My first grader was given the assignment of making a desert diorama. It was one of several land form dioramas they could choose from. This Instructable documents the process using things we had lying around the house.

Items Needed:
Shoe Box
Elmers Glue
Box Cutter
Sky Blue Spray Paint
Desert Camoflage Spray Paint
Red Model Paint
Brown Model Paint
Black Model Paint
Model Paint Thinner
1/2" Foam Sheet Insulation (About 4 square feet worth)
Sharpie Marker
Rubber Snake
Flathead Screw Driver
Green Scrub Pad
Paper Plate
Model Paint Brush
Hot Glue Gun and Glue Sticks
Small Clamps
Spare Cardboard Box
Rocks
Train Model Tree Material

Step 1: Cut Shoe Box.

Cut the front of the shoe box and fold the flaps back into the box. This opens the front of the box for better viewing.

Next, use a hot glue gun or plain old Elmers glue and some clamps to hold the flaps tight during drying. Do this for both sides.

Step 2: The Inner Lining.

Cut some pieces of cardboard to line the inner walls of the shoe box. This gives it a nice smooth even appearance. Again, glue these liners and clamp til dry. We used two pieces to make it the whole way around the inner sides.

Step 3: Line the Bottom of the Box.

Cut a half inch think piece of insulation to fit the interior of the box. Glue and press to attach firmly.

Step 4: Assemble Rock Formations.

Glue insulation scraps together in a stacked way. Allow to dry over night. When the glue has dried, trim the formation with a box cutter or other blade. I basically try to trim all of the right angles and overlaps.

Step 5: Wadi

Glue the rock formations to the bottom lining wherever they seem appropriate. Mark the shape of a wadi with a marker. With a blade, cut the edges of the wadi about 3 or 4mm deep. Cut lengthwise all along the wadi then cut across those lines to breakup the foam. Using a flathead screwdriver, chisel out the broken up area of the wadi being careful not to go too deep. Once the wadi has been generally carved out use a scrub pad (the rough green kind) to smooth out the wadi.

Step 6: Priming and Painting the Interior.

Prime the interior of the box with a non-sprayed paint because the chemicals in spray paint will dissolve the foam quick-style otherwise. Once the primer paint has dried and no foam is visible it is safe to spray paint the sky on the edges. We used some aluminum foil to keep the paint from getting on the top portion of the box. The spray paint only takes 1/2 hour to dry so once the sky was dry the desert sand could be spray painted on.

Step 7: Adding Terrain.

We collected a few rocks from outside and glued them to the desert. I had some tree/bush material left over from other models. You can get this at hobby stores. It comes in bags and is used for model trains etc. We glued these sparsely around the desert. Just a drop of elmers and stick a piece of material in the drop is all it takes.

I also had some left over model paint (red and brown) that I mixed together to get a reddish color for the striations and sides of the wadi.

Step 8: Black Wash and Dry Brushing.

Mix some black enamel model paint and model paint thinner at about a 1:3 ratio. This makes a very thin black paint that will easily run over the terrain and fill in the cracks and crevices. When you got it mixed take a paint brush and liberally apply the wash all over the terrain. When it dries it will highlight the cracks and crevices without painting over the desert. The terrain will be darkened some, but this looks very good after the dry brushing.

Dry brushing is simply spraying some of the desert paint on a paper plate, dabbing a paint brush in the paint and wiping the brush dry on a paper towel. Lightly flick the dried brush all over the terrain. You'll see real fast how it highlights the edges of things and really makes the terrain look realistic.

The desert animal for this project was the snake. We found a perfect one at Party City for $2.50. We glued this to the upper section.