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Shrinkage of estuarine channels in the Haihe basin and control strategies
Published in Zhao-Yin Wang, Shi-Xiong Hu, Stochastic Hydraulics 2000, 2020
Hu Shixiong, Wang Gang, Wang Zhaoyin
The Yellow River had been entered the Bohai Bay from the the Haihe River Mouth three times in the ancient time (AD1048-1128). The Yongding River, one of main tributaries in the Haihe Basin is also famous for its abundant sediment. The sediment from the rivers formed the river mouth bar and the shallow beach in the past. The data from the Huanghua Harbor shows the modern Yellow River sediment can be transported to the south of the Dakou river mouth, but impossible to the Haihe River Mouth. It is similar the analysis of the Yellow River Commission of China. The sediment source of Haihe River Mouth can not be from the north because of the wave breaker of the Tianjin Harbor. The sediment deposit in the mid of the Bohai Bay can not be initiated and does not affect the river mouths. Therefore, the deposit in the local shallow beach, and sediment from coast erosion are main sources of sediment in the estuarine channel.
Dynamic state of river-mouth bar in the Yuragawa River and its control under flood flow conditions
Published in Silke Wieprecht, Stefan Haun, Karolin Weber, Markus Noack, Kristina Terheiden, River Sedimentation, 2016
H. Miwa, K. Kanda, T. Ochi, H. Kawaguchi
Figure 4 shows (a) the temporal variations in the area of the river-mouth bar, (b) the significant wave height at Kyoga-Misaki (30 km far from the river-mouth) and (c) the water discharge at Fukuchiyama for 5 years and 8 months (from May 2010 to December 2015). The datum level was the sea surface at each measurement time, and there was no correction of the datum level because the tidal range was at most 30 cm. The river-mouth bar on the left bank has developed since December 2012 (The survey was started in March 2013). In Figure 4(a), the area of the bar on the right bank shows increases and decreases in the short term, whereas it gradually decreases as a long term tendency. The decreasing rate of the area for four years is approximately 40%. From the short term tendency, it can be seen that the area increased in the winter seasons of 2010, 2012 and 2013, and it decreased in the rainy and summer seasons of 2011 and 2013. As shown in Figure 4(b), Kanda et al. (2012) clarified that the significant wave height over 2.55 m influences the development of the river-mouth bar. Therefore, it can be considered that an increase in the onshore sediment transport may contribute to the increase of the area of the river-mouth bar. A possible reason why the area did not increase in the winter season of 2011 is that the onshore transported sediment from the foreshore may be accumulated on the seabed, where it was eroded by the flood flow in the fall season of 2011. On the other hand, as shown in Figure 4(c), the water discharge over 1,500 m3/s was recorded a total of four times in the summer seasons of 2011 and 2013. In particular, the flood with discharge of about 5,500 m3/s occurred due to the typhoon No.18 in September 2013. The area of the bar was reduced by 17% in 2011 and by 40% in 2013 due to these large flood discharges. Moreover, it is found that the area was gradually reduced in the spring to fall seasons of 2012. The water discharge of 300m3/s classes had frequently occurred during these seasons, these flows might have eroded the river-mouth bar.
Refining the depositional model of the lower Permian Carynginia Formation in the northern Perth Basin: anatomy of an ancient mouth bar
Published in Australian Journal of Earth Sciences, 2022
A. Dillinger, R. Vaucher, D. W. Haig
The lower part of the lower Permian Carynginia Formation records marginal-marine sedimentation during a short-lived cold episode in Western Australia. A previously overlooked, sandstone-rich succession of the otherwise mudstone-prone Carynginia Formation near the cratonic margin of the northern Perth Basin provides new sedimentological and stratigraphic insights into the depositional setting and local paleogeography in the basin. The Woolaga Creek section constitutes the record of (i) storm-dominated lower-shoreface deposition in an area that was shallower than other well-studied sections in the region and (ii) a low-relief mouth bar that formed part of a northwest-prograding, river-dominated delta lobe. These deltaic deposits provide direct evidence of river processes in the Carynginia Formation. Anatomy of the mouth-bar sandstone body indicates that deposition was controlled by high-discharge sediment-laden pulses and their associated waning flows that generated rapidly expanding plumes owing to friction onto the shallow, low-gradient seafloor of the receiving basin. Construction of the delta was driven by seasonal runoff of a meltwater-fed fluvial system that presumably delivered sediment northward across the cratonic margin of the Perth Basin and into the Irwin Sub-basin. Freshwater, sediment-laden influxes into the shallow seaway were likely responsible for particularly stressed physico-chemical conditions adverse to faunal development and diversification. A fluvial influence may explain the sedimentary character and fossil content of other mudstone-prone formations in coeval Western Australian rift basins close to cratonic margins.