Because of the regular nature of the areal unit in raster processing, a number of applications, such as a simulation of a forest fire or an oil spill, are made much simpler. Hydrologic modeling is one such application, so we look at it in some detail, both for its own sake and because it illustrates the power of spatial analyst. An important proviso: If you want to do serious hydrologic investigations, you should use packages designed for the purpose, including those provided as separate software by Esri.
You may not have thought a lot about how water flows over the surface of the Earth, or how to simulate it with a computer, so let’s explore the following:
We enter into a discussion of these topics in the text that follows. Then, in the Step-by-Step section of this chapter, you simulate a hydrological system.