Migration Networks Pattern of China’s Floating Population from the Perspective of Complex Network

Since China’s reform and opening-up,the growing disparity between urban and rural areas and regions has led to massive migration.With China’s Rural Revitalization Strategy and the industrial transfer from the eastern coastal areas to the inland,the migration direction and pattern of the floating population have undergone certain changes.Using the 2017 China Migrants Dynamic Survey(CMDS),excluding Hong Kong,Macao,and Taiwan regions of China,organized by China’s National Health Commission,the relationship matrix of the floating population is constructed according to the inflow place of the interviewees and their outflow place(the location of the registered residence)in the questionnaire survey.We then apply the complex network model to analyze the migration direction and network pattern of China’s floating population from the city scale.The migration network shows an obvious hierarchical agglomeration.The first-,second-,third-and fourth-tier distribution cities are municipalities directly under the central government,provincial capital cities,major cities in the central and western regions and ordinary cities in all provinces,respectively.The migration trend is from the central and western regions to the eastern coastal areas.The migration network has‘small world’characteristics,forming nine communities.It shows that most node cities in the same community are closely linked and geographically close,indicating that the migration network of floating population is still affected by geographical proximity.Narrowing the urban-rural and regional differences will promote the rational distribution this population.It is necessary to strengthen the reform of the registered residence system,so that the floating population can enjoy urban public services comparable to other populations,and allow migrants to live and work in peace.

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.

Early life migration and population discrimination of the small yellow croaker Larimichthys polyactis from the Yellow Sea: inferences from otolith Sr/Ca ratios

The small yellow croaker Larimichthys polyactis is a benthic marine fish species of high ecological and commercial importance and is widely distributed in the northwestern Pacifi c Ocean,especially in the Chinese coastal waters of the Bohai,Yellow,and East China Seas.As a highly migratory species,the whole life migration of L.polyactis has been intensively studied.However,knowledge about its early life migration is scarce,and population divisions are inconsistent,limiting the ability of fishery scientists and administrators to evaluate the design and potential benefits of thorough conservation and resource-management strategies.In the present study,otolith Sr/Ca was analyzed to investigate the early migratory patterns and discriminate the populations of L.polyactis in the Yellow Sea,including two spawning groups and one overwintering group.The variation in Sr/Ca ratios of ontogenetic growth zones,including the nucleus(N),larval(L),metamorphosis(M),juvenile(J),and edge(E)zones,was measured by electron probe microanalysis.The variation in Sr/Ca ratios in early developmental growth zones was generally characterized by an evident downward trend from the N to J zone,which suggests that the early migratory pattern of L.polyactis might be from inshore to nearshore water.Canonical discriminant analysis,based on the otolith Sr/Ca ratios of the N,L,M,and J zones,allowed the successful discrimination of the two populations,namely,the northern and southern Yellow Sea groups,whose diff erences were mainly reflected in the L and J zones.Compared with previous studies,the traditional geographic boundaries(34°N)separating these two populations might be moving northward.The application of otolith Sr/Ca ratios based on ontogenetic stage could improve our understanding of the migration and population discrimination of L.polyactis from the Yellow Sea.

Migration Laws of Floating Population in Mianyang

Based on the overall analysis of the floating population among big and medium-sized cities in China,this paper, by means of statistics and questionnaires, makes a systematical study on the migratory features of the floating population in Mianyang, its employment structure, migrating causes and channels. According to the findings, the author finds a fact that with the strategy of Western Development, and with the construction of science and technology city of Mianyang, the migrating in Mianyang conforms to the general patterns of the migration, which has happened in those big and medium-sized cities in China.In addition,the city has a new but unique feature — economic factor, as the driving force of population migration, is quite distinct from that of those citiesin eastern areas of China.

ON THE RELATIONSHIP BETWEEN MARRIAGE AND POPULATION MIGRATION IN CHINA

As a constant and active factor affecting population migration, marriage has long been neglected. This paper brings to light of the social significance of marriage migration and makes an inquiry into its characteristics, patterns and mechanism. It is thought the marriage plays an important role in hastening population migration. While compared with other forms of population migration, marriage migration is distinctive, showing its own characteristics, such as irreversibility in direction, shorter distance, age long continuity, regional dispersal, gentler fluctuation in number, sexual imbalance, and multiple factors at work. Although the manifestation of marriage migration is complicated, its patterns are clear, that is: pattern 1, women to men’s habitation; pattern 2, men to women’s habitation; and pattern 3, men and women to a third place. It is thought that both the characters and the patterns of marriage migration are determined by its mechanism, because marriage migration is not only a kind of biological action but also a kind of social action, the former of which determines whether it happens, while the latter of which determines how it does. The difference of men’s and women’s social status, that of cities and country, and that of developed and backward areas may result in abnormality of marriage migration, while the socio biological feedback of sexual imbalance and regional environmental deterioration can give rise to some self adjusting mechanism. In the end of the paper, based on a sample analysis, it concludes four tendencies towards marriage migration in China: (1) pair migration is emerging; (2) the changing trend of urban and rural regional relationship of marriage is contrary; (3) urban “island effect” in marriage is weakening; and (4) the potential energy between developed and less developed areas is still strong.

Influencing Factors of Long-Term Residence Intention of Highly Educated Inter-Provincial and Intra-Provincial Floating Population From the Perspective of Social Integration:Take Guangdong Province for Example

Floating population plays an important role in the development of cities,regions,and countries.The economic growth path with Guangdong characteristics is inseparable from the support of highly educated groups.Studying the long-term residence intention of the highly educated floating population is helpful for the city to attract and retain talents.From the perspective of social integration,using CMDS 2017 data and taking Guangdong Province for example,this paper studies the influencing factors of long-term residence intention through SPSS logistic regression,taking intra-provincial and inter-provincial floating population with a bachelor’s degree or above as sample.The main conclusions are:(1)Marital and childbearing status is the primitive influencing factor of long-term residence intention among intra-provincial and inter-provincial floating population.Samples with high income,under social insurance system,being female and having non-agricultural hukou,are tend to prefer long-term residence.Samples who connect with the locals and participate in social public welfare are more likely to stay.(2)Personal age and city livability have a significant positive impact on the long-term residence intention of the inter-provincial highly educated floating population,but agricultural hukou and self-employed laborer status will weaken the long-term residence intention of this group.(3)Participation in townsmen/alumni association has a positive effect on the long-term residence intention of the intra-provincial highly educated floating population,and connection with outlanders also promotes the long-term residence intention of this group.(4)The long-term residence intention of inter-provincial highly educated floating population is usually based on reality,therefore they pay more attention to the development,changes,and livability of the destination city.However,the long-term residence intention of intra-provincial highly educated floating population is usually based on perception,so they pay more attention to whether they like the city.Compared with intra-provincial flows,inter-provincial flows have higher economic and emotional migration costs,more institutional barriers,and more life adaptation problems.Therefore,the government should introduce targeted measures to promote social integration and improve long-term residence intention.

Regularity of population occurrence and migration in the oriental armyworm, Mythimna separata(Walker)

The oriental armyworm,Mythimna separata（Walker）（Lepidoptera：Noctuidae）,is a major migrant pest of grain in China and other Asian countries,causing huge crop production and economic losses nationwide annually.Much of the uniquely difficult aspects of managing M.separata arises from its long-distance migratory behavior.For example,direction and timing of winds from its overwintering regions in the south largely determine where and when large influxes of migrants arrive in the north to oviposit,making prediction of infestations difficult.

The pull of inter-provincial migration of rural labor force and its influence on policy-making

As a social phenomenon closely related to development of economy, the population is always the focis of economists＇ attention. Based on the fifth census in 2001, this paper analyzes labor migration in Hubet Provtnce and establishes an econometric model to analyze the pull according to the push and pull theory,, which is the famous theory on the population flow and migration. It points out that the per capita consumption and the employment rate attract strongly the rural labors and makes a deep exploration into the ensuing problems. Such conclusion is a special reference to the decision-making of government. The government can provide some guidance to the rural labors according to the per capita consumption and the employment rate in order to avoid the futility of blind migration.

Monitoring population dynamics of the migratory Red-crowned Crane (Grus japonensis) at Shuangtaihekou National Nature Reserve,northeastern China,from 1991 to 2012

We studied migratory Red-crowned cranes from 1991-2012 in order to track population dynamics and trends for these cranes over time at Shuangtaihekou,northeastern China.Our results show that the earliest arrival date of the Red-crowned Crane (Grus japonensis) was usually around 1 March in the spring and the latest departure date of the cranes around 8 November.The peak period for the number of cranes observed in the spring was 10-20 March over these 22 years.The staging period in the spring is about 25 days.Comparing the highest number of Red-crowned cranes observed in the spring,the migratory population was around 400 birds in the 1990s,then,increased to over 800 birds in 2000.For a short while,the population maintained itself around 600-800 birds.After that,the population started to decline,until during the most recent years,we observed around 400 birds at peak times of each season.Our results match a similar population change pattern observed in the wintering area for a western population,which has been declining since 2000.There is an urgent need to reinforce protection and management,as well as to maintain and improve the quality of their habitats.

Reconstruct recent multi-population migration history by using identical-by-descent sharing

Identical-by-descent(IBD)is a fundamental genomic characteristic in population genetics and has been widely used for population history reconstruction.However,limited by the nature of IBD,which could only capture the relationship between two individuals/haplotypes,existing IBD-based history inference is constrained to two populations.In this study,we propose a framework by leveraging IBD sharing in multipopulation and develop a method,MatrixiBD,to reconstruct recent multi-population migration history.Specifically,we employ the structured coalescent theory to precisely model the genealogical process and then estimate the IBD sharing across multiple populations.Within our model,we establish a theoretical connection between migration history and IBD sharing.Our method is rigorously evaluated through simulations,revealing its remarkable accuracy and robustness.Furthermore,we apply MatrixiBD to Central and South Asia in the Human Genome Diversity Project and successfully reconstruct the recent migration history of three closely related populations in South Asia.By taking into account the IBD sharing across multiple populations simultaneously,MatrixlBD enables us to attain clearer and more comprehensive insights into the history of regions characterized by complex migration dynamics,providing a holistic perspective on intricate patterns embedded within the recent population migration history.

Analysis on the migration of first-generation Mythimna separata(Walker) in China in 2013

Mythimna separata（Walker） is an important pest which can cause serious damages to cereal crops. In the past two decades, several heavy outbreaks have taken place in northern China. In order to develop a fine-scale method of forecasting outbreaks, population data were collected in northern China using searchlight traps and ground light traps. A background weather pattern analysis and trajectory analysis were performed via the Weather Research and Forecast（WRF） and FLEXPART models. Our results showed that heavy migration of first-generation M. separata appeared in northern China in 2013. In Yanqing District, Beijing, the cumulative number of captured adults in searchlight traps was around 250000 and the daily maximum for trapped moths was 86000. During the peak period, the majority of M. separata moths arrived after 00：00 every night. The sex ratio（female：male） at each monitoring site was greater than 1 and greatly fluctuated with population dynamics. During the migration peak, prevailing downdraft winds benefited M. separata moths to land passively. Trajectory simulation showed that immigrants were from Anhui, Jiangsu and Hubei provinces and most of them could continue to fly into the northeastern regions of China. These results provide technical support for fine-scale forecasting of the outbreak of M. separata at meso-and micro-scale.

Impacts of Migration on Urban Environmental Pollutant Emissions in China: A Comparative Perspective

In recent years,researchers have devoted considerable attention to identifying the causes of urban environmental pollution.To determine whether migrant populations significantly affect urban environments,we examined the relationship between urban environmental pollutant emissions and migrant populations at the prefectural level using data obtained for 90 Chinese cities evidencing net in-migration.By dividing the permanent populations of these cities into natives and migrants in relation to the population structure,we constructed an improved Stochastic Impacts by Regression on Population,Affluence and Technology model(STIRPAT)that included not only environmental pollutant emission variables but also variables on the cities’attributes.We subsequently conducted detailed analyses of the results of the models to assess the impacts of natives and migrants on environmental pollutant emissions.The main findings of our study were as follows:1)Migrant populations have significant impacts on environmental emissions both in terms of their size and concentration.Specifically,migrant populations have negative impacts on Air Quality Index(AQI)as well as PM2.5 emissions and positive impacts on emissions of NO2 and CO2.2)The impacts of migrant populations on urban environmental pollutant emissions were 8 to 30 times weaker than that of local populations.3)Urban environmental pollutant emissions in different cities differ significantly according to variations in the industrial structures,public transportation facilities,and population densities.

Pairwise Shared Genealogical Ancestry in Structured Populations

Simulation was used to investigate the effects of population structure and migration on metrics of pairwise shared ancestry. Random and hierarchical structures, or migration geometries, were examined. Compared to panmictic populations, progress to all qualitative metrics of pairwise ancestry is delayed in structured populations. However, unless migration is very low, the time required is generally less than triple and often less than twice that required in a panmictic population of the same total size. Population structure also increases, to a similar degree, the time required for a population-wide most recent common ancestor (MRCA). As a result, the relationships between various qualitative metrics of pairwise shared ancestry and MRCA time are relatively unaffected by population structure. For example, the mean time to most recent shared ancestor (MRSA) with global sampling of pairs is 40% - 50% of the MRCA time for almost all simulated structures and migration levels. Quantitative pairwise genealogical overlap is strongly affected by population structure. With global sampling, pairwise quantitative overlap never approaches 1.0, as it does in panmictic populations;and instead eventually becomes stationary at much lower values. Possible implications of the present results for human pairwise shared ancestry are discussed. For globally sampled pairs, the longest time to most recent shared ancestor (MRSA) for humans is suggested to be approximately 2100 years before the present. If generation time is 30 years, then all humans are 69th, or closer, cousins. For people with recent European ancestry, the MRSA time may be only half as long, about 1000 years.

Population synthesis of planet formation using a torque formula with dynamic effects

Population synthesis studies into planet formation have suggested that distributions consistent with observations can only be reproduced if the actual Type Ⅰ migration timescale is at least an order of magnitude longer than that deduced from linear theories.Although past studies considered the effect of the Type I migration of protoplanetary embryos,in most cases they used a conventional formula based on static torques in isothermal disks,and employed a reduction factor to account for uncertainty in the mechanism details.However,in addition to static torques,a migrating planet experiences dynamic torques that are proportional to the migration rate.These dynamic torques can impact on planet migration and predicted planetary populations.In this study,we derived a new torque formula for Type Ⅰ migration by taking into account dynamic corrections.This formula was used to perform population synthesis simulations with and without the effect of dynamic torques.In many cases,inward migration was slowed significantly by the dynamic effects.For the static torque case,gas giant formation was effectively suppressed by Type I migration;however,when dynamic effects were considered,a substantial fraction of cores survived and grew into gas giants.

Microgeographic Variation and Inter-Riffle Migration of <i>Rhinichthys atratulus</i>(Pisces: Cyprinidae) in a Small Connecticut Stream, United States

We examined the genetic diversity on a microgeographic scale of Rhinichthys atratulus (Eastern Blacknose Dace) in Allyn Brook, a small tributary in the upper Coginchaug River drainage in Connecticut. By looking at gene flow on a microgeographic scale among populations that had no physical barriers to migration, we tested the null hypothesis that the populations should be homogeneous. We resolved seven polymorphic microsatellite loci and one mitochondrial gene, nd2, in three adjacent populations (<0.5 km) in Allyn Brook and compared these populations to the two closest populations (>5 km) in the Coginchaug River. A dam from the 1920’s in lower Allyn Brook has isolated Allyn-Brook populations from Coginchaug-River populations. Allyn Brook was selected because there are only three riffle habitats in the brook and, therefore, there can be no immigration from upstream populations. Each population has private (i.e., unique) alleles and haplotypes, and there are significant genetic differences between all sites. The Allyn Brook populations are almost as different from one another as they are from the distant populations in the Coginchaug River from which they have been isolated for more than 80 years. These results point to in situ evolution and little migration or gene flow among populations on a microgeographic scale. This raises interesting questions for conservation of genetic diversity of stream fishes.

Population Growth,Available Resources,and Quality of Life:China’s Post-Reform Economic Development

Two opposing intellectual traditions and their contem-porary developments regarding the relations among population, available resources, and quality of life as reflected in economic growth are reviewed. What is at issue is whether population growth is detrimental to or beneficial for economic development. Neither of the extreme views gives a complete picture of the interplay among population, resources, and quality of life. Following previous literature on the topic, this paper establishes a more balanced approach that considers the function linking population and quality of life not constant but variable and regards the limitedness of resources as not absolute but relative to regions and societies. The proposed approach is more flexible in better explaining the relation between population and economic growth. China is examined as a case in point to shed light on the interaction of population growth, economic development, and available resources, and its recent post-economic reform experiences showcase the appropriateness of the synthetic approach.

Environmental Degradation Resulting from Oil Exploitation, and Population Displacement in the NigerDelta, Nigeria

Oil and gas exploration in the Niger Delta region of Nigeria began some fifty four （54） years ago. Since the early sixties till now, oil from this region of the Nigeria has been the major foreign exchange earner for the sustenance of the economy. Unfortunate to note is the fact that since oil exploration and exploitation began in the country in the Niger Delta, the region had not been at peace. The region had suffered all forms of environmental degradation resulting from crude oil spillage and gas flares. The peoples＇ source of livelihood has been destabilized thereby leading to high rate of poverty, social crises/conflict and involuntary migration of people for both security and succour. The people of the region are thus in severe pains and risk of extermination should the present trend of environmental degradation and negligence persist. Thus, this paper addresses the plight of the Niger Delta as a case study of the effect of environmental degradation on human vulnerability. It is believed that continuous existence of the Niger Delta people as a social sect is dependent on how prompt efforts are made to combat the environment nuisance in the region.

The Migration Pathway of the Proto Nuclear Micronesians：A Linguistic Trail

Over the last five decades or so, historical linguists have proposed as many as four different hypotheses concerning the migration pathway of Proto Nuclear Micronesians (i.e. the ancestors of Nuclear-Micronesian-language speakers): Proto Nuclear Micronesians may have reached Micronesia by moving from northern Vanuatu, from the Cristobal-Malaitan region, from the Admiralty or the St Matthias Islands, or even from somewhere in the vast southeast Solomons-New Hebrides region. This article provides an overview of these hypotheses, coming to the conclusion that there is no conclusive linguistic evidence, historical-comparative or otherwise, for any of the hypotheses. In view of this state of affairs, the article makes use of Johanna Nichols‘s population typology model so as to understand better the migration route of Proto Nuclear Micronesians. This innovative model has been developed to investigate geographical distributions of structural properties with a view to making inferences about human migration. In particular, the structural property of possessive classifiers, which is one of the major structural characteristics of Micronesian languages, is selected in order to ascertain how this structural property is distributed in the wider geographical areas surrounding Micronesia.Proto Nuclear Micronesians must have carried their propensity for a large number of possessive classifiers in their language(s) when travelling from somewhere into Micronesia.

Impacts of Rural-urban Migration on Food Consumption

Due to limitation of resource conditions,rural-urban migration leads to increased food consumption and aggravates the tight balance between food supply and demand.This issue has attracted increasing attention.This paper analyzed the food consumption level and structure of migrant workers,changes in food consumption before and after entering the city,the change range of food consumption and the main influencing factors.Data analysis indicated that there are large differences in the quantity and structure of food consumption of migrant workers in different industries and regions.Migrant workers whose food consumption increased after entering the city were more than those whose food consumption decreased.The increase in income and the management of food provided by work units are the main factors influencing the increase in food consumption.

Dynamics and implications of the age profiles of inter-provincial migration in China

This research examines the shifts in age profiles among migrants in China,utilizing microdata derived from four national censuses and two 1%population sample surveys conducted since 1990.Our findings indicate:(1)there has been a surge in age-specific migration intensity across all age groups over the past two decades;(2)the age profiles of the flow floating population differ from both the entire and the residual migrant populations;and(3)the age profiles of China’s flow floating population exhibit a blend of Asian and Western patterns-a prevalence among individuals in their early 20s,typical of Asian patterns,and a broad range of ages post-peak,indicative of Western patterns.Consequently,we propose that future population projections prioritize the flow floating population over the traditionally employed entire floating population.Furthermore,recognizing heterogeneity is critical for accurately understanding migrants in China,necessitating a comprehensive migration policy that safeguards the rights and welfare of these individuals.