On May 20 th 2007, a brief but severe downpour rainstorm occurred in the coastal areas of Maoming and Yangjiang with rainfall of 115 mm per hour. Data from NCEP/NCAR reanalysis with 1°×1° resolution, Do...On May 20 th 2007, a brief but severe downpour rainstorm occurred in the coastal areas of Maoming and Yangjiang with rainfall of 115 mm per hour. Data from NCEP/NCAR reanalysis with 1°×1° resolution, Doppler weather radar, conventional surface observations, high-altitude radiosonde and wind profiler radar were used to analyze characteristics and contributions of synoptic scale and mesoscale systems during this torrential rainstorm. The results showed that:(1) the storm was caused by a quasi-linear mesoscale convective system(MCS) and the slow-movement of this system was the primary trigger of the torrential downpour;(2) water vapor was abundant, nearly saturated and in steady state throughout the atmosphere before the storm; intrusion of the weak dry and cold air in the middle level and a striking "dry above and wet below " structure had increased the atmospheric instability;(3) low-level southwesterly airflow from a low pressure(trough) at the Beibu Gulf provided abundant water vapor at the onset of the rainstorm; a deep dry layer was formed by dry and cold air behind the high-level trough, which facilitated latent heat release;upper-level divergence and low-level convergence circulations also provided vertical uplift for warm and moist air at the lower level;(4) Topography only played a minor role as the MCS developed and strengthened over relatively flat coastal terrain. Low level density flow induced by convection triggered new convective cell generation at the leading edge of the convective system, thereby playing a key role in the change of temperature gradient at lower layers, and resulting in strengthening atmospheric instability.展开更多
To discuss response ability of five functional areas to rainstorm flood in Chongqing,by taking 8 districts（ counties） as research object,monthly occurrence times of heavy rain and rainstorm in different functional a...To discuss response ability of five functional areas to rainstorm flood in Chongqing,by taking 8 districts（ counties） as research object,monthly occurrence times of heavy rain and rainstorm in different functional areas over the years and appearance month of the maximum rainfall were conducted statistics. Results showed that frequency distribution of heavy rain in whole year in different functional areas was different,but it was similar in the same functional zone. Temporal-spatial distribution of rainstorm was more independent,and there were different performances in various districts of each functional area. In urban functional core area and urban functional expansion area,rainstorm times was more,and the maximum precipitation was larger. In urban development new district,rainstorm times and the maximum precipitation were relatively smaller in whole Chongqing. In ecological conservation development area of northeast Chongqing,rainstorm duration was longer,and we needed prevention and control during June- September. In ecological protection area of southeast Chongqing,although rainstorm occurrence times was the most in Chongqing,the heavy rainstorm was less.展开更多
[Objective] The aim was to study one rainstorm process being affected by two weather system. [Method] Influenced by high trough and Mongolia cold front, high latitude trough and subtropical high shear, rainstorm occur...[Objective] The aim was to study one rainstorm process being affected by two weather system. [Method] Influenced by high trough and Mongolia cold front, high latitude trough and subtropical high shear, rainstorm occurred in Jinzhou from October 19 to 22 in 2010. In order to make the analysis clear, there were two precipitation stages. Considering precipitation, weather situation, satellite image and numerical forecast, the rainstorm process was discussed. [Result] There were two raining stages during this precipitation. The first stage was affected by high altitude trough and ground Mongolia cold front, and the last stage was influenced by high altitude trough and subtropical high shear;the high latitude air, low latitude shear,low air torrent,subtropical high and their mutual coupling effect were the main influencing system and cause for this rainstorm. Satellite image suggested that there was convective cloud developing,weakening, disappearing and regenerating around the convective cloud of water vapor passage, showing distinct train operation state. The strengthening and weakening cloud image fitted the real precipitation. Numerical forecast precisely predicted the upper air and ground situation of the generation of rainstorm, especially the report of the east-retreating and south-falling trend of subtropical high;European center forecast fitted reality. There was certain error in predicting T639. Precipitation forecast was fine. [Conclusion] The study provided basis for the meteorological service work in future.展开更多
In this paper, the water equilibrium and ground truth are analyzed for '91.7' rainstormin Sihu drainage area, Hubei Province, China. The flood and waterlogging situation of ' 91.7'rainstorm in this are...In this paper, the water equilibrium and ground truth are analyzed for '91.7' rainstormin Sihu drainage area, Hubei Province, China. The flood and waterlogging situation of ' 91.7'rainstorm in this area are investigated using remote sensing, especially the estimation of inundatedarea, the analysis of temporal and spatial characters of this flood and waterlogging damage. Andthe way of flood-trace using remote sensing is explored. At last, the disastroiis conditions are evalu-ated.展开更多
[ Objective] The study aimed to reveal the output characteristics of non-point nitrogen and phosphorus from a typical small watershed in Yimeng mountainous area during a rainstorm. [Method] The dynamic changes of poll...[ Objective] The study aimed to reveal the output characteristics of non-point nitrogen and phosphorus from a typical small watershed in Yimeng mountainous area during a rainstorm. [Method] The dynamic changes of pollutant concentration, precipitation and flow during the rainstorm on August 12, 2010 were monitored at the outlet of Menglianggu watershed. [ Result] During the rainstorm, the generation of runoff was sudden and ephemeral, and the peak of the runoff lagged behind that of rainfall intensity; the concentration of AN and TN increased firstly and then tended to be stable, while NN concentration had no significance change at the beginning of the rainfall, then improved gradually and tended to be stable fi- nally; DOP concentration had no obvious change during the rainstorm, but the concentration of DIP, DP, PP and TP rose firstly and then tended to be stable, and the peak values appeared before the peak of the flow. In addition, the output concentration of TN and TP was far higher than the standard concentration of water eutrophication. [ Conclusion] The study can provide scientific references for the reasonable control of non-point source pollution pollution in Yimeng mountainous area.展开更多
基金Guangdong Province Science and Technology Project(2017B020244002)National key basic research and development plan(973 plan)project"Typhoon fine structure multi-source data analysis theory and method research"(2015CB452802)+2 种基金National Program on Key Basic Research Project(2015CB452801)National Natural Science Foundation project"Observation and Assimilation Technology of Batch Variational Data and Its Application"(41475102)National Natural Science Foundation of China(41275025)
文摘On May 20 th 2007, a brief but severe downpour rainstorm occurred in the coastal areas of Maoming and Yangjiang with rainfall of 115 mm per hour. Data from NCEP/NCAR reanalysis with 1°×1° resolution, Doppler weather radar, conventional surface observations, high-altitude radiosonde and wind profiler radar were used to analyze characteristics and contributions of synoptic scale and mesoscale systems during this torrential rainstorm. The results showed that:(1) the storm was caused by a quasi-linear mesoscale convective system(MCS) and the slow-movement of this system was the primary trigger of the torrential downpour;(2) water vapor was abundant, nearly saturated and in steady state throughout the atmosphere before the storm; intrusion of the weak dry and cold air in the middle level and a striking "dry above and wet below " structure had increased the atmospheric instability;(3) low-level southwesterly airflow from a low pressure(trough) at the Beibu Gulf provided abundant water vapor at the onset of the rainstorm; a deep dry layer was formed by dry and cold air behind the high-level trough, which facilitated latent heat release;upper-level divergence and low-level convergence circulations also provided vertical uplift for warm and moist air at the lower level;(4) Topography only played a minor role as the MCS developed and strengthened over relatively flat coastal terrain. Low level density flow induced by convection triggered new convective cell generation at the leading edge of the convective system, thereby playing a key role in the change of temperature gradient at lower layers, and resulting in strengthening atmospheric instability.
基金Supported by Chongqing Municipal Frontiers and Application Base Research Program,China(cstc2014jcyjA 20002)Chongqing Municipal Key Laboratory of Institutions of Higher Education,China(WEPKL2013MS-10)+1 种基金Wanzhou District Soft Science Project,China(201404009)Innovation Planning Project for University Students of Chongqing Three Gorges University,China(2014-55)
文摘To discuss response ability of five functional areas to rainstorm flood in Chongqing,by taking 8 districts（ counties） as research object,monthly occurrence times of heavy rain and rainstorm in different functional areas over the years and appearance month of the maximum rainfall were conducted statistics. Results showed that frequency distribution of heavy rain in whole year in different functional areas was different,but it was similar in the same functional zone. Temporal-spatial distribution of rainstorm was more independent,and there were different performances in various districts of each functional area. In urban functional core area and urban functional expansion area,rainstorm times was more,and the maximum precipitation was larger. In urban development new district,rainstorm times and the maximum precipitation were relatively smaller in whole Chongqing. In ecological conservation development area of northeast Chongqing,rainstorm duration was longer,and we needed prevention and control during June- September. In ecological protection area of southeast Chongqing,although rainstorm occurrence times was the most in Chongqing,the heavy rainstorm was less.
文摘[Objective] The aim was to study one rainstorm process being affected by two weather system. [Method] Influenced by high trough and Mongolia cold front, high latitude trough and subtropical high shear, rainstorm occurred in Jinzhou from October 19 to 22 in 2010. In order to make the analysis clear, there were two precipitation stages. Considering precipitation, weather situation, satellite image and numerical forecast, the rainstorm process was discussed. [Result] There were two raining stages during this precipitation. The first stage was affected by high altitude trough and ground Mongolia cold front, and the last stage was influenced by high altitude trough and subtropical high shear;the high latitude air, low latitude shear,low air torrent,subtropical high and their mutual coupling effect were the main influencing system and cause for this rainstorm. Satellite image suggested that there was convective cloud developing,weakening, disappearing and regenerating around the convective cloud of water vapor passage, showing distinct train operation state. The strengthening and weakening cloud image fitted the real precipitation. Numerical forecast precisely predicted the upper air and ground situation of the generation of rainstorm, especially the report of the east-retreating and south-falling trend of subtropical high;European center forecast fitted reality. There was certain error in predicting T639. Precipitation forecast was fine. [Conclusion] The study provided basis for the meteorological service work in future.
文摘In this paper, the water equilibrium and ground truth are analyzed for '91.7' rainstormin Sihu drainage area, Hubei Province, China. The flood and waterlogging situation of ' 91.7'rainstorm in this area are investigated using remote sensing, especially the estimation of inundatedarea, the analysis of temporal and spatial characters of this flood and waterlogging damage. Andthe way of flood-trace using remote sensing is explored. At last, the disastroiis conditions are evalu-ated.
基金Supported by Science and Technology Innovation Project of Linyi City(201011019)Science and Technology Key Project of Shandong Province(2009GG10006015)Science and Technology Project of Huaihe River Commission,the Ministry of Water Resources (SBJ2010003)
文摘[ Objective] The study aimed to reveal the output characteristics of non-point nitrogen and phosphorus from a typical small watershed in Yimeng mountainous area during a rainstorm. [Method] The dynamic changes of pollutant concentration, precipitation and flow during the rainstorm on August 12, 2010 were monitored at the outlet of Menglianggu watershed. [ Result] During the rainstorm, the generation of runoff was sudden and ephemeral, and the peak of the runoff lagged behind that of rainfall intensity; the concentration of AN and TN increased firstly and then tended to be stable, while NN concentration had no significance change at the beginning of the rainfall, then improved gradually and tended to be stable fi- nally; DOP concentration had no obvious change during the rainstorm, but the concentration of DIP, DP, PP and TP rose firstly and then tended to be stable, and the peak values appeared before the peak of the flow. In addition, the output concentration of TN and TP was far higher than the standard concentration of water eutrophication. [ Conclusion] The study can provide scientific references for the reasonable control of non-point source pollution pollution in Yimeng mountainous area.
