Thai Binh River Research Articles

Effectiveness in storing and reducing floods of the red river upstream reservoirs under the incident of Lienmac dyke

The Red river and Thai Binh river’s dyke system includes 56 dikes classified from grade III to special grade with a total length of 2.207,75km which 37.709km of special grade, 553.70km of grade I, 502,43km of grade II and grade III. At the present, on the Red River and Thai Binh River systems, there are 230 existing weak locations, which have not been completely reinforced yet. It might cause unsafety situations of large flood flush and high water levels of rivers for a long time. Therefore, studying the solutions to support the response under unsafety situations of the dike system is a significant meaning topic. The present paper aims to evaluate the effectiveness of solutions using reservoirs at the Red river upstream in order to store and reduce floods in downstream. This also supports the effort to respond the urgent situations upstream such as huge floods, dyke failures in downstream and dyke failure at Lien Mac. In the scope of this paper, one and two-dimensional hydraulic simulation method was utilized, which describes the scenarios to regulate the upstream reservoir of the Red River and hydraulic calculation of the downstream river network. Then, the effectiveness of flood reduction in each scenario can be estimated. Simulation results show that depending on the calculation scenarios, the capacity of reservoirs can be 5.553 million m3 to cut and reduce flood for downstream. The flooded area might be decreased by 47.528 ha in case using a part of the capacity of the construction. The time when the reservoirs completely close the floodgates and do not discharge the flood into downstream is from 27 to 30 hours, this is an important time for the Lien Mac dike to be completely sealed within 24 hours. The time when the reservoirs completely close the floodgates and do not discharge the flood into downstream is from 27 to 30 hours, this is an important time for the Lien Mac dike to be completely closed within 24 hours.

Effects of Covid–19 Pandemic on Surface Water Quality: A Case Study in Hong–Thai Binh River, Vietnam

Effects of Covid–19 Pandemic on Surface Water Quality: A Case Study in Hong–Thai Binh River, Vietnam

The double structure of the Estuarine Turbidity Maximum in the Cam-Nam Trieu mesotidal tropical estuary, Vietnam

The characteristic parameters of the Estuarine Turbidity Maxima (ETM), their aggregates and their tidal variations were investigated within the Cam-Nam Trieu mesotidal estuary (Red River and Thai Binh River system, North Vietnam) at spring tides during the early wet season, wet season and dry season. The structure observed repeatedly highlights the separation of two distinct zones of high turbidity around the salt wedge, separated by a zone of lower turbidity. The upstream part developed at very low salinity (from 0.1 psu) on a quasi-homogeneous water column (at Simpson parameter between ~0.65 and 7–10); tidal pumping associated with salinity-induced flocculation are likely responsible for its formation. A second maximum was observed in the lower layer of stratified waters (at Simpson parameters >10), i.e. in the salt wedge, at higher salinities up to ~12–15 psu; in this downstream part, governed by the gravitational circulation, settling is also seasonally enhanced by the presence of transparent exopolymeric particles (TEP) for salinity >10 psu. Turbidity was higher in the upper part of ETM in the dry season and higher in the lower part of ETM in the wet season. Floc size, excess of density and settling velocity were the highest during dry season. Stronger ETMs occur in dry season than in early wet season and wet season, when the tidal-induced ETM is maximum. The locations of both ETM parts changed seasonally, moving upstream in the dry season and downstream in the wet season. Their length depended on the longitudinal salinity gradient and was highest at low tide than at high tide. The intermediate zone of lower turbidity between these two parts was longer in the wet season.

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

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.

Impacts of Dam Break at Upstream of Lo River on Red River and Thai Binh River Delta

The Red River – Thai Binh River Delta is a large economic area, densely populated, especially Hanoi, the capital of Vietnam. This is the key area protected by the dike system that has been built for nearly 1000 years. Recently, along with the dike system, the Red River – Thai Binh River Delta is also protected by a large reservoir system at upstream. However, this raises concerns about dam safety, and requires assessments about the impact of dam break on the delta to prepare appropriate response measures. This paper applies 2D mathematical simulation model of flood propagation due to dam break at Thac Ba and Tuyen Quang reservoirs. The results clearly show the characteristics of the flood caused by dam break (such as water level, depth, velocity, lag time) in affected areas. Furthermore, overflow incident of main dikes and ring dikes at the downstream areas is also determined for both cases dam break with flood and without flood.

ĐỀ XUẤT CÁC GIẢI PHÁP GIẢM THIỂU TÁC ĐỘNG DO ĐỔ THẢI BÙN CÁT NẠO VÉT Ở VÙNG VEN BIỂN HẢI PHÒNG

Located in the estuary region of the Red - Thai Binh river system, in which the estuarine turbidity maxima occur, the deposition of navigation in waterways to Hai Phong ports is always an urgent problem that needs to be solved. At the present time, it is not easy to use dredged sediment for landfilling or other purposes. Moreover, it is also difficult to dispose of them on the land because of requiring the design and construction of dikes, requiring compaction and drainage of dumped materials. Therefore, disposing of materials at dumping sites in Hai Phong open waters is still an alternative for considering. However, the suspended sediment from the dumping sites can cause influences on the marine environment and ecosystems. Based on the characteristics of natural conditions, socio-economy and ecological environment in Hai Phong coastal areas as well as results of the modeling application (Delft3D model), this paper gives some proposals for appropriate solutions to reduce influences of sediment dumping activities in the Hai Phong open waters. They are: (1) Planning a land for reclamation of dumped materials, (2) Research on the strategies to use dredged sediments as a resource, (3) Finding a best method of dumping, (4) Considering tidal current for daily dumping, (5) Choosing disposal time during neap tide, (6) Restricting disposal in case winds come from SW and S, (7) Reducing time and the number of dumping, increasing amount of sediments in each dumping, (8) Applying technologies in disposal monitoring, (9) Regularly monitoring the environment at the dumping sites and adjacent areas.

Application of the Advanced 2D Multi-electrode Electrical Exploration Method to Survey the Current Condition and Contribute to Assessing Stability of Dykes

One of the important issues to assess the stability of dykes is to survey and assess their current condition. This article introduces some new results obtained from applying Advanced 2D Multi-electrode Electrical Exploration method to survey the current condition of Red River dyke in Hanoi, Cau River and Thai Binh River in Bac Ninh province. Comparing survey results between Advanced 2D Multi-electrode Electrical Exploration method and drilling method show that layering results match each other. However, drilling and sampling method is very difficult to identify objects that cause instability in body and foundation of dyke (seepage caused by sand lens, mud pit inside dyke’s foundation…), while these objects can be identified by the Advanced 2D Multi-electrode Electrical Exploration method. Therefore, instead of traditional surveying method, it is possible to apply the Advanced 2D Multi-electrode Electrical Exploration method to survey the current condition and contribute to assessing the stability of dyke sections to add into and complete the database on dykes for highly efficient management and maintenance of dykes.
 Keywords
 Fractures, determining seepage, heterogeneous, Advanced 2D Multi-electrode Exploration
 References
 [1] Vu Duc Minh, Do Anh Chung, “Introduction to the Advanced Multi-electrode Electrical Sounding method”, VNU. Journal of Mathematics-Physics, No. 31(3), 2015, p. 1-14.[2] Vu Duc Minh, Do Anh Chung, Perfecting the Advanced Multi-electrode Electrical Sounding method”, VNU. Journal of Mathematics-Physics, No. 34(3), 2018, p. 90-103

Assessment of atmospheric conditions over the Hong Thai Binh river watershed by means of dynamically downscaled ERA-20C reanalysis data

Abstract Long-term, high spatial and temporal resolution of atmospheric data is crucial for the purpose of reducing the effects of hydro-meteorological risks on human society in an economically and environmentally sustainable manner. However, such information usually is limited in transboundary regions due to different governmental policies, and to conflicts in the sharing of data. In this study, high spatial and temporal resolution atmospheric data were reconstructed by means of the Weather Research and Forecasting Model-WRF with input provided from the global atmospheric reanalysis of the 20th century (ERA-20C) over the Hong-Thai Binh River watershed (H-TBRW). The WRF model was implemented over the physical boundaries of the study region based on ERA-20C reanalysis data and was configured based on existing ground observation data in Vietnam's territories, and the global Aphrodite precipitation data. With the validated WRF model for H-TBRW, the reconstructed atmospheric data were first reconstructed for 1950–2010, and then were evaluated by time series and spatial analysis methods. The results of this study suggest no significant trend in the annual accumulated precipitation depth, while there were upward trends in annual temperature at both the point and watershed scale. Furthermore, the results confirm that topographic conditions have significant effects on the climatic system such as on precipitation and temperature.

Comparison and Bias Correction of TMPA Precipitation Products over the Lower Part of Red–Thai Binh River Basin of Vietnam

As the limitation of rainfall collection by ground measurement has been widely recognized, satellite-based rainfall estimate is a promising high-resolution alternative in both time and space. This study is aimed at exploring the capacity of the satellite-based rainfall product Tropical Rainfall Measurement Mission (TRMM) Multi-satellite Precipitation Analysis (TMPA), including 3B42V7 research data and its real-time 3B42RT data, by comparing them against data from 29 ground observation stations over the lower part of the Red–Thai Binh River Basin from March 2000 to December 2016. Various statistical metrics were applied to evaluate the TMPA products. The results showed that both 3B42V7 and 3B42RT had weak relationships with daily observations, but 3B42V7 data had strong agreement on the monthly scale compared to 3B42RT. Seasonal analysis showed that 3B42V7 and 3B42RT underestimated rainfall during the dry season and overestimated rainfall during the wet season, with high bias observed for 3B42RT. In addition, detection metrics demonstrated that TMPA products could detect rainfall events in the wet season much better than in the dry season. When rainfall intensity was analyzed, both 3B42V7 and 3B42RT overestimated the no rainfall event during the dry season but underestimated these events during the wet season. Finally, based on the moderate correlation between climatology–topography characteristics and correction factors of linear-scaling (LS) approach, a set of multiple linear models was developed to reduce the error between TMPA products and the observations. The results showed that climatology–topography-based linear-scaling approach (CTLS) significantly reduced the percentage bias (PBIAS) score and moderately improved the Nash–Sutcliffe efficiency (NSE) score. The finding of this paper gives an overview of the capacity of TMPA products in the lower part of the Red–Thai Binh River Basin regarding water resource applications and provides a simple bias correction that can be used to improve the correctness of TMPA products.

STUDIES ON DISTRIBUTION AND FRACTIONATION OF HEAVY METALS IN SEDIMENT OF CAU RIVER, VIETNAM

Cau River, one of the major rivers of Thai Binh River Systems, has been under pressure from discharge from the economic and social development activities of the region. Water and sediment samples will be collected along Cau River to determine the spatial variability of metal in Cau River. Sediments collected from Cau River were extracted sequentially to investigate the distribution and fractionation of metal in Cau River. Results showed that the presence of certain metals in water and sediment with the concentrations ranged in a wide variation. In water Cu (58-181 μg/L), Pb (0.6-1.85 μg/L), Zn (18.1-32.5 μg/L), Cd (0-0.02 μg/L), Ni (3.04-4.41 μg/L), Cr (2.72-5.07 μg/L); in sediment Cu (27.6-401 mg/kg), Pb (0-282 mg/kg), Zn (3.9-71.9 mg/kg), Cd (0.01-2.44 mg/kg), Ni (2.24-5.89 mg/kg), Cr (4.08-11.5 mg/kg). Sequential extraction for study the distribution of metal species in sediment showed that metal mainly concentrated immobile form of residues fraction, organic compound bound fraction and Fe-Mn oxide associated fraction. This dominant existence of metal result in the tendency of metal assimilation in sediment and low bioavailability. However, some toxic metals such as Cd, Cr found moderated soluble form must be studied more for their release to water phase and and bioaccumulation.

Assessing the impact of climate change on the water intake of the headworks on the Red River Basin in Viet Nam

The irrigation systems for the Red River Delta usually get water by pumping and gravity.The results determine the possible minimum water level line in the dry-season months under climate change scenarios (B2, SC5 and SC6 and current scenario is B2, SC4) on the river system of the Red River – Thai Binh River in study areas of project as below: Water levels on the Red River in the dry season under climate change scenarios significantly reduced compared with 2010. At Ha Noi station on Red River, the water levels reduce in 2050 about 6.5cm (B2) and 7.5cm (A2) and 6cm (B1). At Nam Dinh station on Dao River, the water levels reduce in 2050 about 4cm (B2) and 5cm (A2) and 3cm (B1). At Cat Khe on Thai Binh River, the water levels reduce in 2050 about 2cm (B2) and 3cm (A2) and 1.5cm (B1). At An Bai on Kinh Thay River, the water levels reduce in 2050 about 5cm (B2) and 6cm (A2) and 4cm (B1). At Truc Phuong on Ninh Co River, the water levels reduce in 2050 about 6.5cm (B2) and 7.2cm (A2) and 5.8cm (B1). In the scenario in which 50% of the socio-economic development plans are achieved (SC6), the water demand is lower than the scenario of full development (SC5). The decrease in the average water level in the whole Red River system is about 1.3-1.8 cm less than in SC5, and in Thai Binh river this figure is about 1.4-2.1cm. The lowering of the water level under climate change in the river has caused problems for irrigation during the dry season, in order to reach the target level in Hanoi.

Application of Remote Sensing and GIS technology for monitoring coastal changes in estuary area of the Red river system, Vietnam

Coastline is the most dynamic part of seascape since its shape is affected by various factors. Coastal zone is an area with immense geological, geomorphological and ecological interest. Monitoring coastal change is very important for safe navigation, coastal resource management. This paper shows a result of monitoring coastal morphological changes using Remote Sensing and GIS. Study was carried out to obtain intensity of erosion, deposition and sand bar movement in the Red River Delta. Satellite images of ALOS/AVNIR-2 and Landsat were used for the monitoring of coastal morphological changes over the period of 1975 to 2009. Band rationing and threshold technique was used for the coastline extraction. Tidal levels at the time of image acquisition varied from -0.89m to 2.87m. Therefore, coastline from another image at a different tidal level in the same year was considered to get the corrected coastline by interpolation technique. A series of points were generated along the coastal line from 1975 image and were established as reference points to see the change in later periods. The changes were measured in Euclidean distances from these reference points. Positive values represented deposition to the sea and negative values are erosion. The result showed that the Red river delta area expanded to the sea 3500m in Red river mouth, and 2873m in Thai Binh river mouth from 1975 to 2009. The erosion process occurred continuously from 1975 up to now with the average magnitude 23.77m/year from 1975 to 1989 and 7.85m/year from 2001 to 2009 in Giao Thuy area. From 1975 to 2009, total 1095.2ha of settlement area was eroded by sea. On the other hand, land expanded to the sea in 4786.24ha of mangrove and 1673.98ha of aquaculture.

Forecasting the discharge into Hoa Binh reservoir by applying the connecting model marine - imech1D

Da river is the biggest one of three rivers: Da, Thao and Lo which flow into Hong river, so calculating and forecasting correctly the discharge to Hoa Binh reservoir take an important role in managing the task of flood preventing in the Hong - Thai Binh river system. In this paper, a connected hydraulic-hydrological model is developed. The model was applied to forecast the discharge into Hoa Binh reservoir in the flood season 2006. The difference of this connected hydraulic-hydrological model in comparison with the other hydrological models is using the complete Saint-Venant 1D to simulate flow in rivers. Results of verification of the model show that it is good enough for practice.

Optimal operation of Hoa Binh reservoir for flood control on Hong-Thai Binh river system

In the paper the optimal operation of Hoabinh reservoir for flood control on Hong–Thai Binh river system is presented. The findings show that in the flood season in 1996 if the operation of gates and outlets of Hoa Binh reservoir was made base on the calculated release, the water level at Hanoi would be 12.3 m and the water level of Hoa Binh reservoir would be 98 m. So the calculated release from Hoabinh reservoir in August 1996 can be considered as optimal in the mean that the water level at Hanoi can be controlled and the Hoabinh reservoir still have necessary pool for controlling the next floods.

CLAY MINERALOGY OF ALLUVIAL SOILS AND GREY DEGRADED SOILS DERIVED FROM THE SAME RIVER SEDIMENT IN THE RED RIVER DELTA, NORTHERN VIETNAM

Five samples of alluvial soils and 3 samples of grey degraded soils, both derived from the sediments of the Thaibinh River system in the Red River Delta, northern Vietnam, were subjected to clay mineralogical analysis in addition to measurement of pH, organic matter content and particle-size distribution. The pH was comparable between the two soil types. In contrast, the organic matter and clay contents were remarkably lower for grey degraded soils than for alluvial soils. Predominant clay minerals in both soil types were mica and kaolinite; the mica content was higher for alluvial soils while the kaolinite content was higher for grey degraded soils. Chlorite-vermiculite intergrade was detected only in grey degraded soils, whereas vermiculite was present in alluvial soils instead. Absence of goethite in grey degraded soils might be a cause of their grey color. A sign of degradation on the amount (clay content) and type (clay mineralogical composition) of clay minerals was indicated in grey degraded soils in the Red River Delta, leading to decrease in the organic matter content and then to decline in the soil fertility.

ベトナム北部Red RiverおよびThai Binh River流域の窒素濃度

ベトナム北部Red RiverおよびThai Binh River流域の窒素濃度