http://students.uwf.edu/emv5/IntroGIS/4043FinalProjectPresWeblink.ppsx
http://students.uwf.edu/emv5/IntroGIS/4043FinalProjectPresentText.pdf
The above are links to my final project- an assessment of the ways in which GIS can be used in planning a route through Manatee and Sarasota counties for FPL's new Bobwhite-Manatee Transmission Line, and what effects the line's route may have on local residents and the environment. Included also is an estimate of the line's length, and its potential cost.
GIS is an integral tool for planning construction projects like this. A 25 mile 230kV transmission line running through 2 very densely populated counties in south Florida is a huge project to undertake. The route must be strategically planned, so that it doesn't effect too many local residents, and also shouldn't put too much stress on potentially fragile environments. The potential route also must be accurately measured, so that an estimate of cost can be made.
All of the above objectives can only be completed with the assistance of GIS. Maps can be used as powerful visual aids to convey some concern or idea, and can also be used to perform various analyses essential to the transmission line route's planning and construction.
Showing posts with label GIS4043. Show all posts
Showing posts with label GIS4043. Show all posts
Monday, April 27, 2015
Saturday, April 11, 2015
Georeferencing and Editing Data
The term "georeferencing" may not mean much to most people, but it's a pretty important concept for those of us working with GIS. Aerial photos, images of the earth's surface taken remotely, can really only be of use in GIS if they are an accurate spatial representation- otherwise they're really just photos. These raster images can be lined up with an accurate map using control points, and linking places on the aerial photo with places on the map, and thereby stretching and warping the raster graphic as necessary to be spatially correct.
The aerial images on the left side, the north and south portions of the UWF campus, were georeferenced to a vector base map of campus buildings and roads. The text in the upper left corner of the northern photo, and the lower left corner of the south, details the root mean square error of the polynomial transformation. This measure can be lowered by manipulating the control points used to align the aerial photo with the accurate map. Control points create a more accurate transformation when they are placed as far from one another, and in as many different portions of the map as possible. The 2 labeled features- the campus gym and Campus Lane- are edits, added to their respective vector dataset feature classes by the addition of a polygon and a line. These differ from a simple polygon and line drawn on the map in that they are spatially referenced, and their shapes and attributes are actually added to the datasets permanently. The eagle nest location on the right has 2 buffer zones added around it, which represent a conservation easement around the point feature.
The aerial images on the left side, the north and south portions of the UWF campus, were georeferenced to a vector base map of campus buildings and roads. The text in the upper left corner of the northern photo, and the lower left corner of the south, details the root mean square error of the polynomial transformation. This measure can be lowered by manipulating the control points used to align the aerial photo with the accurate map. Control points create a more accurate transformation when they are placed as far from one another, and in as many different portions of the map as possible. The 2 labeled features- the campus gym and Campus Lane- are edits, added to their respective vector dataset feature classes by the addition of a polygon and a line. These differ from a simple polygon and line drawn on the map in that they are spatially referenced, and their shapes and attributes are actually added to the datasets permanently. The eagle nest location on the right has 2 buffer zones added around it, which represent a conservation easement around the point feature.
Monday, March 30, 2015
Geocoding and Network Analysis (and bus maps I never figured out how to make)
I, like most people, have a GPS application on my phone, and when I need to find directions I put in the address and go. Google Maps does the heavy lifting for me. What exactly goes into finding an address though? The process, in reference to GIS, is called geocoding, and it is used in conjunction with network analysis to plan optimal routes for applications in things like EMS and public transportation.
Geocoding addresses is tantamount to querying a database and spatially locating locations associated with house/building numbers, streets and zip codes. The address locator itself is quite customizable though, and can be modified according to the format of the input addresses. The Network Analyst extension in ArcGIS can then be used to create a map like the one above on the left- which depicts a route from an address (11 Yorkshire Drive) to another location. The useful thing about the brown line and the numbered points in that map is that they are more than just graphics of a line and some dots- they are actually recognized by the program as an interconnected route and stops. Several years ago I had a GIS position with county transit, and created bus maps. I remember drawing lines and points on a map as graphics, and cursing my inability to get the lines and points to "recognize" one another as stops and routes. Clearly this would have been the ideal solution for that problem.
Geocoding addresses is tantamount to querying a database and spatially locating locations associated with house/building numbers, streets and zip codes. The address locator itself is quite customizable though, and can be modified according to the format of the input addresses. The Network Analyst extension in ArcGIS can then be used to create a map like the one above on the left- which depicts a route from an address (11 Yorkshire Drive) to another location. The useful thing about the brown line and the numbered points in that map is that they are more than just graphics of a line and some dots- they are actually recognized by the program as an interconnected route and stops. Several years ago I had a GIS position with county transit, and created bus maps. I remember drawing lines and points on a map as graphics, and cursing my inability to get the lines and points to "recognize" one another as stops and routes. Clearly this would have been the ideal solution for that problem.
Tuesday, March 24, 2015
Vector Data Analysis
Analysis of various datasets is a central component in the use and power of GIS as a scientific tool, and is an area that my skills are admittedly a bit limited. Very "entry-level" GIS positions, such as the ones I've held, don't really require the use of these types of analyses, and are mainly centered on the creation of maps as purely visual tools. GIS has a plethora of applications and methods of analysis though, and I look forward to learning more about them in earning this degree.
As a basic introduction to spatial analysis, this map was fairly simple to create. The idea was to produce an output of locations within the above area in DeSoto National Forest in Mississippi that meet some criteria as potential campground sites. The locations had to be within a certain distance of roads and water, and could not overlap a mapped set of "conservation area" locations. ArcGIS, as mentioned previously, includes a wide range of tools to solve this type of problem, including processes to create buffer zones (to isolate locations within specified distances of features), and also tools to further narrow the selection of areas to those meeting multiple criteria. This week's assignment even gave an introduction to creating programming script, using the programming language Python, to run multiple processes at once on various datasets. To be perfectly candid, the notion of writing computer code is a bit intimidating, but (as with most things) starting small and simple, as we did here, definitely reduces some of the anxiety. I believe I may be safe in saying that at this point I am ready, willing and able to begin learning the advanced functions of a GIS.
As a basic introduction to spatial analysis, this map was fairly simple to create. The idea was to produce an output of locations within the above area in DeSoto National Forest in Mississippi that meet some criteria as potential campground sites. The locations had to be within a certain distance of roads and water, and could not overlap a mapped set of "conservation area" locations. ArcGIS, as mentioned previously, includes a wide range of tools to solve this type of problem, including processes to create buffer zones (to isolate locations within specified distances of features), and also tools to further narrow the selection of areas to those meeting multiple criteria. This week's assignment even gave an introduction to creating programming script, using the programming language Python, to run multiple processes at once on various datasets. To be perfectly candid, the notion of writing computer code is a bit intimidating, but (as with most things) starting small and simple, as we did here, definitely reduces some of the anxiety. I believe I may be safe in saying that at this point I am ready, willing and able to begin learning the advanced functions of a GIS.
Monday, March 2, 2015
Searching for Data
We have arrived at the middle of the term, which I was surprised to learn, as it feels like it just started. This is, without question, always the case when one is working too hard to pay attention to these matters. At any rate, mid-term is a perfect excuse for a difficult project, and in that regard the past two weeks did not disappoint. The task assigned was a minimum of one, and a maximum of three, maps with a list of required data- which was to be obtained in the form of free downloads from various government and non-profit websites. Finding the correct data was one thing, putting it together into a cohesive map was quite another.
The first map (top) contains vector data- files with information in the form of points, lines and polygons- and the second (bottom) includes 2 raster graphics- a Digital Elevation Model (the left dataframe) and a digital orthoquad aerial photo (on the right). I lost track of the amount of time I spent creating these maps, but I will estimate that it was quite a bit. I was able to locate all of the data on FGDL.org and LABINS.org, and downloaded it free of charge, but that was definitely the easy part. The plethora of data that's available isn't much help in the way of telling one how to actually use and display said data. The various combinations of layers in the above maps are datasets that I felt would present some spatial data in an interesting way- like the aerial photo on the right in the bottom map, which is overlaid with some data on high flood potential.
In the process of creating the above I can certainly say I downloaded and reviewed a virtual bevvy of interesting spatial data on various geographic phenomena in the state of Florida. There are shapefiles, aerial photos and digital terrain models aplenty on the internet for making maps, provided one takes the necessary time to seek them out and review their contents. That was another important concept of this project- reading metadata and considering the who, when and why of the data's actual collection. Apart from appropriate citation of data sources, this information can assist in decisions regarding accuracy and temporal validity of the spatial data itself. Searching, finding and using appropriate data that is available for various mapping projects is a worthy and important lesson for any aspiring GIS professional, and working on these maps for the past couple of weeks provided no shortage of opportunity to internalize this fact firsthand.
The first map (top) contains vector data- files with information in the form of points, lines and polygons- and the second (bottom) includes 2 raster graphics- a Digital Elevation Model (the left dataframe) and a digital orthoquad aerial photo (on the right). I lost track of the amount of time I spent creating these maps, but I will estimate that it was quite a bit. I was able to locate all of the data on FGDL.org and LABINS.org, and downloaded it free of charge, but that was definitely the easy part. The plethora of data that's available isn't much help in the way of telling one how to actually use and display said data. The various combinations of layers in the above maps are datasets that I felt would present some spatial data in an interesting way- like the aerial photo on the right in the bottom map, which is overlaid with some data on high flood potential.
In the process of creating the above I can certainly say I downloaded and reviewed a virtual bevvy of interesting spatial data on various geographic phenomena in the state of Florida. There are shapefiles, aerial photos and digital terrain models aplenty on the internet for making maps, provided one takes the necessary time to seek them out and review their contents. That was another important concept of this project- reading metadata and considering the who, when and why of the data's actual collection. Apart from appropriate citation of data sources, this information can assist in decisions regarding accuracy and temporal validity of the spatial data itself. Searching, finding and using appropriate data that is available for various mapping projects is a worthy and important lesson for any aspiring GIS professional, and working on these maps for the past couple of weeks provided no shortage of opportunity to internalize this fact firsthand.
Sunday, February 15, 2015
Map Projections, la deuxième partie
I seem to recall saying something last week about finally truly understanding the various concepts of map projection, and how projections and coordinate systems are handled in a GIS. This week I learned I was wrong. The bravado caused by my hubris was a preemptive celebration, and, though I came to a much, much better understanding of projections and coordinate systems with this week's work, I now know that I've only seen the tip of the iceberg. I also had the opportunity this week to search for and download some public GIS data, in the form of shapfiles and aerial photos, which was something I'd only ever dabbled in before.
This map is comprised of 2 ortho quads (each made with 4 quarter sections), created by the USGS, and 3 different vector datasets- Florida county boundaries, major roads, and USGS quad boundaries. The vector line data was in a different coordinate system than the aerial photos, and had to be reprojected in ArcMap to the State Plane Florida North system. The files would have appeared correctly together in the map document if added together in different coordinate systems, but there would be a loss of functionality- which is something I have personally encountered in ArcMap, and never knew how to "fix" it. It isn't enough to merely describe the coordinate system in the metadata, ArcMap has to actually change and export the file in a different projection. The process itself is easy enough, but the theory behind it was a definite challenge for me. I did, after many hours of work, finally get a decent grasp on the general concepts and theory that exist, and run in the background, to accurately display the 3 dimensional earth on a 2 dimensional surface. Additionally, I gained some experience in adding x,y data coordinates from a tabular source to create features on a map- which are the storage tank contamination monitoring sites of Escambia county in the map above. Another procedure that may seem simple and intuitive, but is, in reality, a bit of a complicated process.
This map is comprised of 2 ortho quads (each made with 4 quarter sections), created by the USGS, and 3 different vector datasets- Florida county boundaries, major roads, and USGS quad boundaries. The vector line data was in a different coordinate system than the aerial photos, and had to be reprojected in ArcMap to the State Plane Florida North system. The files would have appeared correctly together in the map document if added together in different coordinate systems, but there would be a loss of functionality- which is something I have personally encountered in ArcMap, and never knew how to "fix" it. It isn't enough to merely describe the coordinate system in the metadata, ArcMap has to actually change and export the file in a different projection. The process itself is easy enough, but the theory behind it was a definite challenge for me. I did, after many hours of work, finally get a decent grasp on the general concepts and theory that exist, and run in the background, to accurately display the 3 dimensional earth on a 2 dimensional surface. Additionally, I gained some experience in adding x,y data coordinates from a tabular source to create features on a map- which are the storage tank contamination monitoring sites of Escambia county in the map above. Another procedure that may seem simple and intuitive, but is, in reality, a bit of a complicated process.
Monday, February 9, 2015
Map Projections (and a long overdue epiphany)
The concept of a map projection isn't difficult to grasp- it's something students in an undergraduate introductory geography class learn as a matter of course. It's the basic procedure of taking the 3-dimensional, (roughly) spherical surface of the earth, and transcribing it to a 2-dimensional surface to make a map. In practice, though, there are a myriad of ways this can be done, and all produce results that differ in a myriad of different respects. To put it simply, different maps, layered together in GIS, will not line up exactly in most cases if they have differing map projections. The kinds of basic GIS functions I've used in jobs I've held thus far haven't necessitated learning much about how this works within the GIS, and it's been a topic I've long felt both a fear of not understanding, and a trepidation about attempting to learn, lest it be beyond my comprehension.
With the creation of the above I can say I finally understand exactly how map projections work both conceptually, and within the use of a GIS. The three different maps of Florida are all done with different map projections, and the difference in area each gives for the 4 selected counties is listed below. Going through the steps of using GIS to re-project these maps as required, and exploring the inherent spatial differences in each, has (finally) illuminated, for me, the arcane knowledge of the map projection. Yes, it is somewhat complicated; no, it isn't beyond my ability to comprehend. I only wish I would've realized this sooner, but I suppose there is a time and place for everything- the truth in which is evident in really any well made map.
Monday, February 2, 2015
ArcGIS Online and Map Packages
ArcGIS, like most modern software, is moving increasingly in the direction of web-based applications and solutions. This development and integration of online GIS was nascent in the version of the program I used last in about 2009, but has evolved into an exceedingly effective and pragmatic component of ESRI's ArcGIS. This week finds us exploring a couple of ESRI's tutorials, and practicing the creation and optimization of map packages.
A map and/or tile package is a convenient means of sharing map data over the internet, as it allows users to share GIS maps without the usual networked database connections to access data sources. Above is a screenshot of a map package (MPK), created to share on the internet. The above MPK can be combined with a tile package (TPK) of basemap data, and would present a creative solution for an organization to share map data among members.
The above is a screenshot of an optimized map package. Optimization is the process of selecting the most appropriate map data to share, using the most appropriate symbology. Any and all practice in making these decisions is invaluable to those practicing to become able GIS professionals- that much I know personally to be true, even with my limited experience. I honestly hope that this course makes use of these online resources further at some point, as those particular areas of expertise will likely only become more lucrative in the future.
A map and/or tile package is a convenient means of sharing map data over the internet, as it allows users to share GIS maps without the usual networked database connections to access data sources. Above is a screenshot of a map package (MPK), created to share on the internet. The above MPK can be combined with a tile package (TPK) of basemap data, and would present a creative solution for an organization to share map data among members.
The above is a screenshot of an optimized map package. Optimization is the process of selecting the most appropriate map data to share, using the most appropriate symbology. Any and all practice in making these decisions is invaluable to those practicing to become able GIS professionals- that much I know personally to be true, even with my limited experience. I honestly hope that this course makes use of these online resources further at some point, as those particular areas of expertise will likely only become more lucrative in the future.
Wednesday, January 28, 2015
The Art/Science of Cartography and GIS
I've often been asked the question "what is GIS?" In response my answer has always been "it's kinda like computer cartography." This is, however, somewhat of a misrepresentation. The manipulation of cartographic data to create maps is surely a large part of working with GIS, but cartography and GIS are not synonyms, as the practice of working with GIS involves spatial analysis and assessment that is not inherent to the definition of cartography. This week was dedicated to the exploring the principles of the art and science of cartography within the GIS framework- achieved by using GIS to manipulate cartographic data to create different maps of Mexico.
Above is a simple choropleth map of Mexico's population by state. This map was easy enough to make, and is pretty self-explanatory- the states of Mexico are colored different shades according to their populations, with the ranges described by the legend. The part that I got a little held up on was the selection of a color ramp for the population classes. How does one select between different shades of reds, greens, purples, yellows, and every other color combination of the rainbow?! My instinct for these kinds of choices has always been to pick whatever color scheme is aesthetically appealing to me personally, but, upon further reflection on this week's lectures and readings, this was probably not the most sensible course. The colors shouldn't detract from the maps thematic content, plain and simple. The scheme above that I ultimately went with is (hopefully) subdued and appropriate. The ancillary elements, including the north arrow, scale bar and legend, are small enough to not detract from the map's information, but are large enough to be legible and visibly present.
I am hopeful that this lesson in cartographic style will serve to improve my map-making abilities, and that in the future I won't be tempted to create maps with what are probably garish and inappropriate color schemes. Which I have admittedly done, because I am an unabashed fan of all things unreasonably gaudy and ostentatious. Seriously, I love bright colors and glitter- but that affinity needn't translate to my professional and academic pursuits.
Above is a simple choropleth map of Mexico's population by state. This map was easy enough to make, and is pretty self-explanatory- the states of Mexico are colored different shades according to their populations, with the ranges described by the legend. The part that I got a little held up on was the selection of a color ramp for the population classes. How does one select between different shades of reds, greens, purples, yellows, and every other color combination of the rainbow?! My instinct for these kinds of choices has always been to pick whatever color scheme is aesthetically appealing to me personally, but, upon further reflection on this week's lectures and readings, this was probably not the most sensible course. The colors shouldn't detract from the maps thematic content, plain and simple. The scheme above that I ultimately went with is (hopefully) subdued and appropriate. The ancillary elements, including the north arrow, scale bar and legend, are small enough to not detract from the map's information, but are large enough to be legible and visibly present.
I am hopeful that this lesson in cartographic style will serve to improve my map-making abilities, and that in the future I won't be tempted to create maps with what are probably garish and inappropriate color schemes. Which I have admittedly done, because I am an unabashed fan of all things unreasonably gaudy and ostentatious. Seriously, I love bright colors and glitter- but that affinity needn't translate to my professional and academic pursuits.
Friday, January 16, 2015
You gotta OWN your map...
Making a map and including all of the necessary data to communicate whatever spatial information you're trying to communicate effectively is one thing, but the presentation itself is quite another. For this week we take a look at elements essential for appropriate map presentation, and your humble blog author is a bit ashamed to admit that in considering these essential map elements for this course I must necessarily disclose that previous maps I've created for past employers may have been a bit lacking....
The above was my submission for class, and you'll notice it includes: title, north arrow, scale bar, inset reference map of Florida, legend, name and data source. Ostensibly all of the necessary elements of a well-presented map. Yours truly was not remiss in including any of these elements in creations submitted to employers in the past, with the exception of one component of arguably tantamount importance- the map's data source. It is sadly true, the cited data source was not something I thought to include in maps I've created previously, and can only describe the omission as one of completely neglectful oversight on my part.
But today is a new day! I am fortunate enough to now be working on a graduate degree, and am finally getting caught up on all of the formal GIS training I've lacked my entire career thus far. This steady review of the basics of GIS is necessary for my continued growth and developing expertise in this very complicated discipline, and for that I am immensely grateful. The map of the UWF campus above is another submission in my nascent journey as a GIS graduate student, and another example of work on my personal endeavors in this GIS nouveau....
Sunday, January 11, 2015
First Lab Assignment! ArcGIS Overview map
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