Daily Archives: October 21, 2011
Investigating human-set fires, and determining optimal sites for expanding tea cultivation in Kenya are the topics of two new university level, ArcGIS 10, Africa-focused GIS activities in the ArcLessons library. Search for the two activities using terms “Africa fires” and “Kenya tea”.
You will gain skills in tabular and spatial data joining, query, analysis, symbolizing, and classifying data, and making a decision in a GIS environment. You should be familiar with computer file management and have some familiarity with ArcGIS. Both lessons emulate real decision making with GIS occurring daily around the world.
The goals of the fires activity include how to use GIS and spatial analysis to study the pattern of human-set fires in Africa and to understand the physical and cultural geography of Africa. The activity begins with this scenario: Hearing about your GIS skills, the United Nations Environment Programme (UNEP) has hired you to analyze the seasonal pattern of wildfires in Africa.
Consider that people set fires in Africa and elsewhere to create and maintain farmland and grazing areas. People use fire to keep less desirable plants from invading cropland or rangeland, to drive grazing animals away from areas more desirable for farming, to remove crop stubble and return nutrients to the soil, and to convert natural ecosystems to agricultural land. In Africa, the area burned shifts from north to south over the year in step with the rainy and dry seasons. Although fires are a part of the natural cycle of seasonally dry grasslands and savannas, some scientists and public health officials are concerned about Africa’s burning frequency. The frequency with which fires return to previously burned areas helps determine what species of plants (and therefore animals) can survive. When the fire-return interval is too short, the land may become degraded and unusable for farming or grazing. The massive amount of burning that occurs in Africa each year creates carbon dioxide, smoke, and aerosol particles, affecting climate and creating a public health hazard.
In the Kenya tea activity, you learn that tea is an important cash crop in the world and in Kenya. The Kenya Tea Development Company is the largest cooperative of growers, representing 28% of Kenya’s total export earnings. Its 400,000 growers cultivate land over 86,000 hectares in size, producing over 700 million kg of tea annually. Hearing about your GIS skills, the Kenya Tea Development Company has hired you to select additional lands that might be suitable for tea cultivation, as follows:
1. It must be grown on moderately high ground, between 914 meters and 2,133 meters above sea level.
2. It cannot be on any water-related land cover, including wetlands.
3. It cannot be in an urban area.
4. It cannot be within 500 meters of a populated place.
5. It cannot be within 2000 meters of a mine.
6. It must be within 5 km of a road, to reduce transport costs.
How might you use these activities to teach and learn about key geographic themes, physical and cultural characteristics of Africa, and gain fundamental GIS skills?
- Joseph Kerski, Esri Education Manager