From the question I think you would like to know how travel impacts tourism and what their inter-relationship is.
Travel is an integral part of tourism. Without tourists being able to get to their chosen destinations there would be no tourism. And in many cases, the travel itself is made part of tourists' experience. An example of this could be a luxury cruise.
Disruptions in travel, which could be due to natural or political reasons, can affect the tourism industry adversely. For example, the recent disruption in air travel due to the volcanic eruption in Iceland had an effect on the tourism industry in Africa, though it wasn't too large.
When tourists find traveling to some destinations becoming more difficult and expensive, they may opt for alternatives that are easier and cheaper to reach. Also, any extra amount that is spent in reaching the destinations, leads to a reduction in what is spent at the destination itself.