WINNIPEG, Manitoba—Canadian exporters of commodities from grain to fertilizer and oil scrambled on Wednesday to divert shipments away from Port of Vancouver, which floods have isolated, but they found few easy alternatives. The disaster, which has killed at least one person, has caused the latest blockage in the congested global supply chain, driving up inflation fears ahead of the holiday shopping season. A month’s worth of rain in two days caused floods and mudslides in British Columbia that wrecked highways and two critical east-west rail lines owned by Canadian National Railway Co and Canadian Pacific Railway leading to Canada’s busiest port. The Trans Mountain oil pipeline and part of an Enbridge Inc gas line have closed as precautions. “That western corridor is our lifeblood,” said John Brooks, CP’s chief marketing officer, at an investor conference on Tuesday. “Just about all commodities to some extent flow through that.” Vancouver’s port moves …