Objective As the spiritual symbol of ethnic minorities, vernacular settlements carry unique ethnic elements and cultural genes. They are the mainstay for promoting rural revitalization, building ethnic cultural self-confidence and community awareness, and enhancing national cohesion, and are also a unique cultural heritage in agricultural civilization and a crystallization of national wisdom. China is home to many ethnic groups, and in the concentrated areas of ethnic minority groups, there still exist quite authentic settlements without being largely disturbed. However, with the rapid advancement of urbanization, the unbalanced and inadequate development in ethnic areas has gradually brought severe challenges such as cultural loss, population loss and slow development to vernacular settlements. Fujian Province is a region where ethnic minorities such as She, Gaoshan, Hui, Manchu and Mongolian have lived together for generations. The natural environment, social economy and ethnic culture in Fujian are significantly heterogeneous. It is urgent to plan and promote ethnic work based on the historical orientation of the new era, and strengthen the achievements of poverty alleviation in ethnic minorities and vernacular settlements thereof, thus effectively contributing to rural revitalization. In view of this, it is of great significance to study the spatial distribution characteristics of vernacular settlements and the driving mechanism thereof for the economic development and cultural inheritance of vernacular settlements in ethnic areas.

Methods This research takes the vernacular settlements in Fujian Province as the research object. The research firstly adopts the geographical concentration index to measure the concentration degree of vernacular settlements in Fujian Province. Then it adopts the average nearest neighbor index method to analyze the spatial distribution type and proximity degree of vernacular settlements in Fujian Province in combination with the spatial distribution vector diagram of vernacular settlements. After that, the research adopts the kernel density estimation method to quantitatively explain the distribution density and aggregation area of vernacular settlements as a whole and fallen into different categories, and to clarify the spatial distribution characteristics of vernacular settlements. On this basis, the research adopts the Geographic detector model to explore the influence of such driving factors as natural environment, location, social economy and policy culture on the spatial distribution of vernacular settlements.

Results The results of this research are as follows. 1) The spatial distribution of vernacular settlements in Fujian Province is extremely uneven, mainly composed of She and Hui settlements, with She settlements occupying the dominant position. The overall number of She settlements decreases from the eastern coastal area to the west area, and most of them are distributed in the county-level areas far from the main urban area. The vernacular settlements in Fujian Province have formed a distribution pattern of "seven cores and three belts" in the shape of "chuan", which is featured by large-scale agglomeration and small-scale dispersion, presenting obvious spatial agglomeration characteristics. In terms of spatial structure, a circle structure with Ningde City as highly dense core area, Shanghang County in Sanming City and Jinjiang City and Hui'an County in Quanzhou City as moderately dense core area, and Ninghua County and Datian County in Sanming City and Nanping City as core area has been formed, with the aforesaid core areas gradually radiating outward. The core agglomeration areas of She settlements are mainly concentrated in Ningde, Sanming, Longyan, Quanzhou and Nanping cities, showing a weak circle structure. The Hui settlements mainly form a core agglomeration area in Quanzhou City, and the Manchu, Mongolian and Miao settlements are few and randomly distributed. 2) The spatial distribution pattern of vernacular settlements in Fujian Province is influenced by multiple factors such as natural environment, location, social economy and cultural policy, among which road network density, cultural policy, population density and economic aggregate are the main influencing factors. Natural factors serve as the basis for settlement siting and construction. The distribution of vernacular settlements in Fujian Province is positively correlated with the natural environment, mostly in the low and middle altitude areas with flat terrain. Location factors are related to the development of vernacular settlements and their connection with the outside world. Traffic density, as a medium for connecting settlements, is weakly negatively correlated with the distribution of vernacular settlements. The density of river system is positively correlated with the distribution of vernacular settlements, and vernacular settlements are concentrated in areas with less developed traffic system and closer to the waters. The coupling relationship between social economy and the distribution of vernacular settlements shows a trend of overall negative correlation and partial positive correlation. Policy and cultural drive are positively correlated with the distribution of settlements and coordinated with the development of settlements.

Conclusion This research shows that the mutual adaptation and coupling of ecological environment and multiple cultures is the endogenous driving force for the development of vernacular settlements. In view of this, the research puts forward the development path of vernacular settlements to provide reference for the protection, inheritance and rural revitalization of vernacular settlements in Fujian Province. In addition, the study of the spatial differentiation characteristics of vernacular settlements and the driving mechanism thereof from the perspective of geography is helpful to the development and protection of vernacular settlements, and can provide some reference for the spatial resource allocation and regional differentiation protection of vernacular settlements.