How to Combine GeoRegionValuePlot with Geographics

Question

 GeoGraphics[{Polygon[
  Entity["City", {"Washington", "DistrictOfColumbia", 
 "UnitedStates"}]], Red, PointSize[0.02], 
  Point /@ Map[
  GeoGridPosition[GeoPosition[#], 
  "Mercator"] &, {checkCashLocation}, {2}], Blue,
  Point /@ 
  Map[GeoGridPosition[GeoPosition[#], 
  "Mercator"] &, {groceryData[[All, {2, 1}]]}, {2}], Green, 
  Point /@ Map[
  GeoGridPosition[GeoPosition[#], 
  "Mercator"] &, {bankLocation}, {2}], Yellow, 
  Point /@ Map[
  GeoGridPosition[GeoPosition[#], 
  "Mercator"] &, {shoppingData[[All, {2, 1}]]}, {2}], Gray, 
  EdgeForm[Red], Polygon /@ top19}]

As you see, I was able to add the edgeForm, but let's assume I want to use colors to represent median income. I know I can use GeoRegionValuePlot like this instance, but I don't know how to combine this graph with GeoGraphics

    GeoRegionValuePlot[top19 -> "AverageHouseValue", MissingStyle -> Opacity[0], ColorFunction -> ColorData["RedBlueTones"]]

Any help will be appreciated.

Answer 1

The answer is simpler than I thought: Assign each plot to a variable, let's assume g1 and g2, then just write: Show[g2,g1]

I wrote g2 before g1 because I want the GeoRegionValuePlot to be below the GeoGraphics

Answer 2

This is a great question and answer, but I had a similar issue and found the documentation very hard to follow. I thought it might help if I gave another example which follows the general principle.

I had some data being plotted with GeoRegionValuePlot which defaults to choosing an appropriate map area to show the results. I wanted to widen this in order to show it on a fixed area - for comparison - and in this case the country of the USA.

plotM = GeoRegionValuePlot[data1, PlotLabel -> data2];
plotA = GeoGraphics[Polygon[Entity["Country", "UnitedStates"]]];
Show[plotM, plotA];

As user34018 says it's as simple as combining the two variables with Show[] as GeoRegionValuePlot evaluates to a GeoGraphics object and can be combined simply with another GeoGraphics object.

Hope that's of use.