dem map

The image is a DEM (Digital Elevation Model )of the Sacremento Valley located in nothern California . A DEM is a digital representation of ground surface topography and are usually obtained by remote sensing than direct survey. This map has a color coordinated chart show the ranges in elevation for its various geographic features in meters.

This image was taken from:http://http://www.google.com/imgres?imgurl=http://www.emporia.edu/earthsci/student/alvarez1/svdem.jpg&imgrefurl=http://www.emporia.edu/earthsci/student/alvarez1/551proj.html&usg=__zU4CgN1HtOSnfArHupBJjnm23fM=&h=723&w=671&sz=184&hl=en&start=0&sig2=7NttZiu9eiXwgtfXa6L2sA&tbnid=J7T6FIXT9fusiM:&tbnh=138&tbnw=128&ei=s1NSTNCDK4GClAfp_tzBBA&prev=/images%3Fq%3Ddem%2Bmap%26hl%3Den%26sa%3DG%26biw%3D1276%26bih%3D579%26gbv%3D2%26tbs%3Disch:1&itbs=1&iact=hc&vpx=924&vpy=204&dur=36&hovh=233&hovw=216&tx=110&ty=95&page=1&ndsp=21&ved=1t:429,r:12,s:0