Feiyantan was the discharge area of Diaokou River distributary of the Yellow River during the period of 1964 to 1976. The coastal erosion feature and morphological evolution at the Feiyantan coast are studied in the l...Feiyantan was the discharge area of Diaokou River distributary of the Yellow River during the period of 1964 to 1976. The coastal erosion feature and morphological evolution at the Feiyantan coast are studied in the light of the topography and section depth, and the corresponding dynamics of wave and current. Results indicate that the protruding topography left after the Diaokou River distributary was abandoned is the main cause of strong coastal erosion. Further research suggests that waves start up the sediment and the tidal current transports it, and the waves and tidal current are combined to be the dominant dynamic mechanism of coastal erosion, in which the tidal residual current takes and transports the sediment outward, thus causing the sediment to wane in the coast.展开更多
The article examines the diverse musical environments for older adults on the West Coast of North America,ranging from descriptions of regional variations in senior community living presented in a variety of sources,i...The article examines the diverse musical environments for older adults on the West Coast of North America,ranging from descriptions of regional variations in senior community living presented in a variety of sources,including fiction,and the place of music in institutional settings to various musical activities designed for older adults.Given that people living on the West Coast have diverse ethno-religious backgrounds,may or may not be sensitive to the music that surrounded them in their formative years at the local and national levels,and have different habits regarding listening to the radio or attending various musical events,additional aspects were taken into account,such as 1980s and 1990s music styles;ethnic musical heritage relevant to the West Coast population;classical,popular,and religious music on the radio;and affordable symphony orchestra programs.The article provides an overview that opens avenues for further exploration of its sub-topics.展开更多
Active atmospheric convection on the monsoon coast is crucial for the Earth’s climate system.In particular,the upscale convective growth(UCG)from ordinary isolated convection to organized convective system is a key p...Active atmospheric convection on the monsoon coast is crucial for the Earth’s climate system.In particular,the upscale convective growth(UCG)from ordinary isolated convection to organized convective system is a key process causing severe weather,but its activities on the monsoon coast are less understood because of the lack of fine-resolution datasets.For the first time,we present the climatology of UCG on a typical monsoon coast using kilometer-mesh radar data from southern China.The UCG undergoes pronounced subseasonal and diurnal variations in the early-summer rainy season.The subseasonal UCG increase is attributed to the onshore flows shifting from easterlies in April to monsoon southwesterlies in June.UCG becomes vigorous following summer monsoon onset,with hotspots near windward coastal mountains.Daytime UCG first peaks near noontime along coastal land,where onshore flows are destabilized by boundary-layer heating and mountains.Afternoon inland peaks and off-coast minimums are recognized due to land–sea thermal contrast and sea-breeze circulation.Nighttime UCG is revived at the coast by nocturnally enhanced southerlies,followed by offshore activity as the convergence of land-breeze northerlies shifts seaward.The UCG thus responds strongly to changing atmospheric conditions,land heating/cooling,and thermally driven local circulations.Our results may help clarify the predictability of monsoon coastal convection.展开更多
This study aims to understand the behavior of the Bugis community in developing vernacular house models in the coastal areas of South Sulawesi Province,along with the factors influencing this behavior,such as knowledg...This study aims to understand the behavior of the Bugis community in developing vernacular house models in the coastal areas of South Sulawesi Province,along with the factors influencing this behavior,such as knowledge,motivation,attitude,locus of control,commitment,concern,and income level.Bugis vernacular houses reflect local wisdom that is adapted to environmental,socio-cultural conditions,and the challenges of modernization.This correlational research was conducted in the regencies of Pangkajene and Kepulauan,Barru,and Bone,with a sample of 300 household heads.The variables analyzed include knowledge,motivation,attitude,locus of control,commitment,concern,and income level.Data were collected through knowledge tests and questionnaires and were analyzed using simple and multiple regression tech-niques.The results show that the Bugis community’s behavior in developing vernacular houses is moderate.Individually,motivation,locus of control,commitment,and concern significantly influence behavior,while knowledge,attitude,and income do not have a significant impact.However,collectively,all independent variables(knowledge,motivation,attitude,locus of control,commitment,concern,and income)affect the behavior of the Bugis community in developing vernacular houses in coastal areas.This study provides valuable insights into the environmental and social adaptations of the Bugis coastal community,as well as efforts to preserve culture through the sustainable development of vernacular houses.展开更多
The coastal zone of Benin is inherited from the last marine oscillations of the Quaternary. A rich and very fragile environment, it presented until the 1960s, a shoreline in dynamic equilibrium over the entire 125 km ...The coastal zone of Benin is inherited from the last marine oscillations of the Quaternary. A rich and very fragile environment, it presented until the 1960s, a shoreline in dynamic equilibrium over the entire 125 km of coastal line. Since the 1960s, with the construction of important development infrastructures (ports, dams, groins), the Beninese coast is now subject to risks of coastal erosion and seasonal flooding due to the overflow of lagoon water bodies. The present study, based on socio-economic surveys in the communes of Ouidah, Comè and Grand Popo, exposes the extent of coastal risks and socio-economic and environmental damage in the southwestern coastal zone of Benin. The results show that in terms of land, 2.9 ha and 5.7 ha of land have been permanently lost to coastal erosion in the communes of Ouidah and Grand Popo respectively. Similarly, 212 ha of crops of all types were affected by the flooding, including 35 ha destroyed, i.e. 6.67 ha, 11.3 ha in Comè, 4.67 ha Ouidah and 14 ha Grand Popo. Also, 6435 buildings were affected, and 4235 huts were damaged. In addition, working tools, food stocks and other items are counted among the losses recorded by coastal hazards with their corollaries of diseases. The cost of losses and damages in the 08 districts amount to 418,000,000f cfa of which 266,000,000f cfa of damage and 152,000,000f cfa of loss.展开更多
The Northeast Pacific coastal ocean, as a typical river-influenced coastal upwelling system, is characterized by significant variability of sea surface partial pressure of carbon dioxide (</span><i><spa...The Northeast Pacific coastal ocean, as a typical river-influenced coastal upwelling system, is characterized by significant variability of sea surface partial pressure of carbon dioxide (</span><i><span style="font-family:Verdana;">p</span></i><span style="font-family:Verdana;">CO</span><sub><span style="font-family:Verdana;">2</span></sub><span style="font-family:Verdana;">, <200 to >1000</span></span><span style="font-family:""> </span><span style="font-family:""><span style="font-family:Verdana;">μ</span><span><span style="font-family:Verdana;">atm). This study reviewed the </span><a name="_Hlk76571454"></a><i><span style="font-family:Verdana;">p</span></i><span style="font-family:Verdana;">CO</span><sub><span style="font-family:Verdana;">2</span></sub><span style="font-family:Verdana;"> variability and its underlying controlling mechanism in this highly dynamic region by bringing together previous scientific findings and historical data. The large </span><i><span style="font-family:Verdana;">p</span></i><span style="font-family:Verdana;">CO</span><sub><span style="font-family:Verdana;">2</span></sub><span style="font-family:Verdana;"> variability reflects the complex interactions between physical processes (riverine input and coastal upwelling) and the biological </span><span style="font-family:Verdana;">responses to the nutrient transportation associated with these physical</span><span style="font-family:Verdana;"> processes, while temperature and air-sea gas exchange play a minor role in affecting </span><i><span style="font-family:Verdana;">p</span></i><span style="font-family:Verdana;">CO</span><sub><span style="font-family:Verdana;">2</span></sub><span style="font-family:Verdana;">. Both the river water and upwelled subsurface water are characterized by higher concentrations of </span><i><span style="font-family:Verdana;">p</span></i><span style="font-family:Verdana;">CO</span><sub><span style="font-family:Verdana;">2</span></sub><span style="font-family:Verdana;"> and nutrients when compared to the coastal surface water. The presence of high chlorophyll-a and low </span><i><span style="font-family:Verdana;">p</span></i><span style="font-family:Verdana;">CO</span><sub><span style="font-family:Verdana;">2</span></sub><span style="font-family:Verdana;"> in river plumes and areas adjacent to upwelling locations showed the intense biological CO</span><sub><span style="font-family:Verdana;">2</span></sub><span style="font-family:Verdana;"> uptake. The influences of riverine input and coastal upwelling thus mainly depend on the competing effect of high background </span><i><span style="font-family:Verdana;">p</span></i><span style="font-family:Verdana;">CO</span><sub><span style="font-family:Verdana;">2</span></sub><span style="font-family:Verdana;"> of river water and upwelled subsurface water vs. the biological dropdown of </span><i><span style="font-family:Verdana;">p</span></i><span style="font-family:Verdana;">CO</span><sub><span style="font-family:Verdana;">2</span></sub><span style="font-family:Verdana;"> resulting from the riverine- and upwelling-associated nutrient supplies. The strength of upwelling-favorable wind plays an important role in the </span><i><span style="font-family:Verdana;">p</span></i><span style="font-family:Verdana;">CO</span><sub><span style="font-family:Verdana;">2</span></sub><span style="font-family:Verdana;"> variability by affecting the intensity of coastal upwelling, with stronger wind speed causing more intense upwelling. The long-term </span><i><span style="font-family:Verdana;">p</span></i><span style="font-family:Verdana;">CO</span><sub><span style="font-family:Verdana;">2</span></sub><span style="font-family:Verdana;"> increasing rate in the Northeast Pacific coast is observed to be lower than that in the North Pacific open ocean.展开更多
Reclamation of tidal flat is one of the main ways to get a dynamic balance of the total amount of plowland. With the development of social economy and the increasing demand for plowland, the contradiction between tida...Reclamation of tidal flat is one of the main ways to get a dynamic balance of the total amount of plowland. With the development of social economy and the increasing demand for plowland, the contradiction between tidal flat reclamation and environment protection becomes more and more outstanding. However, tidal flat reclamation should also follow the dynamic balance of total amount of tidal flat amount. The paper analyzed the history of reclamation and development of Jiangsu mud coast, and calculated the feasible rates of tidal flat reclamation on different stretches respectively, and pointed out that both the economic social benefits of reclamation and the natural erosion-accretion conditions of the coasts should be taken into consideration in deciding the intensity of tidal flat reclamation, so as to satisfy demands on both reclamation and protection of tidal flat resource.展开更多
Two cruises were conducted to study the composition and seasonal variation of tintinnids （Protozoa： Ciliata） in Shantou coast water dudng spring and fall. Remarkable seasonal variations in environmental parameters,...Two cruises were conducted to study the composition and seasonal variation of tintinnids （Protozoa： Ciliata） in Shantou coast water dudng spring and fall. Remarkable seasonal variations in environmental parameters, and tintinnids composition were observed. Tintinnids samples were enumerated and identified from 5 stations. 14 species belonging to 7 genuses of tintinnids were identified, and the dominate species was Leprotintinnus simple in these season. High tintinnids diversity and low abundance occurred in the fall, and on the contrary, low tintinnids diversity and high abundance occurred in the spring. No significant correlation occurred between tintinnids abundance and nutrients. Tintinnids abundance showed negative relationship with salinity （r2=0.63, P 〈 0.05）, maybe this was due to the cold raised water carried sum nutrients rise to the surface water in the fall, rich nutrients and high phytoplankton biomass decrease the importance of tintinnids in the energy flow of aquatic food web.展开更多
The tropical cyclone that lands or passes through Guangxi coast is a serious natural disaster, which brings about strong winds, heavy rains, storm surges and other disasters causing severe damage of property or casual...The tropical cyclone that lands or passes through Guangxi coast is a serious natural disaster, which brings about strong winds, heavy rains, storm surges and other disasters causing severe damage of property or casualties in the coastal region every year. By counting and analyzing the tropical cyclones affecting Guangxi coast from 1950 to 2012, we find that the annual number of tropical cyclones changes significantly, and the maximum value can be up to 9, whereas the minimum value is 0 in some year. The regularity of seasonal distribution of tropical cyclones is obvious, and the peak period is in July, August and September every year, followed by June and October. Most of tropical cyclones come from the east of Philippines. After entering the South China Sea and passing through Hainan province and Leizhou Peninsula, they landed on Guangxi coast once again and caused the mean of peak surge reaching 111.2 cm, which is 2.6 times of non-landing typhoon. The formation of storm surge disaster is directly related to the severe typhoon weather systems, diurnal spring tide and discharge of river flood. Severe typhoons generate huge waves and rainfall, which lead to the rise of water level at the estuary, and would result in significant increasing water when stacking up with the storm surge, and cause huge tidal disaster.展开更多
On the basis of data of drifting bottles＇ tracks and the current measured in anchored stations, as well as temperature and salinity observed in cruise investigations and coastal stations, ADCP current data and AVHRR ...On the basis of data of drifting bottles＇ tracks and the current measured in anchored stations, as well as temperature and salinity observed in cruise investigations and coastal stations, ADCP current data and AVHRR surface sea temperature （SST） data on the western coast of Guangdong, synthetic results of analysis showed that the coastal currents in the west of the mouth of the Zhujiang River were mainly westward in summer, which constituted the north branch of cyclonic gyre in the east of the Qiongzhou Straits. Part of its water flowed westward into the Beibu Gulf through the Qiongzhou Straits. The coastal current pattern was not identical with the traditional current system which flowed westward in the Qiongzhou Straits in winter and eastward in summer. The summertime＇s coastal current was always westward, maybe temporarily turning northeast only when the southwest wind was strong. The important characteristics of coastal current on the western coast of Guangdong, in the Qiongzhou Straits and in the north of the Beibu Gulf were analyzed and their mechanisms also were explained.展开更多
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
This study applies the wavelet analysis to the tidal gauge records, alongshore winds, atmospheric temperature and pressure along the China coast in winter 2008. The analysis results show three events of sea level osci...This study applies the wavelet analysis to the tidal gauge records, alongshore winds, atmospheric temperature and pressure along the China coast in winter 2008. The analysis results show three events of sea level oscillations （SLOs） on the shelf induced by winter storms. The first event occurred from January 9 to 21. The SLO periods were double-peaked at 1.6-5.3 and 7.0-16.0 d with the power densities of 0.04-0.05 and 0.10-0.15 m^2.d, respectively. The second event occurred from February 5 to 18. The SLO period was single-peaked at 2.3-3.5 d with power density of 0.03-0.04 m^2.d. The third event occurred from February 20 to March 8. The SLO periods were double- peaked at 1.5-4.3 and 6.1-8.2 d with the power densities of 0.08-0.11 and 0.02-0.08 me.d, respectively. The SLOs propagated along the coast from Zhejiang in north to Guangdong in south. The phase speeds ranged about 9-29 m/s from Kanmen to Pingtan, 5-11 m/s from Xiamen to Huizhou and 11-22 m/s from Huizhou to Shuidong. The dispersion relation of the SLOs shows their nature of coastal-trapped wave.展开更多
Range Doppler velocities derived from the Envisat advanced synthetic aperture radar（ASAR） wide swath images are analyzed and assessed against the numerically simulated surface current fields derived from the finite ...Range Doppler velocities derived from the Envisat advanced synthetic aperture radar（ASAR） wide swath images are analyzed and assessed against the numerically simulated surface current fields derived from the finite volume coastal ocean model（FVCOM） for the Changjiang Estuary. Comparisons with the FVCOM simulations show that the European Space Agency（ESA） Envisat ASAR based Doppler shift anomaly retrievals have the capability to capture quantitative information of the surface currents in the Changjiang Estuary. The uncertainty analysis of the ASAR range Doppler velocity estimates are discussed with regard to the azimuthal and range bias corrections, radar incidence angles, inaccuracy in the wind field corrections and the presence of rain cells.The corrected range Doppler velocities for the Changjiang Estuary area are highly valuable as they exhibit quantitative expressions related to the multiscale upper layer dynamics and surface current variability around the East China Sea, including the Changjiang Estuary.展开更多
Based on the field surveys and repeated cross-profile observations combined with the comparison of many years’ topog-raphic maps,this study shows the spatial variability and varying patterns of coastal erosion along ...Based on the field surveys and repeated cross-profile observations combined with the comparison of many years’ topog-raphic maps,this study shows the spatial variability and varying patterns of coastal erosion along the west coast of the Taiwan Strait.Regional differentiation in the Meso-Cenozoic coastal tectonics determined the irregular coastline and geological background for large-scale coastal erosion distribution.The intensity of coastal erosion on the west side of the Taiwan Strait is mild in the northern region,severe in the central region and modest in the southern region.The beaches along the coast are mainly backed by dunes,sea-walls or cliffs.The dunes and beaches show periodic erosion and recovery along the coast adjacent to river mouths,while persistent retreat of frontal dunes and beaches tends to occur in other areas.The beach erosion occurs mainly in front of seawalls.Due to the low strength of the unconsolidated sediment the soft cliffs suffer the severest coastline recession.Sea level rise and river sediment discharge reduction are main causes of coastal erosion.Storm surge is common in the studied area and plays an important role in the progress of coastal erosion.Human activities including coastal constructions and sand mining also tend to interfere strongly with the balance of sediment budget in some coastal cells.展开更多
The goal of our work was to locate and quantify changes that occurred in 66% of the Mexican coastline, based on four land cover maps generated by the Mexican Mangrove Monitoring System(SMMM) of the National Commission...The goal of our work was to locate and quantify changes that occurred in 66% of the Mexican coastline, based on four land cover maps generated by the Mexican Mangrove Monitoring System(SMMM) of the National Commission for the Knowledge and Use of Biodiversity(CONABIO) for the years 1970/81, 2005, 2010, and 2015. Our results showed overall dominance of erosion over accretion processes, beaches being the most affected coastal land cover. Emphasis was placed on identification and description of coastline sites in which land was either continuously lost(erosion) or gained(accretion) during the studied time periods. These sites were defined as continuous unidirectional dynamic sites and were compared with previous knowledge about the geodynamics of Mexican coasts. Continuous unidirectional dynamic sites were distributed throughout the study area and within all land cover types, but predominantly corresponded to areas covered by mangroves in the states of Campeche and Nayarit. Finally, we found an intensification of coastal erosion-accretion processes over time;coastline change rates having duplicated between the earliest(1970/81–2005) and the two more recent(2005–2010, and 2010–2015) analysed time periods, with erosion rates for each corresponding period of –3 m/yr,–7.5 m/yr, and –7.3 m/yr,and accretion rates of 2.8 m/yr, 7.3 m/yr, and 6.9 m/yr, respectively.展开更多
Coastline configuration indexes of 34 typical arc-shaped coasts in South China are investigated by the method of principal component analysis, and meanwhile deposition and geomorphologic features of arc-shaped coast a...Coastline configuration indexes of 34 typical arc-shaped coasts in South China are investigated by the method of principal component analysis, and meanwhile deposition and geomorphologic features of arc-shaped coast are also analyzed. The results show: (1) The configuration of arc-shaped coast in South China is of the characteristic of variability and complexity. (2) The wave power and the openings of the bay are the decisive factors to result in the changes of the configuration of the arc-shaped coast in South China, however, incidence direction of the wave has no effect on configuration development of the coast. (3) Commonly, geomorphologic modes of the arc-shaped coast system in South China consist of barriers, lagoons and tidal-inlets, and can be divided into four types:the openings of the bay leaning to the east, the openings of the bay leaning to the south, the openings of the bay leaning to the west and the openings of the bay leaning to the north.展开更多
Coastal dune rocks in China are eolian sands cemented by calcium carbonate under subaerial conditions, widely distributing on the tropical and subtropical coasts of South China. Particular temperature and precipitatio...Coastal dune rocks in China are eolian sands cemented by calcium carbonate under subaerial conditions, widely distributing on the tropical and subtropical coasts of South China. Particular temperature and precipitation as well as local wave and landform conditions are required for the formation of the dune rocks. A correspondence was found between Holocene environmental changes and coastal dune rock development by comparing the features of the sea-level and climate changes in the Holocene period with the ages, scales, and cementation of the dune rocks on the South China coasts. The findings provide well grounded explanation for some problems unresolved in the past researches on the coastal dune rock in South China： （1） There were no dune rocks with ages older than 6000 years in South China because the dune rocks formed before 6000 a BP were covered by the sea water that rose in the later period; （2） the dune rocks with ages of around 3000 a BP were widely found in South China today because the coastal dunes were cumulated on a large scale at that time as a result of temperature falling after the end of Megathermal; （3） Medieval Warm Period was the main period for the eolian dunes to be cemented into the coastal dune rocks in South China; （4） lack of dune rocks of younger than 1000 a BP was accounted for by that the climate conditions in recent one thousand years were not suitable for the cementation.展开更多
Fractal theory was applied to a preliminary discussion of the fractal character and formation mechanism of the coastline of the bedrock coast of China on the basis of GIS (Geographical Information System). Some signif...Fractal theory was applied to a preliminary discussion of the fractal character and formation mechanism of the coastline of the bedrock coast of China on the basis of GIS (Geographical Information System). Some significant conclusions were drawn:(1) The fractal dimensions of the coastline and linear structures of Liaodong Peninsula are 1.0093 and 1.0246 respectively, those of Shandong Peninsula are 1.019 and 1.021 respectively, etc.(2) The fractal dimensions of coastlines of Liaodong Peninsula, Shandong Peninsula, Zhejiang and Fujian-Guangdong tend to increase with the spatial change from north to south.(3)The regional linear structures(including faults)control the basic trends and fractal dimensions of coastlines as a whole in the regions of the bedrock coast of China:the more the controlling effect of linear structures, the smaller the fractal dimensions of coastlines.(4)The substantial constituents of coast and biologic function both play an important role in affecting the fractal dimensions of coastlines of Liaodong Peninsula, Shandong Peninsula, Zhejiang, Fujian-Guangdong and Taiwan Island.展开更多
文摘Feiyantan was the discharge area of Diaokou River distributary of the Yellow River during the period of 1964 to 1976. The coastal erosion feature and morphological evolution at the Feiyantan coast are studied in the light of the topography and section depth, and the corresponding dynamics of wave and current. Results indicate that the protruding topography left after the Diaokou River distributary was abandoned is the main cause of strong coastal erosion. Further research suggests that waves start up the sediment and the tidal current transports it, and the waves and tidal current are combined to be the dominant dynamic mechanism of coastal erosion, in which the tidal residual current takes and transports the sediment outward, thus causing the sediment to wane in the coast.
文摘The article examines the diverse musical environments for older adults on the West Coast of North America,ranging from descriptions of regional variations in senior community living presented in a variety of sources,including fiction,and the place of music in institutional settings to various musical activities designed for older adults.Given that people living on the West Coast have diverse ethno-religious backgrounds,may or may not be sensitive to the music that surrounded them in their formative years at the local and national levels,and have different habits regarding listening to the radio or attending various musical events,additional aspects were taken into account,such as 1980s and 1990s music styles;ethnic musical heritage relevant to the West Coast population;classical,popular,and religious music on the radio;and affordable symphony orchestra programs.The article provides an overview that opens avenues for further exploration of its sub-topics.
基金the Guangdong Major Project of Basic and Applied Basic Research(Grant No.2020B0301030004)the National Natural Science Foundation of China(Grant Nos.42275002 and 42275006)+1 种基金the National Institute of Natural Hazards,Ministry of Emergency Management of China(Grant Nos.ZDJ2024-01 and ZDJ2024-25)the Science and Technology Planning Project of Guangdong Province(Grant No.2023B1212060019).
文摘Active atmospheric convection on the monsoon coast is crucial for the Earth’s climate system.In particular,the upscale convective growth(UCG)from ordinary isolated convection to organized convective system is a key process causing severe weather,but its activities on the monsoon coast are less understood because of the lack of fine-resolution datasets.For the first time,we present the climatology of UCG on a typical monsoon coast using kilometer-mesh radar data from southern China.The UCG undergoes pronounced subseasonal and diurnal variations in the early-summer rainy season.The subseasonal UCG increase is attributed to the onshore flows shifting from easterlies in April to monsoon southwesterlies in June.UCG becomes vigorous following summer monsoon onset,with hotspots near windward coastal mountains.Daytime UCG first peaks near noontime along coastal land,where onshore flows are destabilized by boundary-layer heating and mountains.Afternoon inland peaks and off-coast minimums are recognized due to land–sea thermal contrast and sea-breeze circulation.Nighttime UCG is revived at the coast by nocturnally enhanced southerlies,followed by offshore activity as the convergence of land-breeze northerlies shifts seaward.The UCG thus responds strongly to changing atmospheric conditions,land heating/cooling,and thermally driven local circulations.Our results may help clarify the predictability of monsoon coastal convection.
基金The cost of this research comes from a grant from the government of the Republic of Indonesia,through the Ministry of Education and Culture,Research and Technology with contract number:1225/UN36.11/LP2M/2024。
文摘This study aims to understand the behavior of the Bugis community in developing vernacular house models in the coastal areas of South Sulawesi Province,along with the factors influencing this behavior,such as knowledge,motivation,attitude,locus of control,commitment,concern,and income level.Bugis vernacular houses reflect local wisdom that is adapted to environmental,socio-cultural conditions,and the challenges of modernization.This correlational research was conducted in the regencies of Pangkajene and Kepulauan,Barru,and Bone,with a sample of 300 household heads.The variables analyzed include knowledge,motivation,attitude,locus of control,commitment,concern,and income level.Data were collected through knowledge tests and questionnaires and were analyzed using simple and multiple regression tech-niques.The results show that the Bugis community’s behavior in developing vernacular houses is moderate.Individually,motivation,locus of control,commitment,and concern significantly influence behavior,while knowledge,attitude,and income do not have a significant impact.However,collectively,all independent variables(knowledge,motivation,attitude,locus of control,commitment,concern,and income)affect the behavior of the Bugis community in developing vernacular houses in coastal areas.This study provides valuable insights into the environmental and social adaptations of the Bugis coastal community,as well as efforts to preserve culture through the sustainable development of vernacular houses.
文摘The coastal zone of Benin is inherited from the last marine oscillations of the Quaternary. A rich and very fragile environment, it presented until the 1960s, a shoreline in dynamic equilibrium over the entire 125 km of coastal line. Since the 1960s, with the construction of important development infrastructures (ports, dams, groins), the Beninese coast is now subject to risks of coastal erosion and seasonal flooding due to the overflow of lagoon water bodies. The present study, based on socio-economic surveys in the communes of Ouidah, Comè and Grand Popo, exposes the extent of coastal risks and socio-economic and environmental damage in the southwestern coastal zone of Benin. The results show that in terms of land, 2.9 ha and 5.7 ha of land have been permanently lost to coastal erosion in the communes of Ouidah and Grand Popo respectively. Similarly, 212 ha of crops of all types were affected by the flooding, including 35 ha destroyed, i.e. 6.67 ha, 11.3 ha in Comè, 4.67 ha Ouidah and 14 ha Grand Popo. Also, 6435 buildings were affected, and 4235 huts were damaged. In addition, working tools, food stocks and other items are counted among the losses recorded by coastal hazards with their corollaries of diseases. The cost of losses and damages in the 08 districts amount to 418,000,000f cfa of which 266,000,000f cfa of damage and 152,000,000f cfa of loss.
文摘The Northeast Pacific coastal ocean, as a typical river-influenced coastal upwelling system, is characterized by significant variability of sea surface partial pressure of carbon dioxide (</span><i><span style="font-family:Verdana;">p</span></i><span style="font-family:Verdana;">CO</span><sub><span style="font-family:Verdana;">2</span></sub><span style="font-family:Verdana;">, <200 to >1000</span></span><span style="font-family:""> </span><span style="font-family:""><span style="font-family:Verdana;">μ</span><span><span style="font-family:Verdana;">atm). This study reviewed the </span><a name="_Hlk76571454"></a><i><span style="font-family:Verdana;">p</span></i><span style="font-family:Verdana;">CO</span><sub><span style="font-family:Verdana;">2</span></sub><span style="font-family:Verdana;"> variability and its underlying controlling mechanism in this highly dynamic region by bringing together previous scientific findings and historical data. The large </span><i><span style="font-family:Verdana;">p</span></i><span style="font-family:Verdana;">CO</span><sub><span style="font-family:Verdana;">2</span></sub><span style="font-family:Verdana;"> variability reflects the complex interactions between physical processes (riverine input and coastal upwelling) and the biological </span><span style="font-family:Verdana;">responses to the nutrient transportation associated with these physical</span><span style="font-family:Verdana;"> processes, while temperature and air-sea gas exchange play a minor role in affecting </span><i><span style="font-family:Verdana;">p</span></i><span style="font-family:Verdana;">CO</span><sub><span style="font-family:Verdana;">2</span></sub><span style="font-family:Verdana;">. Both the river water and upwelled subsurface water are characterized by higher concentrations of </span><i><span style="font-family:Verdana;">p</span></i><span style="font-family:Verdana;">CO</span><sub><span style="font-family:Verdana;">2</span></sub><span style="font-family:Verdana;"> and nutrients when compared to the coastal surface water. The presence of high chlorophyll-a and low </span><i><span style="font-family:Verdana;">p</span></i><span style="font-family:Verdana;">CO</span><sub><span style="font-family:Verdana;">2</span></sub><span style="font-family:Verdana;"> in river plumes and areas adjacent to upwelling locations showed the intense biological CO</span><sub><span style="font-family:Verdana;">2</span></sub><span style="font-family:Verdana;"> uptake. The influences of riverine input and coastal upwelling thus mainly depend on the competing effect of high background </span><i><span style="font-family:Verdana;">p</span></i><span style="font-family:Verdana;">CO</span><sub><span style="font-family:Verdana;">2</span></sub><span style="font-family:Verdana;"> of river water and upwelled subsurface water vs. the biological dropdown of </span><i><span style="font-family:Verdana;">p</span></i><span style="font-family:Verdana;">CO</span><sub><span style="font-family:Verdana;">2</span></sub><span style="font-family:Verdana;"> resulting from the riverine- and upwelling-associated nutrient supplies. The strength of upwelling-favorable wind plays an important role in the </span><i><span style="font-family:Verdana;">p</span></i><span style="font-family:Verdana;">CO</span><sub><span style="font-family:Verdana;">2</span></sub><span style="font-family:Verdana;"> variability by affecting the intensity of coastal upwelling, with stronger wind speed causing more intense upwelling. The long-term </span><i><span style="font-family:Verdana;">p</span></i><span style="font-family:Verdana;">CO</span><sub><span style="font-family:Verdana;">2</span></sub><span style="font-family:Verdana;"> increasing rate in the Northeast Pacific coast is observed to be lower than that in the North Pacific open ocean.
文摘Reclamation of tidal flat is one of the main ways to get a dynamic balance of the total amount of plowland. With the development of social economy and the increasing demand for plowland, the contradiction between tidal flat reclamation and environment protection becomes more and more outstanding. However, tidal flat reclamation should also follow the dynamic balance of total amount of tidal flat amount. The paper analyzed the history of reclamation and development of Jiangsu mud coast, and calculated the feasible rates of tidal flat reclamation on different stretches respectively, and pointed out that both the economic social benefits of reclamation and the natural erosion-accretion conditions of the coasts should be taken into consideration in deciding the intensity of tidal flat reclamation, so as to satisfy demands on both reclamation and protection of tidal flat resource.
基金support of this study was provided by the National Science Committee through Grants NSC U0633007,40576052
文摘Two cruises were conducted to study the composition and seasonal variation of tintinnids （Protozoa： Ciliata） in Shantou coast water dudng spring and fall. Remarkable seasonal variations in environmental parameters, and tintinnids composition were observed. Tintinnids samples were enumerated and identified from 5 stations. 14 species belonging to 7 genuses of tintinnids were identified, and the dominate species was Leprotintinnus simple in these season. High tintinnids diversity and low abundance occurred in the fall, and on the contrary, low tintinnids diversity and high abundance occurred in the spring. No significant correlation occurred between tintinnids abundance and nutrients. Tintinnids abundance showed negative relationship with salinity （r2=0.63, P 〈 0.05）, maybe this was due to the cold raised water carried sum nutrients rise to the surface water in the fall, rich nutrients and high phytoplankton biomass decrease the importance of tintinnids in the energy flow of aquatic food web.
基金supported by National Nature Science (Grant No. 41266002)
文摘The tropical cyclone that lands or passes through Guangxi coast is a serious natural disaster, which brings about strong winds, heavy rains, storm surges and other disasters causing severe damage of property or casualties in the coastal region every year. By counting and analyzing the tropical cyclones affecting Guangxi coast from 1950 to 2012, we find that the annual number of tropical cyclones changes significantly, and the maximum value can be up to 9, whereas the minimum value is 0 in some year. The regularity of seasonal distribution of tropical cyclones is obvious, and the peak period is in July, August and September every year, followed by June and October. Most of tropical cyclones come from the east of Philippines. After entering the South China Sea and passing through Hainan province and Leizhou Peninsula, they landed on Guangxi coast once again and caused the mean of peak surge reaching 111.2 cm, which is 2.6 times of non-landing typhoon. The formation of storm surge disaster is directly related to the severe typhoon weather systems, diurnal spring tide and discharge of river flood. Severe typhoons generate huge waves and rainfall, which lead to the rise of water level at the estuary, and would result in significant increasing water when stacking up with the storm surge, and cause huge tidal disaster.
文摘On the basis of data of drifting bottles＇ tracks and the current measured in anchored stations, as well as temperature and salinity observed in cruise investigations and coastal stations, ADCP current data and AVHRR surface sea temperature （SST） data on the western coast of Guangdong, synthetic results of analysis showed that the coastal currents in the west of the mouth of the Zhujiang River were mainly westward in summer, which constituted the north branch of cyclonic gyre in the east of the Qiongzhou Straits. Part of its water flowed westward into the Beibu Gulf through the Qiongzhou Straits. The coastal current pattern was not identical with the traditional current system which flowed westward in the Qiongzhou Straits in winter and eastward in summer. The summertime＇s coastal current was always westward, maybe temporarily turning northeast only when the southwest wind was strong. The important characteristics of coastal current on the western coast of Guangdong, in the Qiongzhou Straits and in the north of the Beibu Gulf were analyzed and their mechanisms also were explained.
基金National Natural Science Foundation of China, No.40671186 No.40271012
文摘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.
基金The National Basic Research Program of China under contract No.2015CB954004the Natural Science Foundation of China under contract Nos 41276006 and U1405233+1 种基金the US National Science Foundation Award under contract No.AGS-1061998(for Zheng)the China Scholarship Council under contract No.201306310082
文摘This study applies the wavelet analysis to the tidal gauge records, alongshore winds, atmospheric temperature and pressure along the China coast in winter 2008. The analysis results show three events of sea level oscillations （SLOs） on the shelf induced by winter storms. The first event occurred from January 9 to 21. The SLO periods were double-peaked at 1.6-5.3 and 7.0-16.0 d with the power densities of 0.04-0.05 and 0.10-0.15 m^2.d, respectively. The second event occurred from February 5 to 18. The SLO period was single-peaked at 2.3-3.5 d with power density of 0.03-0.04 m^2.d. The third event occurred from February 20 to March 8. The SLO periods were double- peaked at 1.5-4.3 and 6.1-8.2 d with the power densities of 0.08-0.11 and 0.02-0.08 me.d, respectively. The SLOs propagated along the coast from Zhejiang in north to Guangdong in south. The phase speeds ranged about 9-29 m/s from Kanmen to Pingtan, 5-11 m/s from Xiamen to Huizhou and 11-22 m/s from Huizhou to Shuidong. The dispersion relation of the SLOs shows their nature of coastal-trapped wave.
基金The National Basic Research Program(973 Program)of China under contract No.2010CB951204European Space Agency-Ministry of Science and Technology of the People’s Republic of China Dragon 3 Cooperation Programme under contract No.10593+1 种基金the State Key Laboratory of Estuarine and Coastal Research,East China Normal University of China under contract No.SKLEC-2012KYYW02the 111 Project under contract No.B08022
文摘Range Doppler velocities derived from the Envisat advanced synthetic aperture radar（ASAR） wide swath images are analyzed and assessed against the numerically simulated surface current fields derived from the finite volume coastal ocean model（FVCOM） for the Changjiang Estuary. Comparisons with the FVCOM simulations show that the European Space Agency（ESA） Envisat ASAR based Doppler shift anomaly retrievals have the capability to capture quantitative information of the surface currents in the Changjiang Estuary. The uncertainty analysis of the ASAR range Doppler velocity estimates are discussed with regard to the azimuthal and range bias corrections, radar incidence angles, inaccuracy in the wind field corrections and the presence of rain cells.The corrected range Doppler velocities for the Changjiang Estuary area are highly valuable as they exhibit quantitative expressions related to the multiscale upper layer dynamics and surface current variability around the East China Sea, including the Changjiang Estuary.
基金supported by the National Science Foundation of China (No.40976057)the State Oceanic Administration of China (No.908-02-03-04)
文摘Based on the field surveys and repeated cross-profile observations combined with the comparison of many years’ topog-raphic maps,this study shows the spatial variability and varying patterns of coastal erosion along the west coast of the Taiwan Strait.Regional differentiation in the Meso-Cenozoic coastal tectonics determined the irregular coastline and geological background for large-scale coastal erosion distribution.The intensity of coastal erosion on the west side of the Taiwan Strait is mild in the northern region,severe in the central region and modest in the southern region.The beaches along the coast are mainly backed by dunes,sea-walls or cliffs.The dunes and beaches show periodic erosion and recovery along the coast adjacent to river mouths,while persistent retreat of frontal dunes and beaches tends to occur in other areas.The beach erosion occurs mainly in front of seawalls.Due to the low strength of the unconsolidated sediment the soft cliffs suffer the severest coastline recession.Sea level rise and river sediment discharge reduction are main causes of coastal erosion.Storm surge is common in the studied area and plays an important role in the progress of coastal erosion.Human activities including coastal constructions and sand mining also tend to interfere strongly with the balance of sediment budget in some coastal cells.
文摘The goal of our work was to locate and quantify changes that occurred in 66% of the Mexican coastline, based on four land cover maps generated by the Mexican Mangrove Monitoring System(SMMM) of the National Commission for the Knowledge and Use of Biodiversity(CONABIO) for the years 1970/81, 2005, 2010, and 2015. Our results showed overall dominance of erosion over accretion processes, beaches being the most affected coastal land cover. Emphasis was placed on identification and description of coastline sites in which land was either continuously lost(erosion) or gained(accretion) during the studied time periods. These sites were defined as continuous unidirectional dynamic sites and were compared with previous knowledge about the geodynamics of Mexican coasts. Continuous unidirectional dynamic sites were distributed throughout the study area and within all land cover types, but predominantly corresponded to areas covered by mangroves in the states of Campeche and Nayarit. Finally, we found an intensification of coastal erosion-accretion processes over time;coastline change rates having duplicated between the earliest(1970/81–2005) and the two more recent(2005–2010, and 2010–2015) analysed time periods, with erosion rates for each corresponding period of –3 m/yr,–7.5 m/yr, and –7.3 m/yr,and accretion rates of 2.8 m/yr, 7.3 m/yr, and 6.9 m/yr, respectively.
文摘Coastline configuration indexes of 34 typical arc-shaped coasts in South China are investigated by the method of principal component analysis, and meanwhile deposition and geomorphologic features of arc-shaped coast are also analyzed. The results show: (1) The configuration of arc-shaped coast in South China is of the characteristic of variability and complexity. (2) The wave power and the openings of the bay are the decisive factors to result in the changes of the configuration of the arc-shaped coast in South China, however, incidence direction of the wave has no effect on configuration development of the coast. (3) Commonly, geomorphologic modes of the arc-shaped coast system in South China consist of barriers, lagoons and tidal-inlets, and can be divided into four types:the openings of the bay leaning to the east, the openings of the bay leaning to the south, the openings of the bay leaning to the west and the openings of the bay leaning to the north.
基金National Natural Science Foundation of China, No.40871020 Guangdong Natural Science Foundation, No.7005836
文摘Coastal dune rocks in China are eolian sands cemented by calcium carbonate under subaerial conditions, widely distributing on the tropical and subtropical coasts of South China. Particular temperature and precipitation as well as local wave and landform conditions are required for the formation of the dune rocks. A correspondence was found between Holocene environmental changes and coastal dune rock development by comparing the features of the sea-level and climate changes in the Holocene period with the ages, scales, and cementation of the dune rocks on the South China coasts. The findings provide well grounded explanation for some problems unresolved in the past researches on the coastal dune rock in South China： （1） There were no dune rocks with ages older than 6000 years in South China because the dune rocks formed before 6000 a BP were covered by the sea water that rose in the later period; （2） the dune rocks with ages of around 3000 a BP were widely found in South China today because the coastal dunes were cumulated on a large scale at that time as a result of temperature falling after the end of Megathermal; （3） Medieval Warm Period was the main period for the eolian dunes to be cemented into the coastal dune rocks in South China; （4） lack of dune rocks of younger than 1000 a BP was accounted for by that the climate conditions in recent one thousand years were not suitable for the cementation.
文摘Fractal theory was applied to a preliminary discussion of the fractal character and formation mechanism of the coastline of the bedrock coast of China on the basis of GIS (Geographical Information System). Some significant conclusions were drawn:(1) The fractal dimensions of the coastline and linear structures of Liaodong Peninsula are 1.0093 and 1.0246 respectively, those of Shandong Peninsula are 1.019 and 1.021 respectively, etc.(2) The fractal dimensions of coastlines of Liaodong Peninsula, Shandong Peninsula, Zhejiang and Fujian-Guangdong tend to increase with the spatial change from north to south.(3)The regional linear structures(including faults)control the basic trends and fractal dimensions of coastlines as a whole in the regions of the bedrock coast of China:the more the controlling effect of linear structures, the smaller the fractal dimensions of coastlines.(4)The substantial constituents of coast and biologic function both play an important role in affecting the fractal dimensions of coastlines of Liaodong Peninsula, Shandong Peninsula, Zhejiang, Fujian-Guangdong and Taiwan Island.
