Answer:The geographic feature on the South Island of New Zealand that makes it difficult for people to settle there is the Southern Alps mountain range. The Southern Alps run the length of the South Island and are the largest mountain range in New Zealand, with peaks rising over 3,000 meters (9,800 feet) above sea level. The rugged terrain, extreme weather conditions, and steep slopes of the Southern Alps make it challenging for people to settle in many areas of the South Island. Additionally, the South Island is prone to earthquakes, floods, and other natural disasters, which can also make it difficult for people to live and work there. Despite these challenges, many people do choose to live in the South Island due to its stunning natural beauty, unique culture, and outdoor recreation opportunities.