# Sea Level Rise - How to mask on relief plot

I want to make a diagram which corresponds to sea level rise in the UK. I'm having trouble with relief plot.

So, corresponding to a 30 metre height increase of the sea, we would get the following diagram

sealevelrise = 30;

ReliefPlot[GeoElevationData[Interpreter["Country"]["UK"], UnitSystem -> "Metric"], DataReversed -> True, PlotRange -> {Full, Full, {sealevelrise, All}}]


Giving,

But I want a colour change at the new sea level instead, e.g from green to blue at the sea line. i.e. we could still see the relief in the white/"underwater". Is there any way to do this?

Clarification: I would like for the relief to be green, and for the sea to be blue and for the relief of both to still be seen. I just would like the point where the sea becomes land to have a colour change.

Side (non-important) question: Is there any way to overlay cities?

I'm not completely sure of what you need, but you might try this (where you can change the color schemes as you prefer):

ImageCompose[
ColorReplace[
ReliefPlot[
GeoElevationData[Interpreter["Country"]["UK"],
UnitSystem -> "Metric"], DataReversed -> True,
PlotRange -> {Full, Full, {0, All}}
, ColorFunction -> "SandyTerrain"]
, White -> Transparent]
,
ColorReplace[
ReliefPlot[
GeoElevationData[Interpreter["Country"]["UK"],
UnitSystem -> "Metric"], DataReversed -> True,
PlotRange -> {Full, Full, {sealevelrise, All}}],
White -> Transparent]
]


The orange-ish parts in the image are the parts that are now underwater.

• @Kuba thanks for the edit, I was in a hurry and forgot to add the plot :) Aug 21, 2018 at 11:05