Central Jiangsu Research Articles

Temporal and spatial characteristics of carbon emissions from cultivated land use and their influencing factors: A case study of the Yangtze River Delta region

This study focuses on the Yangtze River Delta region and employs spatial analysis and geographically and temporally weighted regression (GTWR) to explore the temporal and spatial characteristics of carbon emissions from cultivated land use and their influencing factors. The findings indicate that carbon emissions from cultivated land use in the Yangtze River Delta generally show a decreasing trend, but there has been a significant increase in Anhui Province, mainly due to government efforts to promote agricultural development. Additionally, the spatial distributions of carbon emissions from cultivated land use clearly differ in terms of proximity, with changing temporal and spatial patterns. (1) From 2005 to 2020, there were significant spatial differences in the carbon emission intensity from cultivated land use across the Yangtze River Delta. The emission intensities in the southern areas were generally higher than those in the northeastern and central regions, whereas the western areas presented lower emission intensities. (2) The carbon emission intensity from cultivated land use in the Yangtze River Delta exhibited significant spatial proximity, meaning that neighboring areas had similar emission intensities, presenting a continuous distribution pattern. Contiguous distributions were also observed in parts of northern Anhui, central Jiangsu, and southeastern Zhejiang. (3) The carbon emission intensity from cultivated land use in the Yangtze River Delta showed a trend of high-intensity reductions and low-intensity increases over time and space. The level of agricultural development, scale of farmland management, types of crops planted, income levels of rural residents, intensity of agricultural machinery input, and strength of agricultural financial support significantly impact carbon emissions from cultivated land use. The results provide important references and a theoretical basis for the management and regulation of agricultural carbon emissions in the Yangtze River Delta region.

Field observations on the characteristics of sand ripples on tidal flats

Ripples on tidal flats significantly influence bedform roughness and near-bed turbulence, yet their dynamics in sandy and muddy environments remain incompletely understood. While laboratory studies have elucidated the effects of mud content and extracellular polymeric substances (EPSs) on ripple formation and stability, the interactions between ripple characteristics, EPS, and mud content in natural settings are more complex and not thoroughly explored. To address this gap, we conducted field studies on sand ripples at the central Jiangsu coast, China, using high-resolution drone photogrammetry to accurately measure ripple dimensions. We performed bedload sampling at both ripple crests and troughs to analyze median grain size, mud content, and EPS concentrations. Our results show that the investigated ripple wavelengths range from 34 to 46 mm, and heights vary between 2.7 and 5.3 mm. Ripples developed near tidal creeks show pronounced asymmetry. Significantly, EPS concentrations are markedly higher at the ripple crests than at the troughs, and it follows a power-law relationship with the median grain size. These results highlight the complex intricate relationship between the ripple morphology, environmental forcing conditions, and EPS content. Our findings enrich the understanding of ripple development and the factors influencing current-dominated ripples in natural environments. This research also adds to the better prediction of the bedform roughness and quantification of the near bed sediment transport.

The Impact of Water-Saving Irrigation on Rice Growth and Comprehensive Evaluation of Irrigation Strategies

To explore the effects of different water-saving treatments on rice plant growth and select suitable water-saving irrigation strategies for aerobic rice varieties, we conducted relevant field experiments from June to October 2023 at Jiangsu Runguo Agricultural Development Co., Ltd., China, which is located in a north subtropical monsoon climate where the soil is alkaline sandy loam. Four water treatments were set up, including the control of local conventional irrigation (CK, without water stress), mild water-saving treatment (W1, 20% more water saved than CK), moderate water-saving treatment (W2, 30% more water saved than CK), and severe water-saving treatment (W3, 40% more water saved than CK). The experiment results showed that rice plant heights were inhibited and leaf chlorophyll contents increased under all water-saving treatments compared to CK. Among them, the MDA content in paddy leaves under the W1 treatment decreased, while the activities of SOD and POD were enhanced and the membrane lipid peroxidation capacity of rice was also enhanced. Meanwhile, the results showed that the rice yield and quality under the W1 treatment significantly improved. Based on those experiments, a comprehensive evaluation of rice plant height, chlorophyll content, grain yield, yield components, and rice quality was conducted using the TOPSIS entropy weight method. It was preliminarily concluded that the suitable irrigation scheme for south and central Jiangsu was 20% water-saving irrigation compared with CK. In summary, under the premise of maintaining the economic yield of rice cultivation, an appropriate water irrigation plan helped save water resources and promote rice growth.

Seasonal quantification of the inter-city transport of PM2.5 in the Yangtze River Delta region of China based on a source-oriented chemical transport model and the Michaelis-Menten equation

Regional transport plays a crucial role in the pollution of fine particulate matter (PM2.5) over the Yangtze River Delta region (YRD). A practical joint regional emission control strategy requires quantitative assessment of the contribution of regional transport. In this study, the contribution of inter-city transport to PM2.5 among the 41 cities in the YRD region were quantitatively estimated using a source-oriented chemical transport model, and then the relationship between the cumulative contribution of regional transport and the distance was examined using the Michaelis-Menten equation. The results show that the Michaelis-Menten equation is suitable to represent the relationship between the cumulative contribution and transport distance. The coefficient of determination (r2) of the fittings is greater than 0.9 in 71 % of the cases in the six subregions and four seasons in YRD. Two key parameters in the Michaelis-Menten eq. K1, indicating the maximum contribution of regional transport, and K2, indicating the distance to which the regional transport contribution reach half the maximum contribution, show substantial regional and seasonal variations. The average K1 is 73.6 %, with lower values observed in the northern part of the YRD and higher values in central Jiangsu. K2 is larger in northern Jiangsu, as well as central and southern Zhejiang. The local contribution in autumn and winter is lower than that in spring and summer in the northern part of the YRD. Particularly in northern Jiangsu, the local contribution reaches 90.4 % in summer but drops to 53.0 % in autumn and winter, illustrating significant impacts of regional transport to PM2.5 in autumn and winter in this area. K2 is larger on polluted days, compared to clean days, indicating greater contributions from regional transport to PM2.5 in YRD. The results can serve as a scientific foundation for implementing regional joint prevention and control measures in the YRD region.

Exploring the spatial effects and influencing mechanism of ozone concentration in the Yangtze River Delta urban agglomerations of China.

Ground-level ozone (O3) pollution has emerged as a significant concern impacting air quality in urban agglomerations, primarily driven by meteorological conditions and social-economic factors. However, previous studies have neglected to comprehensively reveal the spatial distribution and driving mechanism of O3 pollution. Based on the O3 monitoring data of 41 cities in the Yangtze River Delta (YRD) from 2014 to 2021, a comprehensive analysis framework of spatial analysis-spatial econometric regression was constructed to reveal the driving mechanism of O3 pollution. The results revealed the following: (1) O3 concentrations in the YRD exhibited a general increasing and then decreasing trend, indicating an improvement in pollution levels. The areas with higher O3 concentration are mainly the cities concentrated in central and southern Jiangsu, Shanghai, and northern Zhejiang. (2) The change of O3 concentration and distribution is the result of various factors. The effect of urbanization on O3 concentrations followed an inverted U-shaped curve, which implies that achieving higher quality urbanization is essential for effectively controlling urban O3 pollution. Traffic conditions and energy consumption have significant direct positive influences on O3 concentrations and spatial spillover effects. The indirect pollution contribution, considering economic weight, accounted for about 35%. Thus, addressing overall regional energy consumption and implementing traffic source regulations are crucial paths for O3 pollution control in the YRD. (3) Meteorological conditions play a certain role in regulating the O3 concentration. Higher wind speed will promote the diffusion of O3 and increase the O3 concentration in the surrounding city. These findings provide valuable insights for designing effective policies to improve air quality and mitigate ozone pollution in urban agglomeration area.

Potential imbalanced differences of grain production in the sustainable development of county cities—a case study of Jiangsu Province

IntroductionGrain production at the regional level is related to the strategic development orientation of the country as a whole, and maintaining the stability of grain production is of great importance in ensuring the sustainable development of the food system. Studying the potential imbalance differences resulting from the spatial and temporal development of grain production and its driving factors will help to reduce the contradiction between the rapid development of the urban economy and the inappropriate use of arable land resources, thus coordinating regional agricultural development and further clarifying the direction and focus of future food security construction work.MethodsThis study focuses on the potential imbalance differences based on spatial and temporal development of grain production in Jiangsu Province during the period 1990–2020, and explores the spatial and temporal patterns and driving mechanisms of grain production spatial autocorrelation model and spatial error model are applied to analysis the spatial and temporal characteristics of grain production and security in Jiangsu Province and their influencing factors.ResultsThe results are as follows: (1) The total amount of food in Jiangsu Province increased by 17.36% during the 30-year period, but the growth rate was lower than the national average. (2) Regional differences are significant, with a significant decline in grain production in southern Jiangsu and growth in northern and central Jiangsu. (3) The center of gravity for grain production has shifted to northern Jiangsu. (4) Grain production is significantly correlated with socio-economic factors such as per capita ownership, sown area, irrigated area, and cultivated area.DiscussionTo ensure the sustainability of food production in the future, attention should be paid to the risk of imbalance in regional food production, coordination of socio-economic factors, promotion of efficient agricultural production, improvement of the relevant policy system and optimization of the food production system.

Investigation on Junior High School Extensive Reading Teaching of the Blackberry English Reading Series from the Perspective of Big Ideas

Big ideas refer to the core concepts and discourse patterns that can connect and organize fragmented knowledge. This article investigates and explores teachers’ comprehension of big ideas and the challenges for applying big ideas in second language (L2) classrooms among junior high school in Jiangsu Province. The findings are as follows: (1) Teachers mainly learn about big ideas through teaching research activities, expert lectures, and open classes, but most of them understand them at a superficial level. (2) The main influencing factors of teachers' big idea construction include insufficient teaching resources, limited time and energy, inadequate methodological guidance, and heavy teaching pressure. They expect to improve their ability to construct big ideas by receiving teaching resources, teaching methods, teaching experience, and teaching theories. (3) There are significant differences among teachers in southern Jiangsu, central Jiangsu and northern Jiangsu in terms of their cognitive level of big ideas, their ability to construct and apply big ideas. However, they all urgently need teaching cases, theoretical guidance, teaching discussions, and training. Pedagogical implications are provided for English teacher education on the construction of big ideas in L2 classrooms.

Evolution Modeling and Protection Scheme for Tidal Flats Under Natural Change and Human Pressure, Central Jiangsu Coast

AbstractAmidst escalating global changes and heightened human activities, tidal flats worldwide are facing a transition from accretion to erosion. In order to quantify the growth pattern of tidal flats and its response to changes in multiple external driving factors, here we established a geometric model, in combination with field surveys, to study the historical behavior (1127–1990) and future trends (2100) of a typical tidal flat system on the Jiangsu coast, China. The results indicate that sediment supply and relative sea level change determine the accretion‐erosion status and the eventual morphological pattern of the tidal flat. If these two factors remain stable and sediment supply can compensate for the increase in sediment accommodation space caused by sea level change, the tidal flat will continue to accrete until its growth limit is reached. Otherwise, tidal flats will face erosion risk, which can be further enhanced by localized land subsidence. Furthermore, changes in the coastal profile show a trend of progressive retreating, with the lower part of intertidal zone being eroded more rapidly than its upper part. This demonstrates that the sediment supply has been reduced to such a level that the present “in‐transition” evolution pattern of central Jiangsu coast will soon be replaced by severe inundation and erosion. Hence, we advocate for a comprehensive, multi‐tiered coastal protection strategy focusing on wave suppression, enhancement of sediment retention, and increased storm resistance. This strategy underscores fundamental underlying mechanisms of the accretion‐erosion transition, which is crucial for the future safeguarding of coastal wetlands globally.

Multi-Objective Optimization of the Planting Industry in Jiangsu Province and Analysis of Its “Water-Energy-Carbon” Characteristics

The modern development of the planting industry needs to not only ensure food supply but also to consider social and environmental issues. This poses higher demands for rational planning of planting structures to achieve green development while meeting demands and conserving resources. Therefore, this paper takes Jiangsu Province as a representative case, accounting for and analyzing the water footprint, energy consumption, and carbon emissions of seven major crops. Based on this analysis, a multi-objective planning model is established to explore the optimization of its planting structure. The results show that: (1) from 2010 to 2020, the overall water footprint of these seven crops in Jiangsu Province initially increased and then decreased, while energy consumption showed a fluctuating upward trend; (2) carbon emissions from planting in Jiangsu Province initially increased and then fluctuated downward over time, and exhibited significant spatial clustering characteristics, with overall emissions being higher in northern Jiangsu, followed by central Jiangsu, and then southern Jiangsu; (3) the optimization results indicate that economic benefits increased by 4.06%, while the carbon emission and grey water footprints decreased by 3.78% and 7.62%, respectively, resulting in comprehensive improvements in economic and ecological benefits. This study can provide theoretical support for adjusting the planting structure in crop-producing areas and promoting the green and sustainable development of the planting industry.

Exploring the Coordinated Development of Smart-City Clusters in China: A Case Study of Jiangsu Province

As urbanization has accelerated, China has started to build smart cities, which have formed smart-city clusters. It is critical to coordinate development within smart-city clusters to enhance the efficiency of city-cluster construction. From the perspective of demographic economics, this study innovatively constructed an evaluation system for the coordinated development of smart-city clusters and utilized the coupled coordination degree model to conduct an in-depth study of smart-city clusters in Jiangsu Province. The results show that there are clear differences in the development between the three regions of Jiangsu Province: Southern Jiangsu, Central Jiangsu, and Northern Jiangsu. The development within Jiangsu Province is imbalanced, where the overall development trend is high in the southern region and low in the northern region. The main driving factors include geography, the Matthew effect, game thinking, and industrial structure. Accordingly, the results suggest the following recommendations for the coordinated development of smart-city clusters: strengthening cross-regional cooperation, promoting data sharing and interoperability, deepening synergistic industrial development, and expanding innovation capacity.

Study on Coupling and Coordination Relationship between Urbanization and Ecosystem Service Value in Jiangsu Province, China

Urbanization has a significant negative impact on both the structure and function of ecosystems, as it is a major part of the human-caused transformation of natural landscapes. Concurrently, the attenuation of ecosystem service values (ESVs) poses critical impediments to urbanization and imperils human well-being. Investigating the interactive coupling and coordination relationship between urbanization and ESV is paramount in informing urban development strategies and environmental preservation efforts. Using Jiangsu Province as a representative case, this study forges an urbanization assessment index framework, estimates ESV, and subsequently delves into the multifaceted nexus between urbanization and ESV. The findings disclose a gradual uptick in urbanization levels in Jiangsu Province, underscored by conspicuous regional disparities typified in the subregions of southern Jiangsu, central Jiangsu, and northern Jiangsu, mirroring the high congruence observed in the economic urbanization subsystem. However, this upward trajectory in urbanization coincides with an overarching descent in ESV, with the most pronounced declines manifesting in regions characterized by elevated urbanization levels, such as Nantong and Suzhou. A robust interrelationship between urbanization and ESV is discernible throughout Jiangsu Province. Nevertheless, certain cities exhibit perturbations and retrogression in the associations between urbanization subsystems and ESV. The coupling coordination between population urbanization and ESV is characterized by disharmony while the coordination of economic urbanization markedly lags. Additionally, several cities are witnessing a progressive deterioration in the coordination relationships between ESV subsystems (food production, soil conservation, gas regulation, and raw material production) and urbanization. In light of these findings, it is recommended that governmental authorities enact measures to harmonize urban development with environmental preservation, safeguard the integrity of ecosystem functions, and facilitate the sustainable management of land resources.

Analysis of the Impact of Land Use Change on Grain Production in Jiangsu Province, China

Located in the Yangtze River Delta region, Jiangsu Province has become the major grain production area of China and plays an important role in ensuring national food security. With rapid economic development and urbanization, the amount of cultivated land has decreased, which greatly affects food security. Based on the statistical data of grain production in Jiangsu Province since 2000 and the remote sensing data of 2000, 2010, and 2020, this paper used the stochastic frontier production function to calculate the output elasticity of various factors and the technical efficiency of grain production. The agglomeration effect of food production was investigated by using spatial correlation analysis. Finally, regression analysis was applied to examine the impact of land use change on grain yield and the technical efficiency of production. The results show that the grain-sown area is the decisive factor for the increase in grain output in Jiangsu Province. The technical efficiency of grain production in the province has been maintained at a relatively high level since 2000, showing a fluctuating upward trend, and the efficiency value in southern Jiangsu Province is greater than that in central and northern Jiangsu. The analysis of the spatial distribution characteristics of grain production technical efficiency shows that grain production has an agglomeration effect. The regression results showed that the complexity of land use and the density of the cultivated land patch were negatively correlated with grain yield and grain production technical efficiency, while the location of cultivated land was positively correlated with grain yield and grain production technical efficiency. The conclusion of this paper has important policy significance for promoting food production and ensuring food security.

Quantitative provenance study of sediments in the coastal tidal flats of central Jiangsu based on grain-size End-Member analysis

The coastal mudflats in central Jiangsu Province are influenced by the sediment supply from the Yangtze River and the abandoned Yellow River. However, the sources of sediment in this area have yet to be confirmed, and quantitative studies have been limited. In this study, we addressed this gap by obtaining sediment core samples with lengths of approximately 100 cm from Dongtai and Sheyang, respectively, on the central coast of Jiangsu Province in 2018. The sediment sources were identified and quantitatively evaluated using a grain-size end-member(EM) model. The findings revealed that (1) Sheyang was decomposed into five EMs, with EMs 1-3 originating from the abandoned Yellow River, EM 4 originating from the Yangtze River and the North Jiangsu radial sand ridges (NJRSR), and EM 5 originating from the NJRSR. Over a century scale, the abandoned Yellow River contributed 73.91% to sediment deposition in Sheyang, while the Yangtze River and the NJRSR contributed 26.09%. (2) Dongtai was decomposed into six EMs, with EMs 1-4 originating from the abandoned Yellow River, EM 5 originating from the Yangtze River, and EM 6 originating from the Yangtze River and the NJRSR. Over a century scale, the abandoned Yellow River contributed 70.55% to sediment deposition in Dongtai, and the Yangtze River and the NJRSR contributed 29.45%. (3) On a temporal scale, the contribution of the abandoned Yellow River to sediment deposition on the central mudflats of Jiangsu Province showed an increasing trend. Spatially, the contribution of the abandoned Yellow River to sediment deposition decreased from north to south. (4) There were significant changes in the sediment sources of Sheyang and Dongtai at the depths of 56 cm and 60 cm, respectively, which both experiencing an increased sediment supply from the abandoned Yellow River. In Dongtai, the sediment on the southern side had increased contributions from the abandoned Yellow River due to a reduction in the sediment supply from the Yangtze River. In Sheyang, the sediment on the northern side had increased contributions from the abandoned Yellow River due to the introduction of Spartina alterniflora, despite no actual changes in the sediment sources.

Mapping large-scale aquaculture ponds in Jiangsu Province, China: An automatic extraction framework based on Sentinel-1 time-series imagery

Aquaculture holds significant importance in supporting food security, economic development, resource conservation, and ecological balance. However, the rapid expansion of aquaculture ponds has caused many environmental problems. Studies on the trends and spatial distribution of aquaculture ponds in Jiangsu province, China, are limited, and there is a lack of aquaculture datasets with a 10-m resolution. This study aimed to develop a novel assessment framework for mapping aquaculture ponds using the Google Earth Engine (GEE) platform and Sentinel-1 time-series images. We integrated multi-threshold segmentation and object-oriented classification to extract spatial data on aquaculture ponds from 2017 to 2021 in Jiangsu Province. Results showed that (1) local adaptive threshold methods could extract data about water bodies more effectively. Based on the time series of each image element, calculating its water frequency could effectively exclude seasonal water. (2) This method could effectively map aquaculture ponds in Jiangsu Province. The overall identification accuracy was higher than 93%, and the Kappa coefficient was higher than 0.87. These results are in accordance with those in the statistical yearbook. (3) The total aquaculture pond area was largest in 2017 (3404.00 km2) and smallest in 2021 (2939.51 km2). The aquaculture pond area in Jiangsu Province showed a slight downward trend over the five-year period. Aquaculture ponds were mainly distributed in central and southern Jiangsu and the coastal areas, with the highest density at the junction of Yangzhou, Taizhou, and Yancheng. (4) From 2017 to 2021, Aquaculture ponds spanning 104.65 km2 (accounting for 55.28% of the total reduced area) were transformed into wetlands. In the coastal zone. Our results substantiate that aquaculture pond removal can accelerate wetland restoration. This study maximised the identification of aquaculture ponds as independent targets. Taken together, these results can provide a reference for aquaculture green development and tail water management in Jiangsu Province.

Spatiotemporal Differentiation and Coupling Coordination Relationship of the Production–Living–Ecological Function at County Scale: A Case Study of Jiangsu Province

Land is multifunctional and includes production, living, and ecological functions (PLEF). Each aspect of PLEF is critical to the stability of human and natural ecosystems, and the balanced coordination of the three is an important guarantee of sustainable development. The study of the coupling and coordinated relationship of the three functions is of great significance to comprehensively optimizing the allocation of territorial space and promoting the coordinated and sustainable development of the national territory. Taking Jiangsu as a case study, based on the perspective of PLEF, this research constructed a PLEF evaluation index system adapted to rapidly urbanizing areas at the county scale and adopted the modified coupling coordination degree model (CCDM) for in-depth analyses of their coupling and coordinated relationships. The results of this study showed that the spatial distribution of PLEF had obvious heterogeneity, with living function (L) and ecological function (E) presenting as high in the south and low in the north, and production function (P) presenting as high in the middle and low in the north and south of Jiangsu; from 2010 to 2020, the production function steadily increased, the living function showed obvious signs of improvement, while the ecological function remained basically stable. The coupling degree and coupling coordination degree formed a spatial pattern with the intersection belt of North and Central Jiangsu and Central and South Jiangsu as the high-value area; from 2010 to 2020, both the coupling degree and the coupling coordination degree showed an upward trend. In the future, differentiated development strategies should be implemented according to the law of coupling and coordinated evolution and different regional characteristics. This study will provide a more appropriate reference for promoting the coordinated development of PLEF in rapidly urbanizing areas and formulating county policy planning.

Distribution characteristics and influencing factors of soil organic carbon in tidal flat wetland of central Jiangsu, China.

We measured winter and summer soil organic carbon (SOC) contents in two typical coastal wetlands, the Spartina alterniflora salt marsh and the non-vegetation mudflat, on the south side of the Chuandong River Estuary in Yancheng, Jiangsu Province. We investigated the spatiotemporal variations of soil organic carbon contents and its driving factors. The results showed that SOC content ranged from 0.75 to 2.38 g·kg-1 in the mudflat area and from 2.07 to 18.59 g·kg-1 in the S. alterniflora salt marsh area, showing a decreasing trend towards the sea. The SOC content in the S. alterniflora salt marsh area was approximately 2.5 to 3.5 times of that in the mudflat area. Within a depth range of 1 m, there was no vertical variation in SOC content in the mudflat area, but an increasing and then decreasing pattern in the S. alterniflora marsh area with the peak occurring in the depth range of 20 to 30 cm. Soil organic carbon content exhibited significant seasonal difference, with higher value in summer than in winter. The summer SOC content was 5% to 10% higher than that in winter in the S. alterniflora marsh area, while it was 43% higher in summer than in winter in the mudflat area. In the S. alterniflora marsh area, soil organic carbon content was positively correlated with soil moisture and salinity, but negatively correlated with sediment particle size. In contrast, there was no significant correlation between soil organic carbon content and soil physicochemi-cal factors in the mudflat area. Those results indicated that the correlation between various soil physicochemical factors and SOC is established on the basis of vegetation cover in coastal wetlands. Our findings could provide valuable insights for the conservation of blue carbon ecosystems in coastal wetlands in China.

The Impact of Urbanization on Food Security: A Case Study of Jiangsu Province

Food security has received extensive academic attention in recent years. However, research results analyzing cultivated land pressure from the perspective of urbanization are relatively few. This study used Jiangsu Province as the study area and analyzed the spatial pattern evolution of cultivated land pressure from 2005 to 2019 by constructing a formula for a cultivated land pressure index. The study used a spatial econometric approach to analyze the spatial relationship between urbanization and cultivated land pressure. Based on the spatial Durbin model, the impact of urbanization on the pressure on cultivated land is analyzed. According to the results, Jiangsu Province showed an obvious north–south divergence in the spatial distribution of the cultivated land pressure index, with the low-value areas of the cultivated land pressure index mainly distributed in northern and central Jiangsu, and the high-value areas mainly distributed in southern Jiangsu. The urbanization level and cultivated land pressure level in Jiangsu Province showed obvious spatial clustering characteristics, and there was a certain overlap between the high- and low-value clustering areas of the two, with significant positive spatial correlation features. The total urbanization had no significant effect on the cultivated land pressure. Population urbanization and industry urbanization showed a significant negative effect on cultivated land pressure in Jiangsu Province, while land urbanization showed a positive effect. Both population and land urbanization had a significant negative spatial spillover effect on cultivated land pressure. Plausible explanations of these results were provided and policy implications were drawn.

Spatial-epidemiological analysis of population aging in counties in Jiangsu Province, 1990-2020

Objective: To analyze the space-time evolution trend of population aging at the county level in Jiangsu Province from 1990 to 2020. Methods: Taking each county of Jiangsu Province as the research object, we selected data from the fourth to the seventh national population censuses. We used the aging coefficient and age concentration rate as static and dynamic indicators to measure the degree of population aging, respectively. We also used spatial correlation analysis to study the spatial and temporal patterns and evolution characteristics of aging in counties in Jiangsu Province. Results: The degree of aging in each county of Jiangsu Province has been deepening, and the degree of aging gradually evolves from high in southern Jiangsu and low in northern Jiangsu to high in central Jiangsu and low in southern and northern Jiangsu and shows obvious spatial aggregation. From 1990 to 2020, the population aging in Jiangsu Province has accelerated, among which the aging from 2010-2020 is the fastest. The aging progress appeares the fastest in 2010-2020. Conclusion: From 1990 to 2020, population aging in Jiangsu Province has been deepening, with the fastest progress in the last decade and an obvious spatial aggregation.

Spatial Differentiation and Driving Factors of Traditional Villages in Jiangsu Province

Jiangsu Province, situated in the Yangtze River basin, has rich traditional village resources and a prominent position in economic development and cultural integration. This study focuses on the analysis of the variation distribution pattern of traditional villages in Jiangsu Province using six batches of traditional village directories with data until 2023 as research samples. By employing ANN, Voronoi graph analysis, and Moran’s I index, the researchers determined the spatial distribution characteristics of rural settlements. Additionally, kernel density and spatial autocorrelation techniques were used to further examine the spatial distribution patterns, and geographic detector detection was introduced. The results showed the following: (1) The spatial distribution of traditional village settlements in Jiangsu Province showed a significant clustering distribution that is mainly concentrated in central Jiangsu Province. (2) The driving factors reflected a strong symbiotic relationship of “air–water–soil–man”. The spatial distribution of traditional villages was mainly driven by the annual mean temperature and soil type. The interaction between factors was dominated by the enhancement relationship between the two factors. (3) According to the detection results of risk areas in the region, the average annual temperature was 17~17.6 °C, the annual precipitation was 133.0~145.7 billion m3, the average annual wind speed was 0.549~0.565 m/s, the GDP was 85,100~204,000 CNY/km−2, and the population density was 2.32~3.91 thousand/km−2. Arable land was the main type of area and was conducive to the gathering of traditional villages. The preservation of rural settlements should take into account the complex and diverse factors that affect their distribution. Additionally, it is crucial to tailor protection strategies to specific local conditions and conduct flexible research.

Spatiotemporal evolution and driving factors of the coupling coordination between county land urbanization and grain production: the case of Jiangsu province, China

How to ensure a coordinated development between land urbanization and grain production has been a key issue that needs to be urgently addressed to achieve sustainable development in China. Taking Jiangsu province as an example, this paper measures the coupling coordination degree (CCD) between county land urbanization and grain production from 2010 to 2020 based on the coupling coordination degree model (CCDM). In addition, the exploratory spatial data analysis method and the space Durbin model are combined to explore the spatial correlation and influencing factors of the CCD between land urbanization and grain production. The main conclusions are as follows: (1) From a temporal perspective, the CCD between county land urbanization and grain production in Jiangsu is dominated by basically coordinated, with an overall stable rising trend and a distribution pattern of Northern Jiangsu > Central Jiangsu > Southern Jiangsu. (2) From the perspective of spatial distribution, the CCD between the two is dominated by basically coordinated in the Southern, Central and Northern Jiangsu regions. The spatial clustering characteristics are significant, and the distribution of counties with basically coordinated shows concentrated and contiguous characteristics. (3) From the perspective of spatial correlation, the CCD between the two shows a low level of positive spatial autocorrelation. The state of agglomeration is significant in Northern Jiangsu, while spatial agglomeration is sporadic in Southern Jiangsu and insignificant in Central Jiangsu. (4) The factors affecting the CCD between county land urbanization and grain production in Jiangsu province are determined by many factors together. Based on a driver perspective, Per capita GDP and chemical fertilizer application intensity have a negative effect on it. Highway network density and mobile internet penetration rate have a positive effect on it. Population density, advanced industrial structure, per capita grain planting area and agro-industrial agglomeration are not significant. This study offers useful insights for promoting the coupled and coordinated development of county urbanization and grain production in China.