克里金插值用于地形平滑处理。参考：https://baike.baidu.com/item/%E5%85%8B%E9%87%8C%E9%87%91%E6%B3%95/5129539?fromtitle=%E5%85%8B%E9%87%8C%E9%87%91%E6%8F%92%E5%80%BC&fromid=3689073&fr=aladdin