Land Data

This post will look at various geographical features around the world, elevation of national parks in the United States, nighttime light data in Europe, and land coverage in Texas.

This map here below shows the elevation features of the Grand Canyon, one of our country’s greatest national parks. The data was collected from USGS. The depths of areas in the United States and around the world were measured using a space shuttle and radar in 2000 under the mission name SRTM, Shuttle Radar Topography Mission. According to the government website, “Endeavour orbited Earth 16 times each day during the 11-day mission, completing 176 orbits” to collect data. The signals of data were at intervals of 1 arc-second, or every 30 meters. Therefore, the data with measures of 1 arc-second are more accurate and precise than the data with samples placed at 3 arc-seconds, or every 90 meters. My map uses the data found with intervals placed at 1 arc-second for the United States. This geographic projection shows the depth of in vertical units measured by meters of the Grand Canyon. The darker the color, the deeper the depth of the canyon. The areas that are lighter and closer to white signify a higher elevation. The red lines in the picture indicate the boundaries of the canyon. The blackest black measures at about a 380 meter elevation, while the lightest white measures at about a 2386 meter elevation.

The second map, here below, shows the change in coverage of lights at night over time in central Europe and the western part of Russia. The data comes from the National Oceanic and Atmospheric Administration. I used data from 1992 and 2012 to show the difference that 20 years of development makes. Where there are more lights, there is more population and urbanization. This projection shows the rapidly increasing population rate. Our world is quickly climbing towards the 8 billion people marker. The red in the map shows the nighttime lights composite for 1992 while the blue shows the nighttime lights composite for 2012. The blue is more widespread, signaling greater development, more cities, and a climbing population. It is visible from this map that large cities have more lights, and therefore more people. Cities such as London, Rome, and Paris are prominently shown on the map with more light. The bottomline is that our population is rapidly growing.

The third and last map, below, shows land coverage data collected from National Land Cover Database. Since I am from Dallas, Texas, I chose to examine more closely the land coverage in the Dallas Fort Worth area. I live near White Rock Lake and am used to being outside a lot, despite the sometimes unbearably hot temperatures, so I thought it would be interesting to look at the land cover in the area that I am most familiar with. In the map you can see the Google Street Map for the DFW area that identifies and labels the major streets and cities in the area. Despite the stereotype that Texas is a barren land with horses and cowboys, it is clear that we have more to offer than just desert, as seen in the legend. Most of the DFW area is classified as developed, medium intensity and high intensity, shown in red. We also have quite a bit of water in the area, like White Rock Lake, Lake Grapevine, and Lake Lewisville, all seen on the map in blue. It was interesting to take a closer look at the coverage in my hometown and to see what QGIS could do to make this projection.