Trend Surface Analysis Research Articles

Differences in spatial distribution of medicinal plant resources in Yinshan region of Inner Mongolia

Yinshan Mountains stands on the southern edge of the Inner Mongolia Plateau, which stretches 1 200 km from east to west and 50 to 100 km from north to south. The rich and varied topographic environment of the Yinshan Mountains has created a variety of vegetation floras, which also makes the species of medicinal plant resources in this area unevenly distributed. Therefore, studying the spatial distribution difference of medicinal plant resources among various banners, counties, and districts in the Yinshan area is of great significance to formulate the protection policy and promote the industry development of medicinal plant. This study is based on the fourth national survey of traditional Chinese medicine resources in Inner Mongolia, regarding the results of the third national survey of traditional Chinese medicine resources. The species of medicinal plant resources in the Yinshan area around 31 banners, counties and districts were counted in detail. Then, using exploratory spatial data analysis(ESDA), trend surface analysis, spatial autocorrelation, geographical detector and other geostatistical analysis methods to analyze the differences in the spatial distribution of medicinal plant resources of the Yinshan area in Inner Mongolia. After discussing and analyzing the experimental results to account for the reasons for the overall trend of change and the degree of aggregation, the author further put forward relevant constructive suggestions. The results show that the areas with the most abundant and concentrated distribution of medicinal plant resources in the Yinshan area are located in Guyang county, Shiguai District of Baotou city, Tutou right banner, and Tuoketuo county; the higher richness and concentrated distribution of medicinal plant resources is in Wulate front banner, Wulate middle banner, Wulate back banner; areas with relatively low abundance and concentrated distribution of medicinal plant resources located in Qingshan district of Baotou city, Saihan district and Yuquan district of Hohhot city; areas with the lowest abundance and concentrated distribution of medicinal plant resources are located in Xincheng district and Huimin district of Hohhot city. It can be concluded that the horizontal distribution difference of multiple ecological factors, the special wetland environment of the river, the vertical difference of elevation, the farmland and other factors have an important influence on the richness of the medicinal plant resources species.

The spatial distribution of the normal reference values of the activated partial thromboplastin time based on ArcGIS and GeoDA.

We explored the variation and spatial distribution of the activated partial thromboplastin time (APTT) reference values of healthy people at different altitudes in China in order to develop a scientific basis for a unified standard. The APTT reference values of 49,020 healthy males (41-75years old) and 32,447 healthy females (41-75years old) were collected from 601 work units and 546 work units in China, respectively. The relationship between the APTT reference values and altitude was tested by correlation analysis. Linear regression analysis and curve analysis were employed to predict the APTT reference values in the whole country. Trend surface analysis, the variation function, kriging interpolation, and Getis-Ord Gi* statistic were utilized to reveal the spatial characteristics of the values. The result showed a significant positive correlation between the APTT reference values and altitude. The APTT values for females were prolonged for a greater amount of time than the males in several same areas in China. The spatial contact forms of the APTT reference values of healthy Chinese were mainly "high-high" and "low-low," which was in accord with the first law of geography. The APTT reference values still showed spatial autocorrelation and regional variation. The values were higher in the western and northern areas than in the eastern and southern areas of China. The APTT reference values of people aged 41-75 in China showed regional differences. The APTT reference values in one area can be estimated by using the best prediction model or can be obtained by the geographical distribution.

Spatial-temporal analysis and visualization of scarlet fever in mainland China from 2004 to 2017

This study retrospectively analyzed the spatio-temporal distribution and spatial clustering of scarlet fever in mainland China from 2004 to 2017. In recent years, the incidence of scarlet fever is increasing. Previous studies on the spatial distribution of scarlet fever in China are mainly focused at the provincial and municipal levels, and there is few systematic report on the spatial and temporal distribution characteristics of scarlet fever on the national level. Based on the incidence information of scarlet fever in mainland China between 2004 and 2017 collected from the China Center for Disease Control, this paper systematically explored the Spatio-temporal distribution of scarlet fever by three methods, contains spatial autocorrelation analysis, Spatio-temporal scanning analysis, and trend surface analysis. The results demonstrate that the incidence of scarlet fever varies by seasons, which is in line with double-peak distribution.The first peak generally occurs from May to June and the second one from November to December, while February and August is the lowest period of incidence. Trend surface analysis indicates that the incidence of scarlet fever in northern China is higher than the south, slightly higher in western compared to the east, and lower in the central part. Additionally, the results show that the clustering regions of scarlet fever centrally distributed in the northeast, northwest, north china and some provinces in the east, such as Zhejiang, Shanghai, Shandong, and Jiangsu.

Associations between geographical environment and systolic pulmonary arterial pressure of Chinese adults: impact analysis and predictive modeling.

Since systolic pulmonary arterial pressure (SPAP) is an important diagnostic indicator for various cardiovascular diseases, it is of great significance to determine scientific SPAP reference value in clinical application. However, the SPAP reference values currently have not been applied under a unified standard, and its formulation does not consider the impacts from geographical environment which has proved to be closely associated with SPAP. This study aims to quantify the impacts of geographical factors on SPAP and formulate scientific SPAP reference values, thereby providing support for more accurate diagnosis. Measured SPAP values of 4550 healthy adults were collected from 88 cities across China, and 11 geographical factors were selected. Four geographical factors with significant impacts on SPAP were determined via correlation analysis, including two positive factors (altitude, soil organic matter) and two negative ones (longitude, annual average temperature). Then partial least-squares regression analysis (PLSR) and trend surface analysis were applied to establish predictive models. Through model test using both collected and simulated SPAP data of control points, the PLSR model was determined to have better prediction accuracy and was selected as optimal model to calculate the SPAP reference values of 2322 cities in China. The predictive results ranged from 22.09 to 31.77mmHg. Finally, hotspot analysis and kriging interpolation method were applied to explore the spatial distribution of SPAP reference values. The result of spatial analysis shows that SPAP reference values of Chinese adults decreased gradually from the West to East in China. This study indicated the significant impacts of geographical environment on SPAP and established predictive model for determining SPAP reference values, which is expected to help enhance clinical diagnostic accuracy.

Statistical evaluation of the geochemical data for prospecting polymetallic mineralization in the Suoi Thau – Sang Than region, Northeast Vietnam

In Northeast Vietnam, Suoi Thau-Sang Than is considered as a high potential area of polymetallic deposits. 1,720 geochemical samples were used to investigate polymetallic mineralization; thereby polymetallic ore occurrences in this study region were discovered and the statistical and multivariate analysis helps to define geochemical anomalies in some northeastern regions, namely Suoi Thau, Sang Than, and Ban Kep. The statistical method and cluster analysis of geochemical data indicate that the Cu, Pb, and Zn elements are good indicators, and most of them comply with the lognormal or gamma distribution. Based on the third-order threshold, the geochemical anomalies of the content of the Cu, Pb, and Zn elements reflect the concentration of copper forming ore bodies in the mineralized zone, and clearly show the concentration in three distinct zones. The trend surface analysis which was employed to determine spatial variations and relationships among these good indicator elements and anomalous areas revealed relative changes in the content of the indicator elements, and they can be considered as regular. Moreover, the goodness of fit obtained trend functions of Pb and Zn, and Cu elements is a third-degree trend surface model. These results indicate that the models can be useful in studying geochemical anomalies and analyzing the tendency of the concentration of indicator elements in the Suoi Thau-Sang Than region. Additionally, it is suggested that the statistical analysis shows a remarkable potential to use the bottom river sediments in the region to investigate polymetallic mineralization. Moreover, geochemical data can help to evaluate geochemical anomalies of the pathfinder elements and potential mineral mapping of the Suoi Thau-Sang Than region in Northeast Vietnam.

Upward continuation and polynomial trend analysis as a gravity data decomposition, case study at Ziway-Shala basin, central Main Ethiopian rift

The first task in quantitative interpretation of a gravity data is separation of the Bouguer anomaly into its regional and residual components which are respectively related to deep and shallow subsurface geology. The decomposition process is subjective and non-unique as there is no single best approach to approximate the low frequency signature. For example, the use of spectral analysis and upward continuation require the wise choice of slope change location and continuation height respectively, which could be chosen differently by different researchers. This requires a need to work on more than one method and select the best to be applied for a given study area. The “best” choice is made based on the anomaly signature of the underlying geology. In this research, the most frequently used methods such as upward continuation and trend surface analysis methods are used and compared to approximate the regional field in Central Main Ethiopian rift bounded between 38000′-39030′E and 7000′-8030′N. The upward continuation height and the order of trend polynomial surface are first chosen, to approximate the regional gravity field signal. Accordingly, an upward continuation height of 6km and first order polynomial trend surface are chosen to be appropriate. Comparison of the two methods shows that the upward continuation technique reflects the shallow source anomalies of the area better than that of the first order linear trend surface. This outcome is verified against the result obtained based on the first vertical derivative method, spectral analysis depth estimation method, well-log data and surface geology of the area. It is therefore recommended to consider the various existing filtering techniques and choose the best candidate for the separation of the regional and residual components of the observed field.

Using opportunistic sightings to assess the suitability of Important Marine Mammal Areas (IMMAs) for cetacean conservation in the Western Mediterranean Sea

The Western Mediterranean Sea connects the Atlantic Ocean with the rest of the Mediterranean Sea through the Strait of Gibraltar. The Western Mediterranean Sea is important area for cetaceans and it contains highly productive feeding areas, such as the Pelagos Sanctuary and the South Balearic eddy. The main aim of this study was to assess the suitability of a group of Important Marine Mammal Areas (IMMAs) for the conservation of cetaceans inhabiting this area. There were 398 (46.44%) opportunistic sightings (OS) within a number of IMMAs and 459 (53.56%) sightings outside of IMMAs in this area. Trend surface analysis was used to select the OSs (GPOSs hereafter) most likely to be observed within IMMAs as a function of their geographical position. Significant differences were found between the observed GPOS rate and the expected GPOS rate weighted by the surface area of each IMMA. Specifically, there were more sightings than expected in the Alboran Sea IMMA than in the North West Mediterranean Sea, Slope, and Canyon System IMMA. In the latter area, there were fewer sightings than expected.

Long-term Growth Variation and Selection of Geographical Provenances of Cunninghamialanceolata (Lamb.) Hook

In order to understand the long-term growth variation of Chinese fir’s geographical provenances and promote long-term genetic improvement, the experimental provenance forest of Chinese fir planted in 1981 was taken as a research object.The provenances originated from southeastern China. The study measured each diameter at breast height (DBH) and tree height at 5, 6, 8, 12, and 33 years of age and analyzed the genetic variation of major growth traits of trees withdifferent provenances at different forest ages. Additionally, the study analyzed the geographical variation of Chinese fir by using the trend surface and principal component analysis (PCA) and evaluated the long-term selection effect of provenance by using juvenile–mature correlation and cluster analysis. The heritability of the DBH, treeheight, and volume of Chinese fir with different provenances reached 0.35–0.76, and with increasing forest age, the heritability of each trait showed a rising and gradually stabilizing trend. There were obvious differences in geographical variation patterns among the tested provenances, and both the DBH and the tree height growth patterns are two-way gradients. This variation pattern is associated with climatic conditions in different regions, and the factors limiting the growth difference of Chinese fir may be the mean temperature in winter and the precipitation in autumn and winter.An early selection age has a significant effect on shortening the timber production cycle of Chinese fir. The selection of trees aged between 6 and 12 years is more conducive to improving the efficiency of the genetic improvement of Chinese fir.The 42 excellent provenances selected from the 33-year-old mature Chinese fir forests have a larger increase in growth than trees with local provenances, which are concentrated in the Wuyi and Xuefeng mountains and are suitable for plantation in the Guangxi Zhuang Autonomous Region and surrounding areas.

Spatial distribution of Brucellosis in Gansu province, 2013-2018

Objective: To analyze the spatial distribution and both hot and cold spots of incidence on Brucellosis in Gansu province from 2013 to 2018. Methods: Based on data from the Infectious Disease Reporting Information System in China, data related to space-time distribution and both hot and cold spots of Brucellosis in Gansu province from 2013 to 2018 were analyzed, by using the ArcGIS 10.5 software and GeoDa 1.6 software. Results: The trend surface analysis showed that the incidence of Brucellosis decreased gradually from the northern to southern parts with slightly higher in the west than in the east of Gansu. Global spatial autocorrelation analysis showed that the Moran's I of Brucellosis in Gansu province from 2013 to 2018 were 0.242, 0.487, 0.424, 0.460, 0.427 and 0.468 (P<0.01), suggesting that the incidence of Brucellosis had spatial clustering features in Gansu province. Local global spatial autocorrelation analysis showed that the number of hot spots were declining in the eastern and north-central regions while the hot spots were increasing in the Hexi area (Wuwei, Zhangye, Jinchang and Jiuquan cities). The cold spots areas were mainly seen in the eastern, southeastern and south of central regions in Gansu province. Conclusions: The incidence of Brucellosis showed obviously spatial clustering characteristics in Gansu province. The number of hot spots were decreasing in the eastern and north of central regions while the hot spots were increasing in the Hexi area, suggesting that the prevention and control measures for Brucellosis should be further strengthened in these areas.

Variation in radial growth and wood density of Cyclocarya paliurus across its natural distribution

As a multiple function tree species, Cyclocarya paliurus is planted and managed for timber production and medicinal use. However, it remains unclear to what extent geographical gradients in growth and wood quality are shaped by the environment. We used data of 197 trees from 22 natural populations to assess geographic variation patterns in radial growth and wood density, and their correlations with environmental factors. Significant differences in mean annual DBH and wood basic density were observed among the 22 populations (p < 0.05). Based on mean annual DBH and wood basic density, the 22 populations were classified into three groups by hierarchical cluster analysis. Within its natural distribution, soil nutrients are more closely associated with DBH growth than are temperature and precipitation. However, correlations between wood density versus altitude and annual precipitation were found (p < 0.01). Trend surface analysis revealed that mean annual DBH growth and wood density displayed an increasing trend from north-west to south-east across its natural distribution. Our study provides valuable insights into the geographical patterns in growth and wood quality of C. paliurus, and an opportunity to improve tree growth and wood quality through phenotypic selection and selecting suitable sites for planting.

Epidemiological and spatial-temporal distribution of several natural focus diseases in Gansu province, 2014-2018

Objective: To analyze the epidemiological and spatial-temporal distribution of Brucellosis, epidemic encephalitis B and hemorrhagic fever with renal syndrome (HFRS) in Gansu province during 2014-2018 so as to provide evidence for the prevention and control of those diseases. Methods: A database was established in Gansu province from 2014 to 2018, using the geographical information system. A spatial distribution map was drawn, with trend analysis and space-time clustering used to study the 3-dimention of the diseases, by using both ArcGIS 10.5 and SaTScan 9.6 softwares. Results: Results from the trend surface analysis showed that the incidence of Brucellosis decreased gradually from north to south parts while the U type curve could reflect the distribution from the east to the west areas. Incidence of epidemic encephalitis B decreased significantly from south to north areas in the province, with incidence higher in the eastern than in the mid-west region. Difference on the incidence of HFRS was not significantly visible in the eastern and western regions, while the incidence was slightly higher in the southern than the northern parts of the province. Spatial and space-time clustering did exist among the 3 diseases in Gansu from 2014 to 2018. The areas with clusters of Brucellosis appeared in the eastern parts during 2014-2015, including 19 counties. The areas with secondary clusters of Brucellosis were seen in the Hexi district, including 4 counties, during 2017-2018. The areas with high incidence of epidemic encephalitis B were clustered in the middle and southeast areas, including 32 counties, during 2017-2018. Areas with most clusters of HFRS appeared in Min county of Dingxi city in 2018, with the areas of secondary clusters in 8 counties of the eastern areas in 2018. Conclusions: The overall incidence rates of the 3 natural focus diseases were in a upward trend and showing obvious characteristics on spatial clustering. According to the distributive characteristics, effective measures should be developed accordingly.

Multipath mitigation based on trend surface analysis applied to dual-antenna receiver with common clock

Multipath mitigation methods based on the intrinsic spatiotemporal repeatability of multipath effect are commonly applied in high-precision Global Navigation Satellite System positioning. Among which multipath hemispherical map (MHM) has the advantages of simplicity of calculation and real-time multipath reduction of static environment or some dynamic environment. However, utilizing the average of residuals as the calibration values will inevitably lead to insufficient or excessive modification of multipath in the lattice. We proposed an advanced multipath elimination method named trend surface analysis-based multipath hemispherical map (T-MHM), which extends the primary MHM by combining the trend surface analysis method to investigate the multipath spatial distribution and trend in each lattice. A short baseline experiment was carried out using a dual-antenna receiver with common clock in campus of East China Normal University. Single-difference carrier residuals were used for relative multipath modeling. The multipath elimination results indicate that, compared with the original approach, the T-MHM improves the dispersion and accuracy of the baseline solution and increases the phase observation residuals reduction rate. It also enhances the modeling of multipath information in both low- and high-frequency bands. Meanwhile, T-MHM is less sensitive to lattice size. In practical applications, larger lattice size can be adopted to improve the computational efficiency and spatial coverage with little loss of accuracy.

An Inproved Up-scaling Algorithm Combined TSA and PSF

Taking the Guanzhong Plain of Shanxi Province as the research area, the combine method of trend surface analysis method (TSA) and point spread function (PSF) (TSA+PSF) were used to up-scale the vegetation temperature condition index (VTCI) retrieved from Landsat 8 images (Landsat-VTCI) from a finer resolution to a coarser resolution. The up-scaled results were compared with VTCI images retrieved from Aqua MODIS (MODIS-VTCI) to provide technical support for the comprehensive application of drought monitoring results on two spatial scales. Meanwhile, a range of indicators, such as the semivariogram function (SVF), the structural similarity (SSIM), the correlation coefficients (r), root mean square errors (RMSE) were used to systematically compared the up-scaled methods. The results show that TSA+PSF performed better than TSA in terms of SSIM, the correlation and RMSE, the up-scaling model TSA+PSF has the higher accuracy, and it is more effective and robust than TSA. The model that uses PSF to analyze trend surface constructed by TSA is an improvement for up-scaling Landsat- VTCI images from a finer resolutions to a coarser resolutions.

Spatial distribution characteristics of tumor marker CA724 reference values in China.

ObjectsThis study aims to explore the Cancer antigen 724 (CA724) reference values spatial distribution characteristics in healthy Chinese adults. The study can provide regional reference for medical diagnosis.Study DesignThe relationship between CA724 and 25 geographical environmental factors was analyzed firstly. Artificial neural network simulation training was used to construct the prediction model. The national forecast distribution map of the CA724 reference values was obtained by the geostatistical mapping method. Analyzing and exploring the influence mechanism of geographical environment factors on CA724 reference values.MethodsCollecting 34470 cases from more than 106 cities healthy adults CA724 reference values via several paper databases in 10 recent years. Correlation analysis, RBF artificial neural networks and trend surface analysis were applied to explore if there was any tendency of spatial variation. The Kriging interpolation of geostatistical analysis was developed to reveal the spatial distribution characteristics of the CA724 reference values.ResultsThe distribution of CA724 reference values of Chinese healthy adults shows a downward trend from south to north. CA724 reference values have negative correlations with latitude, annual sunshine duration and topsoil cation exchange capacity in clay. CA724 have positive correlations with annual mean air temperature, annual mean relative humidity, and annual precipitation amount. High temperature and high humidity environment will reduce gastrointestinal function and breeze various mold bacteria. Lack of sunshine can easily lead to vitamin C deficiency in the body. These will increase the incidence of gastrointestinal diseases and gastric cancer, then increase the CA724 value.ConclusionCA724 reference values show spatial autocorrelation and regional variation. There are some geographical environment factors effected Chinese healthy adults CA724 reference values. Geographic factors such as sunshine, temperature, and humidity have effects on CA724 reference values can provide new ideas and directions of prevention and clinical diagnosis in the future.

Spatial Distribution Characteristics and Evolution Pattern of Air Quality in Henan Province

Urban air pollution is an urgent problem to be solved in the process of rapid urbanization and economic development in China. Based on the daily average data of urban air quality index of Henan province from 2015.1 to 2018.12, this paper utilizes cluster analysis, trend surface analysis and centralizing evolution analysis methods to study the spatial distribution characteristics and evolution pattern of urban air quality in the province. The results show that the air quality in the province presents five air quality systems, which seriously relate to the terrain, the air quality index of the northern cities has always been higher than that of the southern cities, with the latitude increases, the air quality index gradually increases, and the increase rate in the middle region is significantly higher than that in both sides. The province weathers, in the study period, shows 4 grades as good & moderate, lightly polluted, moderately polluted and heavily polluted. Lightly polluted weathers first appear in central and southern cities, moderately polluted and heavily polluted weather first appear in the northern cities, and then spread to the rest cities of the province.

Urban agglomeration of Kunming and Yuxi cities in Yunnan, China: the relative importance of government policy drivers and environmental constraints

Political decisions and policies, as well as bio-physical factors are very important drivers of urban agglomeration, yet studies researching links between those factors, decision-making and landscape change associated with these processes are lacking. The objective of this study was to explore the urban agglomeration pattern and process of Kunming–Yuxi driven by recent political and economic decisions, as well as topographic factors. We used multi-temporal Landsat imagery to create land cover maps and detect land cover changes from 2000 to 2015. The spatial trend surface analysis and lacunarity index were used to quantify the homogenization process of urbanization between Kunming and Yuxi. Land cover maps showed that built-up area increased remarkably reaching about 13% of the total area in 2015, and agricultural land declined from 12.2% in 2000 to 6.7% in 2015. Moreover, more than 90% of urban areas are located in flat areas. Spatial trends revealed the agglomeration of Kunming and Yuxi city. The lacunarity analysis also indicated that the homogeneity of built-up space increased resulting in increased connectivity of the cities. Spatial trends and lacunarity analyses support the finding that moderate urban homogenization and agglomeration formation took place during the past 15 years. The “Integration of urban agglomeration of Kunming and Yuxi cities” agreement signed by the governments of the two cities in 2011, along with other similar policies, has contributed to the urban expansion. Moreover, because of the rough topography of Yunnan Plateau, the urban growth has also been shaped by topographic patterns.

Application of trend surface analysis in early warning model of coal mine gas explosion

Aiming at the catastrophic problem of common coal mine gas explosion, this paper combines the trend surface analysis method to establish a gas explosion warning model, and validates the model through actual data, and the model has good robustness. Through the data fusion of the comprehensive information of gas explosion, the gas and oxygen concentration are selected as the key indicators of the early warning model, and the trend surface analysis of the finite discrete data is established. The trend surface warning model of gas and oxygen concentration is established, and the distribution of key indicators is obtained. Features that enable predictions and warnings of potential gas hazards.

APPLICATION TREND SURFACE MODELS WITH ESTIMATION

This research deal with estimation of trend surface analysis and with spatial data with three models to real spatial data represents a rising ground water. The first method in assessment is to estimation trend surface model parameters by (ml), the second method requires decision on the maximum time difference to be calculated (s). while, the third method need a resolution, and the residuals r of dots to take for the conjecture the f(Dij) parameters. The first and second methods require resolution principle of "neighbor" from determines of "W". These three approaches are applied to real data which represent the ground water levels in 47 wells in mountain region in Sin jar district in Nineveh governorate.

Spatio-Temporal Reorganization of Cropland Development in Central Asia during the Post-Soviet Era: A Sustainable Implication in Kazakhstan

The abandonment and cultivation of croplands in the Eurasian Steppe has become the focus of global and regional food security and agricultural policy-making. A large area of cropland in some post-Soviet countries has proven to be abandoned with the disintegration of the Soviet Union; however, it is unclear as to whether Kazakhstan also experienced a similar change as one of the main food providers for the former Soviet Union. In this study, we used the annual land cover dataset (1992–2015) from the European Space Agency, Climate Change Initiative (ESA-CCI) to detect spatio-temporal characteristics of rainfed and irrigated cropland changes in Kazakhstan. The Mann–Kendall test and regime shift analysis showed that rainfed and irrigated cropland at national level had a significant increasing trend with a significant rising up to 1999 and stagnation during 2000–2015, which was further confirmed with analysis at 14 regions. The greatest contributor to rainfed and irrigated croplands was steppes, followed by shrinkage of water bodies since 2005 to a great extent, rapid urbanization process resulted in losses of a part of irrigated oases. The trend surface analysis indicated that reorganized stable pattern characterized by rainfed cropland in north and irrigated cropland in south was driven by the strategy of the gradual agricultural development of oases. The nonexistence of cycle between the abandonment and recultivation proved that newly-gained cropland from steppe may be less degraded and more productive for sustainable land use in Kazakhstan. In conclusion, this study can provide strong evidence for sustainable land use and a basis for food security policy-making in Kazakhstan, and even all of the Central Asian countries in the future.

The Early Lake Ontario barrier beach: evidence for sea level about 12.8–12.5 cal. ka BP beneath western Lake Ontario in eastern North America

An overstepped, concave‐eastward, barrier beach beneath Holocene mud in western Lake Ontario has been delineated by acoustic and seismic reflection profiles and piston cores, and related to Early Lake Ontario (ELO). The average ELO barrier depth below present mean lake level is 77.4 to 80.6 m, or about −6 to −2.8 m above present sea level. Trend surface analysis of Champlain Sea (Atlantic Ocean) marine limits defined the contemporaneous marine water surface, and projections of this surface pass ~25 m above the outlet sill of the Lake Ontario basin and extend to the ELO palaeo‐barrier, a unique sand and gravel deposit beneath western Lake Ontario. ELO was connected to the Champlain Sea above the isostatically rising outlet sill for up to three centuries after about 12.8 cal. ka BP, while the glacio‐isostatically depressed St. Lawrence River Valley was inundated by the Atlantic Ocean. During the period of this connection, ELO level was confluent with slowly rising sea level, and the lake constructed a transgressive beach deposit with washover surfaces. ELO remained fresh due to a high flux of meltwater inflow. The marine water level connection stabilized water level in ELO relative to its shore and facilitated shore erosion, sediment supply and barrier construction. Glacio‐isostatic uplift of the outlet sill, faster than sea‐level rise, lifted ELO above the Champlain Sea about 12.5 cal. ka. Shortly after, a hydrological deficit due mainly to a combination of diverted meltwater inflow and dry climate, well known from regional pollen studies, forced the lake into a lowstand. The lowstand stranded the barrier, which remains as evidence of sea level, the farthest inland in eastern North America north of the Gulf of Mexico at the time. The highest palaeo‐washover surface provides a sea‐level index point.