Spatial Migration Patterns Research Articles

Spatial patterns of influenza A virus spread across compartments in commercial swine farms in the United States.

Multiple genetic variants of H1 and H3 influenza A viruses (IAVs) circulate concurrently in US swine farms. Understanding the spatial transmission patterns of IAVs among these farms is crucial for developing effective control strategies and mitigating the emergence of novel IAVs. In this study, we analysed 1909 IAV genomic sequences from 785 US swine farms, representing 33 farming systems across 12 states, primarily in the Midwest from 2004 to 2023. Bayesian phylogeographic analyses were performed to identify the dispersal patterns of both H1 and H3 virus genetic lineages and to elucidate their spatial migration patterns within and between different systems. Our results showed that both intra-system and inter-system migrations occurred between the swine farms, with intra-system migrations being more frequent. However, migration rates for H1 and H3 IAVs were similar between intra-system and inter-system migration events. Spatial migration patterns aligned with expected pig movement across different compartments of swine farming systems. Sow-Farms were identified as key sources of viruses, with bi-directional migration observed between these farms and other parts of the system, including Wean-to-Finish and Gilt-Development-Units. High intra-system migration was detected across farms in the same region, while spread to geographically distant intra- and inter-system farms was less frequent. These findings suggest that prioritizing resources towards systems frequently confronting influenza problems and targeting pivotal source farms, such as sow farms, could be an effective strategy for controlling influenza in US commercial swine operations.

Thawing process of high-ice-content frozen soil subjected to saturated steam

Engineering measures based on permafrost protection to inhibit high-ice-content permafrost thawing and subsidence in some areas of the Qinghai-Tibetan Plateau (QTP) are challenging owing to global warming. Hence, early permafrost thawing is an effective method for reducing the later settlement of the upper infrastructure. Saturated steam can thaw permafrost rapidly, but the research on the process and mechanisms of thawing permafrost with steam is lacking. In this study, steam-thawing tests were conducted on four types of frozen soil with high ice contents (20 %, 30 %, 40 %, and 50 % by volume). The temporal and spatial migration patterns of temperature and moisture in permafrost subjected to steam and the resulting thawing rates were analyzed by real-time monitoring of temperature and the volumetric water content (VWC) during the thawing process. Based on this, the mechanism of steam thawing permafrost was analyzed. The results showed that the continuous injection of saturated steam into the permafrost for 2 h resulted in complete thawing of permafrost with all four ice-contents, but the thawing rates were significantly different. The injection of steam led to an increase in VWC of thawed soil within a 5 cm radius by 1.26–1.68 times. The thawing of permafrost at different ranges was dominated by two different modes, pressure-driven water steam migration leading to permafrost thawing at a radius of about 10 cm and thawing of permafrost at the rest of the range by hydrothermal migration induced by temperature and humidity gradient. Compared to other conventional thawing methods, steam thawing is more suitable for targeted pre-thawing of deeply permafrost layers with high ice content.

Northern cod re-establish historical migration patterns linked to capelin: insights from pop-up satellite archival tags

In May 2012–2015, 90 large (85–117 cm) Northern cod ( Gadus morhua) with pop-up satellite archival tags (PSATs) set to release 1 year later were released from offshore spawning aggregations on the northeast Newfoundland shelf. Forty-nine (54%) transmitted or were recovered; 82% migrated inshore and 15% remained offshore (balance predated). Geo-locations were based on release, capture, and surfacing positions, and at tag-recorded depths <50 m, on Kalman-predicted light-based longitudes matched with coastal bathymetry. Migrating fish moved southwestward on average 5° longitude (350 km) and 2° latitude (222 km) to the northeast coast of Newfoundland, southern Labrador, and northern Grand Bank, as historically from similar release points. Migration onset through the Labrador Current (<0 °C) and arrival inshore were correlated with capelin ( Mallotus villosus) peak spawning, inshore duration with capelin, and cod biomass. Both species were delayed a month from historical norms. The probability of a cod remaining inshore after 1 December was 50%, which could impact time-dependent surveys. Fishing exploitation was 6% and predation 5%. Northern cod have re-established historical spatial migration patterns, with capelin a key influence on timing and duration inshore.

Long-term spatiotemporal characteristics of meteorological drought in China from a three-dimensional (longitude, latitude, time) perspective

Currently, there is an absence of an exhaustive elucidation regarding the long-term spatiotemporal characteristics of meteorological droughts in China. Previous studies have predominantly fixated on the lower-dimensional (temporal or spatial) facets of drought events, overlooking critical spatiotemporal details. This paper proposes an integrated processing framework that employs a three-dimensional clustering algorithm to discern drought events and quantifies the spatiotemporal patterns and dynamic attributes of China’s meteorological droughts during 1950–2021 from a three-dimensional perspective encompassing longitude, latitude, and time, capturing comprehensive spatiotemporal information. Additionally, the cross wavelet transform is harnessed to elucidate the impact of teleconnection factors on meteorological drought. The findings underscore that prolonged and extensive meteorological drought events, characterized by heightened severity, primarily manifest during the 1950 s, 1960 s, and 2010 s in temporal, predominantly within the central and western China spatially. From 1950 onwards, the severity, duration, and affected area of meteorological droughts in China exhibit a discernible pattern of initial decline followed by escalation. Into the 2010 s, meteorological droughts became more severe and active. China's meteorological drought displays two relatively prevailing spatial migration patterns: an overarching eastward and westward migration. In the former, the most frequent migration occurs to the east and northeast during its monthly evolution, while the latter involves migration primarily towards the west, southwest, and northwest. The impact of teleconnection factors on meteorological drought shows a spatiotemporal heterogeneity, with ENSO exhibiting a relatively substantial and intricate influencer. This research unearths the latest long-term spatiotemporal dynamics of meteorological drought in China, which contributes to an improved comprehension of drought patterns and behaviors.

Research on Spatial Migration Patterns and Influencing Factors of Western Talents: Based on Data from "Double first-class" Universities in China

The western region's talent loss issue has received widespread attention. Promoting the construction of human resources in the west has become key to forming an important high-quality development pole in western China. This study analyzes the graduate migration data of first-class universities in western China between 2016 and 2020 and draws the following conclusions: Overall, the retention rate of college graduates in western China across seven provinces is high, with a relatively higher retention rate observed in the place of study in four southwestern provinces. The retention rate of different provinces' place of study showed different trends during the period of 2016-2020, and the retention rate of different provinces also showed different trends during the same period. In 2020, western college graduates continued to show a preference for employment in popular provinces such as Guangdong, Beijing, and Shanghai, while they showed a greater inclination towards choosing employment opportunities in the South and Central regions of China. The results based on the directed migration model show that economic factors and natural and educational resources in a city have a greater impact on employment decisions. Analysis of heterogeneity found that graduates from areas with a high sticking rate are more susceptible to population size, human resources, and economic factors, and that cultural resources and transportation resources also have a significant impact on talent migration. Policy recommendations include western provinces taking higher education as a key factor to utilizing employment retention advantages to attract and retain high-quality talents.

Social ties and urban settlement intention of rural-to-urban migrants in China: The mediating role of place attachment and the moderating role of spatial pattern

Using nationally representative data from the 2017 China Migrants Dynamic Survey, this study investigated the mediating role of place attachment and the moderating role of spatial pattern in the association between local network ties and urban settlement intentions among rural-to-urban migrants. We found that local ties were positively associated with urban settlement intention measured by permanent settlement intention (PSI) and place attachment served as a mediating mechanism of this relationship. Results from the moderated path analysis showed that spatial pattern of migration positively moderated the linkage between local ties and PSI, indicating that beneficial role of local ties in urban settlement was more pronounced for inter-provincial migrants than for intra-provincial migrants. This study enhances our understanding of the association between social ties and migrant settlement, elucidating the conditions under which these effects are more pronounced in the context of internal migration. We thus call for a more targeted policy design aimed at integrating rural-to-urban migrants into local communities and eliminating the welfare gaps between migrants and local residents through appropriate intervention measures.

East-west or up the urban hierarchy? Internal migration patterns in Slovakia since post-socialist transformation to COVID-19 pandemic

ABSTRACT Changing spatial patterns of migration are closely related to the transformation of economy and society. Most current studies focus either on international migration or on the migration of particular urban regions. Our study evaluates migration trends in the entire national regional system, and thus it contributes to its comprehensive understanding. The study aims to evaluate the relationship of internal migration from economically lagging eastern to more developed western regions of Slovakia on the one hand, and migration between categories of regions according to the hierarchical position of their urban core on the other hand. The study follows the differential urbanization concept and analyses detailed data on individual migrations in Slovakia in 1996–2020. It thus covers the period from the post-socialist transformation to the COVID-19 pandemic. The results show the increasing intensity of east-west and up the urban hierarchy migration. Due to the significant polarization of migration between the eastern and western regional subsystems, we examined separately in both subsystems the migration excluding flows between the subsystems. The results revealed a concentration of population into metropolitan regions in both subsystems, although the intensity of the processes was lower and the onset of trends delayed in the eastern subsystem. A significant feature of development in the post-socialist period was intensive exurbanation in both subsystems. The study thus points to the importance of subnational and regional approaches to migration research, and reveals trends that can contribute to the explanation of migration development even in countries where such detailed migration statistics are not available.

Exploring spatial feedbacks between adaptation policies and internal migration patterns due to sea-level rise

Climate change-induced sea-level rise will lead to an increase in internal migration, whose intensity and spatial patterns will depend on the amount of sea-level rise; future socioeconomic development; and adaptation strategies pursued to reduce exposure and vulnerability to sea-level rise. To explore spatial feedbacks between these drivers, we combine sea-level rise projections, socioeconomic projections, and assumptions on adaptation policies in a spatially-explicit model (‘CONCLUDE’). Using the Mediterranean region as a case study, we find up to 20 million sea-level rise-related internal migrants by 2100 if no adaptation policies are implemented, with approximately three times higher migration in southern and eastern Mediterranean countries compared to northern Mediterranean countries. We show that adaptation policies can reduce the number of internal migrants by a factor of 1.4 to 9, depending on the type of strategies pursued; the implementation of hard protection measures may even lead to migration towards protected coastlines. Overall, spatial migration patterns are robust across all scenarios, with out-migration from a narrow coastal strip and in-migration widely spread across urban settings. However, the type of migration (e.g. proactive/reactive, managed/autonomous) depends on future socioeconomic developments that drive adaptive capacity, calling for decision-making that goes well beyond coastal issues.

New West and Old West in the Twenty-First Century: The Rich Get Richer

The rural U.S. West is increasingly valued for its unique natural beauty, tourism potential, and the outdoor recreational activities it provides rather than for its grazing potential, lumber mills, or extraction of valuable minerals. With this transition in mind, we examine demographic changes in the region within the context of selective migration. We build on research conducted in the late 1990s that studied the changing spatial patterns of migration and income migration within the rural Mountain West. We update the current economic and demographic structure of the region and then document how 1990s patterns have persisted through an analysis of population concentration and income migration using U.S. Census and Internal Revenue Service data. Positive net migration and income migration have focused on New West (high amenity) counties, whereas the Old West, comprised of government, mining and manufacturing, farming, and other (diversified) counties, has fallen farther behind in income migration. Consequently, selective migration to areas of natural beauty and recreation potential has increasingly transformed the rural New West into its own peculiar geography, distinct in demographics as well as environment from the Old West, revealing a growing spatial inequality between these two areas, especially in income and housing.

A GIS Approach to Identifying Locally the Spatial Migration Patterns and Interactions between Housing Market Areas in Greater Manchester

A GIS Approach to Identifying Locally the Spatial Migration Patterns and Interactions between Housing Market Areas in Greater Manchester

Integrating data types to estimate spatial patterns of avian migration across the Western Hemisphere.

For many avian species, spatial migration patterns remain largely undescribed, especially across hemispheric extents. Recent advancements in tracking technologies and high-resolution species distribution models (i.e., eBird Status and Trends products) provide new insights into migratory bird movements and offer a promising opportunity for integrating independent data sources to describe avian migration. Here, we present a three-stage modeling framework for estimating spatial patterns of avian migration. First, we integrate tracking and band re-encounter data to quantify migratory connectivity, defined as the relative proportions of individuals migrating between breeding and nonbreeding regions. Next, we use estimated connectivity proportions along with eBird occurrence probabilities to produce probabilistic least-cost path (LCP) indices. In a final step, we use generalized additive mixed models (GAMMs) both to evaluate the ability of LCP indices to accurately predict (i.e., as a covariate) observed locations derived from tracking and band re-encounter data sets versus pseudo-absence locations during migratory periods and to create a fully integrated (i.e., eBird occurrence, LCP, and tracking/band re-encounter data) spatial prediction index for mapping species-specific seasonal migrations. To illustrate this approach, we apply this framework to describe seasonal migrations of 12 bird species across the Western Hemisphere during pre- and postbreeding migratory periods (i.e., spring and fall, respectively). We found that including LCP indices with eBird occurrence in GAMMs generally improved the ability to accurately predict observed migratory locations compared to models with eBird occurrence alone. Using three performance metrics, the eBird + LCP model demonstrated equivalent or superior fit relative to the eBird-only model for 22 of 24 species-season GAMMs. In particular, the integrated index filled in spatial gaps for species with over-water movements and those that migrated over land where there were few eBird sightings and, thus, low predictive ability of eBird occurrence probabilities (e.g., Amazonian rainforest in South America). This methodology of combining individual-based seasonal movement data with temporally dynamic species distribution models provides a comprehensive approach to integrating multiple data types to describe broad-scale spatial patterns of animal movement. Further development and customization of this approach will continue to advance knowledge about the full annual cycle and conservation of migratory birds.

Tracking the Spatio‐Temporal Evolution of Foreshocks Preceding the Mw 6.1 2009 L’Aquila Earthquake

AbstractHow faulting processes lead to a large earthquake is a fundamental question in seismology. To better constrain this pre‐seismic stage, we create a dense seismic catalog via template matching to analyze the precursory phase of the Mw 6.1 L’Aquila earthquake that occurred in central Italy in 2009. We estimate several physical parameters in time, such as the coefficient of variation, the seismic moment release, the effective stress drop, and analyze spatio‐temporal patterns to study the evolution of the sequence and the earthquake interactions. We observe that the precursory phase experiences multiple accelerations of the seismicity rate that we divide into two main sequences with different signatures and features: the first part exhibits weak earthquake interactions, quasi‐continuous moment release, slow spatial migration patterns, and a lower effective stress drop, pointing to aseismic processes. The second sequence exhibits strong temporal clustering, fast seismicity expansion, and a larger effective stress drop typical of a stress transfer process. We interpret the differences in seismicity behaviors between the two sequences as distinct physical mechanisms that are controlled by different physical properties of the fault system. We conclude that the L’Aquila earthquake is preceded by a complex preparation, made up of different physical processes over different time scales on faults with different physical properties.

A systematic analysis of the spatial migration patterns and the linkages between market components in Greater Manchester, United Kingdom

PurposeThis paper aims to bring together research on housing market area, submarket and household migration into a systems approach that helps us gain a better understanding of the structure and dynamics of a housing market and identify housing problems for a large metropolitan area.Design/methodology/approachThe paper uses a geographic information system (GIS)-based method with simple quantitative techniques, including spatial analysis, location analysis, house price clustering and cross-tabulation. The analysis is based on migration data from the 2011 Census, house price data from the Land Registry in 2011 for Greater Manchester at the ward level and the output areas level.FindingsThe results show that different submarkets and housing market areas had different patterns of spatial migration and connections with other areas. Through a systematic analysis of migration and house price in combination, it also found a close connection between destination submarkets and the ages of migrants and identified specific problematic patterns for a large metropolitan area.Research limitations/implicationsThe interactions between the owner-occupied sector and the social and private rented sectors are arguably an important omission from the analysis. Also, it is acknowledged that clustering ward units based on price differentials is subject to distortions in terms of specification, size and shape. Moreover, the use of the large samples may result in very small p-values, leading to the problem of the rejection of the predefined hypothesis.Practical implicationsA systematic analysis of migration and house price in combination may be used to gain a better understanding of the housing market dynamics and identify housing problems systematically for a large metropolitan. It may help to identify low-demand areas, high-demand areas and assist planners with decisions in allocating suitable land for new housing constructions.Social implicationsThe GIS-based method introduced in the paper could be considered as an effective approach to provide a better basis for determining policy interventions and public investment designed to allocate land resources effectively and improve transport systems to change existing problematic migration patterns.Originality/valueThis paper fills a gap in the international literature in relation to adopting a systems approach that analyses migration and house price data sets in combination to systematically explore migration patterns and linkages and identify housing problems for a large metropolitan area. This systems approach can be applied in any metropolitan area where migration and house price data are available.

Original

The present paper is an attempt to analyse the spatial patterns of migration, variations in the level of socio-economic development and the relationship between total migration (dependent variable) and selected variables of development (independent variables) among the states of India. The entire research work is based on secondary sources of data, collected from Census of India publications (2011), Migration Table – D Series, Handbook of Statistics of Indian States, Primary Census Abstract of India and Basic Road Statistics of India. The boundary of a state has been taken as the smallest unit of the study. The present study reveals that, from the southern part of the country, the level of migration changes rapidly from high to low grade towards the north. On the other hand, the states lying in the western and eastern part experienced medium to high level of migration in comparison to the north-eastern states having a low level of migration in India. The level of development is high or medium in northern, western and southern states in comparison to the states, lying in the eastern and north-eastern parts of the country.

Migration and City Competitiveness: A Comparative Analysis with Surat as a Special Case

This article provides a brief sketch of the size, composition and spatial pattern of migration in Surat city based on discussions in the existing literature, anecdotal evidences and interactions with the Surat Municipal Corporation (SMC) officials during field trips. It sheds light on migration ‘specificity’ of Surat compared with migration flows in other major cities. The article builds a competitiveness index to rank the four cities in our project: Surat, Pune, Kochi and Ludhiana using the principal component analysis (PCA) technique and interprets the role of migration in building a city’s competitiveness. While migration adds strains on urban resources (e.g., growth of slums) and makes it more ‘vulnerable’, it enriches a city’s supply chains by easing labour market tightness and making it more ‘competitive’ economically. It finds a positive link between migration and a city’s competitiveness in general. Competitiveness is here taken to be a composite of several socio-economic variables, over and above what is generally meant by ‘economic’ competitiveness. Based on the commonalities of the variables that explain the principal components (PC) most (have significant loadings in the component), the PCs are redefined as ‘Absorption Spillover’ and ‘Strength of Pull’. It finds that though Surat is placed in the 2nd rank in terms of overall competitiveness, its competitiveness is primarily driven by ‘Strength of Pull’ rather than ‘Absorption Spillover’. The policy implication is that urban adaptive mechanisms should be redesigned on this dimension to achieve a balanced, inclusive and sustainable competitiveness.

International migration to an economically lagging EU region: case study of Ukraine and Eastern Slovakia

The research on international migration is usually focused on the most attractive destinations of migrations or areas of origin of migration flows suffering from considerable migration loss. This paper analyses the development and spatial patterns of migration from Ukraine to Slovakia with a special emphasis on Eastern Slovakia, which is employed as a case study of an economically lagging region with significant migration loss. The paper aims to assess if such a lagging region can be an attractive destination for migration from Ukraine, and to what extent migration flows from Ukraine can compensate for its migration loss. By using methods of a statistical analysis based on data from various national and international authorities, field research, and semi-structured interviews, the paper contributes to filling the gap in the research of international migration. Despite the economic lagging behind the western regions, Eastern Slovakia has attracted the majority of migrants from Ukraine to Slovakia. Because the structure of migrants from Ukraine is dominated by well-educated and skilled individuals, who are also culturally close to the domestic population and at the same time well adaptable to a host society, such migration flows are not enough to compensate the massive migration loss of Eastern Slovakia fully but can mitigate its negative consequences including loss of human capital.

Selective migration of population in functional urban regions of Slovakia

ABSTRACTMajority of research on urban development perceive migration as internally homogeneous phenomenon that influences growth and spatial redistribution of population. This enables to identify certain general migration patterns, but understanding regularities and consequences requires looking at internal structure of migration. This paper aims to visualise the impact of selective migration to the population structures across multiple spatial scales and in a complex way taking Slovakia as the case study. By this means spatial patterns of migration are demonstrated in a more efficient way. The resulting maps show the impact of migration is selective at various spatial levels regarding age and educational attainment. In comparison with general migration, selective migration shows stronger spatial polarisation in Slovakia.

Exile: Mapping the Migration Patterns of Japanese Canadians Exiled to Japan in 1946

Abstract In 1946, after a period of internment that began in 1942, approximately four thousand Japanese Canadians were exiled to Japan and stripped of their citizenship. More than half were Canadian-born, and the majority of those who had been born in Japan were Canadian citizens. The exiles were given a choice of impossible options: to relocate outside of British Columbia or be sent to Japan. Drawing upon extensive archival research, this study examines the spatial patterns of migration between Japan and Canada with a particular focus on the exile of Japanese Canadians to Japan in 1946. Our findings indicate that the majority of the exiles were from Wakayama, Shiga, and Hiroshima prefectures, where rates of return prior to the 1940s were already high. Although more definitive explanations require further research, our exploratory analysis suggests that regional patterns of exile were likely influenced by the prefectural origin of the original migrants, obligations to re-establish the traditional Japanese agrarian household, and religious practices.

Temporal migration patterns between natal locations of ruby-throated hummingbirds (Archilochus colubris) and their Gulf Coast stopover site

BackgroundAutumn latitudinal migrations generally exhibit one of two different temporal migration patterns: type 1 where southern populations migrate south before northern populations, or type 2 where northern populations overtake southern populations en route. The ruby-throated hummingbird (Archilochus colubris) is a species with an expansive breeding range, which allows opportunities to examine variation in the timing of migration. Our objective was to determine a relationship between natal origin of ruby-throated hummingbirds and arrival at a Gulf coast stopover site; and if so, what factors, such as differences in body size across the range as well as the cost of migration, might drive such a pattern. To carry out our objectives, we captured hummingbirds at a coastal stopover site during autumn migration, at which time we collected feathers from juveniles for analysis of hydrogen stable isotopes. Using the hydrogen stable isotope gradient of precipitation across North America and published hydrogen isotope values of feathers from populations of breeding ruby-throated hummingbirds, we assigned migrants to probable natal latitudes.ResultsOur results confirm that individuals from across the range (30–50° N) stopover along the Gulf of Mexico and there is a positive relationship between arrival day and latitude, suggesting a type 1 migration pattern. We also found no relationship between fuel load (proxy for migration cost) or fat-free body mass (proxy for body size) and natal latitude.ConclusionsOur results, coupled with previous work on the spatial migration patterns of hummingbirds, show a type 1 chain migration pattern. While the mechanisms we tested do not seem to influence the evolution of migratory patterns, other factors such as resource availability may play a prominent role in the evolution of this migration system.

Terrace formation in the upper Bengal basin since the Middle Pleistocene: Brahmaputra fan delta construction during multiple highstands

AbstractFloodplains, paleosols, and antecedent landforms near the apex of the Brahmaputra fan delta in north‐central Bangladesh preserve cycles of fluvial sediment deposition, erosion and weathering. Together these landforms and their associated deposits comprise morphostratigraphic units that define the river's history and have influenced its channel position and avulsion behaviour through the Late Quaternary. Previously, temporal differentiation within these units has not been sufficient to decipher their sequence of deposition, an important step in understanding the spatial pattern of migration of the Brahmaputra River. Holocene units in this region are fairly well established by radiocarbon dating of in situ organic material, but pre‐Holocene units are considered Pleistocene‐aged if organic material is dated >48 000 year BP (the limit of radiocarbon dating) or the sediments are positioned beneath a prominent paleosol, interpreted as a buried soil horizon that developed during a previous sea level lowstand. In such cases, these morphostratigraphic units have been broadly interpreted as Pleistocene without knowing their absolute depositional ages or relative evolutionary chronology. Here we use detailed sediment analysis to better differentiate morphostratigraphic units at the Brahmaputra's avulsion node, establishing the sequence of deposition and subsequent weathering of these bodies. We then test this relative chronology by luminescence dating of the sands beneath these landform surfaces. This work provides the first absolute depositional age constraints of terrace sediments for the Middle to Late Pleistocene Brahmaputra River and upper Bengal basin. The luminescence ages are complemented by detailed compositional trends in the terrace deposits, including clay mineralogy and the degree of weathering. Together, these newly dated and carefully described morphostratigraphic units reflect eustasy‐driven cycles of terrace development by way of highstand floodplain deposition and subsequent lowstand exposure and weathering, along with active tectonic deformation. Defining this Late Quaternary history of terrace development and position of the Brahmaputra River is a first step toward an integrated understanding of basin and delta evolution over multiple glacioeustatic cycles and tectonically relevant timescales.