Rural revitalization needs to recognize and address the diversity of rural areas. Based on statistical data of grain yield and agricultural labor, this paper analyzes the coupled modes of the changes of grain yield and agricultural labor as well as their representations of rural development typology of 183 counties in Northeast China by using standard deviation ellipse, non-parametric test, and so on. The results show that: (1) during 2001-2015, the coupled mode of grain yield and agricultural labor changes of the whole study region turned in 2008. During 2001-2008, its grain yield increased while agricultural labor decreased; but during 2008-2015, both its grain yield and agricultural labor increased. Actually, this is due to degradation that resulted from the comprehensive interactions of many factors. (2) At county level, the proportion of grain yield increased while agricultural labor decreased counties in Northeast China shrank from 45.90% in 2001-2008 to 37.16% in 2008-2015, and the numbers of grain yield decreased while agricultural labor increased counties and grain yield and agricultural labor both decreased counties grew obviously. Spatially, the coupled modes of grain yield and agricultural labor changes evolved in differentiated patterns. (3) Based on the coupled modes of grain yield and agricultural labor changes and other supplementary indicators, this paper classifies the rural development typology at county level in Northeast China into five categories: extensive expansion type, agriculture modernization type, planting-breeding incorporated type, urbanizing type, and eco-environment prioritized type. The results show that these rural development types have certain hierarchical nature and present a structural evolution. Therefore, the coupled modes of grain yield and agricultural labor changes can represent the rural development typology well. (4) Different rural development types in Northeast China are facing different constraints and opportunities. In the light of these facts, this paper proposes the differential promotion strategies targeting specific rural development types. The approaches and strategies developed in this paper could be applied in other regions of China to analyze and address the diversity of rural areas.

Eco-migrant village is a special type of village with the dual significance of poverty alleviation and ecological protection, as well as the indispensable and crucial object for rural revitalization. The spatial deprivation (SD), which resulted from the process of spatial reconstruction, is a new problem emerging in the course of eco-migrant villages revitalization and sustainable development. In order to explore the rule of the SD, this paper constructs a spatial deprivation index (SDI) system with income and employment, education and training, social life, living environment and accessibility of public services as the main contents, based on the data of 70 eco-migrant villages (EMV) of Ningxia in 2017, calculates EMVs' SDI value, and detects the impact factors by geographical weighted regression and GeoDetector. The results show that: (1) the overall level of SD of EMVs is low, but the total index means is 0.023 higher than that of non-EMVs. (2) The spatial and temporal variations of EMVs' SDI are obvious, presenting a time trend of "low - rise - decline" and a spatial distribution pattern of "the lowest in the north - the highest in the middle - the second highest in the south". (3) Ethnic composition, terrain and landform, migration period, essential resources and economic zone are critical factors affecting the SD of EMVs, in which the first three have explanatory capacity of the total SDI, being 22.4%, 10.6% and 14.0%, respectively. SD measurement provides a new objective basis for evaluating production and life of eco-migrants, adjusting and refining policies, so that relevant departments can optimize and reallocate the spatial resources of EMVs to increase their ability and opportunities, and promote the overall revitalization of EMVs.

Village is the object of rural governance and revitalization. It is of great scientific value to carry out the research on the spatial distribution characteristics and influencing factors for comprehensively promoting the implementation of the rural revitalization strategy. This study systematically integrated the multi-source data such as the longitude and latitude coordinates of the village, geo-environment, traffic conditions and socio-economic level, and comprehensively applied spatial analysis, kernel density estimation and Ripley's K-function to describe the spatial distribution characteristics of Chinese villages and identify the influencing factors of village spatial differentiation. The results demonstrated that the evolution of villages follows the life cycle laws of formation, development, stability, decline, and revitalization, which is affected by the natural geographical environment and human, social, and economic factors. The speed, intensity, direction, and outcome of village evolution vary across regions over time. Further analysis results showed that the distribution density of villages in China is 0.353 per square kilometer. Overall, the number of villages in China is larger in the south than in the north, and larger in the east than in the west, and characterized by agglomeration in the southeast and dispersion in the northwest. Villages are most densely distributed in the middle and lower reaches of the Yangtze River and the Huaihe River Basin. With Hu's line as the boundary, the density of villages in the southeast is higher than that in the northwest. The Moran indexes of the kernel density of villages on the scales of province, county and township are 0.580, 0.861 and 0.910, respectively, showing obvious spatial aggregation characteristics. The spatial distribution of villages in each province presents an inverted U-shaped pattern, and the difference is obvious between provinces. The distribution pattern of Chinese villages is the result of the interactive coupling of geographical environment, location conditions, and social and economic factors. The spatial distribution of Chinese villages is relatively concentrated under the conditions of a slope of 6°-8°, an altitude of less than 200 m, rainfall of 1100-1200 mm, average annual temperature of 15-19 ℃, and anthropogenic soil and cultivated vegetation. The spatial distribution of villages is clustered along roads and rivers. The density of villages in the buffer zone of 100-300 m around roads and rivers is the largest, and gradually decreases as the buffer distance increases. Under the background of comprehensively promoting the strategy of rural revitalization, it is urgent to systematically analyze the causes and dynamic mechanism of rural recession, identify the geographical distribution and types of declining villages, and explore the feasible ways and regional models of rural revitalization.

In the face of global environmental challenges, sustainable development has received much attention worldwide, and sustainability science has emerged in the 21st century as a globally well-recognized new area of science. Rural sustainability science, as an important part of sustainability science, is a use-inspired science aimed at understanding and improving the dynamic relationship between people and the rural environment from a transdisciplinary and multiscale perspective. In tandem with urban sustainability science, it provides much needed scientific support for dealing with rural decline and promoting rural sustainable development. In this paper, we first discuss the concepts of sustainability, rural sustainability, and rural sustainability science, and then propose a transdisciplinary integrated framework of rural sustainability science that focuses on agricultural sustainability, community sustainability, and rural human well-being. China is a nation with deep rural roots, complex problems involving interactions among agriculture, farmers, and villages, and huge urban-rural socioeconomic gaps. Since the reform and opening-up in 1978, China's rural areas have developed rapidly, but they still face numerous tough challenges. Rural revitalization strategies are needed for promoting the rural transition toward sustainability, but the necessary scientific basis and appropriate guidelines for formulating such strategies are still lacking. We argue that rural sustainability science can provide theoretical, technical, and decision-making support for the implementation of rural revitalization strategies. Our analysis of the current status of China's rural sustainable development indicates that the transition to sustainability is urgently needed, and so is the science that guides the transition. To address these problems, we call for transdisciplinary research that couples rural society and its environment, focusing on nine core issues in line with the needs of China's rural development and aiming to transfer knowledge of rural sustainability into local adaptive actions.

Poverty includes regional poverty and individual poverty, both of which are featured by multidimensional concept. Regional multidimensional poverty (RMP) is a major theme and content in poverty geography. Because of harsh natural environment, vulnerable economy and inadequate public services, severely impoverished areas (SIAs) are typical and highlighted areas of RMP, which have been the biggest obstacle to poverty alleviation in China. Based on the theory of spatial poverty, this paper defines the notion of impoverished areal system (IAS) and regional multidimensional poverty (RMP), explores their internal connections and proposes the evaluation indictors and measurement method for RMP. Taking 334 severely impoverished counties as research samples, we analyze the multidimensional poverty patterns of SIAs in 2016 by BP neural network model and exploratory spatial data analysis (ESDA). Results show that: (1) RMP is an external manifestation of the coupling imbalance of "human", "environment" and "industry" in the evolution of IAS. It reveals regional disadvantages in natural environment, economic development and social welfare, corresponding to natural poverty, economic poverty and welfare poverty, respectively. (2) The most severely impoverished county, with the poorest services and infrastructure, is found in the Qinghai-Tibet Plateau. From a single dimension of regional poverty, the Welfare Poverty Index (WPI) > Economic Poverty Index (EPI) > Natural Poverty Index (NPI) in the SIAs, whose average is 2.77, 2.66 and 1.89, respectively, indicating that the lack of social welfare and public services for the poor has become the prominent problem in the SIAs. From the perspective of multidimensional poverty, the Qinghai-Tibet Plateau is a high agglomeration region or "hot spot" of RMP, which is significantly higher than other areas in terms of natural poverty, economic poverty and welfare poverty. (3) Both RMP and individual multidimensional poverty are effective measures of poverty targeting. Their matching coefficient (M) can help us to judge the poverty status of some specific areas, e.g., RMP is superior to individual multidimensional poverty in the remote areas, extremely fragile ecological environment and obvious regional disadvantage, where the matching coefficient (M) is higher. RMP can more objectively reflect the true level of geographical capitals, effectively target poor areas and identify determinant impoverishing factors.

Poverty has appeared as one of the long-term predicaments facing human development in the 21st century. The essence of extreme poverty is absolute poverty, where individuals experience long-term shortages of essential resources or suffer from harsh environment. Extreme poverty is the priority for poverty alleviation and the tough row to hoe. We select the major poverty influencing factors from natural and social factors to build an evaluation index system based on spatial poverty and related theories. First, we use Pearson correlation analysis to differentiate poverty impoverishing and alleviation factors. Then, we use GIS and back propagating neural networks to define a natural impoverishing index (NII) and social economic poverty alleviation index (SEPAI), respectively, at provincial, municipal, and county levels. We then calculate a poverty pressure index (PPI) at provincial, municipal, and county levels by combining NII and SEPAI, and explore poverty spatial characteristics. We used the flexible spatial scanning statistical method to identify the severely impoverished counties among the poverty-stricken counties with PPI>1.63, which had higher poverty rate and difficulty in poverty alleviation. Finally, we diagnose dominant factors that differentiate severely impoverished counties, and identify the dynamic mechanism of regional extreme poverty differentiation using the geodetector model. Besides, we construct a theoretical basis for anti-poverty in rural China. The results show that NII and PPI spatial distributions are highly consistent at provincial, municipal, and county levels, with a significant distribution pattern: high in eastern China and low in western China. In contrast, SEPAI has relatively low spatial consistency at provincial, municipal, and county levels. The PPI poverty distribution pattern tends toward large dispersion, small aggregation dividing across the Heihe-Bose Line. A total of 655 poverty-stricken counties were identified, mainly distributed in major ecologically functional and agricultural production areas in China. High risk areas identified by spatial scanning are mainly distributed in the northwest, southwest minority, and border areas. We also identified 208 severely impoverished counties, mostly located in inter-provincial fringe areas. The geodetector model identified seven dominant impoverishing factors, with significant differences between the four identified rural extreme poverty types: terrain detail oriented, location traffic dominated, economic income leading, and ecoenvironment constrained regions.

The concept of cultural landscape genes of traditional settlements (CLGTS) was proposed by Chinese scholars in 2003. Since then, CLGTS has been playing a key role in capturing the deep-level geographic features of traditional settlements. However, there is a lack of work on covering CLGTS from the perspective of semiotics. Now, people are often involved in difficulties when they are trying to explore the nature of cultural landscapes of traditional settlements through using CLGTS. Obviously, it is of great significance to explore the concepts and methods of semiotic mechanism of CLGTS under the support of semiology. To lock this issue, we outline the dialectical features of CLGTS through the following five aspects. (1) For a given traditional settlement, its whole image at the macro-scale is in accordance with its cultural landscape genes at the micro-scale. (2) For the cultural landscape gene of a given traditional settlement, its core characterizations are in accordance with its appearance features. (3) For a given traditional settlement, its self-updating mechanism at local scale is in accordance with its global characterizations. (4) CLGTS can be treated as the scientific analysis method merged with the quantitative and qualitative approaches for dissecting the cultural features of traditional settlements. (5) For a given traditional settlement, its outstanding features of cultural landscape are in accordance with its rich cultural connotation. Then, this work proves the diversity of forms and complexity of spatial structures of CLGTS through ample examples. To some extent, this reveals the nonlinearity, self-organization, as well as self-iteration features of CLGTS. Based on the above, this research presents a conceptual framework of semiotic mechanism of CLGTS. Within the framework, we further summarize the symbols' main features, classifications, and expression ways of CLGTS. Through this work, we make clear the requisite theoretical conditions of making symbols of CLGTS by employing GIS. Ultimately, based on the aforementioned conceptual framework, this paper develops a prototype program for making symbols of CLGTS. The test results of the prototype program with a case of ancient village of Hunan Province show that it can run well in serving to establish a symbol database of CLGTS for a given region. Hence, this research proves that semiotic mechanism of CLGTS will make sense of perfecting the theory of CLGTS and forwarding its digital protection.