Attribute items are in ARC/INFO feature class format. Additional items that were added to the data are: POLYGON attribute description ========= =========== acc_val Acceleration value in percent of gravity of the polygon. The polygon represents the range of acceleration values that are contained within its borders. The polygon is assigned the lowest value allowed within the polygon's borders. The range of values allowed within a polygon is controlled by the contours. Valid values are: 0,4,8,12,16,20,24,28,32, 36,40,60,80,100,120,160,240,320,400 valley A topological indicator that tells whether the area contained within the polygon is a local minima (valley) or not. A value of "1" indicates the area is a local minima. LINE attribute description ========= =========== acc_val Acceleration value in percent of gravity that the contour represents. Valid values are: 0,4,8,12,16,20, 24,28,32,36,40,60,80,100,120,160,240,320,400 valley A topological indicator that tells whether the area contained within the contour is a local minima (valley) or not. A value of "1" indicates the area is a local minima.