Double click the icon for placemark G, and notice that placemarks G and H lie along the Bright Angel Trail (the dotted line on the map). a. The gradient of a surface is a way of expressing the steepness of the landscape by reporting the change in elevation that occurs over some horizontal distance. The gradient can then be easily calculated by dividing the rise in the landscape by the horizontal run required to gain that rise. Using the Status Bar at the bottom of the display, determine the elevation of placemark G and placemark H and calculate the rise, or change in elevation between them. Change in elevation, or rise, from G to H