Spatial Distribution Characteristics of Industrial Remains of the Third Front Construction in the Yangtze River Delta

The industrial remains of the Third Front Construction are the industrial cultural remains left behind by military-industrial development during the Third Front Construction period. These remains hold special value and have complex causes. Exploring their spatial distribution characteristics is of great significance for their protection and utilization. Taking 167 third front construction industrial remains from the Third Front Construction in the Yangtze River Delta as the research object， this study analyzed their spatial distribution characteristics by GIS. The results show that： 1）73% of the remains are located in Anhui Province， and 74% of the remains are distributed in rural areas， forming a functional combination layout model of "military factory， medical care， education， logistics， and management" in the overall spatial area； 2） macroscopically， the spatial distribution shows the characteristics of "overall concentration， scattered areas， one core with many pairs， and uneven distribution"， forming a high-density gathering area in the border area between southern Anhui and western Zhejiang， while Huoshan County， Shucheng County， and Lishui City form two sub-density gathering areas； 3） at the micro level， it exhibites the synchronic characteristics of "relying on deep mountains， being close to water sources， connecting with main roads， relying on villages， and gathering locally" and the diachronic evolution characteristics of "independence turning to integration". The factory area is laid out along mountain gullies， forming four layout types： linear series along gullies， concentrated clusters in wide gullies， parallel arrangements along gullies， and radial patterns branching from forked gullies. Meanwhile， rural Third Front industrial remains rely on the surrounding villages， creating three spatial relationships： independent， connected， and interwoven.