According to the daily precipitation data in Beijing area from 1985 to 2008,rainstorm weather index （10.4-38.8 mm） and climate index （daily precipitation ≥27.5 mm） in Beijing area were obtained by using the deter...According to the daily precipitation data in Beijing area from 1985 to 2008,rainstorm weather index （10.4-38.8 mm） and climate index （daily precipitation ≥27.5 mm） in Beijing area were obtained by using the determination method of extreme climate event index recommended by IPCC. Based on rainstorm weather index,rainstorm climate index and national rainstorm standard,the number of rainstorm days and rainfall amount in past years were calculated,and the correlation of annual number of rainy days,rainstorm days,precipitation and rainstorm amount with the flood disaster ratio of crop was analyzed,and the results showed that annual number of rainy days and rainstorm days couldn＇t reflect flood disaster ratio of crop truly,while annual precipitation and rainstorm amount had obvious linear positive correlation with the flood disaster ratio of crop. In addition,the correlation degree between rainstorm amount calculated by regional climate index and flood disaster ratio of crop was the highest,so it was suggested that rainstorm amount calculated by regional rainstorm climate index could be used to predict and evaluate flood disaster.展开更多
Using T106 numerical products, MM5 simulations in conjunction of Q-vector scheme-computed NCEP results, observations and satellite cloud images, study is undertaken for an exceptionally intense rainstorm event afflict...Using T106 numerical products, MM5 simulations in conjunction of Q-vector scheme-computed NCEP results, observations and satellite cloud images, study is undertaken for an exceptionally intense rainstorm event afflicting the Wenzhou region of Zhejiang province far away from the tropical storm center happening early on the morning of September 4, 1999 （TS9909 hereinafter）. Evidence suggests that, like previously-studied typhoons landing in autumn south of Xiamen to the eastern part of Guangdong, TS9909 has an inverted trough in the central south of the coastal belt of Zhejiang province that produces the rainstorm from the meso convective complex （MCC） on the warm, moist shear inside; the time and order of the magnitude of the rainfall are bound up with the development of the pattern of strong Q-vector divergence gradients during the event for the study area; the NE - SW coastline and the unique topography of the Yandang mountains inside the region are favorable for air lifting are the major contributors to the torrential rains.展开更多
In order to improve the pollution control effect of nitrogen phosphorus and heavy metals in stormwater runoff by using the constructed wetlands factors such as medium plants pretreatments etc.that may influence the re...In order to improve the pollution control effect of nitrogen phosphorus and heavy metals in stormwater runoff by using the constructed wetlands factors such as medium plants pretreatments etc.that may influence the removal efficiency are discussed based on the current studies. The pollution control effect can be enhanced by the improvement of the design methods the components and management of constructed wetlands.The design methods aimed at controlling the stormwater runoff should be based on the hydrological data accumulated for years.The development of novel medium and the selection of plants i.e. flood-tolerant and economical should be considered in advance. The management of constructed wetlands should be enhanced and the database of the stormwater in wetlands should be built.The discussion above should be effective in improving the pollution control effect in stormwater runoff by applying constructed wetlands.展开更多
In order to have an in-depth understanding of road runoff characteristics and the linkages to their influential factors this paper investigates the road runoff quality in a city of South China Shenzhen.Four rainfall e...In order to have an in-depth understanding of road runoff characteristics and the linkages to their influential factors this paper investigates the road runoff quality in a city of South China Shenzhen.Four rainfall events with different characteristics are monitored on a typical urban road.It is noted that the road runoff quality is worse than Grade Ⅳ of environmental quality standards for surface water.This means that the road runoff has posed a serious risk to water environment health. Furthermore the research outcomes indicate that first flush highly varies with rainfall patterns and pollutant species.This means that for road runoff treatment design rainfall patterns as well as pollutant species should be taken into consideration and this is particularly essential to design first flush capturing devices. Additionally the threshold of an initial 3 to 5 mm rainfall depth is suggested to the first flush capturing device design.These results provide useful suggestions to the effective road runoff treatment design.展开更多
Land use/cover change (LUCC) is one of the main boundary conditions which influence many hydrologic processes. In view of the importance of Taihu Lake Watershed in China and the urgency of discovering the impacts of L...Land use/cover change (LUCC) is one of the main boundary conditions which influence many hydrologic processes. In view of the importance of Taihu Lake Watershed in China and the urgency of discovering the impacts of LUCC on storm runoff, two flood events under five land cover scenarios in the Xitiaoxi River Basin of the upstream of Taihu Lake watershed were simulated by distributed hydrologic modeling system HEC-HMS. The influences of each land cover on storm runoff were discussed. It was concluded that under the same rainstorm the ascending order of runoff coefficient and peak flow produced by the 5 different land covers were woodland, shrub, grassland, arable land, and built-up land; the descending order of swelling time were woodland, shrub, grassland, arable land, and built-up land. Scenario of built-up land was the first to reach peak flow, then arable land, grassland, shrub, and woodland. There were close relationships between the runoff coefficients produced by the 5 different land covers. The degrees of impacts on runoff coefficient of land cover change modes were sorted by descending: woodland to built-up land, shrub to built-up land, grassland to built-up land, arable land to built-up land, woodland to arable land, shrub to arable land, arable land to grassland, shrub to grassland, grassland to arable land, and woodland to shrub. Urbanization will contribute to flood disaster, while forestation will mitigate flood disaster.展开更多
This report is a summary of China’s climate,as well as major weather and climate events,during 2021.In 2021,the mean temperature in China was 10.5°C,which was 1.0°C above normal(1981–2010 average)and broke...This report is a summary of China’s climate,as well as major weather and climate events,during 2021.In 2021,the mean temperature in China was 10.5°C,which was 1.0°C above normal(1981–2010 average)and broke the highest record since 1951.The annual rainfall in China was 672.1 mm,which was 6.7%above normal.Also,the annual rainfall in northern China was 40.2%above normal,which ranked second highest since 1961.The rainstorm intensity in the rainy season was strong and featured significant extremes,and disasters caused by rainstorms and flooding were more serious than the average in the past decade.In particular,the extremely strong rainstorm in Henan during July and autumn caused flooding in the middle and lower reaches of the Yellow River with severe consequences.Heatwaves occurred more frequently than normal,and their durations in southern China were longer than normal in summer and autumn.Phased drought was obvious,and caused serious impacts in South China.The number of generated and landfalling typhoons was lower than normal;however,Typhoon In-fa broke the record for the longest overland duration,held since 1949,and affected a wide area.Severe convective weather and extreme windy weather occurred frequently,causing serious impacts.The number of cold waves was more than normal,which caused wide-ranging extremely low temperatures in many places.Sandstorms appeared earlier than normal in 2021,and the number of strong dust storm processes was more than normal.展开更多
Previous studies have mostly focused on the effect of anthropogenic heating（AH） on air pollution events. However, few studies have investigated the impact of AH on the warm-sector precipitation over South China. By ...Previous studies have mostly focused on the effect of anthropogenic heating（AH） on air pollution events. However, few studies have investigated the impact of AH on the warm-sector precipitation over South China. By using the Weather Research and Forecasting model（WRF）coupled with an urban canopy model with appropriate AH release values, the warm-sector heavy rainfall event that occurred over the Pearl River Delta（PRD） during 8 May 2014 was investigated.The results show that the warm-sector precipitation of the PRD is sensitive to the impact of AH.By affecting the convection in the initiation of precipitation, AH can reduce the total precipitation of urban areas by approximately 10%. The possible mechanism by which AH influences the warm-sector heavy precipitation is described as follows： AH induced local convergence shifts towards the border of the PRD and intensified the convection and precipitation therein, by rearranging the thermal distributions of the flow field. In addition, AH changed the local convergence within the urban PRD areas, which was weakened by the homogenous urban thermal environment, and thereby decreased the total urban precipitation.展开更多
基金Supported by Cultivation Fund for Scientific and Technical innovation Project of Higher Education of Ministry of Education of China(708013)National Key Technology R &D Program in the 11th Five Year Plan of China (2008BAK50B02, 2007BAC29B05)~~
文摘According to the daily precipitation data in Beijing area from 1985 to 2008,rainstorm weather index （10.4-38.8 mm） and climate index （daily precipitation ≥27.5 mm） in Beijing area were obtained by using the determination method of extreme climate event index recommended by IPCC. Based on rainstorm weather index,rainstorm climate index and national rainstorm standard,the number of rainstorm days and rainfall amount in past years were calculated,and the correlation of annual number of rainy days,rainstorm days,precipitation and rainstorm amount with the flood disaster ratio of crop was analyzed,and the results showed that annual number of rainy days and rainstorm days couldn＇t reflect flood disaster ratio of crop truly,while annual precipitation and rainstorm amount had obvious linear positive correlation with the flood disaster ratio of crop. In addition,the correlation degree between rainstorm amount calculated by regional climate index and flood disaster ratio of crop was the highest,so it was suggested that rainstorm amount calculated by regional rainstorm climate index could be used to predict and evaluate flood disaster.
基金sponsored jointly by the Natural Science Foundation of China (Grant 4040950009402050084)the Project of Planned National Key Basic Research/Development (2004CB418301)
文摘Using T106 numerical products, MM5 simulations in conjunction of Q-vector scheme-computed NCEP results, observations and satellite cloud images, study is undertaken for an exceptionally intense rainstorm event afflicting the Wenzhou region of Zhejiang province far away from the tropical storm center happening early on the morning of September 4, 1999 （TS9909 hereinafter）. Evidence suggests that, like previously-studied typhoons landing in autumn south of Xiamen to the eastern part of Guangdong, TS9909 has an inverted trough in the central south of the coastal belt of Zhejiang province that produces the rainstorm from the meso convective complex （MCC） on the warm, moist shear inside; the time and order of the magnitude of the rainfall are bound up with the development of the pattern of strong Q-vector divergence gradients during the event for the study area; the NE - SW coastline and the unique topography of the Yandang mountains inside the region are favorable for air lifting are the major contributors to the torrential rains.
基金The National Science and Technology Major Project of China(No.2010ZX07320-002)the National Natural Science Foun dation of China(No.51308032)the Research Funds of Beijing University of Civil Engineering and Architecture(No.101200902)
文摘In order to improve the pollution control effect of nitrogen phosphorus and heavy metals in stormwater runoff by using the constructed wetlands factors such as medium plants pretreatments etc.that may influence the removal efficiency are discussed based on the current studies. The pollution control effect can be enhanced by the improvement of the design methods the components and management of constructed wetlands.The design methods aimed at controlling the stormwater runoff should be based on the hydrological data accumulated for years.The development of novel medium and the selection of plants i.e. flood-tolerant and economical should be considered in advance. The management of constructed wetlands should be enhanced and the database of the stormwater in wetlands should be built.The discussion above should be effective in improving the pollution control effect in stormwater runoff by applying constructed wetlands.
基金The National Science and Technology Major Project of China(No.2012ZX07301-001)the Shenzhen Environmental Research Project,China Postdoctoral Science Foundation(No.2013M530642)
文摘In order to have an in-depth understanding of road runoff characteristics and the linkages to their influential factors this paper investigates the road runoff quality in a city of South China Shenzhen.Four rainfall events with different characteristics are monitored on a typical urban road.It is noted that the road runoff quality is worse than Grade Ⅳ of environmental quality standards for surface water.This means that the road runoff has posed a serious risk to water environment health. Furthermore the research outcomes indicate that first flush highly varies with rainfall patterns and pollutant species.This means that for road runoff treatment design rainfall patterns as well as pollutant species should be taken into consideration and this is particularly essential to design first flush capturing devices. Additionally the threshold of an initial 3 to 5 mm rainfall depth is suggested to the first flush capturing device design.These results provide useful suggestions to the effective road runoff treatment design.
基金Under the auspices of Knowledge Innovation Program of Chinese Academy of Sciences (No. KZCX3-SW-331)
文摘Land use/cover change (LUCC) is one of the main boundary conditions which influence many hydrologic processes. In view of the importance of Taihu Lake Watershed in China and the urgency of discovering the impacts of LUCC on storm runoff, two flood events under five land cover scenarios in the Xitiaoxi River Basin of the upstream of Taihu Lake watershed were simulated by distributed hydrologic modeling system HEC-HMS. The influences of each land cover on storm runoff were discussed. It was concluded that under the same rainstorm the ascending order of runoff coefficient and peak flow produced by the 5 different land covers were woodland, shrub, grassland, arable land, and built-up land; the descending order of swelling time were woodland, shrub, grassland, arable land, and built-up land. Scenario of built-up land was the first to reach peak flow, then arable land, grassland, shrub, and woodland. There were close relationships between the runoff coefficients produced by the 5 different land covers. The degrees of impacts on runoff coefficient of land cover change modes were sorted by descending: woodland to built-up land, shrub to built-up land, grassland to built-up land, arable land to built-up land, woodland to arable land, shrub to arable land, arable land to grassland, shrub to grassland, grassland to arable land, and woodland to shrub. Urbanization will contribute to flood disaster, while forestation will mitigate flood disaster.
基金This work was jointly supported by the National Natural Science Foundation of China[grant number 41875120]a National Key Research and Development Project[grant number 2017YFC1502402].
文摘This report is a summary of China’s climate,as well as major weather and climate events,during 2021.In 2021,the mean temperature in China was 10.5°C,which was 1.0°C above normal(1981–2010 average)and broke the highest record since 1951.The annual rainfall in China was 672.1 mm,which was 6.7%above normal.Also,the annual rainfall in northern China was 40.2%above normal,which ranked second highest since 1961.The rainstorm intensity in the rainy season was strong and featured significant extremes,and disasters caused by rainstorms and flooding were more serious than the average in the past decade.In particular,the extremely strong rainstorm in Henan during July and autumn caused flooding in the middle and lower reaches of the Yellow River with severe consequences.Heatwaves occurred more frequently than normal,and their durations in southern China were longer than normal in summer and autumn.Phased drought was obvious,and caused serious impacts in South China.The number of generated and landfalling typhoons was lower than normal;however,Typhoon In-fa broke the record for the longest overland duration,held since 1949,and affected a wide area.Severe convective weather and extreme windy weather occurred frequently,causing serious impacts.The number of cold waves was more than normal,which caused wide-ranging extremely low temperatures in many places.Sandstorms appeared earlier than normal in 2021,and the number of strong dust storm processes was more than normal.
基金supported by the Special Scientific Research Fund of the Meteorological Public Welfare of the Ministry of Sciences and Technology,China(Grant No.GYHY201406003)the National Natural Science Foundation of China(Grant Nos.41375054,41575064,and 41375052)+1 种基金the Applied Basic Research Programs of the Science and Technology Department of Sichuan Province(Grant No.2015JY0109)the Starting Foundation of Civil Aviation University of China(Grant No.2016QD05X)
文摘Previous studies have mostly focused on the effect of anthropogenic heating（AH） on air pollution events. However, few studies have investigated the impact of AH on the warm-sector precipitation over South China. By using the Weather Research and Forecasting model（WRF）coupled with an urban canopy model with appropriate AH release values, the warm-sector heavy rainfall event that occurred over the Pearl River Delta（PRD） during 8 May 2014 was investigated.The results show that the warm-sector precipitation of the PRD is sensitive to the impact of AH.By affecting the convection in the initiation of precipitation, AH can reduce the total precipitation of urban areas by approximately 10%. The possible mechanism by which AH influences the warm-sector heavy precipitation is described as follows： AH induced local convergence shifts towards the border of the PRD and intensified the convection and precipitation therein, by rearranging the thermal distributions of the flow field. In addition, AH changed the local convergence within the urban PRD areas, which was weakened by the homogenous urban thermal environment, and thereby decreased the total urban precipitation.
