GIS CONCEPTS

For our GIS analyses we used:

IDW (Inverse Distance Weighting) "IDW is a method of interpolation that estimates cell values by averaging the values of sample data points in the neighborhood of each processing cell. The closer a point is to the center of the cell being estimated, the more influence, or weight, it has in the averaging process."

Raster Calculator "The Raster Calculator provides you a powerful tool for performing multiple tasks. You can perform mathematical calculations using operators and functions, set up selection queries, or type in Map Algebra syntax. Inputs can be raster datasets or raster layers, coverages, shapefiles, tables, constants, and numbers."

Clip "Extracts input features that overlay the clip features."

Buffer "Creates buffer polygons to a specified distance around the Input Features. An optional dissolve can be performed to remove overlapping buffers."

Slope "Slope is the rate of maximum change in z-value from each cell."

Feature Class - "Feature classes are homogeneous collections of common features, each having the same spatial representation, such as points, lines, or polygons, and a common set of attribute columns, for example, a line feature class for representing road centerlines. The four most commonly used feature classes in the geodatabase are points, lines, polygons, and annotation (the geodatabase name for map text)."

Topology - "In geodatabases, topology is the arrangement that defines how point, line, and polygon features share coincident geometry. For example, street centerlines and census blocks share common geometry, and adjacent soil polygons share their common boundaries."

(Alll definitions from http://esri.com)