The stratigraphical cross-sections of the Yangtze River incised-valley near the No.l, No.3 and No.4 Nanjing Yangtze River bridges were established with respective bore date and documents. By ^14C age analysis of the s...The stratigraphical cross-sections of the Yangtze River incised-valley near the No.l, No.3 and No.4 Nanjing Yangtze River bridges were established with respective bore date and documents. By ^14C age analysis of the samples of four drilling cores near the No.4 Bridge （to be built）, we can find that the time range of paleo-valley is dated in the LGM at a depth of-60 m to -90 m near Nanjing. It is also indicated that the deep incised-valley channel was narrow and the river flowed swiftly. The ancient Yangtze River deep channel presented partially and deeply incised features near the No.1 Bridge. According to previous publications, much research has been done on the main paleo-channel of the Yangtze River, but few results have been achieved on discharge estimation. In this paper, the incipient velocity and average veIocity of the LGM was calculated with Vc=4.60d^1/3h^1/6, Vc=1.281g（ 13.15. h /d95） √gd, V≈6.5u＊｜h/d90｜^1/6 etc., in terms of the river shape, sedimentary grain size and sequences near the No.3 and No.1 bridges. Moreover, the discharge in Nanjing reach of the Yangtze River during the LGM has been estimated to be around 12,000-16,000 m^3/s according to the relationship of discharge, velocity of flow and cross-section.展开更多
-On the basis of the data obtained from the investigations on some rivers in China and Australia, the author discusses the spatial and temporal changes of various portions of fluvial-estuarine system during postglacia...-On the basis of the data obtained from the investigations on some rivers in China and Australia, the author discusses the spatial and temporal changes of various portions of fluvial-estuarine system during postglacial sea-level rising in present coastal and deltaic areas. The evolution of a fluvial-estuarine system can be divided into four development stages: early transgression, late transgression, stationary and regression. Early transgression brought about filling-in of the paleo-valley formed in low stand of sea level. In response to late transgression the estuaries were created, during the stationary stage the big swamp was developed. The regression led to estuaries to be filled with sediments and then became deltas. At the same locality the fluvial-estuarine system changed with time. In the transgressive period the lower reach of a river changed into an estuary, and then became nearshore area. In the regressive period the nearshore area changed into an estuary , and then became delta.展开更多
基金National Basic Research Program of China, No.2003CB415201-8 National Natural Science Foundation of China. No.40871010 Doctorate Foundation of Linyi Normal University, No.BS08021
文摘The stratigraphical cross-sections of the Yangtze River incised-valley near the No.l, No.3 and No.4 Nanjing Yangtze River bridges were established with respective bore date and documents. By ^14C age analysis of the samples of four drilling cores near the No.4 Bridge （to be built）, we can find that the time range of paleo-valley is dated in the LGM at a depth of-60 m to -90 m near Nanjing. It is also indicated that the deep incised-valley channel was narrow and the river flowed swiftly. The ancient Yangtze River deep channel presented partially and deeply incised features near the No.1 Bridge. According to previous publications, much research has been done on the main paleo-channel of the Yangtze River, but few results have been achieved on discharge estimation. In this paper, the incipient velocity and average veIocity of the LGM was calculated with Vc=4.60d^1/3h^1/6, Vc=1.281g（ 13.15. h /d95） √gd, V≈6.5u＊｜h/d90｜^1/6 etc., in terms of the river shape, sedimentary grain size and sequences near the No.3 and No.1 bridges. Moreover, the discharge in Nanjing reach of the Yangtze River during the LGM has been estimated to be around 12,000-16,000 m^3/s according to the relationship of discharge, velocity of flow and cross-section.
文摘-On the basis of the data obtained from the investigations on some rivers in China and Australia, the author discusses the spatial and temporal changes of various portions of fluvial-estuarine system during postglacial sea-level rising in present coastal and deltaic areas. The evolution of a fluvial-estuarine system can be divided into four development stages: early transgression, late transgression, stationary and regression. Early transgression brought about filling-in of the paleo-valley formed in low stand of sea level. In response to late transgression the estuaries were created, during the stationary stage the big swamp was developed. The regression led to estuaries to be filled with sediments and then became deltas. At the same locality the fluvial-estuarine system changed with time. In the transgressive period the lower reach of a river changed into an estuary, and then became nearshore area. In the regressive period the nearshore area changed into an estuary , and then became delta.
