Maps in the Computer Age

 I. Evolution of map making –A. Hand drawn –B. Aerial photographs from planes –C present : satellite images and computer generated maps  I. Evolution of map making –A. Hand drawn –B. Aerial photographs from planes –C present : satellite images and computer generated maps

 II. Landsat satellites –A. Collect information about Earth’s surface and relays the data to a computer station on Earth. –B. Computers turn the data into an image. –C. Pixels are tiny dots that make up the image. Each one contains information about the color and brightness of a small part of Earth’s surface. –D. The more pixels in the image, the more accurate and “cleaner” it looks.  II. Landsat satellites –A. Collect information about Earth’s surface and relays the data to a computer station on Earth. –B. Computers turn the data into an image. –C. Pixels are tiny dots that make up the image. Each one contains information about the color and brightness of a small part of Earth’s surface. –D. The more pixels in the image, the more accurate and “cleaner” it looks.

–E. Interpreting satellite images  1. Red color = vegetation (trees, grass, crops)  2. Black or blue colors = water  3. Bluish gray color = cities  4. Brown colors = bare land or desert –E. Interpreting satellite images  1. Red color = vegetation (trees, grass, crops)  2. Black or blue colors = water  3. Bluish gray color = cities  4. Brown colors = bare land or desert

 Ichkeul Lake (Arabic: بحيرة اشكل) is a lake in northern Tunisia near the shore of the Mediterranean Sea. The lake and wetlands of Ichkeul National Park are an important stopping-over point for hundreds of thousands of migrating birds each year. Among the lake's visitors are ducks, geese, storks, and pink flamingoes. The park has been on the UNESCO list of World Heritage Sites since 1980, and between 1996 and 2006 the park has also been on the group's list of World Heritage Sites in danger. Dam construction on the lake's feeder rivers has produced major changes to the ecological balance of the lake and wetlands.Because dams have sharply reduced the freshwater inflow to the lakes and marshes, the reedbeds, sedges, and other fresh-water plant species have been replaced with salt- loving plants. These changes have produced a sharp reduction in the migratory bird populations, which depend on the mix of plants that used to exist.According to the UNESCO Website, the Tunisian government has undertaken some steps to retain freshwater and reduce salinity, but some reports from the World Conservation Union suggest that the salinity has already become excessively high and the possibility for rehabilitation may be rapidly disappearing.migrating birdsWorld Heritage Siteslist of World Heritage Sites in dangerDamecologicalreedbedssedgesWorld Conservation Union  Ichkeul Lake (Arabic: بحيرة اشكل) is a lake in northern Tunisia near the shore of the Mediterranean Sea. The lake and wetlands of Ichkeul National Park are an important stopping-over point for hundreds of thousands of migrating birds each year. Among the lake's visitors are ducks, geese, storks, and pink flamingoes. The park has been on the UNESCO list of World Heritage Sites since 1980, and between 1996 and 2006 the park has also been on the group's list of World Heritage Sites in danger. Dam construction on the lake's feeder rivers has produced major changes to the ecological balance of the lake and wetlands.Because dams have sharply reduced the freshwater inflow to the lakes and marshes, the reedbeds, sedges, and other fresh-water plant species have been replaced with salt- loving plants. These changes have produced a sharp reduction in the migratory bird populations, which depend on the mix of plants that used to exist.According to the UNESCO Website, the Tunisian government has undertaken some steps to retain freshwater and reduce salinity, but some reports from the World Conservation Union suggest that the salinity has already become excessively high and the possibility for rehabilitation may be rapidly disappearing.migrating birdsWorld Heritage Siteslist of World Heritage Sites in dangerDamecologicalreedbedssedgesWorld Conservation Union

 Imperial Valley, southern California and northern Mexico. False-color satellite image, in which active vegetation appears red and pink. The All American Canal enters right side of scene and flows westward just north of the U.S.-Mexican border. This is the "last tap" from the Colorado River on the U.S. side of the border. Bright red irrigated cropland is evident in the Imperial Valley of the United States, but crops have less irrigation water in Mexico. Image from NASA GSFC.NASA GSFC  Imperial Valley, southern California and northern Mexico. False-color satellite image, in which active vegetation appears red and pink. The All American Canal enters right side of scene and flows westward just north of the U.S.-Mexican border. This is the "last tap" from the Colorado River on the U.S. side of the border. Bright red irrigated cropland is evident in the Imperial Valley of the United States, but crops have less irrigation water in Mexico. Image from NASA GSFC.NASA GSFC

 Qinetiq released a TopSat micro satellite picture showing how green Saudi Arabia is becoming.According to the firm, the shot (below) is of three kilometre circular fields supported by central pivot irrigation.Water is "mined" from ancient rivers deep below the desert to the surface, and distributed by irrigation. The firm reckons Saudi Arabia is close to self sufficiency in agriculture, with land under cultivation rising from 400,000 acres in 1976 to over eight million acres today.

 III. Computer mapping –A. Digitizing = putting map information into a computer. It converts map locations to numbers so the computer can understand it. It involves using a mouse to trace the map’s features.  III. Computer mapping –A. Digitizing = putting map information into a computer. It converts map locations to numbers so the computer can understand it. It involves using a mouse to trace the map’s features.