1. A method for adapting an aircraft terrain display in response to situational parameters comprising: computing a parameter to characterize terrain roughness for an area of terrain to be displayed; computing a contrast multiplier as a function of the terrain roughness; multiplying the contrast multiplier by a situation parameter that varies depending upon the flight mode of the aircraft; computing a lighting component for each terrain data point; multiplying the lighting component for each data point to obtain a set of terrain data to be displayed; and displaying the terrain data on the display.