The study investigated the trend of extreme flood events in the Pearl River basin during 1951-2010. Stream flow data at 23 gauging stations were used for the study. The Pearson type III distribution was selected for t...The study investigated the trend of extreme flood events in the Pearl River basin during 1951-2010. Stream flow data at 23 gauging stations were used for the study. The Pearson type III distribution was selected for the flood frequency analysis. Results indicate that extreme flood events increase significantly in the Pearl River Basin since 1980. At the 23 gauging stations, there are 16 (70%) stations show positive (increasing) trends in 1981-2010. Most of the 16 stations are located along the West River and North River. While 7 (30%) stations show negative (decreasing) trends, and are found in the East River and the southeast region of the West River Basin.展开更多
During an excavation survey to the Daijiayuan vestige of the Western Zhou Dynasty-Late Spring and Autumn Period at Huoshan in Western Anhui,a ground crack related to tectonic movement and filled with silty fine sand w...During an excavation survey to the Daijiayuan vestige of the Western Zhou Dynasty-Late Spring and Autumn Period at Huoshan in Western Anhui,a ground crack related to tectonic movement and filled with silty fine sand was found. This phenomenon was initially confirmed to be due to seismic liquefaction. Many microscopic seismic relics,such as load structure,flow structure,cutoff plane and flotation of organic matter were found in the directional microscopic analysis of deformation. These discoveries and cognitions prove that there were two earthquake events taking place in the Western Zhou Dynasty-Late Spring and Autumn Period in this area. Above-mentioned works enrich and develop the research methods to identify prehistoric earthquake event in eastern China area to a certain extent.展开更多
A coupled meteorology and aerosol/chemistry model WRF-Chem （Weather Research and Forecast model coupled with Chemistry） was used to conduct a pair of simulations with present-day （PD） and preindustrial （P1） emis...A coupled meteorology and aerosol/chemistry model WRF-Chem （Weather Research and Forecast model coupled with Chemistry） was used to conduct a pair of simulations with present-day （PD） and preindustrial （P1） emissions over East Asia to examine the aerosol indirect effect on clouds. As a result of an increase in aerosols in January, the cloud droplet number increased by 650 cm-3 over the ocean and East China, 400 cm-3 over Central and Southwest China, and less than 200 cm-3 over North China. The cloud liquid water path （LWP） increased by 40-60 g m-2 over the ocean and Southeast China and 30 g m-2 over Central China; the LWP in- creased less than 5 g m-2 or decreased by 5 g m2 over North China. The effective radius （Re） decreased by more than 4 pm over Southwest, Central, and Southeast China and 2 pm over North China. In July, variations in cloud properties were more uniform; the cloud droplet number increased by approximately 250400 cm-3, the LWP increased by approximately 30-50 g m 2, and Re decreased by approximately 3 μm over most regions of China. In response to cloud property changes from PI to PD, shortwave （SW） cloud radiative m-2 over the ocean and 10 forcing strengthened by 30 W W m-2 over Southeast China, and it weakened slightly by approximately 2-10 W m-2 over Central and Southwest China in January. In July, SW cloud radiative forcing strengthened by 15 W m-2 over Southeast and North China and weakened by l0 W m-2 over Central China. The different responses of SW cloud radiative forcing in different regions was related to cloud feedbacks and natural variability.展开更多
基金supported by National Basic Research Program of China (No. 2010CB428405)Special Public Sector Research Program of Ministry of Water Resources(No.201301040 and 201301070)+2 种基金National Natural Science Foundation of China (No. 41001012)Foundation forthe Author of National Excellent Doctoral Dissertation of China (No. 201161)Qing Lan Project and Program for New Century Excellent Talents in University
文摘The study investigated the trend of extreme flood events in the Pearl River basin during 1951-2010. Stream flow data at 23 gauging stations were used for the study. The Pearson type III distribution was selected for the flood frequency analysis. Results indicate that extreme flood events increase significantly in the Pearl River Basin since 1980. At the 23 gauging stations, there are 16 (70%) stations show positive (increasing) trends in 1981-2010. Most of the 16 stations are located along the West River and North River. While 7 (30%) stations show negative (decreasing) trends, and are found in the East River and the southeast region of the West River Basin.
基金This paper is a contribution to Scientific Research Special Project of the Earthquake Calling (200808064)Science and Technology Tackle Key Problem Plan Project of Anhui Province(08010302204)Natural Science Fund of Anhui Province(070415222),China
文摘During an excavation survey to the Daijiayuan vestige of the Western Zhou Dynasty-Late Spring and Autumn Period at Huoshan in Western Anhui,a ground crack related to tectonic movement and filled with silty fine sand was found. This phenomenon was initially confirmed to be due to seismic liquefaction. Many microscopic seismic relics,such as load structure,flow structure,cutoff plane and flotation of organic matter were found in the directional microscopic analysis of deformation. These discoveries and cognitions prove that there were two earthquake events taking place in the Western Zhou Dynasty-Late Spring and Autumn Period in this area. Above-mentioned works enrich and develop the research methods to identify prehistoric earthquake event in eastern China area to a certain extent.
基金supported by the Knowledge Innovation Program of the Chinese Academy of Sciences (KZCX2-YW-Q11-04)the "Strategic Priority Research Program" of the Chinese Academy of Sciences (XDA05100502)
文摘A coupled meteorology and aerosol/chemistry model WRF-Chem （Weather Research and Forecast model coupled with Chemistry） was used to conduct a pair of simulations with present-day （PD） and preindustrial （P1） emissions over East Asia to examine the aerosol indirect effect on clouds. As a result of an increase in aerosols in January, the cloud droplet number increased by 650 cm-3 over the ocean and East China, 400 cm-3 over Central and Southwest China, and less than 200 cm-3 over North China. The cloud liquid water path （LWP） increased by 40-60 g m-2 over the ocean and Southeast China and 30 g m-2 over Central China; the LWP in- creased less than 5 g m-2 or decreased by 5 g m2 over North China. The effective radius （Re） decreased by more than 4 pm over Southwest, Central, and Southeast China and 2 pm over North China. In July, variations in cloud properties were more uniform; the cloud droplet number increased by approximately 250400 cm-3, the LWP increased by approximately 30-50 g m 2, and Re decreased by approximately 3 μm over most regions of China. In response to cloud property changes from PI to PD, shortwave （SW） cloud radiative m-2 over the ocean and 10 forcing strengthened by 30 W W m-2 over Southeast China, and it weakened slightly by approximately 2-10 W m-2 over Central and Southwest China in January. In July, SW cloud radiative forcing strengthened by 15 W m-2 over Southeast and North China and weakened by l0 W m-2 over Central China. The different responses of SW cloud radiative forcing in different regions was related to cloud feedbacks and natural variability.
