Mountains and waters serve as important elements for urban spatial mor-phology, structure and eco-environment. Since scientist Qian Xuesen proposed the concept of landscape city, it has been an effective way for urban...Mountains and waters serve as important elements for urban spatial mor-phology, structure and eco-environment. Since scientist Qian Xuesen proposed the concept of landscape city, it has been an effective way for urban development in case of thousand-city in the same appearance. In the study, we analyzed the con-cept, connotation and approaches and proposed the ways to landscape city.展开更多
Temporal and spatial variations of concentrations of heavy metals including mercury (Hg), zinc (Zn), lead (Pb), arsenic (As), copper (Cu), and cadmium (Cd) in the sediments of the Yangshan Deepwater Harbor...Temporal and spatial variations of concentrations of heavy metals including mercury (Hg), zinc (Zn), lead (Pb), arsenic (As), copper (Cu), and cadmium (Cd) in the sediments of the Yangshan Deepwater Harbor were determined based on 6 cruises in autumn and winter, respectively, from 2010 to 2013. The results demonstrated that the overall concentrations of heavy metals were low and distributed in uniform patterns. The concentrations of Hg, Zn, Pb, and Cd in autumn were significantly higher than those in winter with small fluctuations for As and Cu in terms of seasonal variations. Results of factor analysis showed that Pb, Cd, and Zn were derived from inland industrial and shipping discharges as well as the degradation of organic pollutants in marine environment. While agricultural pollutions, cargo shifting and construction debris from reclamation projects contributed to the sources of Cu, As, and Hg. Ecological risk assessment by Mean Sediment Quality Guideline Quotient (SQG-Q) revealed that the degree for eco-risk of the sediments was low-and-moderate in autumn, higher than that in winter. Hg and Cu were the dominant eco-risk factors. The results of Index of geoaccumulation (Igeo) showed that the whole sites of the sea area were barely influenced by Hg, As, Zn, and Pb, and the extents of Cd and Cu contaminations were in low grade. Contamination degree of all the six heavy metals could be ranked as the following: Cd〉Pb〉Zn〉Hg〉As. According to the results of integrated score of factor analysis, the contamination degree for heavy metals in sediments of the Yangshan Deepwater Harbor was low, despite sites No.5, No.4 and No.3, which were heavily contaminated compared with others.展开更多
Water-inrush in mine is one of the mine disasters caused by mining.In order to assess the risk of roof water-inrush in Wuyang Coal Mine based on the geological material of the coal mine,we built numerical models for t...Water-inrush in mine is one of the mine disasters caused by mining.In order to assess the risk of roof water-inrush in Wuyang Coal Mine based on the geological material of the coal mine,we built numerical models for the roof fracture and seepage development rule by using RFPA2D and COMSOL respectively,to analyze the changes in fracture zone,stress,water pressure and seepage vector with the advancement of working face,and compared the results with the field investigated data.The numerical simulation results indicate that:(1) with the advancement of the working faces,the stress relief range and fracture zone in the overlying strata increased rapidly up to about 90 m,and then tended to remain constant,reaching a final height of about 95 m which agrees with the field investigation;(2) the seepage flow constantly increased with a larger flow volume both in the front and rear area,where the stress concentration are the most serious.展开更多
The paintings in the Yuan Dynasty, because oft.heir unique characteristics of the times, have made a deep and superexcellent track in the history of the Chinese painting, among which the literati landscape paintings r...The paintings in the Yuan Dynasty, because oft.heir unique characteristics of the times, have made a deep and superexcellent track in the history of the Chinese painting, among which the literati landscape paintings represented the subject of the paintings in the Yuan Dynasty. And in the literati paintings, Ni Zan's paintings are the most representative. The application of the pen and ink in his works is concise and thinly scattered, and the artistic conception is cold and desolate. In this paper, with "Map of a fishing village in an autumn sunny day after the rain" as an example, the author analyzes Ni Zan's painting style and the causes of its formation.展开更多
Critical rainfall estimation for early warning of rainstorm-induced flash flood is an inverse rainstorm-runoff process based on warning discharge threshold for a warning station of interest in a watershed. The key asp...Critical rainfall estimation for early warning of rainstorm-induced flash flood is an inverse rainstorm-runoff process based on warning discharge threshold for a warning station of interest in a watershed. The key aspects of critical rainfall include rainfall amount and rainfall duration. Storm pattern affects highly the estimation of critical rainfall. Using hydrological modeling technique with detailed sub-basin delineation and manual for design rainstorm-runoff computation, this study first introduced basic concept and analysis methods on critical rainfall for flash flood early warning, then, investigated the responses of flash flood warning critical rainfall to storm pattern. Taking south branch of Censhui watershed in China as an example, critical rainfall in case of typical storm patterns for early warning of rainstorm-induced flash flood were estimated at 3 warning stations. This research illustrates that storm pattern plays important role in the estimation of critical rainfall and enough attention should also be paid to storm pattern when making a decision on whether a warning to be issued or not.展开更多
Fifty cases of regional yearly extreme precipitation events (RYEPEs) were identified over the Yangtze-Huaihe River Valley (YHRV) during 1979-2016 applying the statistical percentile method. There were five types o...Fifty cases of regional yearly extreme precipitation events (RYEPEs) were identified over the Yangtze-Huaihe River Valley (YHRV) during 1979-2016 applying the statistical percentile method. There were five types of RYEPEs, namely Yangtze Meiyu (YM-RYEPE), Huaihe Meiyu (HM-RYEPE), southwest-northeast-oriented Meiyu (SWNE-RYEPE) and typhoon I and II (TC-RYEPE) types of RYEPEs. Potential vorticity diagnosis showed that propagation trajectories of the RYEPEs along the Western Pacific Subtropical High and its steering flow were concentrated over the southern YHRV. As a result, the strongest and most frequently RYEPEs events, about 16-21 cases with average rainfall above 100 mm, occurred in the southern YHRV, particularly in the Nanjing metropolitan area. There have been 14 cases of flood-inducing RYEPEs since 1979, with the submerged area exceeding 120 km2 as simulated by the FloodArea hydraulic model, comprising six HM-RYEPEs, five YM- RYEPEs, two TC-RYEPEs, and one SWNE-RYEPE. The combination of evolving RYEPEs and rapid expansion of urban agglomeration is most likely to change the flood risk distribution over the Nanjing metropolitan area in the future. In the RCP6.0 (RCPS.5) scenario, the built-up area increases at a rate of about 10.41 km2 (10 yr)-t(24.67 km2 (10 yr)-1) from 2010 to 2100, and the area of high flood risk correspondingly increases from 3.86 km2(3.86 km2) to 9.00 kin2(13.51 km2). Areas of high flood risk are mainly located at Chishan Lake in Jurong, Lukou International Airport in Nanjing, Dongshan in Jiangning District, Lishui District and other low-lying areas. The accurate simulation of flood scenarios can help reduce losses due to torrential flooding and improve early warnings, evacuation planning and risk analysis. More attention should be paid to the projected high flood risk because of the concentrated population, industrial zones and social wealth throughout the Nanjing metropolitan area.展开更多
文摘Mountains and waters serve as important elements for urban spatial mor-phology, structure and eco-environment. Since scientist Qian Xuesen proposed the concept of landscape city, it has been an effective way for urban development in case of thousand-city in the same appearance. In the study, we analyzed the con-cept, connotation and approaches and proposed the ways to landscape city.
基金supported by the Study on the Analysis of the Impacts of Reclamation Engineering on Marine Ecological Environment in Yangshan Deepwater Harbor and Protecting Measures of Shanghai Municipal Science and Technology Commission (No. 12231203402)
文摘Temporal and spatial variations of concentrations of heavy metals including mercury (Hg), zinc (Zn), lead (Pb), arsenic (As), copper (Cu), and cadmium (Cd) in the sediments of the Yangshan Deepwater Harbor were determined based on 6 cruises in autumn and winter, respectively, from 2010 to 2013. The results demonstrated that the overall concentrations of heavy metals were low and distributed in uniform patterns. The concentrations of Hg, Zn, Pb, and Cd in autumn were significantly higher than those in winter with small fluctuations for As and Cu in terms of seasonal variations. Results of factor analysis showed that Pb, Cd, and Zn were derived from inland industrial and shipping discharges as well as the degradation of organic pollutants in marine environment. While agricultural pollutions, cargo shifting and construction debris from reclamation projects contributed to the sources of Cu, As, and Hg. Ecological risk assessment by Mean Sediment Quality Guideline Quotient (SQG-Q) revealed that the degree for eco-risk of the sediments was low-and-moderate in autumn, higher than that in winter. Hg and Cu were the dominant eco-risk factors. The results of Index of geoaccumulation (Igeo) showed that the whole sites of the sea area were barely influenced by Hg, As, Zn, and Pb, and the extents of Cd and Cu contaminations were in low grade. Contamination degree of all the six heavy metals could be ranked as the following: Cd〉Pb〉Zn〉Hg〉As. According to the results of integrated score of factor analysis, the contamination degree for heavy metals in sediments of the Yangshan Deepwater Harbor was low, despite sites No.5, No.4 and No.3, which were heavily contaminated compared with others.
基金Project supports from the National Basic Research Program of China (No. 2010CB226800)the 111 Project (No. B07028)the National Natural Science Foundation of China (Nos. 50974115and 41002087)
文摘Water-inrush in mine is one of the mine disasters caused by mining.In order to assess the risk of roof water-inrush in Wuyang Coal Mine based on the geological material of the coal mine,we built numerical models for the roof fracture and seepage development rule by using RFPA2D and COMSOL respectively,to analyze the changes in fracture zone,stress,water pressure and seepage vector with the advancement of working face,and compared the results with the field investigated data.The numerical simulation results indicate that:(1) with the advancement of the working faces,the stress relief range and fracture zone in the overlying strata increased rapidly up to about 90 m,and then tended to remain constant,reaching a final height of about 95 m which agrees with the field investigation;(2) the seepage flow constantly increased with a larger flow volume both in the front and rear area,where the stress concentration are the most serious.
文摘The paintings in the Yuan Dynasty, because oft.heir unique characteristics of the times, have made a deep and superexcellent track in the history of the Chinese painting, among which the literati landscape paintings represented the subject of the paintings in the Yuan Dynasty. And in the literati paintings, Ni Zan's paintings are the most representative. The application of the pen and ink in his works is concise and thinly scattered, and the artistic conception is cold and desolate. In this paper, with "Map of a fishing village in an autumn sunny day after the rain" as an example, the author analyzes Ni Zan's painting style and the causes of its formation.
文摘Critical rainfall estimation for early warning of rainstorm-induced flash flood is an inverse rainstorm-runoff process based on warning discharge threshold for a warning station of interest in a watershed. The key aspects of critical rainfall include rainfall amount and rainfall duration. Storm pattern affects highly the estimation of critical rainfall. Using hydrological modeling technique with detailed sub-basin delineation and manual for design rainstorm-runoff computation, this study first introduced basic concept and analysis methods on critical rainfall for flash flood early warning, then, investigated the responses of flash flood warning critical rainfall to storm pattern. Taking south branch of Censhui watershed in China as an example, critical rainfall in case of typical storm patterns for early warning of rainstorm-induced flash flood were estimated at 3 warning stations. This research illustrates that storm pattern plays important role in the estimation of critical rainfall and enough attention should also be paid to storm pattern when making a decision on whether a warning to be issued or not.
基金supported by the National Natural Science Foundation of China (Grant Nos. 41205063 & 41330529)the China Meteorological Administration Special Public Welfare Research Fund (Grant No. GYHY201506006)+1 种基金the Project of Development of Key Techniques in Meteorological Forecasting Operation (Grant No. CMAHX20160404)the Huaihe Basin Meteorological Research Foundation (Grant No. HRM201605)
文摘Fifty cases of regional yearly extreme precipitation events (RYEPEs) were identified over the Yangtze-Huaihe River Valley (YHRV) during 1979-2016 applying the statistical percentile method. There were five types of RYEPEs, namely Yangtze Meiyu (YM-RYEPE), Huaihe Meiyu (HM-RYEPE), southwest-northeast-oriented Meiyu (SWNE-RYEPE) and typhoon I and II (TC-RYEPE) types of RYEPEs. Potential vorticity diagnosis showed that propagation trajectories of the RYEPEs along the Western Pacific Subtropical High and its steering flow were concentrated over the southern YHRV. As a result, the strongest and most frequently RYEPEs events, about 16-21 cases with average rainfall above 100 mm, occurred in the southern YHRV, particularly in the Nanjing metropolitan area. There have been 14 cases of flood-inducing RYEPEs since 1979, with the submerged area exceeding 120 km2 as simulated by the FloodArea hydraulic model, comprising six HM-RYEPEs, five YM- RYEPEs, two TC-RYEPEs, and one SWNE-RYEPE. The combination of evolving RYEPEs and rapid expansion of urban agglomeration is most likely to change the flood risk distribution over the Nanjing metropolitan area in the future. In the RCP6.0 (RCPS.5) scenario, the built-up area increases at a rate of about 10.41 km2 (10 yr)-t(24.67 km2 (10 yr)-1) from 2010 to 2100, and the area of high flood risk correspondingly increases from 3.86 km2(3.86 km2) to 9.00 kin2(13.51 km2). Areas of high flood risk are mainly located at Chishan Lake in Jurong, Lukou International Airport in Nanjing, Dongshan in Jiangning District, Lishui District and other low-lying areas. The accurate simulation of flood scenarios can help reduce losses due to torrential flooding and improve early warnings, evacuation planning and risk analysis. More attention should be paid to the projected high flood risk because of the concentrated population, industrial zones and social wealth throughout the Nanjing metropolitan area.