Contour plot show value change

Question

data = Reverse[Reverse /@ Partition[dem[[All, 1]], 121]];
ListContourPlot[GaussianFilter[data, 10], 
 Contours -> {1580, 1670, 1480, 1715}, ContourShading -> None, 
 ColorFunction -> "Pastel", 
 DataRange -> Transpose[dem[[{-1, 1}, {3, 2}]]]]

How to contour plot show value in graphic ? if value=1580 change 350 in show graphic.If value 1670 I want show this value show in picture 370. Thank you

Answer 1

The following is for illustrative purposes. To relabel contours you could just define a function mapping contour value to label. For example:

ContourPlot[x^2 + y^2, {x, -10, 10}, {y, -10, 10}, Contours -> 3, 
 ContourLabels -> (Text[Framed[#3], {#1, #2}, Background -> White] &)]

Re-labeling (trivial function for convenience to illustrate):=

fun[x_] := x/10;
ContourPlot[x^2 + y^2, {x, -10, 10}, {y, -10, 10}, Contours -> 3, 
 ContourLabels -> (Text[Framed[fun@#3], {#1, #2}, 
     Background -> White] &)]