Study on the Spatiotemporal Pattern Evolution and Influencing Factors of Population Aging in Henan Province

This study utilized census data from Henan Province for the years 2000,2010,and 2020 to investigate the spatiotemporal evolution of population aging,defined by the proportion of the population aged 65 and above.Employing spatial analysis techniques such as spatial autocorrelation and the standard deviation ellipse,the research mapped out the progression and distribution of aging demographics.Furthermore,the study delved into the influencing factors of aging using an optimal parameters-based geographical detector.Results indicate a deepening degree of population aging in Henan Province,transitioning from an adult type to an old type structure.There is a marked positive spatial correlation among counties,with high-value aging areas initially decreasing,then increasing,and notably spreading from the central to the central and southern regions of the province.The center of gravity for population aging,specifically around Changge City and Xuchang City,exhibits a trajectory moving southeast before shifting northwest.Factor detection reveals that in 2000,2010,and 2020,the elderly dependency ratio predominantly influences the aging trend,with explanatory powers of 88.4%,87.9%,and 90.9%,respectively.Interaction analysis indicates that the interaction between the old-child ratio and the elderly dependency ratio has a strong explanatory power for the aging patterns in Henan Province,reaching 97.3%,97.0%,and 97.4%,respectively.

Spatial Morphology Evolution Characteristics Analysis of the Resident Population Distribution in Henan, China

The population spatial distribution pattern and its evolving pattern play an important role in regional allocation of social resources and production factors, formulation of regional development plans, construction of a better life society, and promotion of regional economic development. Based on the resident population statistics data of Henan province from 2006 to 2021, with county as the basic study unit, the paper studies the spatial morphology characteristics and its evolution patterns of resident population distribution, by using spatial analysis methods such as population distribution center, standard deviation ellipse, and spatial auto correlation analysis. The results show that: the resident population spatial distribution shows unbalanced state, the population agglomeration areas mainly distribute in the northeast part and north part, where the resident population growth rate is significantly higher than other regions, over time, this trend is gradually becoming significant. The resident population distribution has a trend of centripetal concentration, with the degree and trend of centripetal gradually strengthening. The resident population distribution has obvious directional characteristics, but the significance is not high, the weighted resident population average center is approximately located at (4.13740˚N, 113.8935˚E), and the azimuth of the distribution axis is approximately 11.19˚. The population distribution has obvious agglomeration characteristics, with the built-up areas of Zhengzhou and Luoyang as their centers, where have a significant siphon effect on the surrounding population. The southern and southwestern regions in the province form a relatively stable belt area of Low-Low agglomeration areas.

Spatiotemporal evolution of ecosystem service value and topographic gradient effect in the Da-Xiao Liangshan Mountains in Sichuan Province,China

The Da-Xiao Liangshan mountains are critical ecological function areas and essential ecological barriers in the upper reaches of the Yangtze River in China.This study selected a total of six periods of land use land cover(LULC)data from 1995 to 2020,to estimate the ecosystem service value(ESV)and analyzed its spatiotemporal evolution and topographic gradient divergence.The results showed that:(1)The ESV increased by 1.1 billion yuan,with an increase rate of 1.47%from 1995 to 2020.Two time periods,2005–2010 and 2015–2020,showed more significant increases than other periods.(2)The elevation and slope of mountainous areas determine the type of land use and further influence the spatial pattern of ESV.(3)Although woodland and grassland are the main land use types of the study area(more than 90%),the hydrological regulation function of the water area partially compensated for the impact of the encroachment of the built-up area on the ESV of grassland.(4)The spatial distribution of ESVs showed an inverted V-shaped characteristic as the topographic gradient increased,with the dominant position being the 5th topographic gradient zone.Finally,this study provided relevant recommendations for ecosystem protection and optimization.The findings of this study clarified the influence of topographical factors on the spatial differentiation of ESV and provided novel insights into ecosystem protection.

Spatial-temporal Patterns and Evolution History of Rural Settlements from the Perspective of Inheritance——A Case Study of Lianzhou City,Guangdong Province

Formation and evolution of rural settlement patterns in Lianzhou City,Guangdong Province were analyzed from the perspective of space and time,on the basis of its gazetteer and relevant historical data.The results show that Lianzhou was first founded in the sixth year of Yuanding Period of the Western Han Dynasty,and its development could be roughly classified into 6 stages according to the construction of south–north traffic lines and regional development progress,and it witnessed the fastest development in the Ming and Qing Dynasty.In terms of spatial distribution,rural settlements in the local area show spatial continuity,Lianzhou Town is the core of rural settlement growth in the city,and towns with the most concentrated rural settlements in all stages are located in central-west and northeast parts of the city,and those with lower density of rural settlements are mostly located in minority regions in the north and mountainous areas in the east.On the basis of the above facts,the paper studies the influence of natural geological conditions,immigrant,traffic,economic development and ethnic composition on the establishment and development of rural settlements in Lianzhou City.

Spatial and Temporal Evolution Characteristics of Extreme Precipitation and Isohyets in Ningxia

The multi-scale spatial and temporal evolution characteristics of extreme precipitation and isohyets in Ningxia were studied using daily,monthly,and annual precipitation data from 20 meteorological stations in Ningxia over the last 60 years.The results revealed that the intensity of rainstorms in Ningxia had decreased slightly over the previous 60 years,with the intensity of rainstorms in southern and central Ningxia being higher than in northern areas.Ningxia's annual and seasonal precipitation varied regionally,declining from the southeast to the northwest.Annual,spring and autumn precipitation exhibited a significantly declining trend from 1960 to the early 21^(st)century;summer precipitation displayed a slightly decreasing trend;and winter precipitation showed a significantly increasing trend.Nevertheless,there was a noticeable increase in annual and seasonal precipitation after 2005.From the 1960s to the 2000s,the 200 mm isohyet moved slowly southward,while the 400 mm isohyet jumped southward twice in the 1970s and 2000s before jumping considerably northward in the 2010s to reach their northernmost region.

The Temporal and Spatial Evolution Characteristics Analysis of Jiangsu Tourism Economy

[Objective] The paper aimed to reflect the spatial pattern and temporal and spatial evolution characteristics, the differences between inter-regional tourism economy was measured from the quality aspect, which provided a reference for the local governments in the future tourism development. [Method] Using the location entropy methods, three time periods side of tourism-related date of 2000, 2005, 2007 were selected, from the angle of the spatial pattern and the evolution of the differences within the different scales, the spatial and temporal evolution characteristics of the economic development level of Jiangsu were analysed. [Result] The results showed that from the aspect of spatial evolution pattern, as time goes on, the economic development of Jiangsu tourism has experienced morphological evolution of concentration- dispersion decrease-stability; when it comes to the development of the tourism economy, in recent years, the overall gap between the tourism economy in Jiangsu did not widen, the gap mainly led by the region one after another. According to their volatility, it will be divided into four categories: A Stable type (Wuxi, Xuzhou, Lianyungang and Taizhou), B Increasing type (Huai’an), C Fluctuations type (Nanjing, Changzhou, Suzhou and Yangzhou) and D Depression type (Nantong, Yancheng, Zhenjiang and Suqian). [Conclusion] Location entropy was quoted into tourism economic analysis, the method was simple and easy to understand, the result was accurate and convincing, which provided a reference for travel economic development and investment decision-making of Jiangsu.

The temporal and spatial patterns and potential evaluation of China＇s energy resources development

The issue of China＇s energy supply security is not only the key problem which af- fects China＇s rapid and sustainable development in the 21st century, but also the one which international attention focuses on. Based on the notable characteristic of spatial imbalance between energy production and consumption in China, this paper takes the evolution of China＇s primary energy resources development（excluding hydropower） from 1949 to 2007 as the study object, with the aim to sum up the evolutive characteristics and laws of China＇s energy resources development in the past nearly 60 years. Then, based on comprehensive considerations of coal＇s, oil＇s and natural gas＇s basic reserves, qualities, geological conditions production status, and ecological service function of every province, this paper adopts development potential index （DP）to evaluate the development potential of every province＇s en- ergy resources, and divide them into different ranks. Conclusions are drawn as follows： （1） Generally speaking, China＇s gross energy production was increasing in waves from 1949 to 2007. From the viewpoint of spatial patterns, China＇s energy resources development has shown a characteristic of ＂concentrating to the north and central areas, and evolving from linear-shaped to ＂T-shaped＂ pattern gradually since 1949. （2） The structure evolution of China＇s energy resources development in general has shown a trend of ＂coal proportion is dominant but decreasing, while oil and gas proportions are increasing＂ since 1949. （3） At the provincial scale, China＇s energy resources development potential could be divided into large, sub-large, general and small ranks, four in all. In the future, the spatial pattern of China＇s energy production will evolve from ＂T-shaped＂ to ＂R-shaped pattern＂. These conclusions will help to clarify the temporal and spatial characteristics and laws of China＇s energy resources development, and will be beneficial for China to design scientific and rational energy development strategies and plans, coordinate spatial imbalance of energy production and consumption, ensure national energy supply, avoid energy resources waste and disorderly development, and promote regional sustainable development under the globalization back-ground with changeful international energy market.

Research on temporal and spatial distribution,evolutionary character and mechanism of crustal deformation field before and after the Tangshan earthquake

According to the data of precise relevelling and deformation measurement across faults, the temporal and spatial evolution process of crustal deformation field in the source and peripheral regions of the Tangshan earthquake (1976, M S=7.8), from 22 years before the earthquake to 9 years after, is described with the method of crustal deforma tion pattern dynamics. The crustal unstable zones first occur in the exterior, and then surround the focal region by contracting from the exterior to the interior, when the focal region appears to be unstable but does not lose stability. After the transient stable state, the second unstable process from the exterior to interior appears, which results in the instability of focal region. 'Deformation gap', 'earthquake gap' and 'locked fault zone' occur before instability, and their spatial distributions overlap, but their occurrence times have little differences. The earthquake occurs after the impending pre slide of the faults in the focal region. The studied results of the evolution process of crustal deformation field are identical with each other and with that of numeric simulation of crustal stress field, which supports the evolution model of seismogenic system with a strong body as its core.

Spatial and Temporal Evolution of the Static Water Level of the Cuauhtemoc Aquifer during the Years 1973, 1991 and 2000: A Geographical Approach

In hydrogeology it is of great interest to examine the temporal and spatial evolution of aquifers. There are different ways of modeling an aquifer: physical models, models based on analog and mathematical techniques. Usually, mathematical techniques involve complex operations difficult to understand for some people, such as differential or partial equations. In contrast, our method requires only a basic knowledge of geometry and trigonometry. Moreover, it is only necessary to know the static level of the aquifer at three different dates. Of course, the results may be limited compared to those that use advanced mathematical methods;however, our method provides a first approximation to determine the behavior of the aquifer through time. Overall, our results allowed us to follow the evolution of the aquifer in detail of various areas of increased extraction and in which removal has been increasing, but also of areas with a considerable recharge during the study period.

THE TEMPORAL AND SPATIAL PATTERNS OF ENVIRONMENTAL RISK EVENTS IN THE PAST 30 YEARS IN SHENYANG CITY

The index of Risk Frequency (RF) and other relative indices are used to analyze the temporal and spatial patterns of environmental riskevents in the past 30 years in Shenyang city. The results show that thereexists significant difference of the RFs between periods of 1966-1977 and1978-1991 (t=7.353**, t0.01=2.807). During the past 30 years, there areno significant changes of the spatial patterns of the environmental risk,while the proportions of environmental risk among the districts are extremely different. In Shenyang city, there exists a series of high riskenterprises, and the chemical industry is the one with highest risk.

Temporal and Spatial Evolution of Lakes in the Bashang Plateau for Nearly Recent 30 Years

Lakes are important ecological water sources in the Bashang Plateau. Its expansion or shrinkage directly affects the ecological security of the plateau and its surrounding areas. In this study, Landsat images from 1984 to 2015 were selected to monitor the area of lakes in the Bashang Plateau and to analyze the spatiotemporal evolution and driving forces of lakes in the Bashang Plateau. The results showed that there were 47 lakes in the Bashang Plateau in 2015, with a total area of 37.63 km2, mainly distributed in the central and western regions of the region. From 1984 to 2015, the lakes in Bashang Plateau showed a shrinking trend. At the same time, there are obvious stage differences in lake changes. During 1984-1996, the number of lakes increased by 99 and the total area increased by 124.43 km2. From 1996 to 2015, the number of lakes decreased by 142, and the total area decreased by 183.96 km2. Before 1996, climate change was the dominant factor. However, the shrinkage of lakes after 1996 is the result of climate change and human activities. Among them, the large-scale planting of water consuming crops such as vegetables is the main human activity mode leading to lake shrinkage. This study will help to understand the expansion and contraction factors of the Bashang Plateau lakes in Hebei province and provide a reference for the future protection and management of the lakes.

Evolution and Spatial Patterns of Spheres of Urban Influence in China

This article presents the findings of a study of the spheres of urban influence with regard to all cities in China(not including Hong Kong,Macao and Taiwan Province of China)in the years 1990,2000 and 2009.An optimized gravity model with comprehensive time distance was used to carry out a detailed analysis of the spatial patterns of Chinese spheres of urban influence and the spatial characteristics of urban agglomerations.Such urban agglomerations are characterized by high density population and a developed economy,which are also considered as the national competition unit.This paper initially identifies four spatial patterns of urban agglomerations based on the spatial layout of city groups during their evolution.Some basic characteristics of urban agglomerations are outlined,including the number of cities,the size of cities and the functions of urban centers.These characteristics are examined by using statistical methods and Geographic Information System(GIS).The main findings from this research are that the development stages and structures of urban agglomerations in China vary significantly.It is also clear that the stages and evolution of spatial patterns are strongly affected and dominated by both policy and location factors.

Study of spatial and temporal evolution of Ar and F atoms in SF6/Ar microsecond pulsed discharge by optical emission spectroscopy

The study of sulfur hexafluoride(SF6) discharge is vital for its application in gas-insulated equipment. Direct current partial discharge(PD) may cause SF6 decomposition, and the decomposed products of SF6, such as F atoms, play a dominant role in the breakdown of insulation systems. In this study, the PD caused by metal protrusion defects is simulated by a needle-plate electrode using pulsed high voltage in SF6/Ar mixtures. The spatial and temporal characteristics of SF6/Ar plasma are analyzed by measuring the emission spectra of F and Ar atoms, which are important for understanding the characteristics of PD. The spatial resolved results show that both F and Ar atom spectral intensities increase first from the plate anode to the needle and then decrease under the conditions of a background pressure of400 Pa, peak voltage of-1000 V, frequency of 2 kHz, pulse width of 60 μs, and electrode gap of 5-9 mm. However, the distribution characteristics of F and Ar are significantly different. The temporal distribution results show that the spectral intensity of Ar decreasesfirst and then increases slowly, while the spectral intensity of F increases slowly for the duration of the pulsed discharge at the electrode gap of 5 mm and the pulse width of40-80 μs.

Temporal and Spatial Evolution of Laser-Induced Plasma from a Slag Sample

Laser-Induced Breakdown Spectroscopy （LIBS） has been demonstrated to be an effective method for slag analysis. In order to better clarify the nature of the plasma generated from a slag sample, an Nd：YAG pulse laser at 1064 nm wavelength was used to ablate the slag sample in air. The temporal and spatial evolutions of plasma parameters, including emission intensity, electronic density and plasma temperature, have been studied. It is shown that the electron density and plasma temperature drop off rapidly with the delay time as a result of plasma expansion and cooling. It has been found that the electron density of the whole plasma is close to that of the center regions in the plasma. The results of the spatial distributions on the two-dimensional plane have shown that there is a big region with lower electron density values caused by the recombination process in the center of the plasma. The maximum of the plasma temperature takes place at the regions close to the target, and the border of the plasma front-head has higher plasma temperatures than that of the center part.

Spatial and Temporal Evolution Characteristics of PM2.5 in China from 1998 to 2016

The rapid development of China’s economy and urbanization has given rise to noticeable environmental problems,among which the change of air quality has received extensive attention.The panel data of PM2.5(particles with an aerodynamic diameter of 2.5μm or less)in 343 prefecture-level cities in China from 1998 to 2016 were statistically analyzed to reveal the characteristics of the temporal evolution and spatial variation of China’s air quality in the past two decades.The results show that:1)the overall deterioration trend of air quality is obvious throughout the country.The variation trend of PM2.5 was divided into three phases:rapid-growth phase(1998–2007),lag phase(2006–2011)and mildly-incremental phase(2012–2016),with their average growth rates of 7.19%,-3.59%and 0.52%,respectively.2)The spatial difference of PM2.5 values in China increased significantly with time.Since 2003,the high-value area in the east has expanded rapidly,and polarization became much more pronounced.The change rate of PM2.5 is high in the east and west and low in the middle.The change rates of most areas in the west exceed more than 80%,and in the east lie somewhere between 40%and 60%.In the midlands,the change rate is not large and some regions even show a negative growth.3)The change rate of PM2.5 is also high in areas with higher values.However,in regions where the change rate of PM2.5 is high,the value of PM2.5 is not always high.The high change rate is mainly attributable to the low base value of PM2.5 and the cities concerned belong to sensitive areas.4)According to the PM2.5 warning index,the number of strong,medium,weak and non-warning areas in China is 45,85,159 and 54,respectively.

The spatial-temporal pattern and influencing factors of negative air ions in urban forests, Shanghai, China

Negative air ions are natural components of the air we breathe Forests are the main continuous natural source of negative air ions （NAI）. The spatio-temporal patterns of negative air ions were explored in Shanghai, based on monthly monitoring in 15 parks from March 2009 to February 2010. In each park, sampling sites were selected in forests and open spaces. The annual variation in negative air ion concentrations （NAIC） showed peak values from June to October and minimum values from December to January. NAIC were highest in summer and autumn, intermediate in spring, and lowest in winter. During spring and summer, NAIC in open spaces were significantly higher in rural areas than those in suburban areas. However, there were no significant differences in NAIC at forest sites among seasons. For open spaces, total suspended particles （TSP） were the dominant determining factor of NAIC in sum- mer, and air temperature and air humidity were the dominant determining factors of NAIC in spring, which were tightly correlated with Shanghai＇s ongoing urbanization and its impacts on the environment. R is suggested that urbanization could induce variation in NAIC along the urban-rural gradient, but that may not change the temporal variation pattern. Fur- thermore, the effects of urbanization on NAIC were limited in non-vegetated or less-vegetated sites, such as open spaces, but not in well-vegetated areas, such as urban forests. Therefore, we suggest that urban greening, especially urban forest, has significant resistance to theeffect of urbanization on NAIC.

Temporal and spatial evolution measurement of laser-induced breakdown spectroscopy on hydrogen retention in tantalum

Fuel retention measurement on plasma-facing components is an active field of study in magnetic confinement nuclear fusion devices.The laser-induced breakdown spectroscopy(LIBS)diagnostic method has been well demonstrated to detect the elemental distribution in PFCs.In this work,an upgraded co-axis LIBS system based on a linear fiber bundle collection system has been developed to measure the hydrogen(H) retention on a tantalum(Ta) sample under a vacuum condition.The spatial resolution measurement of the different positions of the LIBS plasma can be achieved simultaneously with varying delay times.The temporal and spatial evolution results of LIBS plasma emission show that the H plasma observably expands from the delay times of 0-200 ns.The diameter of Ta plasma is about 6 mm which is much less than the size of H plasma after 200 ns.The difference in the temporal and spatial evolution behaviors between H plasma and Ta plasma is due to the great difference in the atomic mass of H and Ta.The depth profile result shows that H retention mainly exists on the surface of the sample.The temporal and spatial evolution behaviors of the electron excited temperature are consistent with that of the Ta emission.The result will further improve the understanding of the evolution of the dynamics of LIBS plasma and optimize the current collection system of in situ LIBS in fusion devices.

Spatial-temporal Analysis of Daily Air Quality Index in the Yangtze River Delta Region of China During 2014 and 2016

Urban air pollution is a prominent problem related to the urban development in China, especially in the densely populated urban agglomerations. Therefore, scientific examination of regional variation of air quality and its dominant factors is of great importance to regional environmental management. In contrast to traditional air pollution researches which only concentrate on a single year or a single pollutant, this paper analyses spatiotemporal patterns and determinants of air quality in disparate regions based on the air quality index(AQI) of the Yangtze River Delta region(YRD) of China from 2014 to 2016. Results show that the annual average value of the AQI in the YRD region decreases from 2014 to 2016 and exhibit a basic characteristic of ‘higher in winter, lower in summer and slightly high in spring and autumn'. The attainment rate of the AQI shows an apparently spatial stratified heterogeneity, Hefei metropolitan area and Nanjing metropolitan area keeping the worst air quality. The frequency of air pollution occurring in large regions was gradually decreasing during the study period. Drawing from entropy method analysis, industrialization and urbanization represented by per capita GDP and total energy consumption were the most important factors. Furthermore, population agglomeration is a factor that cannot be ignored especially in some mega-cities. Limited to data collection, more research is needed to gain insight into the spatiotemporal pattern and influence mechanism in the future.

Characteristics of Spatial Structural Patterns and Temporal Variability of Annual Precipitation in Ningxia

[Objective] The aim was to study the characteristics of the spatial structural patterns and temporal variability of annual precipitation in Ningxia.[Method] Using rotated empirical orthogonal function,the precipitation concentration index,wavelet analysis and Mann-Kendall rank statistic method,the characteristics of precipitation on the spatial-temporal variability and trend were analyzed by the monthly precipitation series in Ningxia during 1951-2008.[Result] In Ningxia,the spatial structural patterns of annual precipitation appeared 'North-south type' and 'North-center-south type'.It increased from north to south,the changes of interannual precipitation decreased from north to south.Precipitation changed significantly in month and distributed differently in the Yellow River irrigation area.But it was conversely steady in central arid zone and mountainous area of southern Ningxia.The probability of single abundant precipitation year was higher than single short precipitation year and the continuous short precipitation year was higher than continuous abundant precipitation year.The main cycles were 3a,6a and 10a approximately.In the mid arid zone and the mountainous area of southern Ningxia,the probability of precipitation reduction was about 75% and the Yellow river irrigation area,71.4%,respectively.The reduction in the entire area was about 73.3%.The annual precipitation in the middle arid area and irrigation area was increasing.The variability would change slowly for the intra-annual distribution of precipitation.Especially,the reduction tendency rate in the middle arid area reached 100.0%.[Conclusion] The study provided references for the effective utilization of the local precipitation,and the coordinated development of the regional social economy and ecological environment.

Effect of water level fluctuations on temporal-spatial patterns of foraging activities by the wintering Hooded Crane(Grus monacha)

Background:The Yangtze River floodplain provides important wintering habitats for Hooded Cranes(Grus monacha) in China.Fluctuations in the water level change foraging habitat and food availability,affecting their temporal-spatial patterns of foraging activities.It is of considerable importance to investigate the effect of these fluctuations on food availability for wintering Hooded Cranes and their foraging response to these changes.Understanding their behavior patterns is beneficial in protecting the wintering crane population and restoring their wintering habitats.Methods:A field survey of the winter behavior of cranes was carried out at Shengjin Lake from November in 2013 to April in 2014.Habitat variables,as well as the spatial distribution and behavior patterns of wintering cranes at their foraging sites during five stages of water level fluctuation were collected.Based on this data we analyzed the relationship of foraging behavior relative to water level fluctuations and habitat types.Results:The foraging habitats used by Hooded Cranes varied at the different water level stages.As the water level decreased,the use of meadows and mudflats increased.When the water dropped to its lowest level,the use by the Hooded Crane in the mudflats reached a peak.There were statistically significant differences in time budget in the three types of habitats over the five stages of the water level.In the mudflats,the foraging behavior and maintenance behavior varied significantly with the water level,while the alert behavior showed little variation.Analysis of a generalized linear model showed that the five water level stages and three habitat types had a significant effect on foraging behavior,while the combined effect of these two variables was significant on the foraging time budget and the length of foraging activity of the Hooded Crane.Conclusions:With the decrease in the water level,the use of mudflats by Hooded Cranes increased correspondingly.Food availability in different habitats was affected by changes in the water level.The Hooded Crane adjusted its foraging patterns and made full use of the three available types of habitat in order to acquire enough food in response to fluctuations in the water level.