scholarly journals Research on effects of geo-hydrodynamics on topographic changes in the estuary of Cua Dai, Quang Nam province

2019 ◽  
Vol 19 (3B) ◽  
pp. 105-112
Author(s):  
Dao Dinh Cham ◽  
Nguyen Quang Minh ◽  
Nguyen Thai Son ◽  
Tran Tuan Dung

Accretion and erosion processes recorded in the estuary of Cua Dai, Quang Nam province from 2014 to present have directly affected the issues of flooding drainage system, waterway traffic, aquaculture and seafood exploitation services. These have been drawing special attentions of national and international scientists. So far, several solutions are implemented to overcome these problems such as concreted embankments or dredging operations of the channel to open the sea. The solutions, however, are just temporary to solve immediate situations but not long-term. As a result of passive solutions, the shoreline is still seriously eroded and then the estuary of Cua Dai is re-accreted. Annually, Vietnam government and local offices still spend a large budget and time for recovering and minimizing the effects of such catastrophes without long-term effectiveness. One of the main causes of erosion and accretion of the Cua Dai estuary is hydrodynamic factors and the complex of sediment transportation. The results show that the northeast waves with high frequency and intensity in combination with floods during the Northeast monsoon are considered to be main causes. The accretion of estuary and formation of “Dinosaur island” in front of Cua Dai estuary is partly due to the combined sediment sources caused by the nearshore currents of northeast waves from the north direction and from the river by floods, especially the historical flood event in November, 2017.

2021 ◽  
Vol 13 (15) ◽  
pp. 8303
Author(s):  
Vu Tuan Anh ◽  
Pham Ba Trung ◽  
Kim-Anh Nguyen ◽  
Yuei-An Liou ◽  
Minh-Thu Phan

This paper aims to identify the causes and sources of erosion and deposition at small estuaries in southern central Vietnam under human intervention. The jetty built at the Tam Quan river mouth (Binh Dinh Province, Vietnam) serves as the base for the study. After its completion at the end of 2009, the hydrodynamic and erosion-deposition processes in the region have been significantly altered. Inside the estuary, the waves are not influenced, but the currents are increased during the ebb tide period and decreased during the flood tide timeframe. During the southwest monsoon, the jetty could cause an increase in the deposition process in both frequency and area, whereas the erosion process tends to narrow the area and increase the frequency on the north coast. In contrast, both deposition and erosion processes are increased on the southern coast. About 5859 m3 of sediments are deposited in the channel gate mainly by local sources. During the northeast monsoon, both deposition and erosion processes are located over a narrow area with frequency increased on the north coast, whereas the deposition process is narrowed with higher frequency on the southern coast. The total amount of sediment deposited at the estuary is 56,446 m3, of which 74.2% is from the onsite erosion material, 15.8% from the river and 10% from the longshore transportation. Generally, due to mainly erosion-deposition processes, sediment volume is accumulated during the northeast monsoon with amount 9.6 times more than that the southwest monsoon. The erosion-deposition processes are contributed to by poor practical management and local human activities inland and in the coastal regions, as well as the natural situation, resulting in serious impacts on society, the economy and the environment. Hence, the governance of the erosion-deposition processes and sediment load in small estuaries appear to contribute to the master plan for the local sustainable development of society and the economy.


2000 ◽  
Vol 179 ◽  
pp. 201-204
Author(s):  
Vojtech Rušin ◽  
Milan Minarovjech ◽  
Milan Rybanský

AbstractLong-term cyclic variations in the distribution of prominences and intensities of green (530.3 nm) and red (637.4 nm) coronal emission lines over solar cycles 18–23 are presented. Polar prominence branches will reach the poles at different epochs in cycle 23: the north branch at the beginning in 2002 and the south branch a year later (2003), respectively. The local maxima of intensities in the green line show both poleward- and equatorward-migrating branches. The poleward branches will reach the poles around cycle maxima like prominences, while the equatorward branches show a duration of 18 years and will end in cycle minima (2007). The red corona shows mostly equatorward branches. The possibility that these branches begin to develop at high latitudes in the preceding cycles cannot be excluded.


Author(s):  
Federico Varese

Organized crime is spreading like a global virus as mobs take advantage of open borders to establish local franchises at will. That at least is the fear, inspired by stories of Russian mobsters in New York, Chinese triads in London, and Italian mafias throughout the West. As this book explains, the truth is more complicated. The author has spent years researching mafia groups in Italy, Russia, the United States, and China, and argues that mafiosi often find themselves abroad against their will, rather than through a strategic plan to colonize new territories. Once there, they do not always succeed in establishing themselves. The book spells out the conditions that lead to their long-term success, namely sudden market expansion that is neither exploited by local rivals nor blocked by authorities. Ultimately the inability of the state to govern economic transformations gives mafias their opportunity. In a series of matched comparisons, the book charts the attempts of the Calabrese 'Ndrangheta to move to the north of Italy, and shows how the Sicilian mafia expanded to early twentieth-century New York, but failed around the same time to find a niche in Argentina. The book explains why the Russian mafia failed to penetrate Rome but succeeded in Hungary. A pioneering chapter on China examines the challenges that triads from Taiwan and Hong Kong find in branching out to the mainland. This book is both a compelling read and a sober assessment of the risks posed by globalization and immigration for the spread of mafias.


Author(s):  
Tatiana Vasilievna Pomogaeva ◽  
Aliya Ahmetovna Aseinova ◽  
Yuriy Aleksandrovich Paritskiy ◽  
Vjacheslav Petrovich Razinkov

The article presents annual statistical data of the Caspian Research Institute of Fishery. There has been kept track of the long term dynamics of the stocks of three species of Caspian sprat (anchovy, big-eyed kilka, sprat) and investigated a process of substituting a food item of sprats Eurytemora grimmi to a small-celled copepod species Acartia tonsa Dana. According to the research results, there has been determined growth potential of stocks of each species. Ctenophoran-Mnemiopsis has an adverse effect on sprat population by eating fish eggs and larvae. Ctenophoram - Mnemiopsis is a nutritional competitor to the full-grown fishes. The article gives recommendations on reclamation of stocks of the most perspective species - common sprat, whose biological characteristics helped not to suffer during Ctenophoram outburst and to increase its population during change of the main food item. Hydroacoustic survey data prove the intensive growth of common sprat biomass in the north-west part of the Middle Caspian. According to the results of the research it may be concluded that to realize the volumes of recommended sprat catch it is necessary to organize the marine fishery of common sprat at the Russian Middle Caspian shelf.


2018 ◽  
pp. 149-154

Vera Antonovna Martynenko (17.02.1936–06.01.2018) — famous specialist in the field of studying vascular plant flora and vegetation of the Far North, the Honored worker of the Komi Republic (2006), The Komi Republic State Scientific Award winner (2000). She was born in the town Likhoslavl of the Kali­nin (Tver) region. In 1959, Vera Antonovna graduated from the faculty of soil and biology of the Leningrad State University and then moved to the Komi Branch of USSR Academy of Science (Syktyvkar). From 1969 to 1973 she passed correspondence postgraduate courses of the Komi Branch of USSR Academy of ­Science. In 1974, she received the degree of candidate of biology (PhD) by the theme «Comparative analysis of the boreal flora at the Northeast European USSR» in the Botanical Institute (St. Petersburg). In 1996, Vera Antonovna received the degree of doctor of biology in the Institute of plant and animal ecology (Ekaterinburg) «Flora of the northern and mid subzones of the taiga of the European North-East». The study and conservation of species and coenotical diversity of the plant world, namely the vascular plants flora of the Komi Republic and revealing its transformation under the anthropogenic influence, was in the field of V. A. Martynenko’ scientific interests. She made great contribution to the study of the Komi Republic meadow flora and the pool of medi­cinal plants. She performed inventorying and mapping the meadows of several agricultural enterprises of the Republic, revealed the species composition and places for harvesting medicinal plants and studied their productivity in the natural flora of the boreal zone. The results of her long-term studies were used for making the NPA system and the Red Book of the Komi Republic (1998 and 2009). Vera Antonovna participated in the research of the influence of placer gold mining and oil development on the natural ecosystems of the North, and developed the method of long-term monitoring of plant cover. Results of these works are of high practical value. V. A. Martynenko is an author and coauthor of more than 130 scientific publications. The most important jnes are «Flora of Northeast European USSR» (1974, 1976, and 1977), «Floristic composition of fodder lands of the Northeast Europe» (1989), «The forests of the Komi Republic» (1999), «Forestry of forest resources of the Komi Republic» (2000), «The list of flora of the Yugyd va national park» (2003), «The guide for vascular plants of the Syktyvkar and its vicinities» (2005), «Vascular plants of the Komi Republic» (2008), and «Resources of the natural flora of the Komi Republic» (2014). She also was an author of «Encyclopedia of the Komi Republic» (1997, 1999, and 2000), «Historical and cultural atlas of the Komi Republic» (1997), «Atlas of the Komi Republic» (2001, 2011). V. A. Martynenko made a great contribution to the development of the botanical investigations in the North. Since 1982, during more than 10 years, she was the head of the Department of the Institute of Biology. Three Ph. D. theses have been completed under her leadership. Many years, she worked actively in the Dissertation Council of the Institute of biology Komi Scientific Centre UrB RAS.  The death of Vera Antonovna Martynenko is a heavy and irretrievable loss for the staff of the Institute of Biology. The memory of Vera Antonovna will live in her numerous scientific works, the hearts of students and colleagues.


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