Plot can be extremely affected by the setting of a story and even become a part of the story. It's the setting for all that is to come and even if it's one set on stage, it can convey so much about who the people are and the way they live. Just as in a film, countryside can be a character of its own. But it can also affect plot in other ways.
If you are at a beach, characters can get into physical trouble in the ocean. In the desert, they can be bit by a rattlesnake, or if the story takes place in horse country, characters can be distinguished by whether the character is able to ride or not. "Jaws" is a classic film that uses setting almost as a character and that "character" totally influences the plot. A wide ocean, no one around to help and a very, very big and dangerous shark. In the opening scene when the girl is attacked, there is no better example of setting affecting plot.
Elements Keep Characters Trapped
Being snowed in and trapped on a mountaintop affect plot in the extreme. Many times the setting is the beginning of the plot itself. Trapped in space, trapped under water, trapped period. Without setting, no James Cameron movie would ever be made. But Cameron was really following in the footsteps of Ridley Scot who directed the first "Alien." The tag line for that film's advertising says it all about setting influencing plot: "In Space No One Can Hear You Scream."
Setting As Story
The gorgeous Italian countryside, the streets of Paris, the austerity of Russia, the beginnings of American; all these locations are where a setting is part of the story. These places help define the story and move it forward. No merchant ivory film is set in downtown Altoona. And no film is ever made about a young girl going off to Altoona and discovering herself and becoming a model and finding the love of her life, as in "Funny Face," starring Audrey Hepburn. In that classic film, Paris is the setting and every moment is influenced by the characters, look, special characteristics and main attractions of The City Of Lights.
A city about to be hit by a meteor, a bridge overtaken by a monster, a tsunami on the way; the setting in these is specific because of what dangers they offer to create and advance the plot. In "Cloverfield," a monster runs rampant through the downtown section of New York City and setting gives the monster essentially his playground for creating mayhem. But the plot moves forward because this setting determines the kind of people who we can focus on, in this case, downtown loft renters who are in their twenties and just starting their lives. The clash of these two elements is truly setting meeting plot.