Fujian Coastal Area Research Articles

Predicting the potential suitable distribution area of the apple snail Pomacea canaliculata in China based on multiple ecological niche models.

The high-risk invasive apple snail Pomacea canaliculata has greatly threatened the agriculture, ecosystem integrity and public health. In order to provide scientific evidence for effective prevention and control of P. canaliculata, a most suitable ecological niche model was selected to predict the potential suitable distribution areas of P. canaliculata in China. Based on 377 reported occurrence points and 19 bioclimatic variables, four ecological niche models, MaxEnt, GARP, BIOCLIM, and DOMAIN, the potential geographic suitable distribution areas were predicted for the invasive snail. Then, the results of different models were analyzed and compared with two statistical criteria, the area under the Receiver Operating Characteristic curve (AUC) and Kappa value. The results showed that all of the four ecological niche models could simulate the snail's distributions very well. More specifically, the MaxEnt model outperformed the others in all aspects of predicting the snail's potential distribution (AUC=0.955±0.004, Kappa=0.845±0.017), followed by GARP and DOMAIN. Although BIOCLIM offered the lowest prediction accuracy, its AUC was 0.898±0.017 and its Kappa value was 0.771±0.025. Based on the MaxEnt model, the prediction results showed that the potential suitable distribution areas of P. canaliculata were mainly located in the south of 30° N in China, but there was some regions spreading over the north of 30° N. The potential areas accounted for 13.2% of the national land in area. Notably, Guangdong, Guangxi, Hunan, Chongqing, Zhejiang and the coastal areas of Fujian were potentially high-risk areas. In conclusion, this study would be an important reference for the prevention and control of the invasive apple snail P. canaliculata and it also would be an example of predicting the potential distribution of aquatic alien species on large scale.

Distribution characteristics of the intensity and extreme intensity of tropical cyclones influencing China

To address the deficiency of climatological research on tropical cyclones (TCs) influencing China, we analyze the distributions of TCs with different intensities in the region, based on the best-track TC data for 1949–2011 provided by the Shanghai Typhoon Institute. We also present the distributions of 50- and 100-yr return-period TCs with different intensities using the Gumbel probability distribution. The results show that TCs with different intensities exert distinctive effects on various regions of China and its surrounding waters. The extreme intensity distributions of TCs over these different regions also differ. Super and severe typhoons mainly influence Taiwan Island and coastal areas of Fujian and Zhejiang provinces, while typhoons and TCs with lower intensities influence South China most frequently. The probable maximum TC intensity (PMTI) with 50- and 100-yr return periods influencing Taiwan Island is below 890 hPa; the PMTI with a 50-yr return period influencing the coastal areas of Fujian and Zhejiang provinces is less than 910 hPa, and that with a 100-yr return period is less than 900 hPa; the PMTI with a 50-yr return period influencing the coastal areas of Hainan, Guangdong, and the northern part of the South China Sea is lower than 930 hPa, and that with a 100-yr return period is less than 920 hPa. The results provide a useful reference for the estimation of extreme TC intensities over different regions of China.

GW24-e2425 Cardiovascular Disease Risk Factors and Vascular Damage in Subjects with Prehypertension/Hypertension from the Coastal Areas of Fujian, China

ObjectivesIn this study, we evaluated the associated cardiovascular disease (CVD) risk factors and vascular damage of prehypertension/hypertension in a Chinese population from the coastal areas of Fujian province.MethodsA total of...

Statistics and Analysis of Typhoons Landing and Failure Mechanism of Coastal Low-Rise Buildings in China

In order to reveal the status of typhoon landfall in China coastal areas, the coastal areas and frequency of typhoon landing were compared with the statistical analysis in the paper for nearly 50 years; combined with the wind pressure of low-rise buildings under typhoon in China's coastal, structures damage of low-rise buildings were investigated. The results show that, the southwest coast of Guangdong landfall the largest number of typhoon landing, while the coastal areas of Fujian and Zhejiang have larger number of strong typhoons; turbulence great impact on surface air pressure; It was also found that the high suction pressure zones occurred around the windward roof edges at a wind azimuth of 450,and wind pressure along the roof corner just behind the roof ridge. The results of the present study are expected to be useful for the future development of a simple approximate formula for the low-rise buildings of the coastal area for design use.

Resources status analysis of large yellow croaker in Guanjinyang using von Bertalanffy growth equation and fishing mortality parameters

Based on the fishery resources monitoring data collected in Guanjingyang sea in Fujian from 2010 to 2011,the present study analyzed the biological characteristics(n=2 098)of large yellow croaker(Larimichthys crocea),including body length and weight,growth and death,sex ratio,and sexual maturity.von Bertalanffy growth equation and parameters of mortality rate have been used to analyze the current resources status of large yellow croaker in Guanjingyang sea,meanwhile,biological characteristics(inflexion age and critical age,etc.)of fishery have been discussed.The results indicate that the average body length is 132.6 mm,with the group of predominant body length 110-150 mm,accounting for 55.96%;the average body weight is 45.1 g,with the group of dominant weight 10-50 g,accounting for 61.77%.The juvenile large yellow croaker and recruit population have been the main catch targets.The relationship between length and weight was expressed as:W=2.001×10-5L3.006.The growth parameters of von Bertalanffy formula estimated by ELEFAN were L∞=385.4 mm,k=0.43 and t0=-0.32a,respectively,and flexion age is 2.2 years.Compared with the data obtained about large yellow croaker in Fujian,value of L∞ has declined from 555.4 to the current 385.4,flexion age from 2.97 to 2.2,all these trends show that the group has been in serious status characterized with miniaturization and lower age.In addition,the growth coefficient shows an apparent increase from 0.36 to 0.43,which indicates a speed-up growth in large yellow croaker.Total death coefficient(Z),natural death coefficient(M)and the coefficient of fishing death(F)are 3.12,0.45 and 2.67 respectively;the exploitation rate in recent years was 0.856.The increasing trend of M value may be related to the deterioration of marine environment in coastal areas of Fujian;and,due to the high-intensity catch of large yellow croaker,fishing death of such species is increasing sharply,from 0.84 to 2.67,which indicates that the stock of large yellow croaker has been over-exploited.Under the current resources status in Guanjingyang sea,great effort should be made to reduce fishing mortality and protect its environment so as to protect large yellow croaker.And due to the miniaturization and low age of large yellow croaker resources,controlling the catchable age(t0)is suggested to be the main management.

Evaluation of Pollution Source of the Bays in Fujian Province

Abstract Based on investigation data of pollution sources of seven bays in Fujian province (Luoyuan Bay, Quanzhou Bay, Xiamen Bay, Sansha Bay, Xinghua Bay, Meizhou Bay and Dongshan Bay), the pollutant source composition, total amount and distribution character of pollution sources are evaluated in this article. The result shows that: Pollution Sources of the Bays in Fujian province are mainly land-based pollution. Agricultural pollution source makes up the largest percentage of the land-based pollution sources, followed by domestic pollution source and soil erosion while industrial pollution source makes up the smallest percentage. Sea-based pollution sources come mainly from aquaculture pollution while vessel-source makes up only a very small percentage. Among the seven bays, Meizhou Bay has the largest amount of COD discharged into sea and Dongshan Bay the smallest; Xinghua Bay has the largest amount of TN, TP and Luoyuan Bay the smallest. The concept of pollutant load per unit tidal prism is introduced to evaluate the pollution pressure of each bay. The research can be a scientific support of the total amount control of pollution discharged into bay and promote the socioeconomic sustainable development in Fujian coastal area.

MAGNETIC FIELD AND BASEMENT FEATURES ANALYSIS IN THE EAST CHINA SEA

Based on the new magnetic data in the East China Sea,the characteristics of magnetic anomalies have been analyzed ,magnetic basement been calculated and the features of basement and geology also analyzed. The magnetic anomalies change differently from west to east. From land to shelf and to the middle of the Okinawa Trough,the magnetic anomalies change between positive and negative,the highest negative magnetic anomaly also arises in Fujian coastal area and magnetic basement of this area changes between 5 km and 11 km. From the middle of Okinawa Trough to Ryukyu Islands arc,magnetic anomalies change from positive to negative and the magnetic basement of this area changes between 7 km and 12 km. From Ryukyu fore-arc basin to Ryukyu Trench,magnetic anomalies change between positive and negative and it is positive in the middle and negative in the two sides of this area and the magnetic basement changes between 7.5 km and 11 km.

Luminescence chronology of “Old Red Sand” in Jinjiang and its implications for optical dating of sediments in South China

A weathered deposit in South China is widespread on the coastal areas of Fujian and Guangdong provinces, China. This deposit consists of slightly cemented, medium-to fine-grained sands, and is characterized by its colors of red, brown red, light reddish brown or dark yellowish orange, and is usually called “Old Red Sand”. The uncertainty in its formation age has been a major obstacle to the study of this type of deposit. In this paper, optically stimulated luminescence (OSL) techniques were used to date the “Old Red Sand” sediments from Jinjiang, Fujian Province, China. The effect of the geochemical behavior of uranium and thorium in sediment during chemical weathering on estimation of annual dose was investigated. The results show that the change in annual dose due to weathering poses a major problem for the optical dating of such weathered sediments. The optical dating of these weathered deposits will produce erroneous ages if average annual dose during burial cannot be correctly estimated. For the profiles studied, the OSL dates obtained on samples from the upper part do not represent the burial age of the samples. It is highly likely that they are underestimated due mainly to the accumulated radioactive elements as a result of chemical weathering. It is concluded that changes in annual dose due to chemical weathering must be considered when dating similar sediments in South China. With a detailed analysis of the OSL dating results, the chronology of the marine terraces in this area was suggested. The lowest terrace was formed at ∼3.5 ka and the second terrace was dated to ∼74 ka. The age of the highest terrace may not be established accurately, but is inferred to be older than the apparent OSL date of ∼77 ka and so is the Paleolithic artifacts from it.

Crustal movement and deformation in Taiwan and its coastal area

Based on the station velocity data obtained from Fujian coastal GPS network and Taiwan-Luzon GPS network and the data obtained from IGS permanent stations commonly used in the data processing of both networks, the uniformity of reference frames and velocity fields of both GPS networks is realized. It has been discovered from the analysis on the velocity field in Taiwan and its coastal areas that the horizontal crustal movements in the coastal area of Fujian, Taiwan Strait and the northern part of Taiwan Island are fully consistent. The movement direction is around 26.0°E by S and the rate is about 39 mm/a. The opposite variation occurs in the coastal mountain area in the eastern part of Taiwan Island with the movement direction of 30.0°N by W and the movement rate of about 33.3 mm/a. In the southern end of Taiwan Island, the movement direction is 50.0°S by W and the movement rate is about 13 mm/a. If the geometric center of Fujian coast is used as the reference datum, Taiwan Island has a consistent (except its north end) NW-trending movement with the direction of around 50.0°N by W. The maximum rate of 61 mm/a occurs along the eastern coast and decreases gradually towards west. The analysis of strain field indicates that Taiwan and its coastal area have a uniform strain field with the principal compressive strain direction of N48.0°W and the principal tensile strain direction of N42.0°E. The principal compressive strain rate along the eastern coast of Taiwan Island is 3.436×10−7/a, which decreases gradually towards west and reaches 1.861×10−8/a to Fujian coast. The collision and underthrust of Philippine Sea plate with Eurasian plate in the eastern part of Taiwan Island can be considered as the principal force for the crustal movement, deformation and great earthquake occurred in Taiwan and its coastal area. The direction of principal compressive stress in the area is about N55.0°W.

The thermal history of the miarolitic granite at Xincun, Fujian Province, China

The thermal history of the late Mesozoic miarolitic granite has been studied based on zircon U-Pb dating, whole rock Rb-Sr dating and K-Ar dating of muscovite, biotite and K-feldspar from the same rock sample. From the beginning of zircon crystallization to the closure of K-Ar system of biotite, the granite body had a slow cooling rate (11.0°C/Ma) and an ascending rate (0.07 mm/a). From the end of this stage to the closure of K-Ar system of K-feldspar, the granite body increased its cooling rate (45°C/Ma) and ascending rate (0.36 mm/a). The thermal history of the Xincun granite with a slow cooling rate at the early stage and a fast cooling rate at the late stage may have been related to the fact that the Fujian coastal area had very high geothermal gradient in the late Mesozoic and evident decrease in geothermal gradient in the early Cenozoic.

Late Mesozoic intrusive complexes in the coastal area of Fujian, SE China: the significance of the gabbro-diorite–granite association

The Pingtan and Daiqianshan igneous complexes, southeastern China, are typical of calc-alkaline series developed at active continental margins. These two complexes are dominated by granites or gabbros, with minor diorites and granodiorites, and these rock types closely coexisted both temporally and spatially. The major and trace element signatures of gabbros indicate they were crystallised from high aluminium basaltic magmas, which were generated from metasomatised upper mantle. The typical metaluminous calc-alkaline composition, trace element patterns and Sr–Nd isotopes indicate the granites in the complexes are I-type granites, which may have been generated from the deeper crust by a thermal contribution from the mantle. Field relationships, petrography and geochemistry favour a mechanical mingling together with a limited chemical mixing between high aluminium basaltic magma and granitic magma, resulting in the formation of diorites or granodiorites. The essentially bimodal character of these complexes reflects the general character of back-arc extensional magmatism, which was induced by the subduction of the Pacific plate beneath the Eurasian continent in late Mesozoic time.

A mafic-ultramafic rock belt in the Fujian coastal area, southeastern China: a geochemical study

Geological and geochemical evidence supports the non-ophiolitic origin of the mafic-ultramafic rocks exclusively exposed along the Changle-Nanao fracture zone in the Fujian coastal area, southeastern China. The spinels of the ultramafic rocks have very high Cr # [ 100 × Cr (Cr + Al) = 0.85] , and the gabbros contain abundant calcic plagioclases, FeTi oxides and amphiboles, are are rich in TiO 2, total iron, and light rare earth elements. It is probable that the mafic-ultramafic rocks are originally formed at a local extensional environment on the continental side of the subduction zone and eventually thrust in the compressional environment onto the Jurassic volcanic rocks or metamorphic rocks in the Yenshan (upper Triassic-upper Cretaceous) orogen. It is likely that the Yenshan subduction zone exists along the East Taiwan longitudinal valley rather than the Changle-Nanao fracture zone. The pre-Cenozoic tectonic evolution of the eastern Fujian coastal area and Taiwan is also discussed.