The short story "Krakatau" by Jim Shepard was published in his 1996 collection, Batting for Castro. In this story collection, he does draw upon some of his own experiences, most importantly those of his growing up in a working class family and eventually teaching in the elite Williams College, and thus having a personal understanding of the clash of socioeconomic cultures he details in some of the stories.
He also did grow up with a brother suffering from mental illness and has said that this experience tends to make him more sensitive to the experiences of people with mental illness and their friends and families. That being said, though, he still cautions readers against the "autobiographical fallacy", pointing out that while he make take certain elements from his personal experience, his stories are purely fictional.
In an interview, he gave the humorous example of a family friend calling him to express sympathy for his loss after he published the story "The Mortality of Parents;'' he explained to the friend that actually his parents were alive and well, and that the story was just a story.
Yes. Shepherd describes early conflicts with his "rage-filled" brother in the the essay "Get Away From Me." He also describes his own fascination with tidal waves, and makes a metaphoric connection between a tidal wave or volcano and his brother. The story itself connects investigating a natural disaster with investigating family dysfunction. The protagonist in "Krakatau" is studying a volcanic eruption, while his own brother was the "eruptive" person in his life, sort of like his own personal volcano. You can definitely infer that Shepherd drew on his real life relationship with his brother.