In this study,the distribution pattern of meiofauna from nine sandy beaches at six latitudinal gradients along Chinese coast between 18 and 40?N was studied on their meiofauna abundance to examine the effect of latitu...In this study,the distribution pattern of meiofauna from nine sandy beaches at six latitudinal gradients along Chinese coast between 18 and 40?N was studied on their meiofauna abundance to examine the effect of latitudinal gradients.In general,meiofauna abundance was lower in four subtropical beaches in Xiamen(24?N) and Zhoushan(29?N) than that in other beaches.Meiofauna abundance differed little between tropical and temperate beaches.The taxonomic structure of meiofauna showed a dominance of nematode in colder area.The relative composition of turbellarians and polychaetes increased in warmer area.In addition to latitudinal gradient,salinity,oxygenation,sediment grain size affect also the meiofauna latitudinal distribution.As for horizontal distribution,the highest meiofauna abundance was found in low tidal zone at tropical beaches,and in middle tidal zone at temperate beaches.The horizontal distribution of meiofauna was controlled by both physical and biotic factors including feeding and anthropogenic activities.Although meiofauna abundance exhibited a horizontal difference,the composition of meiofaunal main taxa was unanimous horizontally at all beaches at the same sampling latitude.展开更多
Since the beginning of the 20th century, tideland reclamation as a huge project has continuously extended from inland to the sea for the socioeconomic development, like Zhejiang, Jiangsu and other coastal regions in C...Since the beginning of the 20th century, tideland reclamation as a huge project has continuously extended from inland to the sea for the socioeconomic development, like Zhejiang, Jiangsu and other coastal regions in China. The increase of land area alleviated the contradiction of supply and demand between human and land, which provided the guarantee for agricultural production and industrial development. However, marine ecological environment has been seriously damaged due to the increasing scale of tideland reclamation. This paper took the Hangzhou Bay in the Yangtze River Delta as a study area to explore the evolution law, socioeconomic effect and eco-environmental effect of reclaimed land from 1985 to 2015. The result showed that as follows:(1) The area of tideland reclamation was 460.67 km^2 with 16.57% cultivated land and 15.93% construction land, and its land use was inefficient;(2) Land use change has spatial and temporal difference, the speed of tideland reclamation had been increasing from 1985 to 2015 in time and the scale of reclaimed land in the southern(84.07%) of Hangzhou Bay was larger than the northern region(15.93%) in space;(3) The evolution law of land use was from tideland to swampland and coastal waters to agricultural facility land, to cultivated land to industrial-mining land to idle land, rural-urban construction land, and formed obviously hierarchical structure;(4) Effect analysis of land use change found that the socio-economic effect had increased but the eco-environmental effect had decreased from 1985 to 2015, it reflected socio-economic effect was acquired through sacrificing eco-environmental effect;(5) It pointed out the existing problems on land extensive inefficient, environmental degradation and economy excessive growth without scientific planning, and offered some suggestions in land comprehensive improvement project, industrial transformation and upgrading and scientific planning and legal safeguardto promote sustainable development in the Hangzhou Bay in the new period.展开更多
Meiofauna samples from intertidal sediments of Qingdao No.2 Bathing Beach, China, were collected for field study, and subjected to organic enrichment in a laboratory microcosm experiment for 21 d. There were three dif...Meiofauna samples from intertidal sediments of Qingdao No.2 Bathing Beach, China, were collected for field study, and subjected to organic enrichment in a laboratory microcosm experiment for 21 d. There were three different treatments including non-organic addition as the control, low-organic enrichment (2 g DW green algae per 150 mL) and high-organic enrichment (10 g DW green algae per 150 mL). After 21 d, the meiofauna richness decreased in both organic enrichment treatments. Among the three treatments, total meiofauna abundance was significantly different, and the control groups had higher abundance than the other two treatment groups. However, the responses of the meiofauna abundance in the two organic enrichment treatments were non-significantly different. The relationship of meiofaunal abundance and nematode/copepod ratios to organic matter and oxygen level in the microcosm experiments were discussed.展开更多
Undrained behaviour of sand under low cell pressure was studied in static and cyclic triaxial tests. It was found that very loose sand liquefies under static loading with the relative density being a key parameter for...Undrained behaviour of sand under low cell pressure was studied in static and cyclic triaxial tests. It was found that very loose sand liquefies under static loading with the relative density being a key parameter for the undrained behaviour of sand. In cyclic triaxial tests, pore water pressures built up during the cyclic loading and exceeded the confining cell pressure. This process was accompanied by a large sudden increase in axial deformation. The necessary number of cycles to obtain liquefaction was related to the confining cell pressure, the amplitude of cyclic loading and the relative density of sand.In addition, the patterns of pore water pressure response are different from those of sand samples with different relative densities. The test results are very useful for expounding scour mechanism around coastal structures since they relate to the low stress behaviour of the sand.展开更多
We present a stochastic critical slope sandpile model, where the amount of grains that fall in an overturning event is stochastic variable. The model is local, conservative, and Abelian. We apply the moment analysis t...We present a stochastic critical slope sandpile model, where the amount of grains that fall in an overturning event is stochastic variable. The model is local, conservative, and Abelian. We apply the moment analysis to evaluate critical exponents and finite size scaling method to consistently test the obtained results. Numerical results show that this model, Oslo model, and one-dimensional Abelian Manna model have the same critical behavior although the three models have different stochastic toppling rules, which provides evidences suggesting that Abelian sandpile models with different stochastic toppling rules are in the same universality class.展开更多
Potential sandy coast erosion and socio-economic impacts under sea level rise scenarios as well as socio-economic pathways were assessed in Liaodong Bay.Results show that sea level is projected to rise by 20-43 cm in ...Potential sandy coast erosion and socio-economic impacts under sea level rise scenarios as well as socio-economic pathways were assessed in Liaodong Bay.Results show that sea level is projected to rise by 20-43 cm in Liaodong Bay by 2100.And dry land loss increases in all sea level rise scenarios,with the maximum loss of 32.1 km2 in 2100 under RCP8.5.Coastal erosion results in forced migration,and the forced migration is higher under SSP3 than other pathways due to its higher population growth rate,reaching the highest of 3.1×10^4 under SSP3/RCP8.5 in 2100.Moreover,the differences of forced migration among all scenarios increas after 2050,and the migration increasing rates tend to decrease under RCP2.6 and RCP4.5.The maximum economic loss due to coastal erosion will reach 8.05 billion yuan under SSP5/RCP8.5 in 2100,in which land loss cost is two order less than migration cost,and the share of total erosion-induced economic loss in local GDP varies from 1.12‰ to 4.76‰ under all scenarios,which is an important indicator to draw local government's attention to take measures such as beach nourishment,especially for tourist beaches.Optimally,it is recommended by cost-benefit analysis to carry out nourishment mainly on beaches with high value,while there is no need for nourishment in areas where erosion impacts are negligible.展开更多
This paper emphatically introduces the general situation, financial evaluation and competitive edge of both Xiangjiaba and Xiluodu hydropower stations, and briefs the preparatory works of Wudongde and Baihetan hydropo...This paper emphatically introduces the general situation, financial evaluation and competitive edge of both Xiangjiaba and Xiluodu hydropower stations, and briefs the preparatory works of Wudongde and Baihetan hydropower stations.展开更多
No simple solution to flood prevention is accessible. This research provides a brief summary of the hydrologic and hydraulic methodology that can be used to develop specific details that integrated the flood informati...No simple solution to flood prevention is accessible. This research provides a brief summary of the hydrologic and hydraulic methodology that can be used to develop specific details that integrated the flood information tool. It permits rapid analysis of a wide variety of stream discharge data and topographic mapping to avoid the flood hazard over entire floodplain boundaries. This paper focuses on the water floodplain hazard in Wadi Asla-Jaddah-Saudi Arabia. The most common type of rainfall in the study area is that accompanied by thunderstorms, which usually fall during the winter season as well as in the spring. The primarily evaluation of this problem and the solution is contemplate. The more essential and ＂doable＂ elements of a solutions and recommendations are discussed in this research.展开更多
基金supported by the National Natural Science Foundation of China (Nos.40906063,40730847,41106122,and 41076090)
文摘In this study,the distribution pattern of meiofauna from nine sandy beaches at six latitudinal gradients along Chinese coast between 18 and 40?N was studied on their meiofauna abundance to examine the effect of latitudinal gradients.In general,meiofauna abundance was lower in four subtropical beaches in Xiamen(24?N) and Zhoushan(29?N) than that in other beaches.Meiofauna abundance differed little between tropical and temperate beaches.The taxonomic structure of meiofauna showed a dominance of nematode in colder area.The relative composition of turbellarians and polychaetes increased in warmer area.In addition to latitudinal gradient,salinity,oxygenation,sediment grain size affect also the meiofauna latitudinal distribution.As for horizontal distribution,the highest meiofauna abundance was found in low tidal zone at tropical beaches,and in middle tidal zone at temperate beaches.The horizontal distribution of meiofauna was controlled by both physical and biotic factors including feeding and anthropogenic activities.Although meiofauna abundance exhibited a horizontal difference,the composition of meiofaunal main taxa was unanimous horizontally at all beaches at the same sampling latitude.
基金funded by the grants from the Major Project of National Social Science Foundation of China (15ZDA021)National Natural Science Foundation of China (Grant Nos.41130748, 41471143)
文摘Since the beginning of the 20th century, tideland reclamation as a huge project has continuously extended from inland to the sea for the socioeconomic development, like Zhejiang, Jiangsu and other coastal regions in China. The increase of land area alleviated the contradiction of supply and demand between human and land, which provided the guarantee for agricultural production and industrial development. However, marine ecological environment has been seriously damaged due to the increasing scale of tideland reclamation. This paper took the Hangzhou Bay in the Yangtze River Delta as a study area to explore the evolution law, socioeconomic effect and eco-environmental effect of reclaimed land from 1985 to 2015. The result showed that as follows:(1) The area of tideland reclamation was 460.67 km^2 with 16.57% cultivated land and 15.93% construction land, and its land use was inefficient;(2) Land use change has spatial and temporal difference, the speed of tideland reclamation had been increasing from 1985 to 2015 in time and the scale of reclaimed land in the southern(84.07%) of Hangzhou Bay was larger than the northern region(15.93%) in space;(3) The evolution law of land use was from tideland to swampland and coastal waters to agricultural facility land, to cultivated land to industrial-mining land to idle land, rural-urban construction land, and formed obviously hierarchical structure;(4) Effect analysis of land use change found that the socio-economic effect had increased but the eco-environmental effect had decreased from 1985 to 2015, it reflected socio-economic effect was acquired through sacrificing eco-environmental effect;(5) It pointed out the existing problems on land extensive inefficient, environmental degradation and economy excessive growth without scientific planning, and offered some suggestions in land comprehensive improvement project, industrial transformation and upgrading and scientific planning and legal safeguardto promote sustainable development in the Hangzhou Bay in the new period.
基金funded by the National Natural Science Foundation of China(NOs.40730847,40906063,41076090)
文摘Meiofauna samples from intertidal sediments of Qingdao No.2 Bathing Beach, China, were collected for field study, and subjected to organic enrichment in a laboratory microcosm experiment for 21 d. There were three different treatments including non-organic addition as the control, low-organic enrichment (2 g DW green algae per 150 mL) and high-organic enrichment (10 g DW green algae per 150 mL). After 21 d, the meiofauna richness decreased in both organic enrichment treatments. Among the three treatments, total meiofauna abundance was significantly different, and the control groups had higher abundance than the other two treatment groups. However, the responses of the meiofauna abundance in the two organic enrichment treatments were non-significantly different. The relationship of meiofaunal abundance and nematode/copepod ratios to organic matter and oxygen level in the microcosm experiments were discussed.
基金supported by the National Natural Science Foundation of China(No.50009002)Minstry of Science and Technology Project(No.2001AA616020)Parts of this work were supported by the EU SCARCOST project
文摘Undrained behaviour of sand under low cell pressure was studied in static and cyclic triaxial tests. It was found that very loose sand liquefies under static loading with the relative density being a key parameter for the undrained behaviour of sand. In cyclic triaxial tests, pore water pressures built up during the cyclic loading and exceeded the confining cell pressure. This process was accompanied by a large sudden increase in axial deformation. The necessary number of cycles to obtain liquefaction was related to the confining cell pressure, the amplitude of cyclic loading and the relative density of sand.In addition, the patterns of pore water pressure response are different from those of sand samples with different relative densities. The test results are very useful for expounding scour mechanism around coastal structures since they relate to the low stress behaviour of the sand.
基金国家自然科学基金，the State Key Laboratory of Laser of China
文摘We present a stochastic critical slope sandpile model, where the amount of grains that fall in an overturning event is stochastic variable. The model is local, conservative, and Abelian. We apply the moment analysis to evaluate critical exponents and finite size scaling method to consistently test the obtained results. Numerical results show that this model, Oslo model, and one-dimensional Abelian Manna model have the same critical behavior although the three models have different stochastic toppling rules, which provides evidences suggesting that Abelian sandpile models with different stochastic toppling rules are in the same universality class.
基金supported by the NMDIS Youth Fund Study on the contribution rate of sea level rise to coastal erosion of typical coastal segments(2018).
文摘Potential sandy coast erosion and socio-economic impacts under sea level rise scenarios as well as socio-economic pathways were assessed in Liaodong Bay.Results show that sea level is projected to rise by 20-43 cm in Liaodong Bay by 2100.And dry land loss increases in all sea level rise scenarios,with the maximum loss of 32.1 km2 in 2100 under RCP8.5.Coastal erosion results in forced migration,and the forced migration is higher under SSP3 than other pathways due to its higher population growth rate,reaching the highest of 3.1×10^4 under SSP3/RCP8.5 in 2100.Moreover,the differences of forced migration among all scenarios increas after 2050,and the migration increasing rates tend to decrease under RCP2.6 and RCP4.5.The maximum economic loss due to coastal erosion will reach 8.05 billion yuan under SSP5/RCP8.5 in 2100,in which land loss cost is two order less than migration cost,and the share of total erosion-induced economic loss in local GDP varies from 1.12‰ to 4.76‰ under all scenarios,which is an important indicator to draw local government's attention to take measures such as beach nourishment,especially for tourist beaches.Optimally,it is recommended by cost-benefit analysis to carry out nourishment mainly on beaches with high value,while there is no need for nourishment in areas where erosion impacts are negligible.
文摘This paper emphatically introduces the general situation, financial evaluation and competitive edge of both Xiangjiaba and Xiluodu hydropower stations, and briefs the preparatory works of Wudongde and Baihetan hydropower stations.
文摘No simple solution to flood prevention is accessible. This research provides a brief summary of the hydrologic and hydraulic methodology that can be used to develop specific details that integrated the flood information tool. It permits rapid analysis of a wide variety of stream discharge data and topographic mapping to avoid the flood hazard over entire floodplain boundaries. This paper focuses on the water floodplain hazard in Wadi Asla-Jaddah-Saudi Arabia. The most common type of rainfall in the study area is that accompanied by thunderstorms, which usually fall during the winter season as well as in the spring. The primarily evaluation of this problem and the solution is contemplate. The more essential and ＂doable＂ elements of a solutions and recommendations are discussed in this research.
