Bohai Gulf Research Articles

Changes in Sources and Composition of Beach Waste in Coastal Cities around the Bohai Sea of China during the Tourist Peak and Off-Peak Seasons.

Beach waste is an important pollutant in the Bohai Sea and coastal cities around the Bohai Sea and has raised many social and environmental concerns in China. The semi-closed characteristics of the Bohai Sea, the well-developed tourism, the special industrial structure and residents' living habits endow the beach waste around Bohai sea with a unique character that should be explored. This study investigated changes in the sources and composition of beach waste in coastal cities around the Bohai Sea of China during the tourist peak and off-peak seasons. Beach waste from twenty beaches in thirteen coastal cities around the Bohai Sea was sampled and analyzed in March and August 2021, respectively. The results showed that beach waste around the Bohai Sea was characterized by large quantities and small weights and was greatly affected by human coastal activities. The sources and composition of beach waste from different coasts and different seasons varied, whereas the overall trend was consistent. In terms of composition, beach waste in both the tourist peak season and off-peak season was mainly composed of plastics, fabrics and paper, which accounted for more than 70% of the total in weight. Meanwhile, the proportion of plastics in the total quantity of beach waste was greatest (maximum of up to 71%) and exhibited seasonal fluctuations, trending higher in the tourist peak season than in the off-peak season. In contrast, trends in the proportion of paper and fabrics in the total quantity and total weight of beach waste were relatively stable in different seasons. In terms of sources, beach waste mainly derived from human coastal activities, the proportion of which in the total quantity of beach waste in the tourist peak season reached 70.55% and was 11% higher than that in the tourist off-peak season. Shipping/fishing activities were the second largest source of beach waste, and their proportion in the total quantity of beach waste in the tourist peak season was 5% lower than that in the tourist off-peak season, as the tourist peak season around the Bohai Sea coincides exactly with the fishing moratorium. The quantity of smoking-related waste only accounted for 9.35% and 7.73% of beach waste in the tourist peak and off-peak seasons, respectively. The special semi-enclosed structure of the Bohai gulf, surrounded by land on three sides, aggravated the accumulation of beach waste on the coast. Source reduction and classified recovery, collaborative management of marine waste and beach waste, and joint prevention and control mechanisms of three provinces (Liaoning, Hebei and Shandong) and one municipality (Tianjin) were suggested for comprehensive management of beach waste in coastal cities around the Bohai Sea of China. This study provided valuable information for beach waste management in coastal cities around the Bohai Sea of China.

Discovery of Fusarium proliferatum f. sp. malus domestica Causing Apple Replant Disease in China.

Apple replant disease (ARD) is the most serious threat facing the apple industry globally. ARD is mainly manifested as decreased plant growth, serious root rot disease, and considerable yield loss. Microbial factors are the dominant factors leading to the occurrence of ARD. Research on soil-borne pathogenic fungi leading to the occurrence of ARD in China is limited. In the present study, we selected 16 replanting orchards from the Northwest Loess region and around the Bohai Gulf. Diseased roots and rhizosphere soil from healthy apple trees and trees showing ARD symptoms were sampled at random. High-throughput sequencing was used to study the fungal communities in the rhizosphere soil, which showed that the composition of the rhizosphere soil fungal community of ARD-symptomatic and healthy apple trees was different. Nectriaceae at the family level and Fusarium at the genus level dominated the rhizosphere soil fungal community in the two regions, while for healthy apple trees, the relative abundance of Mortierella, Minimedusa, Tetracladium, and Chaetomium was higher. Tissue separation and serial dilution were used to separate fungi, and a total of 89 genera and 219 species were obtained, most of which were Fusarium. Fusarium was further confirmed to be the most abundant pathogen species leading to the occurrence of ARD in China through pathogenicity assays. A pathogenicity assay was carried out by the dip-and-cut technique using different host plants. It was found that Fusarium MR5 showed strong aggressiveness to apple rootstocks. Diseased seedlings specifically exhibited chlorosis of the leaves, browning from the edge of the leaf, followed by rolling and yellowing of the leaves, resulting in wilting and eventually death. Strain MR5 was preliminarily identified as F. proliferatum according to the morphological and cultural characteristics. A maximum likelihood analysis of identities based on six gene sequence (ITS, TUB2, IGS, mtSSU, RPB2, and the TEF gene) alignments between the MR5 strain and other strains showed 99 to 100% homology with F. proliferatum. Based on our test results, strain MR5 was identified as F. proliferatum f. sp. malus domestica, which is of great significance for finding new measures to control ARD in China.

Dynamic characteristics analysis of an in-service SYMS based on long-term field monitoring

The soft yoke mooring system (SYMS), which is widely used in China Bohai Bay and Gulf of Mexico, is the main mooring structure used by floating production storage and offloading (FPSO) in shallow water. Due to its multi-joint connection mode, the SYMS can realize the weathervane effect and ensure that FPSO vessel is at a position with the minimized ocean environmental loading. However, the complexity of ocean environmental loads and the non-linearity of SYMS structures make it difficult to predict the motion behaviors and force states that will be experienced by in-service SYMS, which can affect estimations of structural health status. Dynamic characteristics analysis of in-service SYMS is capable of addressing this complex problem and providing accurate estimations for improving mooring system design and safety. In this paper, a multi-body dynamic model for long-term service SYMS is established. Based on the data from a field monitoring system, the long-term motion characteristics of an in-service SYMS is analyzed. By combining the multi-body dynamic model with monitoring data, the long-term internal force statuses of each hinge joint is calculated. Then, the distribution of hinge joints load and horizontal restoring force are obtained, which provide effective numerical references for service life predictions of future SYMS and safety analysis of in-service SYMS.

Structural Formation, Evolution, and Genetic Mechanisms of Fault in Controlling Hydrocarbon Migration of Unconventional Rocks: A Case Study of Zhuangnan Fault

Zhuangnan fault zone was affiliated with Gubei subsag of the Zhanhua sag in Jiyang Depression, Bohai gulf basin. Zhuangnan fault zone has two functions as the main east-west strike-slip accommodation structure. That is, on the one hand, Zhuangnan fault zone inherited the rules of development of regional tectonic. On the other hand, the present structure framework of Zhanhua sag was reconstructed by Zhuangnan fault zone. In the study, there are four main seismic reflectors: T0, T1, T2, and T6. They are the basis for researching the planar and vertical features of Zhuangnan fault zone. The structural formation, evolution, and genetic mechanisms of Zhuangnan fault zone are studied from three aspects of geometry, kinematics, and dynamics. In geometry, by the closure interpretation of 43 south-north interpretation sections and 24 east-west interpretation sections, the result indicates that Zhuangnan fault zone has its special regularity and characteristic which has three-piece planar characterization (eastern part, middle part, and western part). Three types of plane combination forms are determined: arched, linear, and “S” curved type. The plane combination structure styles of the Zhuangnan fault zone mainly include feather row, horsetail, grid, diagonal, and parallel style. These planar structural features play an important role in indicating the fault zoning of Zhuangnan fault zone. Based on the plane and section structural styles of Zhuangnan fault zone and the analysis of dynamic evolution, it is found that Zhuangnan fault zone has a succession relationship between deep and shallow fault systems. From tectonic evolution and regional dynamic point of view, this paper discusses the activity law of the Zhuangnan fault zone and the boundary faults on the east and west sides of Jiyang Depression, which are Changdi fault, Wuhaozhuang fault, and Chengnan fault, respectively. This study provides a new and more reasonable explanation for the unique structural characteristics of Zhuangnan fault zone and further confirms the important role and regulation mechanism of Zhuangnan fault zone.

Influence of seasonal migration on the development of the insecticide resistance of oriental armyworm (Mythimna separata) to λ-cyhalothrin.

The seasonal long-distance migration of pests amongst different seasonal habitats may encounter different degrees of insecticide selection pressure, but knowledge of the evolution of resistance and the underlying mechanisms remains sparse. Here, we show that the development of resistance of the oriental armyworm Mythimna separata (Walker), a notorious agricultural pest that migrates between northern and northeast China seasonally across the Bohai Gulf, is influenced by seasonal migration. There are two conspicuous migrations of M. separata, the northeastwards population in the second half of May and the returning population in the second half of August, between northern and northeast China per year, and the abundance values of migrants from April to October are significantly different. The resistance levels of seasonal migratory populations to λ-cyhalothrin vary in different months, and the resistance levels and estimated frequency of the resistance allele of the first northeastward population (second half of May, May.-2) in spring are significantly higher than those of the returning populations in autumn. Moreover, resistance decline was observed in migrating population Jul.-2, with the resistance levels in the F1 progeny higher than those in their F2 progeny. Synergism tests indicate that cytochrome P450 monooxygenases (P450s) play a major role in resistance. Enzymatic assays show that P450 activity is significantly correlated with resistance levels in migratory populations, indicating that increased P450 activity is the main mechanism of resistance. The expression levels and correlation analysis of the relative expression of P450s with resistance levels show that three (CYP9A144, CYP9G40, and CYP6B79) out of 23 genes from CYP6 and CYP9 subfamilies are potentially involved in resistance to λ-cyhalothrin. Our results show that the resistance of M. separata to λ-cyhalothrin is unstable and likely to be metabolically driven by enhanced P450 activity mediated by the overexpression of multiple P450 genes. Notably, the development of resistance is probably affected by seasonal migration.

Blubber fatty acid compositions in different geographic populations of finless porpoise in Chinese waters: implications for thermal adaptation

The stratification of blubber fatty acids (FAs) is a widely used strategy in marine mammals and can be influenced by many factors, including their diet, environmental temperature, and physiological status. There are 3 distinct finless porpoise species/subspecies in Chinese coastal and inland waters in a wide range from 20°N to 40°N. The biochemical stratification of the blubbers of finless porpoises in different regions may provide valuable information for understanding their environmental adaptations. The FA compositions of 4 geographic populations of finless porpoise (FP) collected from the Bohai Gulf, East China Sea, South China Sea, and Yangtze River were therefore analyzed and compared. The blubber FA compositions of finless porpoises were dominated by ΣMUFAs, followed by ΣSFAs and ΣPUFAs, and were generally consistent with those of other cetaceans. The blubber of finless porpoises was significantly stratified with increasing levels of ΣMUFAs and decreasing levels of ΣSFAs and ΣPUFAs from the inner to the outer layers. The 3 marine populations shared more similarities in their FA compositions and stratifications compared to the freshwater porpoises, particularly regarding the PUFAs in the inner layers, which might have been mainly influenced by the diet compositions of marine and freshwater porpoises. Contrary to what was expected, in the 3 marine populations, the SFA and MUFA levels showed opposite correlations (negative and positive, respectively) with habitat temperatures, possibly indicating an adaptation mechanism in finless porpoises characterized by a trade-off between the insulation and fluidity properties of the blubber through the adjustment of the compositions and gradients of MUFAs and SFAs across the blubber depth in response to environmental temperature/latitude changes.

Interactive effects of salinity and SOM on the ecoenzymatic activities across coastal soils subjected to a saline gradient

Salinity and soil organic matter (SOM) are key edaphic factors that exert substantial influence on soil microbial activity. To understand the interactive effects of both factors on microbial activity, nine ecoenzymes involved in C, N, P and S cycling were assayed across a saline gradient (coastal areas of the Bohai Gulf, CN). The electrical conductivity (EC) of the soils ranged from 0.14 to 13.65 dS m−1. The response of the ecoenzymatic activities (EEAs) to salinity followed a nonlinear relationship due to the interaction of SOM and salinity on EEAs. The nonlinear response demonstrated divergent patterns below and above an EC of 2 dS m−1. Specifically, when EC < 2 dS m−1, no correlation between EEAs and conductivity was observed and EEAs had a positive correlation with SOM; when EC > 2 dS m−1, the EEAs were negatively correlated with conductivity and no correlation with SOM was observed. Substrate amendment at EC < 2 dS m−1 significantly improved EEAs that reached the levels similar to those of non-saline soils, while EEAs remained unrecovered when EC > 2 dS m−1. This EC value may stand as critical (threshold) salinity. Under higher EC conditions, EEAs are mainly affected by salinity while SOM has no critical role. This becomes reversed when salinity (as EC) drops below the critical value. This study provides with a numerical salinity reference for the potential of the land ‘to be reclaimed by organic matter addition’ and assists in defining strategies for soil reclamation based on the proposed salinity threshold.

Characteristics of coastal aquifer contamination by seawater intrusion and anthropogenic activities in the coastal areas of the Bohai Sea, eastern China

• 60,000 km 2 of coastal aquifers are affected by seawater (saltwater) intrusion around Bohai Gulf. • Palaeo-saltwater intrusion strongly affected groundwater evolution in Bohai Bay and Laizhou Bay. • The seawater intrusion caused the enrichment of fluorine in coastal aquifers. • Nitrate pollution increased in the coastal areas is a consequence of anthropogenic activities. A comprehensive study was performed to identify the origins of salinity and the geochemical processes governing hydrochemistry, and to distinguish the role of evaporation, mixing, and water–rock interaction from seawater intrusion (SWI) or palaeo-saltwater intrusion (PSWI) on groundwater chemistry in the coastal aquifer around the Bohai sea in China. For these purpose, geochemical and multivariate statistical methods were applied. The results indicated that the intrusion area around the Bohai sea can be divided into: (i) the palaeo-saltwater intrusion zone (including the south of Laizhou Bay, Tianjin, and Panjin on the north of Liaodong Bay), and (ii) the modern seawater intrusion zone. The analysis of selected ions (Na + /Cl − and Br − /Cl − ) and isotopic compositions showed that the saltwater intrusion is the predominant factor of increasing salinity in groundwater, followed by water–rock interaction (e.g. mineral weathering and ion exchange), and evaporation. Sources of specific ions (Ca and F) are dominated by mineral weathering-dissolution rather than the saltwater intrusion. Furthermore, anthropogenic activities are the dominant cause of groundwater nitrate pollution in the coastal area around Bohai sea. This type of pollution is most serious in Liaodong Bay due to the industrial waste, fertilizers, pesticides, and domestic sewage. It is followed by pollution in Qinhuangdao due to agricultural and domestic factors, and pollution in Laizhou Bay due to domestic sewage. The source of high fluorine in groundwater is the dissolution of fluorine-containing minerals caused by saltwater intrusion. The degree of groundwater fluorine pollution is as follows: Liaodong Bay < Tianjin < Qinhuangdao < Laizhou Bay.

The Rates and the Determinants of Hypertension According to the 2017 Definition of Hypertension by ACC/AHA and 2014 Evidence-Based Guidelines Among Population Aged ≥40 Years Old

Background:In November 2017, the American College of Cardiology/American Heart Association (ACC/AHA) updated their definition of hypertension from 140/90 mm Hg to 130/80 mm Hg.Objectives:We sought to assess the situation of hypertension and the impact of applying the new threshold to a geographically and ethnically diverse population.Methods:We analyzed selected data on 237,142 participants aged ≥40 who had blood pressure taken for the 2014 China National Stroke Screening and Prevention Project. Choropleth maps and logistic regression analyses were performed to estimate the prevalence, geographical distribution and risk factors of hypertension using both 2017 ACC/AHA guidelines and 2014 evidence-based guidelines.Results:The present cross-sectional study showed the age- and sex-standardized prevalence of hypertension was 37.08% and 58.52%, respectively, according to 2014 evidence-based guidelines and 2017 ACC/AHA guidelines. The distribution of hypertension and risk factors changed little between guidelines, with data showing a high prevalence of hypertension around Bohai Gulf and in south central coastal areas using either definition. The age- and sex-standardized prevalence of newly labeled as hypertensive was 21.44%. Interestingly, the high prevalence region of newly labeled as hypertensive was found in the north China.Conclusion:The prevalence of hypertension increased significantly on 2017 ACC/AHA guidelines compared to the prevalence when using 2014 evidence-based guidelines, with high prevalence areas of newly labeled as hypertensive now seen mainly in north China. There need to be correspondingly robust efforts to improve health education, health management, and behavioral and lifestyle interventions in the north.

Analysis of the relationship between geography and body color with the genetic diversity in the Echiura worm Urechis unicinctus based on the mitochondrial COI and D-loop sequences

Urechis unicinctus is the only Echiurini species distributed in Bohai Gulf of China. The wild populations of this species have sharply declined in China due to overfishing. Over 150 samples from Bohai Gulf were collected in the present study, which were classified into five populations according to their geographic areas and body colors. The genetic diversity and population structure of these populations were investigated by mitochondiral COI and D-loop sequences. The haplotype diversity of U. unicinctus based on COI and D-loop sequences were still high. In addition, the evolution rate of D-loop region could faster than the COI gene of U. unicinctus. Meanwhile, over 99% genetic diversity was contributed by different individuals within populations. Moreover, phylogenetic trees did not show clear geographic or color cluster. Our findings indicated that this species in Bohai Gulf of China should be treated as a whole population.

Ordos Block (Basin) is a key to understand early continental evolution and tectonic regime of the North China Craton

<p indent="0mm">The Ordos Block is one of the key elements of the North China Craton (NCC), and the Precambrian compositions and structures record the early-stage evolution of the NCC, such as cratonization of early continental crust, Paleoproterozoic mobile belts, Meso- and Neoproterozoic rifting, and platform development. Many basic issues on the early-stage tectonic evolution bear upon the Ordos Block. The following are some new achievements in fundamental geology of the Ordos Block. (1) Drill cores reveal that the Ordos Block possesses Neoarchean-Paleoproterozoic metamorphic basement. The Neoarchean granitic gneisses and Paleoproterozoic pelitic gneisses and granites of the Ordos Block are quite similar in geochemistry and metamorphism to the Paleoproterozoic metamorphic complexes and migmatite of the central and northern portions of the NCC. (2) The proto-Ordos Basin is an intra-cratonic basin with old crystalline basements. Precambrian sedimentary successions are mostly made with the Changcheng and Jixian systems, with the Qingbaikou and Nahua systems being largely absent. The Sinian or Ediacaran strata are partially preserved. The Paleozoic sequence of the Ordos Block is consistent with that of the rest parts of the NCC. (3) A Greater Ordos Basin existed in the Late Triassic, which extended eastward to the Bohai Gulf and Xuhuai belt. Precambrian basement rocks of the Lüliang and Taihang mountains were exhumed due to the NW-SE crustal shortening in the Mid-Late Jurassic, leading to the disruption of the Greater Ordos Basin. The Ordos Basin in a narrow sense was formed largely since the Late Jurassic. (4) The Ordos Basin proper is now surrounded by major active faults. Precambrian metamorphic rocks, which outcrop discontinuously beside the major faults, are compatible well with their counterparts in the other parts of the NCC in many respects like geochronology, geochemistry, and metamorphism. (5) The Ordos Block was in an extensional setting during Cretaceous and Cenozoic times, as manifested by rift basins, such as the Early Cretaceous rift zone in the western Ordos Basin and the Tertiary Shanxi, Weihe and Yinchuan grabens. The Lüliang and Taihang mountains were further uplifted as a result of crustal stretching. Recent studies confirm that the Ordos Block and the other parts of the NCC share the identical metamorphic basement and Mesoproterozoic-Paleozoic sedimentary sequences. Therefore, reconstructing tectonic history of the NCC should be based on careful analysis and logical explanation of geologic data as well as the reevaluation of some long-held conceptions. There have remained a number of disputes on how the North China continent originated and evolved. The Ordos Block can serve as an archive for solving the crux of the problems.

Provenance and paleoclimatic implications of loess deposits in Shandong Province, eastern China

AbstractThe loess deposits in Shandong Province in eastern China potentially provide valuable insights into past environmental changes. However, their precise provenance and paleoclimatic implications are unclear. We studied three loess sections located in the piedmont of the Central Shandong Mountains (PCSM) and in an offshore island in Bohai Gulf. Both the glacial loess and interglacial paleosol units are characterized by a coarse grain size, indicating a proximal sediment source. Using the “grain size–transport distance” model established for the Chinese Loess Plateau (CLP), the estimated source-sink distance is ~200–300 km for the PCSM loess and ~100–200 km for the coastal loess. This suggests that fluvial deposits of the Yellow River system in the North China Plain and sediments on the adjacent continental shelf are the major provenance for the Shandong loess. In contrast to the CLP, the Shandong loess does not show a consistent pattern of coarse grain size and low magnetic susceptibility values in glacial loess compared with interglacial paleosols, likely due to frequent changes in dust sources caused by diversions of the Yellow River and local hydroclimatic conditions. Nevertheless, the loess-paleosol alternations in the Shandong loess are a product of global glacial–interglacial cycles.

Vibrio marinisediminis sp. nov., Isolated from Marine Sediment.

A novel Gram-stain-negative, facultative anaerobic, motile bacterium, designated as 404T, was isolated from a marine sediment sample in the Bohai Gulf, China. Growth was observed at 10-35°C (optimum, 20-25°C) and in the presence of 1.0-6.0% (w/v) NaCl (optimum, 1.0-3.0%). Phylogenetic analysis based on 16S rRNA gene sequences indicated that the strain 404T belonged to the genus Vibrio, showing the highest sequence similarity to Vibrio renipiscarius KCTC 42287T (97.6%). The draft genome is 4.5Mb in length, containing 4278 protein-coding genes, 60 tRNA genes and 9 rRNA genes, and DNA G+C content is 44.1mol%. Strain 404T contains phosphatidylglycerol, phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylcholine, and phospholipid as the main polar lipids, and the predominant quinone is ubiquinone Q-8. The major cellular fatty acids (>8.0%) are C16 : 1ω6c and/or C16 : 1ω7c, C16 : 0, C18 : 1ω6c and/or C18 : 1ω7c. Strain 404T shows some typical characteristics among the members of genus Vibrio, while it can be clearly distinguished from the closely related type strains through genome analysis (average nucleotide identity and digital DNA-DNA hybridization values), fatty acid composition and a series of physiological and biochemical characteristics. On the basis of the polyphasic analysis, strain 404T is considered to represent a novel species of the genus Vibrio, for which the name Vibrio marinisediminis sp. nov., is proposed. The type strain is 404T (= MCCC 1H00367T = KCTC 62958T).

Halomonas marinisediminis sp. nov., A Moderately Halophilic Bacterium Isolated from the Bohai Gulf.

A novel Gram-stain-negative, moderately halophilic bacterium, designated strain 204T, was isolated from a marine sediment sample in the Bohai Gulf, Yellow Sea, China. Cells of strain 204T are aerobic, motile, cocci or short rods with two lateral flagella. Growth was observed at 15-40°C (optimum, 30°C), pH 6.0-9.0 (optimum, 7.0-7.5) and in the presence of 1.0-18.0% (w/v) NaCl (optimum, 3.0-8.0%). Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain 204T belonged to the genus Halomonas, showing highest sequence similarity to Halomonas alimentaria YKJ-16T (98.08%), followed by Halomonas sediminicola (97.47%), Halomonas fontilapidosi (97.14%), Halomonas halodenitrificans (96.98%), Halomonas ventosae (96.92%), and Halomonas shengliensis (96.85%). The draft genome is 3.8Mb in length, containing 3673 protein-coding genes, 62 tRNA genes and 10 rRNA genes, and DNA G+C content is 62.7mol%. Strain 204T contains phosphatidylglycerol, phosphatidylethanolamine, and diphosphatidylglycerol as the main polar lipids, and the predominant respiratory quinone was ubiquinone Q-9. The major cellular fatty acids (> 5%) are C18:1ω7c, C16:1ω7cand/or C16:1ω6c, C16:0 and C12:03-OH. Strain 204T was clearly distinguished from the closely related type strains through phylogenetic analysis, dDNA-DNA hybridization, fatty acid composition data and a range of physiological and biochemical characteristics comparisons. On the basis of the polyphasic analysis, strain 204T is considered to represent a novel species of the genusHalomonas, for which the nameHalomonas marinisediminissp. nov. is proposed. The type strain is 204T (= MCCC 1H00366T = KCTC 62957T).

Phenological responses of apple tree to climate warming in the main apple production areas in northern China

To reveal the spatio-temporal variation characteristics of apple's phenology and their critical response time period and intensity to the temperature change in the main production areas of northern China, we chose Fushan, Wanrong and Akesu to respresent the Bohai Gulf, the Loess Plateau and Xinjiang apple production areas, respectively. Apple's phenology data of buds opening (BO), first leaf unfolding (LU), first flowering (FF), fruit maturing (FM), end of leaf coloring (LC) and the end of leaf fall (LF) at the three stations during 1996-2018 were used to analyze the changes of phenological occurrence dates and different growth stage lengths. Partial least squares (PLS) regression was applied to identify the impacts of climate warming on different phenology events at daily resolution. Results showed that regional mean occurrence dates of apple's BO, LU and FF advanced by a rate of 0.36, 0.33 and 0.23 day per year, respectively. However, apple's LF postponed by 0.68 d·a-1. The FM and LC showed different trends among all the sites. The length of fruit growing period (FG) and that of tree growing period (TG) extended at average rates of 1.20 and 0.82 day per year. Apple's spring phenophases dates at all stations correlated negatively with mean temperature during early January to pre-phenophases date, with a 1 ℃ increase inducing an advancement of 3.70, 3.47 and 3.48 days for apple's BO, LU and FF, respectively. In contrast, apple's autumn phenophases correlated positively with mean temperature 21-72 days before the phenophases date, and its correlation with mean temperature was lower than the correlation for spring phenophases. Generally, the effect of temperature on spring phenophase was stronger than that of autumn phenophase, and the extension of FG and TG was mainly caused by the advance of spring phenophase. The responses of apple's phenophases to climate warming differed across all the stations. Temperature had the greatest impact on the development of apple industry in Akesu, less in Wanrong, and with the least influence in Fushan. Our results could provide theoretical basis for response to climate change for apple industry in different areas of China.

Diurnal variations of greenhouse gases emissions from reclamation mariculture ponds

Dissolved concentrations, saturation status, and emission fluxes of greenhouse gases (GHGs) in two reclamation mariculture ponds in the Bohai Gulf, China, were measured using the static headspace gas chromatography method and computed using a two-layer model of diffusive gas exchange. The study was conducted during August 2016 to assess diurnal variations in GHGs emissions. The main influencing factors of GHGs emissions from the ponds under the disturbance of artificial management were identified using Spearman correlation analyses and multiple stepwise regression analyses. Results showed that dissolved GHGs concentrations were stable throughout the day, whereas GHGs emission fluxes showed a clear diurnal variation with larger daytime values. The diurnal variation of N2O emission fluxes was greater than that of CO2 and that of CH4. Results also showed that pH of pond water was negatively correlated with CO2 and N2O emission fluxes and that air temperature was positively correlated with CH4 and N2O emission fluxes. In addition, ammonia (NH4+-N) was positively correlated with CH4 emission fluxes; water temperature and salinity were positively correlated with N2O emission fluxes. The estimated annual emissions from the reclamation aquaculture in Tianjin and the Bohai Rim region were 2.53 × 105 kg C–CO2, 6.94 × 103 kg C–CH4 and 1.11 × 103 kg N–N2O, and 3.42 × 107 kg C–CO2, 9.36 × 105 kg C–CH4 and 1.50 × 105 kg N–N2O respectively, indicating the important contribution of this fishery sector to GHGs emissions.

Mass windborne migrations extend the range of the migratory locust in East China

Abstract Migratory insect pests pose a substantial challenge to global food security. These issues are particularly acute when pest incursions occur considerably beyond the expected range, through natural migration or human‐aided transport, because the lack of species‐specific control strategies and a potential absence of species‐specific natural enemies in the newly‐invaded area may lead to rapid establishment of a new pest. One such threat is posed by the Oriental migratory locust Locusta migratoria manilensis in China, which, historically, has been restricted to eastern China from the Bohai Gulf southwards, and now threatens to expand its range into the agriculturally important region of northeast China. We analyzed data from a recent outbreak of migratory locusts in Heilongjiang Province (extreme northeast China), &gt; 700 km north of its current known range, and identified the source region, timing of arrival and probable migratory routes of this incursion. We further show that warming temperatures in this region will likely allow subsequent invasions to establish permanent populations in northeast China, and thus authorities in this important crop‐producing region of East Asia should be vigilant to the threat posed by this species.

Dynamic analyses of pile-supported bridges including soil-structure interaction under stochastic ice loads

The Gulf of Bohai has a huge area of floating ice in winter each year, and when seawater freezes, significant uncertainties are introduced in the offshore structural design. In this study, a complete bridge analysis model is proposed to investigate the dynamic responses of offshore bridges in the Bohai Sea subjected to stochastic ice loads by floating sea ice. Based on a real stochastic ice load spectrum, a simulation methodology to generate the stochastic ice load process is proposed. The soil resistance is modelled utilising the American Petroleum Institute-based cyclic p-y, t-z, and Q-z springs. A dynamic analysis is conducted in the time domain utilising the finite element method and considering stochastic ice loads. The influences of undrained soil strength and water depth on the dynamic behaviours of the bridge are systematically investigated. The results show that the dynamic responses of bridges in deep water are much larger than those in shallow water, and the soil–structure interaction (SSI) can substantially affect the structural vibrations. The result from the method can also be used to identify the most critical condition for bridge design under ice loads.

Multiscale analysis on spatiotemporal dynamics of energy consumption CO2 emissions in China: Utilizing the integrated of DMSP-OLS and NPP-VIIRS nighttime light datasets

CO2 emissions caused by socioeconomic development and energy consumption in China have put enormous pressure on emissions reduction for Chinese government. In response to CO2 emissions reduction in China, this study integrated the Defense Meteorological Satellite Program’s Operational Linescan System (DMSP-OLS) stable nighttime light (SNL) data and Suomi National Polar-orbiting Partnership (NPP) Visible Infrared Imaging Radiometer Suite (VIIRS) composite data, and established the integrated nighttime light datasets from 1992 to 2016. The estimated CO2 emissions model utilizing the integrated nighttime light datasets and statistical CO2 emissions at the provincial level from 1995 to 2016 were established. Finally, spatiotemporal dynamics of CO2 emissions were simulated from multiscale. The results clearly showed that: (1) The fitting results of regression relationship between DMSP-OLS SNL data and NPP-VIIRS composite data met the accuracy requirements. The CO2 emissions estimated model was valid. (2) The total amount of energy consumption CO2 emissions in China had increased from 1889.3340 Mt in 1995 to 4683.3165 Mt in 2016, with a total growth of 2.47 times. (3) The high CO2 emissions regions were clearly agglomerated in eastern coastal China from the pixel scale, the highest CO2 emissions provinces were concentrated in Hebei and Shandong, the high CO2 emissions prefecture cities were concentrated in Around Bohai Gulf area, eastern coastal China and some developed cities, and the high CO2 emissions counties were concentrated in eastern coastal China and western energy intensive counties. (4) The relatively-slow growth accounted for the highest proportion among the five growth types, and the CO2 emissions rapid growth regions were concentrated in eastern China at provincial, prefectural and county scale. The western regions accounted for the largest area proportion in five growth types at prefectural scale. We provided policy implications based on the results, which was beneficial to propose mitigation CO2 emissions reduction in China.

Performance Assessment for Combined GPS and BDS Real-time Precise Point Positioning in the Coastal Region of Bohai Gulf, China

Qu, L.; Huang, H.; Du, M., and Acharya, T.D., 2019. Performance assessment for combined GPS and BDS real-time precise point positioning in the coastal region of Bohai Gulf, China. In: Lee, J.L.; Yoon, J.-S.; Cho, W.C.; Muin, M., and Lee, J. (eds.), The 3rd International Water Safety Symposium. Journal of Coastal Research, Special Issue No. 91, pp. 271-275. Coconut Creek (Florida), ISSN 0749-0208.In this study, we focus on the performance assessment of combined Global Positioning System (GPS) and BeiDou Navigation Satellite System (BDS) real-time Precise Point Positioning (PPP) in the coastal region of Bohai Gulf, China. Firstly, 120 Global Navigation Satellite System (GNSS) stations from Multi-GNSS Experiment (MGEX) network of the International GNSS Service (IGS) were processed to generate ultra-rapid precise orbit of both GPS and BDS satellites, updated with the interval of three hours. Secondly, real-time precise satellite clock errors were estimated to compensate the orbit error with 24 regional stations from Crustal Monitor of Network of China (CMONOC) and MGEX networks. Finally, with those products, the performances of GPS-only, BDS-only and combined GPS and BDS real-time PPP were compared and evaluated. The experimental result illustrated that the ultra-rapid orbit accuracy of BDS-2 satellites was still worse than that of GPS satellites which was sub-decimeter level. Among three types of orbital satellites of BDS-2, the orbital accuracy of medium Earth orbit (MEO) and inclined geosynchronous orbit (IGSO) satellites were at decimeter level while for geostationary Earth orbit (GEO) satellites was at meter-level. The MEO satellites had the best accuracy while the GEO satellites performed the worst. In addition, the 3D accuracy of BDS-only real-time PPP was 10 cm better. Although the accuracy of BDS-2 real-time PPP was still worse than that of GPS and more time was taken for convergence. By adding BDS on top of GPS, the accuracy in the east, north and up components improved 40.0%, 33.3% and 18.5%, respectively, and the convergence time reduced 36.3%, 15.4% and 58.3%, respectively compared to the GPS only.