Understanding geography and using GIS as an analytical tool in education and research requires a sensitivity to and an awareness of scale. This provides a framework for understanding how events and processes influence each other. Any phenomena we are studying at one scale can be influenced by phenomena operating on other scales. For example, traffic patterns affect local neighborhood zoning and movement, but also affect regional land use and reflect regional patterns of trade. They also reflect and can be studied in the context of national or international migration, economics, and demographic characteristics. Climate is another complex phenomenon that operates at multiple scales. It affects weather on a local scale but also affects such global phenomena such as ice pack at the poles, sea level, and the location of deserts, rainforests, monsoons, and consequently, human settlement, agriculture, clothing and building styles, and much more. In between, at a regional scale, climate is affected by landforms, such as mountains, prevailing winds, and even eruptions of volcanoes. Thus, to fully understand our complex world, we must look at processes across multiple scales.
Scale is about size. It can be relative or absolute. Scale can be about space, or about time, since things that occur across space almost always have a temporal component. For example, think about wildfires versus glacial advance. They have different spatial scales and different temporal scales. There is also a thematic scale, having to do with the grouping of attributes such as water quality or weather variables.
Scale is a theme that runs through all of geographic analysis, because geographic analysis has to do with trends, patterns, relationships across space and, often, time as well.
Consider the different processes operating on this landscape on a local scale, photographed on the ground, versus those operating at a regional scale, photographed out an airplane window of the same location.
Several types of scale exist within geographic analysis. They are interrelated and are equally important. They are also important far beyond geography, in any discipline where spatial aspects are considered, such as in epidemiology, biology, earth science, or business marketing. GIS can be used in a wide variety of ways to teach about each type of scale, which I discuss in a video on: http://esriurl.com/scalematters. I will discuss the different types of scale in the next blog.
How might you use GIS to teach about scale?
- Joseph Kerski, Education Manager