GIS 6005 Module 3 - Terrain Visualization

Module 3 of GIS 6005 - Communicating GIS was an exploration of various methods used to convey three-dimensional terrain on a two-dimensional map. The first exercise was a combination of contour lines and hypsometric tinting to illustrate how the rapidly the elevation changes throughout the mapped study area. Contour lines are 'lines of equal elevation above a datum. If a contour was actually drawn on the earth, it would trace a horizontal path that is constant in elevation [Kimberling, 2012, p. 217]. Additionally, hypsometric tinting is 'a method of "coloring between contour lines" that visually enhances the relative elevation cures for contours while maintaining the absolute portrayal of relief [Kimberling, 2012, p. 220]. A shown in the map below, the shades of the color ramp in the legend directly coincide with the elevation provided [in meters above sea level] at each contour line. For the symbology of the hypsometric tint, a green was used for the lowest elevations, which suggest a valley, and oranges / yellows for mid-elevations, and white for the highest, suggesting white capped mountains; this was the color scheme that was suggested in [Kimberling, 2012].

For the second a third portion of the lab, traditional and multi-directional hillshading effects were employed to actively display dimensionality on a printed terrain. Hillshading, or relief shading, uses a simulated light-source to provide relief on a map; however, the use of a singular light source creates overdeveloped, illuminated surfaces and dark, overbearing shadows. The solution to this problem is to utilize multiple light sources which will effectively reduce these extreme lighting characteristics found in traditional hillshading. The map below is a land classification map of a study area located in Yellowstone National Park. As shown in the legend, there are many various vegetation types that can be found on the map. To give the user a sense of depth and relief, a multi-directional hillshade effect was applied to the Digital Elevation Model and the land classification layer's transparency was set to 50%. This allows the texture of the landscape to be experienced by the viewer as they gather information on vegetation types found throughout the study area.

Part four of the lab was 'draping' a remotely sensed RaDAR imagery over a Triangulated Irregular Network Digital Terrain Model to give three-dimensionality to the orthophotos. The RaDAR imagery was gathered from a portion of Death Valley, California and can be seen in the image below.

This lab was a great opportunity to explore some techniques to give depth / relief to a two-dimensional map. A lot of material was covered in the text that we did not apply in the lab, but this assignment did provide a great foundational knowledge for future applications.

Informational sources:

Kimberling, A.J. (2012). Map Use: Reading, Analysis, Interpretation (7th edition). ESRI Press Academic.

GIS 6005 Module 2 - Coordinate Systems

 'A map projection is a geometric transformation of the earth's spherical or ellipsoidal surface onto a flat map surface' [Kimberling, 2012, p. 57]. The different map projections and their applications were the subject material covered in Module 2 of Communicating GIS. While the intensity and depth of map projections is well beyond the scope of this blog post, a great starting point on this subject is the ESRI documentation regarding coordinate systems; you can find the resource at this link:

Geographic vs Projected Coordinate Systems

Essentially, lab assignment two was applying different projected coordinate systems to various maps and examining how they affected the land masses differently. As the round surface is projected onto a flat surface [developable surface], some integrity will be lost; this will either be in distance, area, angles, or distances [Kimberling, 2012]. Each of the different projection types will preserve some of these qualities while distorting others. It is up to the cartographer to determine which projected coordinate system is appropriate for each case. 

The final part of the lab was to pick a state and determine which coordinate system was the best choice to create an accurate map. As shown in the map below, I chose to map the state of Texas. I primarily decided on Texas because a custom projection system was the best option. Two of the most popular projection systems, State Plane and UTM, were not appropriate because the state crosses numerous zones in each of these systems, which would cause major distortion to the map. Conclusively, this map was drawn using the NAD 1983 [2011] Texas Centric Mapping System Lambert projected coordinate system, which is a conformal PCS that preserves the actual geometry of the state. 

This lab was very intriguing and informative; the subject of projected coordinate systems is complex and deep, but this module was an excellent introduction to the complexity of this subject.

Informational sources:

Environmental Science Resource Institute (2024). Geographic vs Projected Coordinate System. https://www.esri.com/arcgis-blog/products/arcgis-pro/mapping/gcs_vs_pcs/#:~:text=A%20projected%20coordinate%20system%20(PCS)%20is%20a%20GCS%20that%20has,to%20know%20how%20to%20draw.

Kimberling, A.J. (2012). Map Use: Reading, Analysis, Interpretation (7th edition). ESRI Press Academic.

GIS 6005 Module 1 - Map Design and Typography

Module One of GIS 6005 - Communicating GIS revolved around cartographic design principles and typographical principles that should be followed to create effective maps. The five design principles studied were as follows:

• Visual Contrast
• Legibility
• Figure-ground organization
• Hierarchical organization 
• Balance

These principles were practiced in all five parts of the lab while typographical design, or labelling, was introduced into the last three sections of the assignment.

For part one, datasets of the Austin, Texas metropolitan area were provided and were to be compiled into a cartographic reference map for tourists coming to the city. A simple layout was provided with all required map elements, but the final map [shown below] does not incorporate any of the original layout's elements. Here is a brief synopsis of the five design principles and how they were applied to the final map:

Visual contrast 'relates to how map features differ from each other and their background' [Kimberling, 2012, p.133]. This was achieved by using bright colors for the symbology of the feature classes that are emphasized against the earthy tones of the background. Legibility is 'the degree to which something can be read and deciphered' [Kimberling, 2012, p. 132]. Careful consideration was given to the font types, size, and font colors throughout the map, ensuring they can be read at a reasonable distance. Figure-ground organization is 'a perceptual phenomenon in which our mind and eye work together to spontaneously organize what we are viewing into two contrasting impressions - the figure, on which our eye settles, and the amorphous ground below or behind it' [Kimberling, 2012, p. 136]. To achieve this aesthetical organization, a darker color was used for the focal point of the map to visually bring it to the forefront of the page. Visual hierarchy is 'the graphic structuring of the features that make up a map' [Kimberling, 2012, p. 137]. This hierarchy is simply achieved by ensuring the focal point of the map [Travis County] has the most visual weight, the title / subtitle are second to the map, and the remaining map elements hold the least amount of visual weight, not stealing unnecessary attention from the user's eyes. Finally, balance 'involves the harmonious organization of the mapped area and any marginalia on the [map]...' [Kimberling, 2012, pg. 140]. This design principle offers much more flexibility than the others, is more subjective in nature, and is achievable through many differing methods. For this map, it has a more symmetrical, or formal, balance with the map dead center and the marginalia organized on both sides at the bottom of the map. This balance is highly contrasting with the balance achieved in part two of the lab [see next map below].

Part two of this lab was creating a map for a lumber company that illustrates how much land can be harvested in two land leases, both located in the state of Alaska; all five design principles introduced in part one were to be addressed and applied in this map as well [see below], but the final product is quite different between the two maps.

Part three of this assignment still focused on the five cartographic design principles, but introduced labelling practices into the design process. There are typographical standards that provide the cartographer with general guidelines, but sacrifices sometimes need to be made to achieve the desired result. A map of San Francisco, California and some of its major landmarks was the required deliverable. Here are a couple design principles that were followed in the creation of this map: first, since the map is of San Francisco, this text was given the most weight by using a bold, larger font than the rest of the labels. A sans serif font was used in the labelling of all cities and neighborhoods because that is a cartographic standard; manmade landmarks are labelled with a sans serif font. The parks were labelled with a serif font in a green hue that is contrasting to the shade of green used in the parks themselves. Also, the spacing was increased between the letters of these labels because it spreads the labels out over a larger area, visually conveying that areal features are being labelled. Lastly, a serif font was also used for natural features in a brown hue that is contrasting to the shade of brown that was used for the land mass. Since there are roadways all over the map, they were displayed in a light shade of grey, and a halo was used on most labels that overlaid the streets to increase legibility. These decisions led to a map that is visually balanced, aesthetically pleasing, and hierarchically organized to emphasize which landmarks are most important on the map.

Finally, for part four and five, the deliverable was a map of Mexico and its significant landmarks. The same principles that were applied in step three were relevant to step four and five also, but more considerations had to be taken because the amount of labelling on this map was somewhat daunting. In step four, the only labelling that was required was the rivers. This provided an opportunity to explore the various settings to achieve a desirable result. As shown in the map below, a blue, italicized, and serif font was used for the text elements, but they were manipulated in a way that they curve along the linework of the feature class. Once these labels were added to the map and properly formatted, cities, states, and the capitol city were added to the map. Once all the labels were on the map, it was apparent that design choices, and sacrifices, were going to be required to create a legible end product. The first decision was to reduce the number of cities that were included on the map; to accomplish this, all cities that had a population less than 250,000 people were eliminated. This greatly enhanced the legibility, but it was still highly congested around the capitol city. Due to the small size of the District of Mexico, and it being a federal district [not a state], it was eliminated from the map as well. These design choices led to a final product [see below] that was substantially more legible than one displaying the label for every feature class.

Overall, this lab assignment was very fulfilling and provided numerous opportunities to get familiar with the cartographic and typographic design principles that are required to create an effective, high-quality map.

Sources:

Kimerling, A. J. (2012). Map Use: reading, analysis, interpretation (7th ed). Esri Press Academic.