# Display the flood zone near Elicott City MD

Ellicott City, Maryland was the site of a serious flash flood several years ago, due to the local topography. How can we use the Wolfram Language to make a graphic that shows the area at risk of flooding? It might help to find the lowest elevation near Ellicott City, and use ResourceFunction["GeoElevationGraphics3D"].

• I tried ResourceFunction["GeoElevationGraphics3D"][Entity["City", {"EllicottCity", "Maryland", "UnitedStates"}]] in the cloud but unfortunately it ran out of memory for my plan. Could that be a starting point though? May 10, 2023 at 1:38

Locate the center and fix the range of the shown map:

center = Entity["City", {"EllicottCity", "Maryland", "UnitedStates"}];
range = Quantity[4, "Miles"];


Get an idea of where we are:

GeoGraphics[GeoCenter -> center, GeoRange -> range]


data = GeoElevationData[center, GeoRange -> range,
GeoProjection -> Automatic, UnitSystem -> "Imperial"];
{mi, ma} = QuantityMagnitude[MinMax[data]]
(*    {80.2862, 605.287}    *)


Draw a relief map with a "flood level" manipulator:

Manipulate[ReliefPlot[data, DataReversed -> True, PlotRange -> {level, ma}],
{level, mi, ma}]


• Oh how nice ($+1$). May 10, 2023 at 10:38
• It does look like a very unfortunate place to build a city: ReliefPlot[GeoElevationData[GeoCenter -> GeoPosition[{39.26777632053404, -76.7941653003265}], GeoRange -> Quantity[1, "Miles"], GeoProjection -> Automatic, UnitSystem -> "Imperial"], DataReversed -> True, PlotRange -> {180, 500}] May 10, 2023 at 16:24