Modeling a stadium dome with UVs? Beginning with Blender, I would like to create a stadium dome like the following one:

This is how it looks when textured:

This is the texture used:

This is the UV mapping:

Now you may ask why I don't reuse that model? It's because I'd like to assign a texture with different dimensions so the original UV mapping wouldn't be right. So while I'm on it, I'd rather learn the entire process on how to do it.
Edit:
For instance, I'd like to map it to a texture like the following:

In this case, I would like to map the lower half, so the mountains and a little above to the straightened part of the dome, and map the rest to the spherical part.
Question:
How could I recreate more or less the same dome in Blender?
This is a very easy thing to make in Blender.
Step one- Take a sphere and select the bottom half faces, then delete that part.
You can now scale the top half of the sphere on the Z axis to look slightly less spherical.
Step two- In Edit Mode select the bottom-most edges of the half-sphere and press E then Z to extrude it down on the Z axis, then type &quot;-.1&quot; to move the extruded part down just a bit, then press Enter/return
Step three- Before doing anything else, press Shift+R to repeat the action. This will extrude another part 0.1 down the Z axis off of the already extruded part. For reference, Shift+R is the hotkey you use in Blender to repeat the previous action.
Image of result for reference:

This should get the result you want.
EDIT If you want to unwrap a UV texture to your model, then you have to give the object a material, and add an image texture with the image you want to the color input of the material node.