Riverine carbon flux from the Red River system (Viet Nam and China): a modelling approach

Recently, the Asian rivers have faced the strong reduction of riverine total suspended solids (TSS) flux due to numerous dam/reservoir impoundment. The Red river system is a typical example of the Southeast Asian rivers that has been strongly impacted by reservoir impoundment in both China and Vietnam, especially in the recent period. It is known that the reduction in total suspended solids may lead to the decrease of some associated elements, including nutrients (N, P, Si) which may affect coastal ecosystems. In this paper, we establish the empirical relationship between total suspended solids and total phosphorus concentrations in water environment of the Red river in its downstream section from Hanoi city to the Ba Lat estuary based on the sampling campaigns conducted in the dry and wet seasons in 2017, 2018 and 2019. The results show a clear relationship with significant coefficient between total suspended solids and total phosphorus in the downstream Red river. It is expressed by a simple equation y = 0.0226x0.3867 where x and y stand for total suspended solids and total phosphorus concentrations (mg/l) respectively with the r2 value of 0.757. This equation enables a reasonable prediction of total phosphorus concentrations of the downstream Red river when the observed data of total suspended solids concentrations are available. Thus, this work opens up the way for further studies on the calculation of the total phosphorus over longer timescales using daily available total suspended solids values.

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Controlling factors of seasonal and spatial variation of riverine CO2 partial pressure and its implication for riverine carbon flux

The Science of The Total Environment ◽

10.1016/j.scitotenv.2021.147332 ◽

2021 ◽

pp. 147332

Author(s):

Jinke Liu ◽

Guilin Han

Keyword(s):

Partial Pressure ◽

Spatial Variation ◽

Carbon Flux ◽

Controlling Factors ◽

Co2 Partial Pressure ◽

Riverine Carbon Flux

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Assessment of the sustainability of the rice-maize cropping system in the Red River Delta of Vietnam and developing reduced tillage practices in rice-maize system in the area

Journal of Vietnamese Environment ◽

10.13141/jve.vol5.no1.pp1-7 ◽

2014 ◽

Vol 5 (1) ◽

pp. 1-7

Author(s):

Thi Thanh Ly Le

Keyword(s):

Cropping System ◽

River Delta ◽

Red River ◽

Viet Nam ◽

Red River Delta ◽

Maize Crop ◽

Tillage Practices ◽

Land Use Efficiency ◽

The North ◽

System Sustainability

Rice and maize are global staple food and play an important role in world’s food security strategy. Vietnam is one of rice leading export countries but annually it has to import a considerate amount of maize for cattle food processing. Red River Delta in the north of Vietnam is the second rice bucket of the country, which is responsible for more than 20% of total rice production. The priority crops in the areas are rice and maize and rice-maize system is the leading cropping system in the area. Currently, it is reported that the rice-maize cropping system is not sustainable and its profit is reducing in most of production areas in the Red River Delta. Improving rice cropping system aims is not only to increase rice and maize yields and production but also to improve the land use efficiency, decline the cost of the production and to increase system sustainability. To increase sustainability there must be a linkage of various factors. This review emphasizes on increasing rice-maize crop sustainability by applying appropriate agriculture practices such as reducing chemical fertilization and intensive tillage. Gạo và ngô là nguồn lương thực chính cho toàn cầu và đóng một vai trò quan trọng trong chiến lược an ninh lương thực của thế giới. Việt Nam là một trong những nước dẫn đầu về xuất khẩu gạo nhưng hàng năm vẫn phải nhập một số lượng lớn ngô để chế biến thức ăn gia súc. Đồng bằng sông Hồng là một trong hai vựa lúa lớn của Việt Nam sản xuất khoảng 20% sản lượng lúa gạo của cả nước. Ở đồng bằng sông Hồng, lúa và ngô là hai cây trồng chính là hệ canh tác lúa-ngô là cơ cấu cây trồng hàng đầu trong vùng. Tuy nhiên, trong những năm gần đây, rất nhiều đánh giá cho thấy hệ thống canh tác lúa-ngô là hệ thống canh tác không bền vững và các lợi nhuận của mang lại từ cơ cấu canh tác ở hầu hết các khu vực sản xuất ở vùng đồng bằng sông Hồng của Việt Nam đã và đang giảm dần. Do đó, việc cải thiện cơ cấu canh tác lúa -ngô không chỉ nhằm mục đích tăng năng suất lúa và ngô mà còn nâng cao hiệu quả sử dụng đất, giảm chi phí sản xuất và tăng cường hệ thống canh tác bền vững. Tuy nhiên, để tăng tính bền vững của hệ thống canh tác thì phải liên kết nhiều yếu tố khác nhau. Bài viết này dựa vào các kết quả nghiên cứu của các tác giả khác nhau để đưa ra những giải pháp tích cực làm tăng tính bền vững của hệ thống canh tác lúa - ngô bằng cách áp dụng các phương pháp canh tác hợp lý như giảm sử dụng phân hóa học và các biện pháp canh tác thâm canh như áp dụng phương pháp làm đất tối thiểu.

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ĐẶC ĐIỂM HỆ THỐNG SÔNG CỔ VÀ TÁC ĐỘNG NHÂN SINH DỰA TRÊN KẾT QUẢ MÔ HÌNH TIẾN HÓA TỈ LỆ LỚN KHU VỰC CHÂU THỔ SÔNG HỒNG

Tạp chí Khoa học và Công nghệ Biển ◽

10.15625/1859-3097/19/4/12706 ◽

2020 ◽

Vol 19 (4) ◽

pp. 463-478

Author(s):

Mai Duc Dong ◽

Phung Van Phach ◽

Nguyen Trung Thanh ◽

Duong Quoc Hung ◽

Pham Quoc Hiep ◽

...

Keyword(s):

Late Pleistocene ◽

River System ◽

River Network ◽

River Delta ◽

Red River ◽

River Systems ◽

Red River Delta ◽

The World ◽

History Of

The Simclast model has been verified and applied effectively in simulating the delta development for some major deltas in the world. In this study, we applied the model Simclast for simulating the history of the Red river delta development in late Pleistocene-Holocene. Results of the model reveal that the mainland of study area had reduced rapidly during transgression period (10,000-8,000 BP). The morphology changed significantly in the paleo-Red and Day river systems, but slightly in the paleo Thai Binh river system. The paleo-river network had been active in upper part before 11,000 BP and then shifted seaward until 2,000 BP. The river-sea interaction causes erosion and accumulation; as a result the morphology changed remarkably. The paleo-Thai Binh river had been inactive until 5,500 BP and then it was active but the morphology had not varied remarkably. The recent coastline generated from Simclast is relatively in accordance with the present coastline.

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Data assimilation method in flood forecasting for Red river system using high performent computer

Vietnam Journal of Mechanics ◽

10.15625/0866-7136/37/1/5213 ◽

2015 ◽

Vol 37 (1) ◽

pp. 29-42

Author(s):

Nguyen Thanh Don ◽

Nguyen Van Que ◽

Tran Quang Hung ◽

Nguyen Hong Phong

Keyword(s):

Data Assimilation ◽

Flow Rate ◽

New Technologies ◽

Weather Forecasting ◽

Initial Conditions ◽

River System ◽

Red River ◽

Time Dependent ◽

Complex Case ◽

Flood Model

Around the world, the data assimilation framework has been reported to be of great interest for weather forecasting, oceanography modeling and for shallow water flows particularly for flood model. For flood model this method is a power full tool to identify time-independent parameters (e.g. Manning coefficients and initial conditions) and time-dependent parameters (e.g. inflow). This paper demonstrates the efficiency of the method to identify time-dependent parameter: inflow discharge with a real complex case Red River. Firstly, we briefly discuss about current methods for determining flow rate which encompasses the new technologies, then present the ability to recover flow rate of this method. For the case of very long time series, a temporal strategy with time overlapping is suggested to decrease the amount of memory required. In addition, some different aspects of data assimilation are covered from this case.

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River hydrology and recent suspended sediment flux in the Red River: implication for assessing soil erosion and sediment transport/deposition processes

Vietnam Journal of Science and Technology ◽

10.15625/0866-708x/54/5/7197 ◽

2016 ◽

Vol 54 (5) ◽

pp. 614

Author(s):

Dang Thi Ha ◽

Alexandra Coynel

Keyword(s):

Particulate Matter ◽

Suspended Particulate Matter ◽

Water Discharge ◽

River System ◽

Deposition Process ◽

High Water ◽

Sediment Flux ◽

Red River ◽

Hydrological Conditions ◽

Suspended Particulate

Based on a database of daily water discharge and daily suspended particulate matter concentrations along the Red River and at the outlet of the main tributaries (Da and Lo) during the 2005-2010 period, covering contrasting hydrological conditions, the water and sediment fluxes transported by the Red River system were determined. The results showed that only 21% of the discharge is derived from the upper Red River, 54% and 25% being derived from the Da and the Lo Rivers, respectively. In contrast, the distribution of suspended particulate matter (SPM) load is very different of that observed for water discharge: most SPM were eroded from the upstream catchment located in China (78%). Moreover, annual SPM fluxes (FSPM) showed a strong spatial variability between upstream watershed and the outlet of the river. The mean inter-annual FSPM was 30 Mt/yr (i.e. specific flux of 741 t/km²/yr) at the LaoCai site, 38 Mt/yr (i.e. 792 t/km²/yr) at the PhuTho gauging site, 29 Mt/yr (i.e. 193 t/km²/yr) at the SonTay gaugng station. Its values were 4.1 Mt/yr (i.e. 80 t/km²/yr) and 6.6 Mt/yr (i.e. 191 t/km²/yr) for the Da and Lo rivers, respectively. Between the LaoCai and PhuTho sites, both erosion and sedimentation processes occurred together, but strongly depended on the hydrological conditions. Between the PhuTho and SonTay sites, the important loss of SPM flux suggested a dominant deposition process in the floodplain during high water before the delta. These results proved the complex processes of erosion/sedimentation occurring on the Red River watershed.

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