Based on monthly precipitation data during 1961-2008 in 50 stations in Fushun,drought and flood indicators of three counties were calculated with Z index method. The geographical and seasonal distribution characterist...Based on monthly precipitation data during 1961-2008 in 50 stations in Fushun,drought and flood indicators of three counties were calculated with Z index method. The geographical and seasonal distribution characteristics of Fushun were analyzed,and so was the impact of droughts and floods on food production. It shows that,since 1961,there are 7 poor harvest years in Fushun,with quadrennial caused by continuous seasonal floods or droughts,two years by year drought,one year by summer flood.展开更多
Rainfall temporal patterns significantly affect variability of flash flood behaviors,and further act on hydrological model performances in operational flash flood forecasting and warning.In this study,multivariate sta...Rainfall temporal patterns significantly affect variability of flash flood behaviors,and further act on hydrological model performances in operational flash flood forecasting and warning.In this study,multivariate statistical analysis and hydrological simulations(XAJ and CNFF models) were combined to identify typical rainfall temporal patterns and evaluate model simulation capability for water balances,hydrographs,and flash flood behaviors under various rainfall patterns.Results showed that all the rainfall events were clustered into three types(Type 1,Type 2,and Type 3) in Anhe catchment in southeastern China.Type 1 was characterized by small total amount,high intensity,short duration,early peak moment,and concentrated hourly distribution.Type 3 was characterized by great total amount,low intensity,long duration,late peak moment,and uniform hourly distribution.Characteristics of Type 2 laid between those of Type 1 and Type 3.XAJ and CNFF better simulated water balances and hydrographs for Type 3,as well as all flash flood behavior indices and flood dynamics indices.Flood peak indices were competitively simulated for all the types by XAJ and except Type 1 by CNFF.The study is of significance for understanding relationships between rainfall and flash flood behaviors and accurately evaluating flash flood simulations.展开更多
Estuaries are usually affected by compound flooding triggers that cause diverse territorial damages.While fluvial flood risk assessment frameworks are well established in the literature,integrated management instrumen...Estuaries are usually affected by compound flooding triggers that cause diverse territorial damages.While fluvial flood risk assessment frameworks are well established in the literature,integrated management instruments that deal with estuarine flood risk remain incomplete and often lacking.This research presents a methodology to extract relevant information from multiple sources post-event and a database building process that is applied to two contrasting estuaries(the Tagus River estuary in Portugal,and the Shannon River estuary in Ireland)in the Western European coastal area.Overall,a total of 274 documents were analyzed and the information was stored in two databases.Multiple correspondence analysis was applied to extract the most informative and relevant estuarine flood indicators.An integrated estuarine flood risk assessment framework is presented and discussed based on the extracted indicators.The framework is driven by two distinct dimensions(oceanic and hydrographic)and revealed the transversal position of triggers of estuarine floods,reflecting the compounding effects usually present in these areas.The results also highlight two levels of flood risk mostly based on damage typology.展开更多
Proposed are a set of new regional flood/drought indices and a scheme of grading their severity whereby 1951-2000 summer wet/dry events are investigated for North China (NC) in terms of 160 station monthly precipitati...Proposed are a set of new regional flood/drought indices and a scheme of grading their severity whereby 1951-2000 summer wet/dry events are investigated for North China (NC) in terms of 160 station monthly precipitation data from NCC (China National Center of Climate).Results suggest that 7 heavy droughts during 1951-2000 are 1965,1968,1972,1980,1983,1997 and 1999,while 6 heavy floods are 1954,1956,1959,1964,1973 and 1996. Based on 1951-2000 summer flood/drought severity graded by the new scheme,atmospheric circulation characteristics associated with the disasters over the NC are addressed in terms of monthly NCEP (National Centers for Environmental Prediction) reanalysis of geopotential heights,winds,surface temperature and PW (precipitable water).Evidences suggest that prominent anomalies benefiting to the heavy droughts occur over the Northern Hemisphere.The variations over middle-high latitudes especially the negative ones on Ural Mountain to western Siberia deepen the normal trough there and are indicative of stronger than normal cold air activity. At middle latitudes,remarkable positive anomalies present on the south to Baikal lead to the fact that the normal ridge shifts eastward over NC concomitant with anomaly sinking motion in the whole troposphere,which is helpful for the maintenance of the continent high.And the opposed ones over Korea and Japan force the trough moving eastward running against northwestward shifting of the western Pacific subtropical high.In addition,the anomaly west-east pressure gradient at middle latitudes profits northerly flow there.The southerly monsoon flow at low levels is weaker than normal with weak East Asian summer monsoon,and the related water vapor transportation is also weak with deficit PW over NC.Besides,sea surface temperature (SST) rises in the equatorial eastern and central Pacific and associated convective region moves to the east accordingly companied with weak Walker circulation in the droughts.And the opposed situations will occur during the floods.展开更多
基金Supported by Fushun Government Financed Subject(20071209)
文摘Based on monthly precipitation data during 1961-2008 in 50 stations in Fushun,drought and flood indicators of three counties were calculated with Z index method. The geographical and seasonal distribution characteristics of Fushun were analyzed,and so was the impact of droughts and floods on food production. It shows that,since 1961,there are 7 poor harvest years in Fushun,with quadrennial caused by continuous seasonal floods or droughts,two years by year drought,one year by summer flood.
基金National Natural Science Foundation of China,No.42171047,No.42071041。
文摘Rainfall temporal patterns significantly affect variability of flash flood behaviors,and further act on hydrological model performances in operational flash flood forecasting and warning.In this study,multivariate statistical analysis and hydrological simulations(XAJ and CNFF models) were combined to identify typical rainfall temporal patterns and evaluate model simulation capability for water balances,hydrographs,and flash flood behaviors under various rainfall patterns.Results showed that all the rainfall events were clustered into three types(Type 1,Type 2,and Type 3) in Anhe catchment in southeastern China.Type 1 was characterized by small total amount,high intensity,short duration,early peak moment,and concentrated hourly distribution.Type 3 was characterized by great total amount,low intensity,long duration,late peak moment,and uniform hourly distribution.Characteristics of Type 2 laid between those of Type 1 and Type 3.XAJ and CNFF better simulated water balances and hydrographs for Type 3,as well as all flash flood behavior indices and flood dynamics indices.Flood peak indices were competitively simulated for all the types by XAJ and except Type 1 by CNFF.The study is of significance for understanding relationships between rainfall and flash flood behaviors and accurately evaluating flash flood simulations.
基金supported by the projects FORLAND–Hydrogeomorphologic Risk in Portugal:Driving Forces and Application for Land Use Planning(PTDC/ATPGEO/1660/2014)MOSAIC.pt-Multi-source Flood Risk Analysis for Safe Coastal Communities and Sustainable Development(PTDC/CTA-AMB/28909/2017)+2 种基金funded by the Portuguese Foundation for Science and Technology(FCT),Portugalfunded by FCT(SFRH/BD/111166/2015)the data provided by the project DISASTER(PTDC/CS-GEO/103231/2008)also funded by FCT and the following institutions:Administrac a o do Porto de Lisboa(APL),and Autoridade Nacional de Emergência e Protecao Civil(ANEPC)。
文摘Estuaries are usually affected by compound flooding triggers that cause diverse territorial damages.While fluvial flood risk assessment frameworks are well established in the literature,integrated management instruments that deal with estuarine flood risk remain incomplete and often lacking.This research presents a methodology to extract relevant information from multiple sources post-event and a database building process that is applied to two contrasting estuaries(the Tagus River estuary in Portugal,and the Shannon River estuary in Ireland)in the Western European coastal area.Overall,a total of 274 documents were analyzed and the information was stored in two databases.Multiple correspondence analysis was applied to extract the most informative and relevant estuarine flood indicators.An integrated estuarine flood risk assessment framework is presented and discussed based on the extracted indicators.The framework is driven by two distinct dimensions(oceanic and hydrographic)and revealed the transversal position of triggers of estuarine floods,reflecting the compounding effects usually present in these areas.The results also highlight two levels of flood risk mostly based on damage typology.
基金"National Key Program for Developing Basic Sciences-Research on the Formation Mechanism and Prediction Theory of Severe Climate Disasters in China"G1998040901-3
文摘Proposed are a set of new regional flood/drought indices and a scheme of grading their severity whereby 1951-2000 summer wet/dry events are investigated for North China (NC) in terms of 160 station monthly precipitation data from NCC (China National Center of Climate).Results suggest that 7 heavy droughts during 1951-2000 are 1965,1968,1972,1980,1983,1997 and 1999,while 6 heavy floods are 1954,1956,1959,1964,1973 and 1996. Based on 1951-2000 summer flood/drought severity graded by the new scheme,atmospheric circulation characteristics associated with the disasters over the NC are addressed in terms of monthly NCEP (National Centers for Environmental Prediction) reanalysis of geopotential heights,winds,surface temperature and PW (precipitable water).Evidences suggest that prominent anomalies benefiting to the heavy droughts occur over the Northern Hemisphere.The variations over middle-high latitudes especially the negative ones on Ural Mountain to western Siberia deepen the normal trough there and are indicative of stronger than normal cold air activity. At middle latitudes,remarkable positive anomalies present on the south to Baikal lead to the fact that the normal ridge shifts eastward over NC concomitant with anomaly sinking motion in the whole troposphere,which is helpful for the maintenance of the continent high.And the opposed ones over Korea and Japan force the trough moving eastward running against northwestward shifting of the western Pacific subtropical high.In addition,the anomaly west-east pressure gradient at middle latitudes profits northerly flow there.The southerly monsoon flow at low levels is weaker than normal with weak East Asian summer monsoon,and the related water vapor transportation is also weak with deficit PW over NC.Besides,sea surface temperature (SST) rises in the equatorial eastern and central Pacific and associated convective region moves to the east accordingly companied with weak Walker circulation in the droughts.And the opposed situations will occur during the floods.
