The significant differences of atmospheric circulation between flooding in the Huaihe and Yangtze River valleys during early mei-yu (i.e., the East Asian rainy season in June) and the related tropical convection wer...The significant differences of atmospheric circulation between flooding in the Huaihe and Yangtze River valleys during early mei-yu (i.e., the East Asian rainy season in June) and the related tropical convection were investigated. During the both flooding cases, although the geopotential height anomalies always exhibit equivalent barotropic structures in middle to high latitudes at middle and upper troposphere, the phase of the Rossby wave train is different over Eurasian continent. During flooding in the Huaihe River valley, only one single blocking anticyclone is located over Baikal Lake. In contrast, during flooding in the Yangtze River valley, there are two blocking anticyclones. One is over the Ural Mountains and the other is over Northeast Asia. In the lower troposphere a positive geopotential height anomaly is located at the western ridge of subtropical anticyclone over Western Pacific (SAWP) in both flooding cases, but the location of the height anomaly is much farther north and west during the Huaihe River mei-yu flooding. Fhrthermore, abnormal rainfall in the Huaihe River valley and the regions north of it in China is closely linked with the latent heating anomaly over the Arabian Sea and Indian peninsula. However, the rainfall in the Yangtze River valley and the regions to its south in China is strongly related to the convection over the western tropical Pacific. Numerical experiments demonstrated that the enhanced latent heating over the Arabian Sea and Indian peninsula causes water vapor convergence in the region south of Tibetan Plateau and in the Huaihe River valley extending to Japan Sea with enhanced precipitation; and vapor divergence over the Yangtze River valley and the regions to its south with deficient precipitation. While the weakened convection in the tropical West Pacific results in moisture converging over the Yangtze River and the region to its south, along with abundant rainfall.展开更多
Using daily outgoing long-wave radiation (OLR) data from the National Oceanic and Atmospheric Administration (NOAA) and the National Center for Environmental Prediction/National Center for Atmospheric Research (N...Using daily outgoing long-wave radiation (OLR) data from the National Oceanic and Atmospheric Administration (NOAA) and the National Center for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) reanalysis data of geopotential height fields for 1979-2006, the relationship between persistent heavy rain events (PHREs) in the Huaihe River valley (HRV) and the distribution pattern of convective activity in the tropical western Pacific warm pool (WPWP) is investigated. Based on nine cases of PHREs in the HRV, common characteristics of the West Pacific subtropical high (WPSH) show that the northern edge of the WPSH continues to lie in the HRV and is associated with the persistent "north weak south strong" distribution pattern of convective activities in the WPWP. Composite analysis of OLR leading the circulation indicates that the response of the WPSH to OLR anomaly patterns lags by about 1-2 days. In order to explain the reason for the effects of the distribution pattern of convective activities in the WPWP on the persistent northern edge of the WPSH in the HRV, four typical persistent heavy and light rain events in the Yangtze River valley (YRV) are contrasted with the PHREs in the HRV. The comparison indicates that when the distribution pattern of the convective activities anomaly behaves in a weak (strong) manner across the whole WPWP, persistent heavy (light) rain tends to occur in the YRV. When the distribution pattern of the convective activities anomaly behaves according to the "north weak south strong" pattern in the WPWP, persistent heavy rain tends to occur in the HRV. The effects of the "north weak south strong" distribution pattern of convective activities on PHREs in the HRV are not obvious over the seasonal mean timescale, perhaps due to the non-extreme status of convective activities in the WPWP.展开更多
With the IAP/LASG GOALS model, the relationships between the floods in the Yangtze River valley arid sea surface temperature anomalies (SSTA) in the Pacific and Indian Oceans in 1998 have been studied. The results sho...With the IAP/LASG GOALS model, the relationships between the floods in the Yangtze River valley arid sea surface temperature anomalies (SSTA) in the Pacific and Indian Oceans in 1998 have been studied. The results show that the model can reproduce the heavy rainfall over the Yangtze River valley in the sum-mer of 1998 forced by global observational sea surface temperatures (SST). The model can also reproduce the observed principal features of the subtropical high anomalies over the western Pacific. The experiments with the observed SST in different ocean areas and different periods have been made. By comparing the ef-fects of SSTA of different ocean areas on the floods, it is found that the SSTA in the Indian Ocean are a ma-jor contributor to the floods, and the results also show that the SSTA in the Indian Ocean and the western Pacific have a much closer relationship with the strong anomalies of the subtropical high over the western Pacific than the SSTA in other concerned areas. The study also indicates that the floods and subtropical high anomalies in the summer of 1998 are more controlled by the simultaneous summertime SSTA than by SSTA in the preceding winter and spring seasons.展开更多
[Objective] The research aimed to analyze temporal and spatial variation of strong precipitation caused flood and agricultural disaster loss in Huaihe River basin of Anhui Province during Meiyu period of 2007.[Method]...[Objective] The research aimed to analyze temporal and spatial variation of strong precipitation caused flood and agricultural disaster loss in Huaihe River basin of Anhui Province during Meiyu period of 2007.[Method] On the basis of rainfalls of each station in Huaihe River basin of Anhui,rainfall data during Meiyu period of 2007 and flood disaster data in the same period,the temporal and spatial distribution characteristics of strong precipitation caused flood during Meiyu period of 2007 and its harm on agriculture were analyzed.The variation rule,distribution characteristics of strong precipitation during Meiyu period in Huaihe River basin of Anhui and its relationship with agricultural disaster loss were discussed.[Result] During Meiyu period of 2007 in Huaihe River basin of Anhui,the rainstorm was more,and the rainfall was large.The precipitation variation showed 'three-peak' trend.Rainfall in Huaihe River basin during Meiyu period of 2007 was greatly more than that homochronously in Yangtze River basin.The rain area over 400.0 mm during Meiyu period mainly located in Huaihe River basin,and the rain area over 600.0 mm mainly located from area along Huaihe River to central Huaibei.The rainfall during Meiyu period gradually decreased toward south and north by the north bank of Huaihe River as the symmetry axis.The rainfall in area along Huaihe River showed wavy distribution in east-west direction.The flood disaster loss index and disaster area of crops in Huaihe River basin of Anhui both increased as rainfall in Meiyu period.[Conclusion] The research provided theoretical basis for flood prevention,disaster reduction and agricultural flood-avoiding development in Huaihe River basin.展开更多
A hydrological simulation in the Huaihe River Basin(HRB) was investigated using two different models: a coupled land surface hydrological model(CLHMS), and a large-scale hydrological model(LSX-HMS). The NCEP-NCAR rean...A hydrological simulation in the Huaihe River Basin(HRB) was investigated using two different models: a coupled land surface hydrological model(CLHMS), and a large-scale hydrological model(LSX-HMS). The NCEP-NCAR reanalysis dataset and observed precipitation data were used as meteorological inputs. The simulation results from both models were compared in terms of flood processes forecasting during high flow periods in the summers of 2003 and 2007, and partial high flow periods in 2000. The comparison results showed that the simulated streamflow by CLHMS model agreed well with the observations with Nash-Sutcliffe coefficients larger than 0.76, in both periods of 2000 at Lutaizi and Bengbu stations in the HRB, while the skill of the LSX-HMS model was relatively poor. The simulation results for the high flow periods in 2003 and 2007 suggested that the CLHMS model can simulate both the peak time and intensity of the hydrological processes, while the LSX-HMS model provides a delayed flood peak. These results demonstrated the importance of considering the coupling between the land surface and hydrological module in achieving better predictions for hydrological processes, and CLHMS was proven to be a promising model for future applications in flood simulation and forecasting.展开更多
To comprehensively investigate characteristics of summer droughts and floods in the Yangtze River valley, a meteorological and hydrological coupling index (MHCI) was developed using meteorological and hydro- logical...To comprehensively investigate characteristics of summer droughts and floods in the Yangtze River valley, a meteorological and hydrological coupling index (MHCI) was developed using meteorological and hydro- logical data. The results indicate that: (1) in representing drought/flood information for the Yangtze River valley, the MHCI can reflect composite features of precipitation and hydrological observations; (2) compre- hensive analysis of the interannual phase difference of the precipitation and hydrological indices is important to recognize and predict annual drought/flood events along the valley; the hydrological index contributes more strongly to nonlinear and continuity features that indicate transition from long-term drought to flood conditions; (3) time series of the MHCI from 1960-2009 are very effective and sensitive in reflecting annual drought/flood characteristics, i.e. there is more rainfall or typical flooding in the valley when the MHCI is positive, and vice versa; and (4) verification of the MHCI indicates that there is significant correlation between precipitation and hydrologic responses in the valley during summer; the correlation coefficient was found to reach 0.82, exceeding the 0.001 significance level.展开更多
According to historical records, there are 264 drought and flood years, occurred in the upper and middle reaches of the Changjiang (Yangtze) River during last 1020 years from 961 to 1980. The evolutionary law and deve...According to historical records, there are 264 drought and flood years, occurred in the upper and middle reaches of the Changjiang (Yangtze) River during last 1020 years from 961 to 1980. The evolutionary law and developing trend of drought and flood years are studied. The distribution of drought and flood years are non-uniform and the dry and flood seasons in a year are concentrated. At the angle of monsoon circulation, at present the climate in the upper and middle reaches of the Changjiang River is just in the late stage of frequent drought period and the early stage of least flood period. In addition, the cycle of drought and flood and the feature of drought and flood occurred in the upper, middle and lower reaches of the Changjiang River are analyzed. It shows that the short period less than 10 years is in the majority, and the drought and flood occurred most frequently in the middle and lower reaches of the Changjiang River.展开更多
This paper discusses the role of geologic structures in the occurrence of floods and how to prevent flood in the middle reaches of the Yangtze River, and gives the author's suggestion that the Luoshan Qiakou be ex...This paper discusses the role of geologic structures in the occurrence of floods and how to prevent flood in the middle reaches of the Yangtze River, and gives the author's suggestion that the Luoshan Qiakou be expanded and the land reclaimed from Dongting Lake be returned to the lake in compliance with the law of geology.展开更多
Three stochastic mathematical models for calculation of the reservoir flood regulation process, river course flood release, and flood risk rate under flood control were established based on the theory of stochastic di...Three stochastic mathematical models for calculation of the reservoir flood regulation process, river course flood release, and flood risk rate under flood control were established based on the theory of stochastic differential equations and features of flood control systems in the middle reach of the Huaihe River from Xixian to the Bengbu floodgate, comprehensively considering uncertain factors of hydrology, hydraulics, and engineering control. They were used to calculate the flood risk rate with flood regulation of five key reservoirs, including the Meishan, Xianghongdian, Nianyushan, Mozitan, and Foziling reservoirs in the middle reach of the Huaihe River under different flood frequencies, the flood risk rate with river course flood release under design and check floods for the trunk of the Huaihe River in conjunction with relevant flood storage areas, and the flood risk rate with operation of the Linhuaigang Project under design and check floods. The calculated results show that (l) the five reservoirs can withstand design floods, but the Xianghongdian and Foziling reservoirs will suffer overtopping accidents under check floods; (2) considering the service of flood storage areas under the design flood conditions of the Huaihe River, the mean flood risk rate with flood regulation of dykes and dams from Xixian to the Bengbu floodgate is about 0.2, and the trunk of the Huaihe River can generally withstand design floods; and (3) under a check flood with the flood return period of 1 000 years, the risk rate of overtopping accidents of the Linhuaigang Project is not larger than 0.15, indicating that it has a high flood regulation capacity. Through regulation and application of the flood control system of the Linhuigang Project, the Huaihe River Basin can withstand large floods, and the safety of the protected area can be ensured.展开更多
The present paper shows that a seasonal prediction for the large scale flooding and waterlogging of the mid-lower Yangtze/ Huaihe River basins in the summer of 1991 made successfully in early April 1991.The seasonal f...The present paper shows that a seasonal prediction for the large scale flooding and waterlogging of the mid-lower Yangtze/ Huaihe River basins in the summer of 1991 made successfully in early April 1991.The seasonal forecasting method and some predictors are also introduced and analyzed herein. Because the extra extent of the abnormally early onset of the plum rain period in 1991 was unexpected,great efforts have been made to find out the causes of this abnormality. These causes are mainly associated with the large scale warming of SST surrounding the south and east part of Asia during the preceding winter,while the ENSO-like pattern of SSTA occurred in the North Pacific.In addition,the possible influence of strong solar proton events is analyzed.In order to improve the seasonal pre4iction the usage of the predicted SOl in following spring/summer is also introduced.The author believes thatthe regional climate anomaly can be correctly predicted for one season ahead only on the basis of physical understanding of the interactions of many preceding factors.展开更多
Taking the rainstorm flood disaster of Huaihe River basin as the research object,according to the principles of risk assessment for natural disasters,starting from the fatalness of inducing factors and the vulnerabili...Taking the rainstorm flood disaster of Huaihe River basin as the research object,according to the principles of risk assessment for natural disasters,starting from the fatalness of inducing factors and the vulnerability of hazard bearing body,the weight of each impact factor was calculated by using AHP. By using spatial analysis and statistical function of GIS,the integrated risk chart of rainstorm flood disaster in Huaihe River basin was obtained. The results showed that the high risk areas of rainstorm flood disaster in Huaihe River basin mainly distributed in the southern part of Henan,the central northern part of Anhui and eastern part of Jiangsu Province. Due to higher fatalness of inducing factors in southern Henan,there was high risk in the region. Central Anhui and east Jiangsu were not only high-fatalness zones but also high vulnerability zones of population and economy.展开更多
In this paper, we investigated the potential of Advanced Microwave Scanning Radiometer for Earth Observation System (AMSR-E) for flood monitoring. The proposed approach was based on the polarized ratio index (PRI), wh...In this paper, we investigated the potential of Advanced Microwave Scanning Radiometer for Earth Observation System (AMSR-E) for flood monitoring. The proposed approach was based on the polarized ratio index (PRI), which was computed by using AMSR-E data at 37GHz, vertically and horizontally polarized brightness temperature values and the water surface fraction (WSF) got by using the PRI at 37GHz. Moderate Resolution Imaging Spectrora-diometer (MODIS) data were used to validate the WSF values. The analysis of flood and waterlogging using the WSF map on July 6, 2003 indicates that the use of WSF for flood and waterlogging disaster assessment is feasible. Utilizing the correlation of WSF derived from AMSR-E and water area derived from MODIS, the water area of the Huaihe River Basin were computed by only using AMSR-E data in the summer of 2003, which overcame the influence of cloud on water estimation using MODIS data during flood.展开更多
By means of analysing the historical data of flood-drought grade series in the past 2000 years(A.D.0-1900),especially in the last 5000 years (1470-1900) , this paper revealed the spatial-temporaldistribution features ...By means of analysing the historical data of flood-drought grade series in the past 2000 years(A.D.0-1900),especially in the last 5000 years (1470-1900) , this paper revealed the spatial-temporaldistribution features of severe flood and drought in Yellow River Valley. Statistical methods of varianceanalysis, probability transition and the principles of scale correspondence were employed tocomprehensively predicate 90's tendency of severe flood and drought in the Yellow River Valley. In addi-tion, this paper pointed out the possible breaching dikes, sectors and the flooding ranges by future's se-vere flood, meanwhile estimating the associated economic losses and impact to environment.展开更多
Based on the summer precipitation data from the Huaihe River valley and the middle and lower reaches of the Yangtze River from 1922 to 2007,we analyzed the interannual and interdecadal oscillation and probability dist...Based on the summer precipitation data from the Huaihe River valley and the middle and lower reaches of the Yangtze River from 1922 to 2007,we analyzed the interannual and interdecadal oscillation and probability distribution characteristics of summer precipitation in the Huaihe River valley during the same period,using the wavelet transform and generalized extreme distribution methods.Whereby,we studied the climate background of East Asia Summer Monsoon (EASM),Sea Surface Temperature (SST),East Asia telecorrelation circulation,and their relationship with the interannual and interdecadal oscillation of summer precipitation in the Huaihe River valley.We further compared the difference of interdecadal oscillation of summer precipitation and the relevant climate background between the Huaihe River valley and the middle and lower reaches of the Yangtze River.The results show that:1) The intensity change of quasi-biennial oscillation (QBO) of summer precipitation in the Huaihe River valley is consistent with that of interdecadal oscillation.The summer precipitation in the Huaihe River valley has been more than normal since the end of the 1990s,and the QBO is very significant.Meanwhile,the probability of occurrence of extreme heavy rainfall increased obviously.2) The interdecadal oscillation of summer precipitation in the Huaihe River valley has a close relationship with the Pacific Decadal Oscillation (PDO) and interdecadal oscillation of EASM.When PDO is in the cold phase and EASM weakens,the summer precipitation will be greater than normal.3) QBO of summer precipitation in the Huaihe River valley is mainly controlled by that of EASM,and it has a relationship with a circulation pattern of "positive-negative-positive" from the high to the low latitudes in East Asia.4) There is interdecadal phase difference in summer precipitation between the Huaihe River valley and the middle and the lower reaches of the Yangtze River,which is mainly related to the intensity and position of West Pacific subtropical high.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 of RYEPEs...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 km^2as simulated by the Flood Area 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(RCP8.5)scenario,the built-up area increases at a rate of about 10.41 km^2(10 yr)^(-1)(24.67 km^2(10 yr)^(-1))from 2010 to 2100,and the area of high flood risk correspondingly increases from 3.86 km^2(3.86 km^2)to 9.00 km^2(13.51 km^2).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
基金supported by the National Natural Science Foundation of China(Grant No.40925015)the National Program on Key Basic Research Project(Grant Nos.2010CB950403and2012CB417203)
文摘The significant differences of atmospheric circulation between flooding in the Huaihe and Yangtze River valleys during early mei-yu (i.e., the East Asian rainy season in June) and the related tropical convection were investigated. During the both flooding cases, although the geopotential height anomalies always exhibit equivalent barotropic structures in middle to high latitudes at middle and upper troposphere, the phase of the Rossby wave train is different over Eurasian continent. During flooding in the Huaihe River valley, only one single blocking anticyclone is located over Baikal Lake. In contrast, during flooding in the Yangtze River valley, there are two blocking anticyclones. One is over the Ural Mountains and the other is over Northeast Asia. In the lower troposphere a positive geopotential height anomaly is located at the western ridge of subtropical anticyclone over Western Pacific (SAWP) in both flooding cases, but the location of the height anomaly is much farther north and west during the Huaihe River mei-yu flooding. Fhrthermore, abnormal rainfall in the Huaihe River valley and the regions north of it in China is closely linked with the latent heating anomaly over the Arabian Sea and Indian peninsula. However, the rainfall in the Yangtze River valley and the regions to its south in China is strongly related to the convection over the western tropical Pacific. Numerical experiments demonstrated that the enhanced latent heating over the Arabian Sea and Indian peninsula causes water vapor convergence in the region south of Tibetan Plateau and in the Huaihe River valley extending to Japan Sea with enhanced precipitation; and vapor divergence over the Yangtze River valley and the regions to its south with deficient precipitation. While the weakened convection in the tropical West Pacific results in moisture converging over the Yangtze River and the region to its south, along with abundant rainfall.
基金This study was supported by the "National Key Programme for Developing Basic Science" projects under Grant No. 2004CB418303the National Natural Science Foundation of China under Grant No. 40705022.
文摘Using daily outgoing long-wave radiation (OLR) data from the National Oceanic and Atmospheric Administration (NOAA) and the National Center for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) reanalysis data of geopotential height fields for 1979-2006, the relationship between persistent heavy rain events (PHREs) in the Huaihe River valley (HRV) and the distribution pattern of convective activity in the tropical western Pacific warm pool (WPWP) is investigated. Based on nine cases of PHREs in the HRV, common characteristics of the West Pacific subtropical high (WPSH) show that the northern edge of the WPSH continues to lie in the HRV and is associated with the persistent "north weak south strong" distribution pattern of convective activities in the WPWP. Composite analysis of OLR leading the circulation indicates that the response of the WPSH to OLR anomaly patterns lags by about 1-2 days. In order to explain the reason for the effects of the distribution pattern of convective activities in the WPWP on the persistent northern edge of the WPSH in the HRV, four typical persistent heavy and light rain events in the Yangtze River valley (YRV) are contrasted with the PHREs in the HRV. The comparison indicates that when the distribution pattern of the convective activities anomaly behaves in a weak (strong) manner across the whole WPWP, persistent heavy (light) rain tends to occur in the YRV. When the distribution pattern of the convective activities anomaly behaves according to the "north weak south strong" pattern in the WPWP, persistent heavy rain tends to occur in the HRV. The effects of the "north weak south strong" distribution pattern of convective activities on PHREs in the HRV are not obvious over the seasonal mean timescale, perhaps due to the non-extreme status of convective activities in the WPWP.
基金the"National Key Programme for Developing Basic Sciences"--Research on the Formation Mechanism and Prediction Theory of Severe Climate Disasters in China(G1998040900)the National Natrual Science Foundation of China under Grant No.40135020the Project ZKCX2-SW-2t0
文摘With the IAP/LASG GOALS model, the relationships between the floods in the Yangtze River valley arid sea surface temperature anomalies (SSTA) in the Pacific and Indian Oceans in 1998 have been studied. The results show that the model can reproduce the heavy rainfall over the Yangtze River valley in the sum-mer of 1998 forced by global observational sea surface temperatures (SST). The model can also reproduce the observed principal features of the subtropical high anomalies over the western Pacific. The experiments with the observed SST in different ocean areas and different periods have been made. By comparing the ef-fects of SSTA of different ocean areas on the floods, it is found that the SSTA in the Indian Ocean are a ma-jor contributor to the floods, and the results also show that the SSTA in the Indian Ocean and the western Pacific have a much closer relationship with the strong anomalies of the subtropical high over the western Pacific than the SSTA in other concerned areas. The study also indicates that the floods and subtropical high anomalies in the summer of 1998 are more controlled by the simultaneous summertime SSTA than by SSTA in the preceding winter and spring seasons.
基金Supported by Meteorological Open Research Fund of Huaihe River basin,China(HRM200805)Soft Science Research Plan of Ministry of Science and Technology,China(2007GXS3D087)
文摘[Objective] The research aimed to analyze temporal and spatial variation of strong precipitation caused flood and agricultural disaster loss in Huaihe River basin of Anhui Province during Meiyu period of 2007.[Method] On the basis of rainfalls of each station in Huaihe River basin of Anhui,rainfall data during Meiyu period of 2007 and flood disaster data in the same period,the temporal and spatial distribution characteristics of strong precipitation caused flood during Meiyu period of 2007 and its harm on agriculture were analyzed.The variation rule,distribution characteristics of strong precipitation during Meiyu period in Huaihe River basin of Anhui and its relationship with agricultural disaster loss were discussed.[Result] During Meiyu period of 2007 in Huaihe River basin of Anhui,the rainstorm was more,and the rainfall was large.The precipitation variation showed 'three-peak' trend.Rainfall in Huaihe River basin during Meiyu period of 2007 was greatly more than that homochronously in Yangtze River basin.The rain area over 400.0 mm during Meiyu period mainly located in Huaihe River basin,and the rain area over 600.0 mm mainly located from area along Huaihe River to central Huaibei.The rainfall during Meiyu period gradually decreased toward south and north by the north bank of Huaihe River as the symmetry axis.The rainfall in area along Huaihe River showed wavy distribution in east-west direction.The flood disaster loss index and disaster area of crops in Huaihe River basin of Anhui both increased as rainfall in Meiyu period.[Conclusion] The research provided theoretical basis for flood prevention,disaster reduction and agricultural flood-avoiding development in Huaihe River basin.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant No. XDA05110202)the National Natural Science Foundation of China (Grant Nos. 41175073, 41471016, and U1133603)
文摘A hydrological simulation in the Huaihe River Basin(HRB) was investigated using two different models: a coupled land surface hydrological model(CLHMS), and a large-scale hydrological model(LSX-HMS). The NCEP-NCAR reanalysis dataset and observed precipitation data were used as meteorological inputs. The simulation results from both models were compared in terms of flood processes forecasting during high flow periods in the summers of 2003 and 2007, and partial high flow periods in 2000. The comparison results showed that the simulated streamflow by CLHMS model agreed well with the observations with Nash-Sutcliffe coefficients larger than 0.76, in both periods of 2000 at Lutaizi and Bengbu stations in the HRB, while the skill of the LSX-HMS model was relatively poor. The simulation results for the high flow periods in 2003 and 2007 suggested that the CLHMS model can simulate both the peak time and intensity of the hydrological processes, while the LSX-HMS model provides a delayed flood peak. These results demonstrated the importance of considering the coupling between the land surface and hydrological module in achieving better predictions for hydrological processes, and CLHMS was proven to be a promising model for future applications in flood simulation and forecasting.
基金supported by project GYHY201106050the National"973"Program of China under Grant No.2011CB403404,and Project No.2009Y002
文摘To comprehensively investigate characteristics of summer droughts and floods in the Yangtze River valley, a meteorological and hydrological coupling index (MHCI) was developed using meteorological and hydro- logical data. The results indicate that: (1) in representing drought/flood information for the Yangtze River valley, the MHCI can reflect composite features of precipitation and hydrological observations; (2) compre- hensive analysis of the interannual phase difference of the precipitation and hydrological indices is important to recognize and predict annual drought/flood events along the valley; the hydrological index contributes more strongly to nonlinear and continuity features that indicate transition from long-term drought to flood conditions; (3) time series of the MHCI from 1960-2009 are very effective and sensitive in reflecting annual drought/flood characteristics, i.e. there is more rainfall or typical flooding in the valley when the MHCI is positive, and vice versa; and (4) verification of the MHCI indicates that there is significant correlation between precipitation and hydrologic responses in the valley during summer; the correlation coefficient was found to reach 0.82, exceeding the 0.001 significance level.
文摘According to historical records, there are 264 drought and flood years, occurred in the upper and middle reaches of the Changjiang (Yangtze) River during last 1020 years from 961 to 1980. The evolutionary law and developing trend of drought and flood years are studied. The distribution of drought and flood years are non-uniform and the dry and flood seasons in a year are concentrated. At the angle of monsoon circulation, at present the climate in the upper and middle reaches of the Changjiang River is just in the late stage of frequent drought period and the early stage of least flood period. In addition, the cycle of drought and flood and the feature of drought and flood occurred in the upper, middle and lower reaches of the Changjiang River are analyzed. It shows that the short period less than 10 years is in the majority, and the drought and flood occurred most frequently in the middle and lower reaches of the Changjiang River.
文摘This paper discusses the role of geologic structures in the occurrence of floods and how to prevent flood in the middle reaches of the Yangtze River, and gives the author's suggestion that the Luoshan Qiakou be expanded and the land reclaimed from Dongting Lake be returned to the lake in compliance with the law of geology.
基金supported by the National Natural Science Foundation of China(Grant No.51139001)
文摘Three stochastic mathematical models for calculation of the reservoir flood regulation process, river course flood release, and flood risk rate under flood control were established based on the theory of stochastic differential equations and features of flood control systems in the middle reach of the Huaihe River from Xixian to the Bengbu floodgate, comprehensively considering uncertain factors of hydrology, hydraulics, and engineering control. They were used to calculate the flood risk rate with flood regulation of five key reservoirs, including the Meishan, Xianghongdian, Nianyushan, Mozitan, and Foziling reservoirs in the middle reach of the Huaihe River under different flood frequencies, the flood risk rate with river course flood release under design and check floods for the trunk of the Huaihe River in conjunction with relevant flood storage areas, and the flood risk rate with operation of the Linhuaigang Project under design and check floods. The calculated results show that (l) the five reservoirs can withstand design floods, but the Xianghongdian and Foziling reservoirs will suffer overtopping accidents under check floods; (2) considering the service of flood storage areas under the design flood conditions of the Huaihe River, the mean flood risk rate with flood regulation of dykes and dams from Xixian to the Bengbu floodgate is about 0.2, and the trunk of the Huaihe River can generally withstand design floods; and (3) under a check flood with the flood return period of 1 000 years, the risk rate of overtopping accidents of the Linhuaigang Project is not larger than 0.15, indicating that it has a high flood regulation capacity. Through regulation and application of the flood control system of the Linhuigang Project, the Huaihe River Basin can withstand large floods, and the safety of the protected area can be ensured.
文摘The present paper shows that a seasonal prediction for the large scale flooding and waterlogging of the mid-lower Yangtze/ Huaihe River basins in the summer of 1991 made successfully in early April 1991.The seasonal forecasting method and some predictors are also introduced and analyzed herein. Because the extra extent of the abnormally early onset of the plum rain period in 1991 was unexpected,great efforts have been made to find out the causes of this abnormality. These causes are mainly associated with the large scale warming of SST surrounding the south and east part of Asia during the preceding winter,while the ENSO-like pattern of SSTA occurred in the North Pacific.In addition,the possible influence of strong solar proton events is analyzed.In order to improve the seasonal pre4iction the usage of the predicted SOl in following spring/summer is also introduced.The author believes thatthe regional climate anomaly can be correctly predicted for one season ahead only on the basis of physical understanding of the interactions of many preceding factors.
文摘Taking the rainstorm flood disaster of Huaihe River basin as the research object,according to the principles of risk assessment for natural disasters,starting from the fatalness of inducing factors and the vulnerability of hazard bearing body,the weight of each impact factor was calculated by using AHP. By using spatial analysis and statistical function of GIS,the integrated risk chart of rainstorm flood disaster in Huaihe River basin was obtained. The results showed that the high risk areas of rainstorm flood disaster in Huaihe River basin mainly distributed in the southern part of Henan,the central northern part of Anhui and eastern part of Jiangsu Province. Due to higher fatalness of inducing factors in southern Henan,there was high risk in the region. Central Anhui and east Jiangsu were not only high-fatalness zones but also high vulnerability zones of population and economy.
基金Under the auspices of the Foundation of the Ministry of Science and Technology (No 2003DKA1T007, No 2005DFA20010)
文摘In this paper, we investigated the potential of Advanced Microwave Scanning Radiometer for Earth Observation System (AMSR-E) for flood monitoring. The proposed approach was based on the polarized ratio index (PRI), which was computed by using AMSR-E data at 37GHz, vertically and horizontally polarized brightness temperature values and the water surface fraction (WSF) got by using the PRI at 37GHz. Moderate Resolution Imaging Spectrora-diometer (MODIS) data were used to validate the WSF values. The analysis of flood and waterlogging using the WSF map on July 6, 2003 indicates that the use of WSF for flood and waterlogging disaster assessment is feasible. Utilizing the correlation of WSF derived from AMSR-E and water area derived from MODIS, the water area of the Huaihe River Basin were computed by only using AMSR-E data in the summer of 2003, which overcame the influence of cloud on water estimation using MODIS data during flood.
文摘By means of analysing the historical data of flood-drought grade series in the past 2000 years(A.D.0-1900),especially in the last 5000 years (1470-1900) , this paper revealed the spatial-temporaldistribution features of severe flood and drought in Yellow River Valley. Statistical methods of varianceanalysis, probability transition and the principles of scale correspondence were employed tocomprehensively predicate 90's tendency of severe flood and drought in the Yellow River Valley. In addi-tion, this paper pointed out the possible breaching dikes, sectors and the flooding ranges by future's se-vere flood, meanwhile estimating the associated economic losses and impact to environment.
基金supported by State Key Laboratory of Severe Weather,Chinese Academy of Meteorological Sciences,COPES Program (Grant No.GYHY200706005)China-Japan Intergovernmental Cooperation Program from Japan International Cooperation Agency (JICA)
文摘Based on the summer precipitation data from the Huaihe River valley and the middle and lower reaches of the Yangtze River from 1922 to 2007,we analyzed the interannual and interdecadal oscillation and probability distribution characteristics of summer precipitation in the Huaihe River valley during the same period,using the wavelet transform and generalized extreme distribution methods.Whereby,we studied the climate background of East Asia Summer Monsoon (EASM),Sea Surface Temperature (SST),East Asia telecorrelation circulation,and their relationship with the interannual and interdecadal oscillation of summer precipitation in the Huaihe River valley.We further compared the difference of interdecadal oscillation of summer precipitation and the relevant climate background between the Huaihe River valley and the middle and lower reaches of the Yangtze River.The results show that:1) The intensity change of quasi-biennial oscillation (QBO) of summer precipitation in the Huaihe River valley is consistent with that of interdecadal oscillation.The summer precipitation in the Huaihe River valley has been more than normal since the end of the 1990s,and the QBO is very significant.Meanwhile,the probability of occurrence of extreme heavy rainfall increased obviously.2) The interdecadal oscillation of summer precipitation in the Huaihe River valley has a close relationship with the Pacific Decadal Oscillation (PDO) and interdecadal oscillation of EASM.When PDO is in the cold phase and EASM weakens,the summer precipitation will be greater than normal.3) QBO of summer precipitation in the Huaihe River valley is mainly controlled by that of EASM,and it has a relationship with a circulation pattern of "positive-negative-positive" from the high to the low latitudes in East Asia.4) There is interdecadal phase difference in summer precipitation between the Huaihe River valley and the middle and the lower reaches of the Yangtze River,which is mainly related to the intensity and position of West Pacific subtropical high.
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 km^2as simulated by the Flood Area 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(RCP8.5)scenario,the built-up area increases at a rate of about 10.41 km^2(10 yr)^(-1)(24.67 km^2(10 yr)^(-1))from 2010 to 2100,and the area of high flood risk correspondingly increases from 3.86 km^2(3.86 km^2)to 9.00 km^2(13.51 km^2).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.