[Objective] The research aimed to analyze the variations of rainstorm frequency, intensity and period in the flood season in Guangzhou. [Method] Based on the daily precipitation data in Guangzhou City during 1951-2010...[Objective] The research aimed to analyze the variations of rainstorm frequency, intensity and period in the flood season in Guangzhou. [Method] Based on the daily precipitation data in Guangzhou City during 1951-2010, the interannual and interdecadal variation characteristics of rainstorm in the flood season in recent 60 years were analyzed by using the linear regression analysis, correlation analysis, wavelet analysis and so on. Moreover, the relationship between the rainstorm in the flood season and annual average temperature was analyzed. [Result] In recent 60 years, the rainstorm amount and days in the flood season in Guangzhou respectively increased with 6.23 mm/10 a and 0.27 d/10 a linear trends. The most rainstorm days (rainfall) was in 2001 and was 15 d (1 085.7 mm). There was no rainstorm in the least year (1990). The interannual variations of rainstorm amount and days in the flood season in Guangzhou obviously increased in recent 20 years. The decadal and interannual variations of rainstorm in the prior and latter flood seasons had the difference. The trend in the prior flood season increased and in the latter flood season slightly decreased. The positive correlation between the rainstorm days and the annual average temperature in the flood season in Guangzhou was significant, and the relative coefficient was 0.22, which passed α=0.02 significance level test. The total rainstorm days in the prior flood season in Guangzhou City mainly had 4.2-year interannual and 52.9-year interdecadal periodic variations. The total rainstorm days in the latter flood season mainly had 5.5-year interannual and 18.4-year interdecadal periodic variations. [Conclusion] The research provided the scientific basis for the precipitation forecast in the flood season.展开更多
The lower Yellow River still faces the threat of flood due to the unusual precipitation caused by global environmental change, river channel sedimentation, hidden danger in the dike and unfavorable river regime of ＂h...The lower Yellow River still faces the threat of flood due to the unusual precipitation caused by global environmental change, river channel sedimentation, hidden danger in the dike and unfavorable river regime of ＂hanging river＂. According to the characteristics of the dike-break flood of the Yellow River, this paper has simulated, in six different scenarios, the dike-break flood routing by inputting the terrain data, typical historical flood data and land use data of study area to two-dimensional unsteady flow model. The results show that： firstly, the routing process of flood will occupy other rivers on the way and return to the rivers after reaching the lower reaches; secondly, in the same river reach, flood inundating area of north band is bigger than that at corresponding location of south bank under the same historical flood; thirdly, it is different in the degree of flood inundation in different regions due to different geographical locations in flood plain; fourthly, the area of mainstream where flood is deep and flow velocity is quick is relatively smaller, but the area of non-mainstream, where flood is shallow and flow velocity is slow, is relatively big; and finally, the possible influenced area of the dike-break flood is 141,948 km^2.展开更多
on January 5, a consortium composed of Hong Kong-listed Kerry Properties Ltd., Shangri-La Asia Ltd. and Singapore-listed Wilmar International Ltd. announced their success in
After having completed river regulation work in recent years, the dike distance up the reach of Lutaizi has been extended to 1.5 2.0 km in the Huaihe river. When the middle flood happened,such as those in 1956, 1982 ...After having completed river regulation work in recent years, the dike distance up the reach of Lutaizi has been extended to 1.5 2.0 km in the Huaihe river. When the middle flood happened,such as those in 1956, 1982 and 1991, flood can pass through safely. If the flood of 1% frequency happens, the flood discharge at Lutaizi will be larger than safe flood discharge 10000 m 3/s in downstream Lutaizi. By storing flood with the Linhuaigang sluice, the discharge of Lutaizi will not be over 10000 m 3/s. Cities in downstream Lutaizi will be free from flood.展开更多
文摘[Objective] The research aimed to analyze the variations of rainstorm frequency, intensity and period in the flood season in Guangzhou. [Method] Based on the daily precipitation data in Guangzhou City during 1951-2010, the interannual and interdecadal variation characteristics of rainstorm in the flood season in recent 60 years were analyzed by using the linear regression analysis, correlation analysis, wavelet analysis and so on. Moreover, the relationship between the rainstorm in the flood season and annual average temperature was analyzed. [Result] In recent 60 years, the rainstorm amount and days in the flood season in Guangzhou respectively increased with 6.23 mm/10 a and 0.27 d/10 a linear trends. The most rainstorm days (rainfall) was in 2001 and was 15 d (1 085.7 mm). There was no rainstorm in the least year (1990). The interannual variations of rainstorm amount and days in the flood season in Guangzhou obviously increased in recent 20 years. The decadal and interannual variations of rainstorm in the prior and latter flood seasons had the difference. The trend in the prior flood season increased and in the latter flood season slightly decreased. The positive correlation between the rainstorm days and the annual average temperature in the flood season in Guangzhou was significant, and the relative coefficient was 0.22, which passed α=0.02 significance level test. The total rainstorm days in the prior flood season in Guangzhou City mainly had 4.2-year interannual and 52.9-year interdecadal periodic variations. The total rainstorm days in the latter flood season mainly had 5.5-year interannual and 18.4-year interdecadal periodic variations. [Conclusion] The research provided the scientific basis for the precipitation forecast in the flood season.
基金The State Scientific Research Plan, No.96-920-09-01
文摘The lower Yellow River still faces the threat of flood due to the unusual precipitation caused by global environmental change, river channel sedimentation, hidden danger in the dike and unfavorable river regime of ＂hanging river＂. According to the characteristics of the dike-break flood of the Yellow River, this paper has simulated, in six different scenarios, the dike-break flood routing by inputting the terrain data, typical historical flood data and land use data of study area to two-dimensional unsteady flow model. The results show that： firstly, the routing process of flood will occupy other rivers on the way and return to the rivers after reaching the lower reaches; secondly, in the same river reach, flood inundating area of north band is bigger than that at corresponding location of south bank under the same historical flood; thirdly, it is different in the degree of flood inundation in different regions due to different geographical locations in flood plain; fourthly, the area of mainstream where flood is deep and flow velocity is quick is relatively smaller, but the area of non-mainstream, where flood is shallow and flow velocity is slow, is relatively big; and finally, the possible influenced area of the dike-break flood is 141,948 km^2.
文摘on January 5, a consortium composed of Hong Kong-listed Kerry Properties Ltd., Shangri-La Asia Ltd. and Singapore-listed Wilmar International Ltd. announced their success in
文摘After having completed river regulation work in recent years, the dike distance up the reach of Lutaizi has been extended to 1.5 2.0 km in the Huaihe river. When the middle flood happened,such as those in 1956, 1982 and 1991, flood can pass through safely. If the flood of 1% frequency happens, the flood discharge at Lutaizi will be larger than safe flood discharge 10000 m 3/s in downstream Lutaizi. By storing flood with the Linhuaigang sluice, the discharge of Lutaizi will not be over 10000 m 3/s. Cities in downstream Lutaizi will be free from flood.
