Analysis of Proposed Electric Power Transmission Line Corridor

This project involved analyzing the suitability of a proposed power line transmission construction corridor across several metrics. The corridor's interaction with conservation lands, with residences and with schools were all looked at with an eye toward minimizing its impact upon them while also limiting the construction costs for the transmission line as much as feasible while still respecting the other constraints.

• Bobwhite Manatee Transmission Line Corridor Selection & Proofing Project [Powerpoint File]

• Slide Breakdown to accompany powerpoint presentation

Georeferencing & ArcScene

This week's primary assignment involved taking aerial photos that had absolutely no geographical reference metadata, importing them into ArcGIS and georeferencing them with existing map data. This was familiar territory for me, as this has been the main activity I've done with GIS software as an archaeologist. I was provided with two rasters that showed portions of the UWF campus as well as projected vector files for campus buildings and roads. By associating points on the rasters with points in the vector layers, I rectified the raster layers in short order, getting them aligned with their vector counterparts. The rasters were in fairly good order, so there was not a lot of error in their placement, even though one of the rasters had been deliberately warped to make georeferencing it somewhat more complicated.

A secondary task this week was to produce an exaggerated 3D style map based on the georeferenced map I created using ArcScene.

Georeferenced UWF Campus Map

UWF 3D Map

Case Study for GIS in the Utility and Communications Industry

Over the past 3 weeks, I've been part of a working group that gathered and summarized several case studies in GIS implementation for the utility and communications industries.

I looked specifically at the case of the DuPage Water Commission

When the commission started looking to GIS an alternative to paper mapping and institutional memory when it came to keeping track of its assets and resources, the established solutions for water utilities were found to be inappropriate. Ultimately, the DWC found a useful model that scaled well to their needs from another industry, the ArcGIS Pipeline Data Model.

Geocoding & Route Mapping

This week I was given a set of addresses and was required to geocode them, i.e. associate them with their proper locations on a map. In order to do so, I downloaded the TIGER/Line file from the U.S. Census Bureau for Lake County, FL, which is where the addresses were located. The TIGER/Line file is a topologically correct vector line dataset for streets and addresses in the U.S., which means that the dataset is made up of edges (usually road segments) and junctions (crossroads) such that a path or paths can be calculated from one junction to another. The TIGER/Line file also associates house numbers with street segments, as well as zip codes and a wealth of other addressing data.

To geocode my set of addresses, I ran a geocoding tool in ArcGIS, which correctly placed 68% of the addresses. A 32% miss rate is not acceptable, so I had to look at the addresses that went unmatched and manually locate them (with the help of google maps in this case). I was able to do this successfully with all but one address that seemed to have been misspelled, leaving me with a 95% success rate, which was good enough for the purposes of this exercise.

With my geocoded data, I was then able to use ArcGIS' Network Analyst tool to do some simple routing analysis, creating a route based on three arbitrarily selected road stops. A route was then created that minimized travel time and hit all three stops.

Optimal Routing Example for Lake County, FL

Vector Analysis Mapping

This week, I got a chance to practice with the vector analysis tools in GIS in order to produce a map that depicts the goldilocks zones for camping in a portion of DeSoto National Forest in Mississippi. Given vector maps of roads, water features and conservation zones in the study area, I was tasked with mapping out areas that were no less than 300 meters from a road, either 150 meters from a lake or 500 meters from a river and which were not within designated conservation areas.

To produce a layer with polygons that met these criteria I used ArcGIS' tools for creating buffers and overlays. Firstly, I created polygon features of buffers around the road and water features, designating the buffers as listed above in the buffer tool. Once I had separate buffer layers for roads and for water features, I was able to use the overlay tool to create a layer based on the intersection of the buffer layers, i.e. another polygon layer that only had features where BOTH buffer layers covered an area. Once I had that, I then used the erase tool to remove any portions of the intersection layer that intersected with anything within the conservation areas feature I was provided.

Ultimately, what I produced amounted to (300 meter buffer around roads) AND (150 meter buffer around lakes/500 meter buffer around rivers) BUT NOT (within conservation area).

Once I had created that feature, representing the most suitable places to camp in the study area, I created a simple map of the area, which is below.

Suitable Camping Sites in SW Perry County, MS

Data Collection

This assignment required us to find GIS data on our own. We were each assigned a particular Florida county and required to find a range of mapping data that covered that county. There were 9 types of data that were required. Once found, we had to integrate all of that data in no more than three maps.

The challenges if this assignment were, firstly to be able to find all of this data. Florida does have GIS clearinghouses online that provide a wealth of GIS data, but searching for particular datasets is still rather tricky. Secondly, all the data needed to be transformed so that all shapefiles and rasters had the same projection coordinate system, and would thereby line up properly.

The search for data was complicated two main factors. First, while GIS datasets themselves are (hopefully) created with a great deal of metadata that lays out important information - such as datums, coordinate systems, dates that the data was collected and so on - the websites that provide searchable indices for data do not themselves have much in the way of search oriented metadata that would make searching for datasets fairly easy. Searching on these sites called to mind search engines from the mid-nineties before Google revolutionized search. Second, learning the jargon based search terms that produce the desired result is a skill that has to be learned. Progress was made on that front, but the bare bones search features provided by data providers is a problem that should be addressed.

The data transformation, by comparison, was relatively easy. All the data collected was based on the same datum, so transformation was fairly straightforward. Once all the data files were assessed as to their extant projection and datum, there were easily transformed.

From there it was simply a matter of creating maps that included all this data. As the assignment was primarily about gathering and preparing data, the cartographic phase of this assignment was slighted to some degree, especially as there were a lot of busy data layers to crowd into three maps.

Basic Road and Town Map of Hillsborough, FL

Hydrography of Hillsborough, FL

Vegetative Land Cover for Hillsborough, FL

Acquiring Data & Standardizing Projection Coordinate Systems

Continuing last week's focus on projection systems, this week we were required to acquire map data from a variety of sources and integrate them into a single map document after ensuring that all the shape files and raster data involved were projected onto the same projection coordinate system. This also included adapting a spreadsheet that contained spatial and attribute data so that it could be successfully imported and projected by ArcGIS. This file had latitude and longitude coordinates for petroleum storage tanks in Escambia County in degrees/minutes/seconds format, which ArcGIS cannot recognize. So, within the spreadsheet, columns were added that converted the d/m/s coordinates into decimal degrees, which ArcGIS can use. Once this was done, the file could be imported and then converted into a shape file. This was then used along with aerial photos and vector files - for Florida's counties, major roads, and the Florida Department of Environmental Protection's digital orthophoto quadrant map - to create the map below, which shows the locations and types of petroleum tanks in two quadrants located in Escambia County.

Petroleum Storage Tanks in South Escambia County, FL

Projections & Projection Coordinate Systems

This week's assignment dealt with identifying and transforming projections and projection coordinate systems of map data so that data from different sources with differing projections (and sometimes unidentified projections) can be integrated accurately. My primary task was to take a shapefile with data provided with in an Albers Equal Area PCS format and to transform it (locally only, within the .mxd file I used for the project) to two other projection coordinate systems (while all three maintained the same geographic coordinate system and datum).

The resulting map shows all three coordinate sytems' version of Florida and its counties. Four counties were selected, and their areas calculated in each coordinate system in square miles, highlighting the differences between the systems. As two of the systems were created for the north and western portions of Florida (UTM 16 & State Plane Florida, North), they tended to have more distortion of areas calculated for counties in the southeast as compared to those in the northwest of the state.

Florida Displayed in Three Different Coordinate Systems

ArcGIS Online & Map Packages.

This week's exercise for Intro to GIS involved making use of ESRI's online map sharing functionality. I updated my existing ESRI account to ESRI's online training materials and worked through the basics of two of ESRI's online courses. The first exercise (yosemite_operational_data) involved creating a small map that I posted up on ESRI's web mapping site. The second (tree_basemap) covered the creation of a map package that was uploaded to ESRI's site and made public. Such packages allow the sharing of maps, including their operational data, so that they can be used accessed and used by peers or by the public to do spatial analyses, update attributes or simply navigate via the map.

yosemite_operational_data

tree_basemap

GIS & Cartography

This week, the assignment spanned three maps and stretched current skills while introducing new ones. One map involved using a raster Digital Elevation Model (the topo map), one dealt with managing multiple layers with a great deal of overlapping data (and having those only display specified data, while the third involved creating a new shapefile via selection of specific data.

Own Your Map

This week's Intro to GIS assignment focussed on creating a professional looking map layout. The process of creating the map per the instructions was designed to provide practice with the ArcGIS layout tools as well as manipulating data frames and layers.

Behold! A very basic chloropleth map based on country population as of 2007.

Introduction

I'm here by way of Providence, RI, where I recently got back into IT with a unix sysadmin gig that I'm doing to get out of the debt I've accumulated since I got my masters in landscape archaeology back in 2008.  Since then, I've had the privilege of digging in London and Iceland for a bit before I had to move back to the States.  I'm hoping to get into a fully funded PhD program in a couple of years, although I wouldn't be all that broken up if I just ended up working for a CRM firm instead.

I've been interested in GIS since I started the process of switching careers from IT to archaeology, but didn't get the kind of in depth GIS training I'd expected from my Masters program, so I thought the archaeology track here looked like a good option (especially since I couldn't find any appealing GIS programs near where I am).