Why are there Fujian tulou? What does it have to do with the local environment and people's lives?

Fujian tulou is a unique large-scale rammed earth residential building in mountainous areas in the world, and it is a creative masterpiece of adobe architecture. Fujian Tulou originated in Song and Yuan Dynasties and matured in the late Ming and early Qing Dynasties and the Republic of China. The oldest and youngest world heritage earth buildings are located in Chuxi earth buildings. Qing Ji Tower with a diameter of 66 meters has a history of 600 years, while Shanqing Tower with a diameter of 3 1 meter has a history of only 30 years. The formation of Fujian Tulou is related to several famous Han immigrants from the Central Plains in history. During the Yongjia period of the Western Jin Dynasty, that is, in the 4th century, there were frequent wars and natural disasters in the north, and the local people moved southward on a large scale, which opened the prelude to the continuous migration of Han people from the Central Plains to Fujian for thousands of years. The immigrants from the Central Plains who entered southern Fujian merged with local residents, forming the Fulao nationality with Minnan dialect as its characteristic. The Han nationality in the Central Plains who migrated from Ganzhou, Jiangxi Province to the mountainous areas in western Fujian Province constitutes another important ethnic group in Fujian-the Hakka ethnic group characterized by Hakka dialect. Fujian Tulou is located in Nanshan District, southwest Fujian, which is the meeting place of Fulao and Hakka. The terrain is steep and sparsely populated. At that time, wild animals appeared and bandits were everywhere. Living in groups is not only the requirement of the deep-rooted Confucian traditional concept in the Central Plains, but also the realistic need to gather strength and resist foreign enemies. Fujian tulou is built on the mountain with reasonable layout. It absorbs the "Feng Shui" concept of traditional architectural planning in China, adapts to the living and defense requirements of people living together, and skillfully uses the narrow flat land in mountainous areas and local building materials such as raw soil, wood and pebbles. It is a self-contained, economical, strong and defensive high-rise building type with great aesthetic feeling. These unique residential buildings in mountainous areas have pushed the long-standing rammed earth technology to the extreme.