Public Library, Large Meeting Room
Schedule: First Tuesday of each month, 12:00-1:00 pm

Date: February 3rd 2015, 12:00 – 1:00 pm

Presenter: Frances Biles, Geographer, USFS PNW Forestry Sciences Laboratory

Title: A Mean High Water Composite Shoreline for Southeast Alaska


Shorelines are an essential base layer needed for maps and geospatial analyses.  MHW_Composite is a digital geospatial data set depicting a continuous mean high water (MHW) shoreline for southeast Alaska (SEAK) using the best available data. NOAA is the authoritative producer of shoreline products, however only about 2/3 of SEAK has been mapped by NOAA to date. MHW_Composite combines all the NOAA data into one map. Where NOAA shoreline data does not exist, the next-best available source is used. Where shoreline data is missing, or where precision or accuracy of existing data is exceedingly poor, new lines are digitized from high-resolution digital orthophotography.  MHW_Composite will be used to update the NHD and will also be available for download from the Southeast Alaska GIS Library.

Date: March 3rd 2015, 12:00 – 1:00 pm

Presenter: Bruce Simonson, GIS Manager, City and Borough of Juneau

Title:  CBJ’s 2013 Data Acquisition – Overview and Sample Analyses.


In the spring of 2013, the CBJ acquired a comprehensive dataset of orthoimagery and topography for much of the developable portions of the borough.  This presentation will showcase the 4 band aerial photography, LiDAR topography, associated DEMs, contours, and related data.  

Several examples of analysis will be offered using these datasets.

Date: April 7th 2015, 12:00 – 1:00 pm

Presenter: Carl Koch, Wildlife Biologist, Alaska Department of Fish and Game

Title: Resource Selection and Diet of martens on Kuiu Island


Theory predicts animals will select resources that benefit fitness. We investigated population dynamics, resource selection and diet by martens on Kuiu Island in southeast Alaska over a six year period. Using VHF telemetry data we developed a resource selection function (RSF) with program R and then assigned RSF scores to a predictive surface map (raster). The categorical variables used in the RSF models were: unproductive forest, timber volume classes, non-forested habitat, logged and thinned stands. The continuous variables were: elevation, distance from shore, stream density and edge density. The best RSF model according to AICc criteria contained the following variables: stream density, distance from shore, elevation and all three forest volume classes. We found that elevation had an especially strong negative coefficient while high-volume forest had a high positive coefficient. We also estimated a relative index of dietary biomass using Bayesian mixing models with stable isotope data. We found that salmon biomass occurred in very high proportions during all years of our study. Small mammal (especially vole) estimates were chronically low throughout our study. Seasonally available salmon carcasses are an important alternative food source in what is likely an otherwise food stressed marten population.

If you are interested in presenting at the Spatial Analysis Discussion Group, please send a short description or your presentation to our GIS Coordinator, Kim Homan at Additionally, if you would like more information about the SADG presentations or would like to be added to the email list, please contact us. 

December 2nd, 2014, 12:00 - 1:00 pm - Dave Gregovich, ADF&G Division of Wildlife Conservation
Raster processing and analysis in R.

Although R programming takes some time for familiarization, raster processing and analysis in the R environment can oftentimes be elegant and intuitive. Raster values are easily accessible, and raster math and reclassification are straightforward, with syntax that mimics that used for working with matrices and data frames. Raster stacks (= multiband rasters) allow relatively quick processing of spatially overlapping covariate data. The basics of working with rasters in R are illustrated, using the ‘raster’ package. Basic raster manipulations, including calculations within a raster and across the cells in a raster stack are presented. Conversion of vector data to raster format, and of R raster objects to external formats (eg. geoTiff, IMG, ESRI GRID) are performed. Some experience working in the R environment will be helpful to take advantage of this presentation. A laptop with R 3.0.3 and the ‘rgdal’ and ‘raster’ libraries installed will be handy but not absolutely necessary.

November 4th, 2014, 12:00  - 1:00 pm, Jason Waite, ADF&G Division of Wildlife Conservation
Estimating wolf and marten densities using spatially-explicit, capture-recapture (SECR) methods.

Spatially-explicit capture-recapture (SECR) models are an extremely useful and flexible extension of traditional capture-recapture methods for studying animal populations. Data sources can include live trapping, DNA sampling, acoustic recordings, proximity detectors (e.g., camera trapping), or any other related field method that record occurrences of known or identifiable individuals. Unlike traditional capture-recapture methods that provide only an estimate of population size of an ambiguous region, SECR methods provide estimates of animal density in a well-defined area of interest. Further, the spatial variation of density within this region can be modeled as a function of any number of spatial covariates, such as cover type, elevation, slope, or distance to road. The fundamentals of SECR analysis using both Bayesian and maximum-likelihood methods will be introduced, as well as some example applications of some simple SECR models to data from live-trapped marten and wolf DNA from hair snares.  Advanced extensions to the basic SECR models, including spatial covariates, custom detection functions, and cost surfaces will also be examined.

October 7th, 2014, 12:00  - 1:00 pm - Mark Riley, US Forest Service
5-meter IfSAR DEM to Augment Spectral Separability for Vegetation Mapping on the Copper River Delta.

A statewide contract to iteratively collect, process, and deliver 5-meter digital elevation models from airborne Interferometric Synthetic Aperture RADAR (IfSAR) has been underway for three years.  In 2013, the US Forest Service received delivery of this data set for the Copper River Delta area in South-central Alaska.  In a prior recent study, satellite-based ALOS Phased Array type L-band Synthetic Aperture RADAR (Palsar) was tested as an input component to the vegetation mapping process, and the overall effect on the vegetation mapping process was minimal, with primary differentiation influence only for mesic wet herbaceous types.  The finer spatial resolution and wavelength characteristics of contemporary airborne P- and X-band IfSAR show that it has potential, as an auxiliary input, to contribute substantially to a more accurate vegetation map by enhancing the spectral separability of more traditional passive sensor data.
This presentation will also provide an IfSAR delivery status update for Southeast Alaska.

Related Links: 

September 2nd, 2014, 12:00 -1:00 pm - Julie Nielsen and Andrew Seitz, UAF School of Fisheries and Ocean Sciences

Net Squared Displacement analyses: a new model selection framework for analyzing and categorizing animal movement patterns.

Researchers are able to obtain increasingly detailed information on the movement of many species thanks to advances in electronic tagging technology such as GPS and satellite tags. However, advances in development of methods for analysis of animal movement data have not been as rapid. We introduce a new framework for the analysis of animal movement data that is based on the Net Squared Displacement (NSD) statistic, which is derived from random walk theory. This simple analysis framework, which was developed during the study of moose migration in Scandinavia, allows the characterization and analysis of animal trajectories in terms of behavior such as migration, foraging, or home range occupation. In this talk, we will describe this new analysis method and provide examples of its application for the analysis of human and Pacific halibut movement in Alaska.

5/6/14 Christal Rose (USFS), A Map Tour of the National Forests in Alaska

4/8/14 Dave Gregovich (ADFG), Analysis of wildlife movement and space use in southeast Alaska: case studies from the cast of characters.

Southeast Alaska bears, goats, moose, elk, deer, wolves, and wolverines have been outfitted with GPS collars by Alaska Department of Fish and Game, Division of Wildlife Conservation (ADF&G-DWC) personnel to investigate spatial patterns of movement. This data can yield valuable information on habitat preference, extent of dispersal, and seasonal migration patterns, which can in turn inform responsible management of these species and their habitat. Additionally, the analytical results from one species can in turn be used to inform spatial models of one or more other species. Case studies highlighting the diversity of species, workflows, results, and implications of such analyses are presented.

3/4/2014 Quinn Tracy (CBJ) The role of GIS at the City and Borough of Juneau.  

2/4/2014 Tom Ainsworth (NOAA) Digital Weather Services in Southeast Alasa: how weather forecasting is changing and what it means for GIS applications.


2/6/13 Jason Amundson (UAS) Dynamics of Iceberg-Choked Fjords.

1/12/13 Ursula Jones (NWS) The importance of Weather Observations.

12/12/12 Jamie Womble (NPS): Unraveling the mystery of post-breeding season migration patterns of harbor seals from a marine protected area in Alaska.

11/7/12 Terri Morganson (ESRI): New imagery tools in arcgis 10.1.

10/17/12 Jason Siefert (SEALAB): Science at 90 degrees South.

9/4/12 David Gregovich (ADFG): Resource Selection Functions based on GPS telemetry data for multiple species.

4/12/12 Steve Lanwermeyer: The Marine Exchange of Alaska's vessel tracking network.

3/7/12 Kim Homan (SEAK GIS Library): Using Arcgis online to handle data.

2/1-3/12 Cross Boundary Data Integration Workshop II.

1/11/12 Ron Simenhoise (Kensington Mine): A new tool to forecast glide avalanches.

12/7/11 Mandy Lindeberg (NOAA): An overview of ShoreZone.

11/2/11 Richard Carstensen (TNC): Using the 1948 US Navy aerial photography to study succession in the Tongass.

10/19/11 Mayumi Arimitsu (USGS): Geostatistics and Spatial Point Pattern Analysis in Nearshore Areas Characterized by Convoluted Shorelines.

3/3/11 Dave Gregovich (USFW): GIS modelling of the projected effects of climate change on alpine patch distribution in southeast Alaska.

2/2/11 Julie Nielsen (UAF): Kriging methods.

12/1/10 Will Jensen (RDI): Web-based GIS services.

11/10/10 Sanjay Pyare (UAS): Bio-geographical patterns across the Alexander Archipelago and reconstruction of paleogeographic conditions that may have influenced landscape genetics.

10/6/10 Terri Morganson (ESRI): What's new with the ArcGIS10 software.

9/8/10 Julie Nielsen (UAF): Methods for analysis of fish movement.

8/5/10 Carl Dierking (NOAA): The PRISM spatial climate dataset.

6/3/10 Mike Plivelich (UAS): Overview of the SE AK GIS library at UAS. 

5/6/10 Erik Johnson (USFS): Southeast Alaska hydrographic data collaboration.

4/1/10 John Caouette (TNC): Conifer tree species distributions in Alaska's temperate rainforests.

3/4/10 Colin Shanley (TNC): On the development of a 3-tier nested estuarine classification for southeast Alaska.

2/4/10 Terry Schwarz (DNR): Analysis of select stream discharge models in southeast Alaska. 

12/9/09 Carl Dierking (NOAA): National Weather Service gridded weather analysis and forecasts. 

11/4/09 Mark Riley (USFS): SPOT HRS DEM Evaluation and Z accuracy comparison to ASTER GDEM and National Elevation Dataset (NED) for the Chugach National Forest.

9/30/09 Frances Biles (USFS): Watershed mapping across international boundaries.