Rural space is a regional concept that refers to all areas outside the urban areas (Cassidy et al.,2010; Zhang et al., 2023). One of the most essential characteristics of rural space is function, and its change might signal a change in the land use of the area (Long et al., 2016; Tu et al., 2018; Argent, 1999). Rural multi-functional (RMF) originated from the agricultural multi-function and land use multi-function systems of the EU at the end of the 20th century (Yang et al., 2023a;Feinerman and Falkovit, 1991; Sophie et al., 2007). The OECD (Organization for Economic Co-operation and Development) noted that agriculture performs a variety of roles in restoring rural landscapes and preserving biodiversity in addition to producing food and fiber and supporting the sustainable growth of agriculture (García-Llorente et al., 2012; Marsden and Sonnino, 2008; Renting et al., 2013). Coordinating the contradictions between economic growth, life improvement, and ecological conservation in rural areas has become a pressing issue that must be addressed. Therefore, many studies have begun to expand the research scope of RMF (Jerzy Banski and Monika, 2010; Liu and Liu, 2012). In a given stage of social development, RMF refers to the beneficial role of a specific rural system to nature or mankind by giving play to its own attributes and its joint role with other systems in a larger regional space in a certain stage of social development (Li et al., 2015; Long et al., 2007; Agnoletti, 2014).

Rural reconstruction and evolution have become key issues in geographical studies (Agnoletti, 2014). For example, some studies that were primarily based on geography were gradually integrated into the disciplines of economics, sociology, landscape ecology, and biology and investigated the spatial distribution characteristics of rural connotation, classification, function, culture, and environment from various scientific perspectives (Kunitsa, 2012; Li et al., 2021). In establishing the evaluation index system, many studies have taken the geo-relational territorial system as the theoretical basis; classified the functional types of RMF in terms of resources, environment, humanities, economy, and other dimensions; analyzed the mechanism of differentiation of rural territorial development; and clarified the way of development of rural territorial sub-districts (Zhao et al., 2022). In terms of the research methodology, the data are usually quantified through the comprehensive index evaluation method, and then techniques such as the Gini coefficient, neural network model, local spatial autocorrelation, and gray correlation method are applied to study the delineation of rural functions and the evolution law (Zhen et al., 2024; Ma et al., 2023). For regions with different characteristics, how to establish a targeted RMF indicator system is a research hotspot.

With the continual advancement of urbanization and industrialization in China, the urban and rural economic structures and demographics are continuously recombining (Hualou, 2012; Xiong et al., 2021). It has led to many issues in rural regions, such as extensive and inefficient land use, chaotic construction, a lack of infrastructure and public services, encroachment on agricultural production space, and environmental deterioration (Yang et al., 2023b; Hu et al., 2020).

In particular, the Liaoning Coastal Economic Belt in Northeast China is both a national grain production functional area and a port industrial belt with international competitiveness. The Liaoning Coastal Economic Zone has a good agricultural foundation, concentrating half of the province’s agricultural population, accounting for approximately half of the province’s agricultural output, and accounting for approximately 40% of the province’s sown area and output of major grain crops. However, there is an imbalance in the structure of supply and demand of agricultural products, and there are many people with little land, little arable land, little fresh water, and high pollution from agricultural sources, resulting in serious pollution of the water environment ( Ma and Zheng, 2018). Its rural development has always been in a weak position. The key to treating “rural sickness” is to appropriately construct the RMF identification system, optimize the rural “living, production, ecology” space, and achieve the multifunctional and coordinated development of rural space (Liu, 2020; Long et al., 2021).

Since 2000, China’s development paradigm has shifted, with the relationship between urban and rural areas changing and rural construction entering a new phase. In 2013, the Central Government’s Document No. 1 centered on the three rural issues and provided a top-level design for rural development in order to solve the problems of the three rural issues. In 2023, Liaoning Province issued the “14th Five-Year Plan for Modernization of Agriculture and Rural Areas in Liaoning Province,” marking the beginning of a new phase. Based on the background of the Rural Revitalization Strategy, this study aimed primarily to (1) establish an RMF index system and describe the features of rural regional spatial–temporal diversification in the research area in 2000, 2013, and 2023; (2) measure the coupling and interacting relationship between mutual promotion and mutual stress of living, production, and ecosystem, as well as perform spatial comparison and time series analysis; (3) investigate the primary drivers of the geographical difference in RMF level in the research region using Geodetector, as well as the action intensity of various factors on spatial–temporal distribution. The findings of this study will provide new research ideas for exploring rural regional space diversification and achieving multifunctional and coordinated rural space development in Liaoning Province.

The two-dimensional graph theory clustering method was used to provide measures for rural development (Zhang et al., 2020 ; Chang et al., 2017). In this way, it can maintain the relative constancy of natural resources and socioeconomic data within each county and maintain the continuity and integrity of administrative divisions. We classified 30 counties in the Economic Belt as having six categories of rural development and proposed management methods (Figure 7).

Coordination and optimization area (Zone I). The RMF value is 0.233–0.252–0.458, indicating undeveloped functions and a mild imbalance of three functions. This area’s physical position and socioeconomic status are both deplorable. In recent years, there has been a certain amount of idle land in these regions representative of typical resource-depleted cities in Liaoning Province, which directly impacts the land usage rate, output rate, and utilization efficiency of villages. Therefore, the first step is to reinvigorate inefficient and idle land, to rationally manage the land use scale and layout of villages, and to strengthen the rehabilitation of old and damaged dwellings. The second step is to comprehend the “dual strategic posture” of the Economic Belt and the integration of western Liaoning into Beijing, Tianjin, and Hebei, promote distinctive agriculture, and improve agricultural machinery and agronomy integration system development. The third requires adhering to ecological priority by aiming for carbon neutrality and emission peak, reducing rural household and production waste, and preventing environmental morbidity.

Potential lifting area (Zone Ⅱ). The RMF value is 0.272–0.391–0.280, which is characterized by living function, strong development strength, and tremendous potential. Some counties are adjacent to metropolitan regions, where secondary and tertiary industries have a solid development base. The per capita net income of farmers can reach 20,000 yuan (RMB), ranking first in the province for several years in a row and indicating that the proportion of property and transfer income of rural residents in this region is high. However, there is wasteful internal friction and low-level repeated construction in land use, which obstructs the efficiency of industrial integration and the optimal utilization of land resources. In the future, we should mobilize villagers to establish a business model by taking shares in villagers’ homesteads and agreeing on specific cooperation methods, dividend methods, and compensation methods to provide a strong guarantee for the economic increase of rural residents. We will conduct experimental projects to change rural residential land, revitalize deteriorating historic dwellings, and optimize rural house layout.

Moderate lifting area (Zone Ⅲ). The RMF value is 0.339–0.390–0.386, with agriculture production being the most important function, and the three functions are strongly coordinated. This area is part of the “western Liaoning Corridor.” The East is a transportation center that connects North and Northeast China. As a national commodity grain base, this area is an important part of the main agricultural production area of Liaoning Province. All counties should accelerate agricultural supply-side structural reform, increase cultivated land output efficiency, strengthen agricultural structure adjustment, and prioritize the processing of agricultural goods and export of healthy food as rural pillar industries. While strengthening the agricultural production function, we should focus on the prevention and management of agricultural film pollution to avoid agricultural pollution.

Key promotion area (Zone Ⅳ). The RMF value is 0.284–0.404–0.381, which is characterized by a high level of non-agricultural production and comprehensive rural development. This is the “Northeast Asia International Trade Center.” In the future, the first steps will highlight the leading role of the comparative advantage function of non-agricultural industries and strive to cultivate and expand three new industries: clean energy, tourism, and healthcare, and further consolidate and enhance the development of rural enterprises and tourism. The second step will establish a modern green agriculture cluster represented by planting, breeding, and processing of agricultural products, develop the agricultural complementary industry, and promote farmers’ sustained and stable increase in production and income. The third phase will delineate the red line for regional ecological protection and reduce the use of high-quality cultivated land and ecological land for non-agricultural industry growth.

Ecological guarantee area (Zone Ⅴ). The RMF value is 0.207–0.328–0.656, which is characterized by high agglomeration conditions of natural resources, strong functions of ecological maintenance and stability, and weak living and production functions. This area is a part of the mountains and hills in Eastern Liaoning. It is the province’s most abundant source of ecological resources and the primary supplier of ecological goods. Regional water resources are plentiful, with the per capita water volume reaching 3968 km³, ensuring the smooth growth of regional industrial development, urban building, and other activities. The development of this region should take the initiative to launch eco-agricultural products and eco-tourism products and actively develop the processing industry of agricultural and sideline products with green and ecological characteristics in conjunction with the border economy and national characteristics. Concurrently, a village landscape corridor, village leisure and greening ecological corridor, the regional water network space, and the waterfront area should be constructed.

Comprehensive development area (Zone Ⅵ). The RMF value is 0.382–0.422–0.280, which indicates an obvious industrial agglomeration effect and high people’s living standards. This area has a strong non-agricultural production function, and the attraction and radiation of cities increase the rural economic level. However, the per capita cultivated land area is declining, the reserve resources of cultivated land are severely depleted, and the contradiction between man and land is becoming increasingly prominent. The rural economy ignores the improvement of the rural living environment and the natural environment. While strengthening regional industrial agglomeration, regional development should fully protect rural residents’ housing and production land needs, establish a dynamic supervision system for the balance of cultivated land occupation and compensation, and pilot a project linking the increase and decrease of urban and rural construction land, in order to ensure the dynamic balance of agricultural production land and non-agricultural production land. The ease, livability, and comfort of the living environment will be improved by further optimizing the building of supporting infrastructure for rural life.

According to the findings, RMF has an extremely substantial spatial positive link with the passage of time. At the same time, the coupling coordination degree is showing a “gradual upward” trend from reluctant coordination to good coordination, and the gap across counties is shrinking. Natural resources have switched to socioeconomic variables and policy environment as the dominating drivers of RMF spatial differentiation during the last 20 years. The rapid non-agricultural transformation of agricultural production factors, the increasing empty and waste of village construction land, and the deep poverty of some rural areas are the most prominent structural contradictions in the development of the Economic Belt at this stage.

In view of the general distribution pattern of RMF vulnerable areas and local prominent strong areas in the study area, the Economic Belt urgently needs to promote benign and coordinated multi-functional development while optimizing and upgrading rural regional functions. Development plans should adopt a cluster development strategy in conjunction with advantageous rural industries, increase the radiation and driving function of strong areas, achieve complementary, mutual, and linking growth between villages and villages, and close the regional gap. At the same time, it is important that development actively protects the ecology and promotes the sustainable development of the village. Given the continued deterioration of the rural ecological function, we must focus on ecological building, optimize the structure of rural ecosystems, integrate development, and enhance the rural ecosystem’s overall economic, social, and ecological advantages in the future. We must continuously explore new rural industries, new formats, new models, and new technologies to realize the sustainable development of rural ecosystems.