The pictures below show a custom cover that requires a considerable amount of sewing skills to fabricate and the lower pictures are a simple tarpaulin with pieces of reinforced clear plastic to create a ground seal. Part of the fun of a personal structure is coming up with new ideas and one of those is Shrink Wrap which is used to protect boats and marine equipment for storage.
Here is a web site to check out: Dr-Shrink.com provides all the materials and instruction manuals you need. As far as your dome frame is concerned, you will need to anchor the segments that touch the ground on both ends so that the shrink wrap band can be tightened around the bottom of the dome. I recommend that you spread out painters plastic under your project in order to keep things clean. Shrink wrap is very static prone and will collect dust easily. That dust hurts the adhesion of the shrink wrap to itself. You can get zippered closures that install where ever you want them after the dome has been covered . There are videos on how to shrink wrap almost anything if you just “Google” shrink wrap. Please remember to provide ventilation in any structure you create. Any type of synthetic covering that is considered water proof will also stop air flow. If you are working or sleeping in a contained area, you could suffer asphyxiation. Take care and have fun.