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Zoning Evaluation of Hourly Precipitation in High-resolution Regional Numerical Models over Hainan Island
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作者 冯箫 吴俞 +1 位作者 杨薇 李勋 《Journal of Tropical Meteorology》 SCIE 2023年第4期460-472,共13页
This study assesses the performance of three high-resolution regional numerical models in predicting hourly rainfall over Hainan Island from April to October for the years from 2020 to 2022.The rainfall amount,frequen... This study assesses the performance of three high-resolution regional numerical models in predicting hourly rainfall over Hainan Island from April to October for the years from 2020 to 2022.The rainfall amount,frequency,intensity,duration,and diurnal cycle are examined through zoning evaluation.The results show that the China Meteor-ological Administration Guangdong Rapid Update Assimilation Numerical Forecast System(CMA-GD)tends to forecast a higher occurrence of light precipitation.It underestimates the late afternoon precipitation and the occurrence of short-duration events.The China Meteorological Administration Shanghai Numerical Forecast Model System(CMA-SH9)reproduces excessive precipitation at a higher frequency and intensity throughout the island.It overestimates rainfall during the late afternoon and midnight periods.The simulated most frequent peak times of rainfall in CMA-SH9 are 0-1 hour deviations from the observed data.The China Meteorological Administration Mesoscale Weather Numerical Forecasting System(CMA-MESO)displays a similar pattern to rainfall observations but fails to replicate reasonable structure and diurnal variation of frequency-intensity.It underestimates the occurrence of long-duration events and overestimates related rainfall amounts from midnight to early morning.Notably,significant discrepancies are observed in the predictions of the three models for areas with complex terrain,such as the central,southeastern,and southwestern regions of Hainan Island. 展开更多
关键词 hainan island hourly precipitation regional numerical model zoning evaluation
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Granite thermal reservoirs in Lingshui area of Hainan Island and their significance to geothermal resources,China
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作者 Xiaorui Yun Ying Zhang +2 位作者 Dingyong Liang Yanming Qu Haifeng Chen 《Energy Geoscience》 2023年第4期159-170,共12页
Hainan Island located at the southernmost tip of the continental crust of the South China Plate,has high terrestrial heat-flow values,widely-distributed hot springs,and rich geothermal resources.Intensified researches... Hainan Island located at the southernmost tip of the continental crust of the South China Plate,has high terrestrial heat-flow values,widely-distributed hot springs,and rich geothermal resources.Intensified researches on the origin and potentials of geothermal resources can promote Hainan Island's development into a clean energy island.To determine the geological conditions for the formation of geothermal resources in southern Hainan Island,we collected core samples of granites from the Baocheng batholith in southern Hainan Island and conducted systematic analysis in respect of petrology,geochronology,geochemistry,and petrophysical property.The results of this study are as follows.The Baocheng batholith in the southern Hainan Island has a crystallization age of 98.42±0.56 Ma,making it the product of magmatism in the early stage of the Late Cretaceous.It mainly consists of high-K calc-alkaline granites,which were intruded by intermediate-to-mafic veins.The Baocheng batholith has a high radioactive heat generation rate of 2.712-6.843μW/m^(3),with an average of 3.846μW/m^(3),a radioactive heat-flow value of 30.768 μW/m^(2)and a heat-flow contribution rate of 38.95%-43.95%.As shown by the results of their thermophysical property analysis,the granites have high thermal conductivity and can serve as highquality geothermal reservoirs.In combination with previous geological and geophysical data,the geothermal model of the Lingshui area was established in this study.The deep structure indicates the presence of high-conductivity and low-resistivity layers in the basement of the Baocheng batholith.It can be inferred thereby that asthenospheric upwelling may occur and that there exist two magma vents at depth in the batholith.Therefore,magmatic heat at depth and granites with high radioactive heat generation rate serve as the main heat sources in the Lingshui area. 展开更多
关键词 hainan island Geothermal energy Baocheng batholith GRANITE Radioactive heat flow Thermal conductivity
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Three-dimensional P-wave velocity structure of the crust beneath Hainan Island and its adjacent regions,China 被引量:10
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作者 李志雄 雷建设 +3 位作者 赵大鹏 武巴特尔 沈繁銮 丘学林 《地震学报》 CSCD 北大核心 2008年第5期441-448,共8页
Using over 3 500 first P arrival times recorded by nine digital seismic stations from Hainan Digital Seismic Net-work during 1999~2005,a 3-D P-wave velocity model of the crust under Hainan Island and adjacent regions... Using over 3 500 first P arrival times recorded by nine digital seismic stations from Hainan Digital Seismic Net-work during 1999~2005,a 3-D P-wave velocity model of the crust under Hainan Island and adjacent regions has been determined. The results show that the pattern of velocity anomalies in the shallower upper crust is somewhat associated with the surface geological tectonics in the region. A relative low-velocity anomaly appears north of the Wangwu-Wenjiao fault zone and a relative high-velocity anomaly appears south of the Wangwu-Wenjiao fault zone,corresponding to the depressed areas in north Hainan Island,where many volcanoes are frequently active and geothermal values are relatively higher,and the uplifted and stable regions in central and south of the Hainan Is-land. In the middle and lower crust velocities are relatively lower in east Hainan than those in west Hainan,possi-bly suggesting the existence of the upwelling of hot materials from the mantle in east Hainan. The pattern of veloc-ity anomalies also indicates that NW faults,i.e.,the Puqian-Qinglan fault,may be shallower,while the E-W Wangwu-Wenjiao fault may be deeper,which perhaps extends down to Moho depth or deeper. 展开更多
关键词 三维速度 P波 地壳结构 海南岛
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Variation of soil fertility and carbon sequestration by planting Hevea brasiliensis in Hainan Island, China 被引量:12
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作者 CHENG Chun-man WANG Ru-song JIANG Ju-sheng 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2007年第3期348-352,共5页
The development of rubber industry depends on the sustainable management of rubber plantation. To evaluate the environmental effects of planting Hevea brasiliensis on a subsystem of tropical forest ecosystem, the vari... The development of rubber industry depends on the sustainable management of rubber plantation. To evaluate the environmental effects of planting Hevea brasiliensis on a subsystem of tropical forest ecosystem, the variation of soil fertility and carbon sequestration under rubber plantation within 30-year life period were investigated in Hainan Island. Results showed that (1) with the increase of stand age of rubber plantation, soil fertility decreased all along. From 1954 to 1995, soil organic matter, total N, available K and available P decreased by 48.2%, 54.1%, 56.7% and 64.1%, respectively. (2) If the complete return of litters was considered without additional fertilizer application to the soil of the rubber plantations, the consumption periods for P, N, K, Mg were only 825 years, 329 years, 94 years and 65 years, respectively~ To improve soil fertility is essential for rubber plantation development. (3) The C sequestration of rubber trees per hectare accounts for 272.08 t within 30-year life period and 57.91% of them was fixed in litters. In comparison with C sequestration by rain forest (234.305 t/hm^2) and by secondary rain forest (150.203 t/hm^2), rubber forest has more potentials for C fixation. On the base of above results, the following measures would benefit the maintenance of soil fertility and the development of rubber industry, including applying fertilizer to maintain the balance of soil nutrients, intercropping leguminous plant to improve soil fertility, reducing the collection of litters, optimizing soil properties to improve element P availability such as applying CaCO3. The information gathered from the study can be used as baseline data for the sustainable management of rubber plantation elsewhere. 展开更多
关键词 soil fertility carbon sequestration rubber plantation hainan island
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A wind tunnel simulation of the dynamic processes involved in sand dune formation on the western coast of Hainan Island 被引量:10
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作者 LI Sen LIU Xianwan +2 位作者 LI Huichuan ZHENG Yinghua WEI Xinghu 《Journal of Geographical Sciences》 SCIE CSCD 2007年第4期453-468,共16页
The western coast of Hainan Island exhibits a savanna landscape. Many types of sand dunes, including transverse dune ridges, longitudinal dune ridges, elliptical dunes, coppice dunes, and climbing dunes, are widely di... The western coast of Hainan Island exhibits a savanna landscape. Many types of sand dunes, including transverse dune ridges, longitudinal dune ridges, elliptical dunes, coppice dunes, and climbing dunes, are widely distributed in the coastal zone. In winter, high-frequency and high-energy NE winds (dominant winds) are prevalent, with a resultant drift direction (RDD) of S35.6°W. In spring, low-frequency and low-energy SW secondary winds prevail, with a RDD of N25.1°E. Wind tunnel simulations revealed that the airflow over the dune surface is the main factor controlling the erosion and deposition patterns of dune surfaces and the morphological development of dunes. In the region's bidirectional wind environment, with two seasonally distinct energy levels, the airflow over the surface of elliptical dunes, barchan dunes, and transverse dune ridges will exhibit a transverse pattern, whereas the airflow over longitudinal dunes ridges exhibits a lateral pattern and that over climbing dunes exhibits a climbing-circumfluent pattern. These patterns represent different dynamic processes. The coastal dunes on the western coast of Hainan Island are influenced by factors such as onshore winds, sand sources, coastal slopes, rivers, and forest shelter belts. The source of the sand that supplements these dunes particularly influences the development pattern: when there is more sand, the pattern shows positive equilibrium deposition between dune ridges and dunes; otherwise, it shows negative equilibrium deposition. The presence or absence of forest shelter belts also influences deposition and dune development patterns and transformation of dune forms. Coastal dunes and inland desert dunes experience similar dynamic processes, but the former have more diversified shapes and more complex formation mechanisms. 展开更多
关键词 western coast of hainan island coastal dune surface airflow dynamic processes wind tunnel simulation
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Mean water level setup/setdown in the inlet-lagoon system induced by tidal action—a case study of Xincun Inlet,Hainan Island in China 被引量:7
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作者 GONG Wenping SHEN Jian WANG Daoru 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2008年第5期63-80,共18页
With the tides propagating from the open sea to the lagoon, the mean water level (MWL) in the inlet and lagoon becomes different from that at the open sea, and a setup/setdown is generated. The change of MWL (setup... With the tides propagating from the open sea to the lagoon, the mean water level (MWL) in the inlet and lagoon becomes different from that at the open sea, and a setup/setdown is generated. The change of MWL (setup/setdown) in the system imposes a great impact on regulating the development of tidal marshes, on determining the long-term water level for harbor maintenance, on the planning for the water front development with the flood control for the possible inundation, and on the interpretation of the historical sea level change when using tidal marsh peat deposits in the lagoon as the indicator for open sea' s sea level. In this case study on the mechanisms which control the setup/setdown in Xincun Inlet, Hainan in China, the 2-D barotropic mode of Eulerian - Lagrangian CIRCulation (ELCIRC) model was utilized. After model calibration and verification, a series of numerical experiments were conducted to examine the effects of bottom friction and advection terms, wetting and drying of intertidal areas, bathymetry and boundary conditions on the setup/setdown in the system. The modeling results show that setup occurs over the inlet and lagoon areas with an order of one tenth of the tide range at the entrance. The larger the bottom friction is, a larger setup is generated. Without the advection term, the setup is reduced clue to a decrease of water level gradient to compensate for the disappearance of the advection term. Even without overtides, a setup can still be developed in the system. Sea level rise and dredging in the inlet and tidal channel can cause a decrease of setup in the system, whereas shoaling of the system can increase the setup. The uniqueness of the Xincun Inlet with respect to MWL change is that there is no evident setdown in the inlet, which can be attributed to the complex geometry and bathymetry associated with the inlet system. 展开更多
关键词 tidal inlet water level setup/setdown ELCIRC hainan island
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Three-dimensional crustal movement and the activities of earthquakes,volcanoes and faults in Hainan Island,China 被引量:8
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作者 Yaxuan Hu Ming Hao +1 位作者 Lingyun Ji Shangwu Song 《Geodesy and Geodynamics》 2016年第4期284-294,共11页
Hainan Island is a seismic active region, where Qiongshan M7.5 earthquake occurred in 1605 and several seismic belts appeared in recent years, especially the NS trending seismic belt (NSB) located in the northeast p... Hainan Island is a seismic active region, where Qiongshan M7.5 earthquake occurred in 1605 and several seismic belts appeared in recent years, especially the NS trending seismic belt (NSB) located in the northeast part of the island. Here is also a magmatic active region. The lava from about 100 volcanoes covered more than 4000 km^2. The latest eruptions occurred on Ma'anling-Lei Huling volcanoes within 10,000 years. The neotectonic movement has been determined by geological method in the island and its adjacent areas. In the paper, the present-day 3D crustal movement is obtained by using Global Positioning System (GPS) data observed from 2009 to 2014 and leveling observations measured in 1970s and 1990s respectively. The results show the horizontal movement is mainly along SEE direction relative to the Eurasian Plate. The velocities are between 4.01 and 6.70 mm/a. The tension rate near the NSB is less than I mm/a. The vertical movement shows the island uplifts as a whole with respect to the reference benchmark Xiuyinggang. The average uplifting rate is 2.4 mm/a. The rates are 2-3 mm/a in the northwest and 3-5mm/a in the northwest. It shows the deformation pattern of the southwest island is upward relative to the northeast, which is different from the result inferred from the coastal change and GPS. Haikou and its adjacent region present a subsidence in a long time. The southern part of the middle segment of the Wangwu-Wenjiao fault uplifts relative to the northern. Meanwhile, the western part uplifts relative to the eastern NSB. The vertical crustal motion and the two normal faults nearly correspond to the terrain. The NSB is located along the Puqiangang-Dazhibo fault, which is assessed as a segmented fault with a dip of 80°-90° and party exposed. The 3D deformations and other studies reveal the present activities of earthquakes, volcanoes and the faults. The small earthquakes will still occur in the NS belt and the volcanoes are not active now. 展开更多
关键词 hainan island Horizontal movement Vertical movement EARTHQUAKE VOLCANO FAULT Seismic belt
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Exploring suitability for tropical crop cultivation in Hainan Island by SOTAL methodology 被引量:9
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作者 Zhang Xue-lei S.Mantel +1 位作者 Zhang Gan-lin V.W.P.van Engelen 《Journal of Geographical Sciences》 SCIE CSCD 2001年第4期40-46,共7页
A SOTER-based automatic procedure for qualitative land evaluation is developed. This procedure was created in the automated land evaluation system (ALES). The objective was to design a procedure that allows for a quic... A SOTER-based automatic procedure for qualitative land evaluation is developed. This procedure was created in the automated land evaluation system (ALES). The objective was to design a procedure that allows for a quick separation of potentially suitable from non-suitable SOTER units for the intended land use, indicating constraints to different kinds of land use. Different kinds of land are unequal1y suited to various uses, land eva1uation is the assessment of the suitability of a tract of land for a specified kind of land use. In practice this implicates the comparison (matching) between the requirements of a specified land use and the properties of the land. Land evaluation concepts and definitions are treated in the paper. The ALES is a computer program that allows land evaluators to build their own knowledge-based system with which they can compute the physical and economical suitability of map units in accordance with FAO framework for land evaluation. The ALES program works with so-called decision trees, being hierarchical multiway keys in which the leaves are results (e.g., severity levels of land qualities), and the interior nodes of the tree are decision criteria (e.g., land characteristic values). These trees are traversed by the program to compute an evaluation using actual land data for each map unit. SOTAL is a SOTER-based qualitative model developed in ALES for physical land evaluation in which presently three land utilization types (LUTs) are distinguished, i.e., cultivated banana, coffee and rubber under different input and technological conditions. These LUTs are characterized by 11 landuse requirements and evaluated by matching the land use requirements with the corresponding land qualities. The paper elaborates on the criteria used in SOTAL for land quality assessment and how a final suitability rating is achieved on the basis of the rated land qualities. Results are visualized through G1S-generated maps as products in response to the specific information and data needs of decision and policy makers. 展开更多
关键词 EVALUATION tropical crops HaiSOTER hainan island
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Helium,Argon and Carbon Isotopic Compositions of Spring Gases in the Hainan Island,China 被引量:7
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作者 XU Sheng ZHENG Guodong XU Yongchang 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2012年第6期1515-1523,共9页
Chemical and isotopic compositions have been measured for N2-He-rich bubbling gases discharging from hot springs in the Hainan Island, Southern China. Observed 3He/4He ratios (0.1-1.3 RA) indicate the occurrence of ... Chemical and isotopic compositions have been measured for N2-He-rich bubbling gases discharging from hot springs in the Hainan Island, Southern China. Observed 3He/4He ratios (0.1-1.3 RA) indicate the occurrence of a mantle component throughout the island, which has been highly diluted by a crustal radiogenic 4He component. The occurrence of mantle-derived helium is high in the northern island (12%-16% of total He) and gradually decreases towards southern coast (1%-3% of total He). Such a distribution pattern is most likely controlled by the Pleocene-Quaternary volcanic activities in the northern island and groundwater circulation along the deep major faults. The 4~Ar/36Ar and N2/Ar ratios suggest that N2 and Ar of the hot spring gases are mostly meteoric. Although 13C values of CO2 (-20%0 to -27%0) with low concentrations are consistent with the biogenic origin, the combination of SHe/4He and 51SCco2 suggests a two end-member mixing of mantle and crustal components with CO2/3He ratios of 2x 109 and 8 1011, respectively. However, the low CO2/3He ratios (1- 22106) can not be ascribed in terms of the simple mixing but has to be explained by the addition of radiogenic 4He and loss of CO2 by calcite precipitation in the hydrothermal system, which is most likely controlled by the degree of gas-water-rock interaction. 展开更多
关键词 He-Ar-C isotopes mantle-derived He hot spring gas hainan island
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Characteristics and Preliminary Causes of Tropical Cyclone Extreme Rainfall Events over Hainan Island 被引量:6
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作者 Xianling JIANG Fumin REN +3 位作者 Yunjie LI Wenyu QIU Zhuguo MA Qinbo CAI 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2018年第5期580-591,共12页
The characteristics of tropical cyclone(TC) extreme rainfall events over Hainan Island from 1969 to 2014 are analyzed from the viewpoint of the TC maximum daily rainfall(TMDR) using daily station precipitation dat... The characteristics of tropical cyclone(TC) extreme rainfall events over Hainan Island from 1969 to 2014 are analyzed from the viewpoint of the TC maximum daily rainfall(TMDR) using daily station precipitation data from the Meteorological Information Center of the China Meteorological Administration, TC best-track data from the Shanghai Typhoon Institute,and NCEP/NCAR reanalysis data. The frequencies of the TMDR reaching 50, 100 and 250 mm show a decreasing trend[-0.7(10 yr)^(-1)], a weak decreasing trend [-0.2(10 yr)^(-1)] and a weak increasing trend [0.1(10 yr)^(-1)], respectively. For seasonal variations, the TMDR of all intensity grades mainly occurs from July to October, with the frequencies of TMDR 50 mm and 100 mm peaking in September and the frequency of TMDR 250 mm [TC extreme rainstorm(TCER) events]peaking in August and September. The western region(Changjiang) of the Island is always the rainfall center, independent of the intensity or frequencies of different intensity grades. The causes of TCERs are also explored and the results show that topography plays a key role in the characteristics of the rainfall events. TCERs are easily induced on the windward slopes of Wuzhi Mountain, with the coordination of TC tracks and TC wind structure. A slower speed of movement, a stronger TC intensity and a farther westward track are all conducive to extreme rainfall events. A weaker northwestern Pacific subtropical high is likely to make the 500-h Pa steering flow weaker and results in slower TC movement, whereas a stronger South China Sea summer monsoon can carry a higher moisture flux. These two environmental factors are both favorable for TCERs. 展开更多
关键词 hainan island tropical cyclones extreme rainfall events CHARACTERISTICS CAUSES
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Hydrological eco-service of rubber plantations in Hainan Island and its effect on local economic development 被引量:3
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作者 JIANG Ju sheng , WANG Ru song (Research Center for Eco Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China. 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2003年第5期701-709,共9页
The impacts of economic forest on global environmental change(GEC) are one of the hot issues in environmental study. Based on the 3 year observation data and 40 year climate data, GEC and analysis of the hydrologica... The impacts of economic forest on global environmental change(GEC) are one of the hot issues in environmental study. Based on the 3 year observation data and 40 year climate data, GEC and analysis of the hydrological dynamic characteristics of rubber plantations and estimate of the water balance in the rubber plantations in Hainan Island were made. The results showed that the rainfall intercepted by the canopy of the plantations accounted for 11 45% of the annual rainfall, the total runoff for 23 71%, the total evaporation and transpiration for 63 24%, the soil moisture storage for 1 6%. Analysis of the 40 year rainfall data in the 19 counties of Hainan Island during 1951—1990 showed that the large scale substitution of the natural vegetation with the rubber plantations had no significant effect on the local rainfall in Hainan Island. The main reasons are (1) 80% of the rainfall in Hainan is brought by typhoons; (2) the proportion of 11 6% rubber plantations in total forest coverage in Hainan is not enough to influence the local rainfall in Hainan Island; and (3) although the rubber plantation is artificial vegetation, it has the similar function to the tropical rain forest. Analysis of the total water resource and total GDP of Hainan in 1997 showed that the economic benefit resulted from the water resource was 1 0 RMB Yuan/m 3 The value of hydrological of the rubber plantation in Hainan was 113 9 million RMB Yuan/a when compared with the tropical rain forest. The paper reaches conclusion that the hydrological eco service function of rubber plantation has been enhanced after transformed from natural vegetation, which includes the natural service and powerful social service. 展开更多
关键词 eco service rubber plantation hydrological function hainan island
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U-Pb Isotope Geochronology of Syntectonic Granites from Hainan Island,South China:Constraints on Tectonic Evolution of the Eastern Paleo-Tethys Ocean 被引量:3
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作者 ZHOU Yang YAN Yi +5 位作者 LIU Hailing CAI Jianxin ZHOU Mengfei ZHANG Xinchang WANG Yin SHEN Baoyun 《Journal of Ocean University of China》 SCIE CAS CSCD 2020年第6期1315-1330,共16页
Since the recognition of the Indosinian orogeny in northern Vietnam,Triassic orogens have been widely identified around the western and southwestern boundaries of the South China block.The paleo-Tethys sutures stretch... Since the recognition of the Indosinian orogeny in northern Vietnam,Triassic orogens have been widely identified around the western and southwestern boundaries of the South China block.The paleo-Tethys sutures stretch from west to southeast,from Jinshajiang-Ailaoshan via NE Vietnam to Hainan Island;these sutures exhibit and develop voluminous Permian-early Triassic magmatism and numerous high-strain shear zones.As ophiolites related to the paleo-Tethys are lacking on Hainan Island,the eastward extension of the Indosinian orogeny and subduction and closure time of the paleo-Tethys Ocean on Hainan Island remain controversial.Here,an integrated kinematic and geochronological study has been conducted on two shear zones,called the Xiaomei and Mangsan shear zones.U-Pb zircon dating yields an age of early Triassic(252-251 Myr)for Xiaomei syntectonic granites which formed in the same tectonic setting and presented the similar nanoparticles to the Indosinian granites from Ailaoshan ductile shear zone,including the strawberry-like and flower-like nanoparticles.The NE-trending Mangsan shear zone represented by the gneissic granites with middle Permian ages(264-262 Myr)formed in the same tectonic setting as the Wuzhi-shan granites that were proposed as I-type granites.These middle Permian gneissic granites with arc affinity may represent an arc setting related to the NW subduction of the paleo-Tethys.The analyses reveal that granites with late Triassic ages(235-232 Myr)in the Xiaomei shear zone have the characteristics of A-type granites.The late Triassic extensional events on Hainan Island may be related to the subduction of the paleo-Pacific Plate beneath the East Asian continent. 展开更多
关键词 Indosinian orogeny hainan island Xiaomei shear zone Mangsan shear zone syntectonic granites PALEO-TETHYS
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Geomorphology of the Boao coastal system and potential effects of human activities-Hainan Island,South China 被引量:2
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作者 ZHUDakui YINYong PeterMARTINI 《Journal of Geographical Sciences》 SCIE CSCD 2005年第2期187-198,共12页
The Boao coastal system along the eastern coast of Hainan Island is a dynamic delta-tidal inlet-barrier formed during the late Holocene. The delta developed inside a shallow lagoon barred by a sandy barrier with a nar... The Boao coastal system along the eastern coast of Hainan Island is a dynamic delta-tidal inlet-barrier formed during the late Holocene. The delta developed inside a shallow lagoon barred by a sandy barrier with a narrow, shallow tidal inlet opening. Two major distributary channels separated by small islands characterize the delta. The lagoon is silting up receiving and trapping sediments from both the river and, in minor measure during storms, through the tidal inlet opening and barrier washovers. The barrier at the tidal inlet is highly dynamic and changes its form, accreting (migrating spit) against the inlet during fair-weather conditions and being eroded during storms and river floods. The delta has almost completely filled the lagoon and major concerns exist on the effect that ongoing large development plans may have on the environment. These concerns include the effect on floods and rate of siltation once banks of the islands have been stabilized and floodwater and sediment load are impeded from spreading over the lowlands, and the effect of increasing pollutant loads from the new facilities on the ecosystems of the increasingly restricting lagoon water and on the seashores. 展开更多
关键词 ESTUARY coastal barrier coastal erosion tidal inlet flooding prevention LAGOON Boao hainan island Wanquan River delta Ground-Penetrating Radar
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The mesoscale numerical simulation of the flow field of the Hainan Island and the Leizhou Peninsula 被引量:7
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作者 Tu Xiaoling, Zhou Mingyu and Sheng Shaohua National Research Center for Marine Environmental Forecast, Beijing 100081, China 《Acta Oceanologica Sinica》 SCIE CAS CSCD 1993年第2期219-235,共17页
The flow field over Hainan Island and the Leizhou Peninsula in summer and winter is discussed with three-dimensional mesoscale model developed in the University of Virginia and using the representative meteorological ... The flow field over Hainan Island and the Leizhou Peninsula in summer and winter is discussed with three-dimensional mesoscale model developed in the University of Virginia and using the representative meteorological data of January and July.Simulation results indicate that the local weather characteristics over the Hainan Island are distinctly influenced by theWuzhi Mountain terrain. The cloudy or rainfall weather over the northeast of the Wuzhi Mountain occurs easily, under proper large-scale conditions of flow, temperature and humidity. while west wind prevails. The overcast or rainfall weather is often induced by strong convection in the afternoon over west of the Hainan Island under easterly prevailing wind. 展开更多
关键词 The mesoscale numerical simulation of the flow field of the hainan island and the Leizhou Peninsula FLOW
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^(226)Ra and ^(228)Ra tracer study on nutrient transport in east coastal waters of Hainan Island,China 被引量:2
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作者 Ni SU Jin-zhou DU Tao JI, Jing ZHANG 《Water Science and Engineering》 EI CAS 2011年第2期157-169,共13页
Material fluxes (e.g., nutrients) from coastal waters to offshore areas play an important role in controlling the water quality of the adjacent sea areas not only by increasing nutrient concentration hut also by cha... Material fluxes (e.g., nutrients) from coastal waters to offshore areas play an important role in controlling the water quality of the adjacent sea areas not only by increasing nutrient concentration hut also by changing nutrient structures. In this study, naturally occurring isotopes, ^226Ra and ^228Ra, were measured with the alpha spectrometry in the Wenjiao-Wenchang and Wanquan estuaries and adjacent sea areas along the east coast of Hainan Island. The excess ^226Ra and ^228Ra activities were observed by comparison with the values derived from the conservative mixing of freshwater and seawater end-members in both estuaries. Using a one-dimensional diffusion model, the horizontal eddy diffusion coefficient of 3.1 6 × 10^5 cm^2/s, for nutrients diffusing from their sources, was derived from 228Ra activities. Consequently, the corresponding nutrient fluxes flowing into the coastal waters were assessed. The results can provide useful information for the study of the mixing and exchange processes of coastal waters as well as dissoluble pollutant transport in this sea area. 展开更多
关键词 Ra isotope ^226Ra and 228Ra tracers horizontal eddy diffusion coefficient nutrient flux east coastal waters of hainan island
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Typhoon events recorded in coastal lagoon deposits,southeastern Hainan Island 被引量:8
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作者 ZHOU Liang GAO Shu +5 位作者 YANG Yang ZHAO Yangyang HAN Zhuochen LI Gaocong JIA Peihong YIN Yong 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2017年第4期37-45,共9页
Coastal lagoon deposits provide evidence for the magnitude and frequency of past tropical cyclones prior to instrumental records and historical documentation.In the present study,we attempt to analyze the sedimentary ... Coastal lagoon deposits provide evidence for the magnitude and frequency of past tropical cyclones prior to instrumental records and historical documentation.In the present study,we attempt to analyze the sedimentary records containing typhoon information for the northern South China Sea region.For this purpose,sediment cores were collected from two coastal lagoons in the southeastern Hainan Island,and were analyzed in laboratory to derive the data sets about grain size,organic and inorganic carbon contents,and deposition rates.The grain size and organic-inorganic carbon data were used to formulate the proxies of typhoon events.The deposition rates,as calculated using the CRS 210 Pb method,are around 0.5 mm/a for both lagoons,on the basis of which an age model is established.Within the cores,sedimentary layers associated with 35 typhoon events have been identified.On such a basis,a 350 year history of local typhoon activities is reconstructed by incorporating the 210 Pb dating results,typhoon-induced sedimentation patterns and the historical documents.A comparison of the frequency of typhoon occurrence with the regional climate records indicates that the observed changes in tropical cyclone activity patterns,as revealed by the lagoon sedimentary records,may be related to El Ni?o,Pacific Decadal Oscillation(PDO),North Atlantic Oscillation(NAO),sunspot,and other potential climate drivers that affect the tropical cyclone variability.This study demonstrates that the sedimentary record of storms can be analyzed in combination with historical documents,to provide meaningful information on past storm activities and their long-term variability. 展开更多
关键词 paleostorms typhoon-induced deposits grain size loss on ignition hainan island
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Tidal currents in the coastal waters east of Hainan Island in winter 被引量:2
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作者 Min LI Lingling XIE +4 位作者 Xiaolong ZONG Junyi LI Mingming LI Tong YAN Ronglei HAN 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2022年第2期438-455,共18页
Using the 25-h continuing hydrographic observations at three successive stations in February 2012 and the mooring time series of current observations from January to March 2015,the tidal currents and tidal energy flux... Using the 25-h continuing hydrographic observations at three successive stations in February 2012 and the mooring time series of current observations from January to March 2015,the tidal currents and tidal energy fluxes in the coastal waters east of Hainan Island in the northwestern South China Sea were analyzed.The diurnal and semidiurnal(using K_(1) and M_(2) as proxies,respectively)tidal currents and associated isopycnal undulations were derived with harmonic analysis.Results show that the velocities of the diurnal and semidiurnal tides derived from the 25-h observations are comparable to those from the mooring series.The semi-major axes of the tidal ellipses were O(4-7 cm/s)for barotropic tides and O(2-4 cm/s)for baroclinic tides.The directions were in NE-SW at deeper stations to N-S at the shallowest station for the diurnal tide and from NW-SE to NE-SW for the semidiurnal tide.Both the diurnal and semidiurnal isopycnal fl uctuations reached O(5 m),O(8 m),and O(10 m)at the cross-shelf stations(H03,H04,and H05)from 35 m,45 m,to 55 m,respectively,showing insignifi cant vertical variation,and the barotropic signals were predominate.The baroclinic diurnal tide showed fi rst-mode structures at H03-05,as does the semidiurnal tide at H03.The semidiurnal tide at H04 and H05 exhibited higher-mode structures.The time series of both the alongshore and cross-shore components reveal the vertically propagation features of the baroclinic tidal phase and energy.The calculated horizontal energy fl uxes of the diurnal and semidiurnal internal tides decreased from O(0.1 W/m)at H05 to O(0.01 W/m)at H03,implying a propagation and dissipation of energy from off shore to inshore. 展开更多
关键词 tidal current barotropic tide internal tide energy flux east of hainan island
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SLCO1B1 &ApoE Gene Polymorphism Analysis of the Li People in Hainan Island and Its Clinical Significance 被引量:4
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作者 Heqiu Ruan Linlin Zhan +4 位作者 Zihe Wang Mengjuan Xia Zhichao Ma Shengmiao Fu Xinping Chen 《Journal of Biomedical Science and Engineering》 2021年第3期130-141,共12页
Objective: To analyze the distribution characteristics and clinical significance of SLCO1B1 and ApoE gene polymorphisms of the Li people in Hainan Island. Method: Selecting 502 high school students of the Li people fr... Objective: To analyze the distribution characteristics and clinical significance of SLCO1B1 and ApoE gene polymorphisms of the Li people in Hainan Island. Method: Selecting 502 high school students of the Li people from five cities and counties in Hainan Island (namely, Qiongzhong County, Dongfang City, Ledong County, Baoting County and Wuzhishan City) as research subjects in September, 2019;Applying PCR-fluorescence probe method to detect SLCO1B1 and ApoE genotypes of the Li people in Hainan Island, and statistically analyzing the distribution characteristics of gene frequency and the distribution differences in gene polymorphisms between different genders. Meanwhile, detecting the SLCO1B1 and ApoE gene of 527 people from the Han people in five regions mentioned before, so as to analyze the distribution differences of the SLCO1B1 and ApoE gene between the Han people and the Li people. Results: The frequency of each genotype of SLCO1B1 in the Li people in Hainan Island is: *1a/*1a 6.77%, *1a/*1b 27.09%, *1b/1b 41.63%, *1a/*5 0.00%, *1a/*15 4.78%, *1b/15 16.93%., *5/*5 0.00%, *5/*15 0.00%, *15/*15 2.79%;And that of ApoE is: e2/e2 0.40%, e2/e3 17.73%, e2/e4 2.39%, e3/e3 65.54%, e3/e4 12.55%, e4/e4 1.39%. There is no significant difference (P > 0.05) in other genotypes except weak metabolic genotypes (*5/*5, *5/*15 and *15/*15) between the Han and the Li peoples. Conclusion: The gene frequency of SLCO1B1 weak metabolic genotype is dramatically higher in the Li people of Hainan Island than that of the Han people in both Hainan Island and Central and South China, but there is no significant difference in ApoE gene frequency among them. Therefore, clinicians should adjust the dosage of statins and select the types of lipid-lowering drugs according to the differences in patients’ genotypes, and strengthen the management of patients with ApoE4 risk gene. 展开更多
关键词 The Li People in hainan island SLCO1B1 APOE Gene Polymorphisms Statin Medicine
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Analysis of Risks in Hainan Island Typhoon Hazard Factor Based on GIS 被引量:2
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作者 ZHANG Zhong-wei ZHANG Jin-hong +2 位作者 ZHAO Zhi-zhong LIU Shao-jun XIE Rui-hong 《Meteorological and Environmental Research》 CAS 2011年第1期31-34,共4页
[Objective] The aim of this paper was to analyze the risks in the typhoon hazard factors in Hainan Island. [Method] Taking the theory and method of natural disasters evaluation as starting point and supporting point, ... [Objective] The aim of this paper was to analyze the risks in the typhoon hazard factors in Hainan Island. [Method] Taking the theory and method of natural disasters evaluation as starting point and supporting point, and selecting Hainan province as the research target, where the typhoon disaster occurred relatively serious, based on the typhoon data during 1958-2008, with happening frequency of typhoon hazard-formative factors, maximum rainfall, potentially devastating effects of typhoon winds as evaluation indexes, the typhoon disaster risk evaluation index system and evaluation model were established. And by dint of GIS technique, Hainan island typhoon disaster risk zoning of hazard-formative factors and grading were prepared. [Result] Typhoon occurred frequently in Hainan and there were no certain rules of its annual changes. The monthly changes mainly happed during July to October. The highly dangerous area of typhoon mainly distributed in east coast area. The annual daily precipitation decreased from central mountainous area to the surroundings; typhoon hided in the destructive highly risked area in east, south and west area; low disastrous area occurred in the middle area; the risks of disastrous factors weakened from east area to west area. The distribution area of each level was that low dangerous area>mild dangerous area>highly dangerous area>secondary low dangerous area>highly dangerous area. [Conclusion] The study supplied scientific reference for the government in the united organization and direction of disaster relief work. 展开更多
关键词 TYPHOON Hazard-formative Factors Risk assessment hainan island China
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Morphometric study confirms the presence of only Vatica mangachapoi on Hainan Island, China 被引量:1
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作者 Junjie Guo Shuaibin Shang Jie Zeng 《Journal of Forestry Research》 SCIE CAS CSCD 2018年第3期636-643,共8页
To date only one species of the genus Vatica Linn.(Dipterocarpaceae) has been identified, and a subspecies and three varieties have been reported on Hainan Island, China. However, it remained controversial whether the... To date only one species of the genus Vatica Linn.(Dipterocarpaceae) has been identified, and a subspecies and three varieties have been reported on Hainan Island, China. However, it remained controversial whether the species was Vatica mangachapoi or a new species Vatica hainanensis, and whether the subspecies or varieties are taxonomically valid. We evaluated here morphometric variations of 133 trees collected from nine populations and herbarium specimens of Vatica spp. using 16 traits of leaf and fruit. Among these, leaf traits varied more within and among populations than did fruit traits. Four traits of ratios were more stable than directly-measured traits within and among populations. The ranges of lamina length, lamina width and height of maximum lamina width point were the greatest among the 16 traits, while number of lateral veins varied least among the 12 directly-measured traits. Measurements from all 9 populations overlapped for each morphological trait, and variation of each trait was continuous among both individuals and populations. The range of variation did not distinguish any specimen from V mangachapoi as described in the flora of Southeast Asia By cluster analysis, individuals of each population as wel as specimens of each variety formed no distinct clusters The published varieties thus were characterized by no distinguishing variations in comparison with the nine sampled populations. In conclusion, the new species V hainanensis as well as the subspecies and varieties were not supported by our comparisons, and only V. man gachapoi without any subspecies or varieties occurs on Hainan Island, China. 展开更多
关键词 Vatica Linn. Vatica mangachapoi Morphological variability Cluster analysis hainan island
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