Journal Science and Technology Water Resources
Tạp chí của Viện Khoa học Thủy lợi Việt Nam
Investigating the behavior of steel beam with web openings using sap2000 software in steel structure works
In this article, we investigate experimentally and numerically the performance of beams with web openings when subjected to two concentrated loads acting on the upper flange of the beam. Indicators such as: deflection between beams, stress at the edge of the hole, stress at the upper flange of the beam, etc. were measured during the experiment campaign. At the same time, numerical simulation of the experiment was performed using SAP2000 software. The numerical simulation analysis using SAP2000 software and experiment show very similar results. It can be concluded that numerical simulations using SAP2000 software can predict with high reliability and anticipate dangerous locations when designing with less cost than surveying by experiment.
Study of auto-calibration and validation method on swat model in river basin
The SWAT model (Soil and Water Assessment Tool) has been widely used. It is a semi-distributed hydrological model built to simulate the effects of land use management and climatic factors on water source, sediment and organic matter content in river basin system with soil types, with different land use conditions for a period or forecast for a long time. Besides its outstanding advantages, the SWAT model also requires a large number of input parameters, the process of parameterizing, calibrating and verifying the model with manual methods is facing many difficulties in the implementation process. This is an extremely important step to evaluate the accuracy of simulation model results, however, with a large number of parameters and complexity across sub-basins, changing and detection each parameter to determine the sensitivity in the process of calibration and validation really takes a lot of time and affects the quality of the model. Therefore, in this study, it is necessary to focus on detailed research on the method of auto-calibration and validation the model to reduce time, volume and improve the quality of the model to determine the highest sensitivity parameters and influence in the model The SWAT model result was calibrated and validated by comperison of observed data against simulated of monthly streamflow where parameters were adjusted based on the sensitivity analysis in auto-calibration methods. The research results provide a useful method with powerful tools, saving time and effort to increase the quality, consistency and accuracy of the model.
Solutions to improve governance quality of the irrigation management companies
In general, irrigation management companies have had innovations in organization, management mechanism for exploitation irrigation systems creating favorable conditions for more effective performance of irrigation systems, closer to reality water demand of water users, however, governance quality of the irrigation management companies is generally low. Governance for management organization lacks science, so production costs are still high, fuel consumption is high, and labor productivity is low. This study proposes solutions to improve organizational structure and several governance mechanisms to improve governance quality of the irrigation management companies
Dam failure is a risky phenomenon beyond human subjective will. The damage and impact caused by dam failure is huge. However, calculating and predicting the characteristics of dam failure is very difficult and complicated. The problem of dam failure has been studied hundreds of years ago using many methods such as physical models, mathematical models, actual statistics...., However, the research method using physical models still proves to be effective, has advantages and is increasingly being improved. This article presents simulation methods of two types of dams: local material dams and concrete dams (roller compacted concrete and gravity concrete).
Restoring and conserving traditional rural landscape: International experience and lessons for Vietnam
The landscape question has never been as pressing in the historical development of the rural as today. Landscape loss, traditional landscape conflicts with urbanization, new countryside construction and lack of vision for plans to restore and conserve rural landscapes have become increasingly frequent problems over the past two decades. The problems around the keeping or changing landscape have contributed to larger economic, social, and environmental problems affecting the rural areas and new countryside construction, primarily space and soil for production and residential land, social differentiation, poverty, deforestation, lost green space, water surface and environmental degradation... At the same time, they have been due to a combination of multiple causes. The strong impact of the urbanization process has made the face of the traditional rural landscape has undergone many major changes, the process of village hardening has disrupted the spatial structure and landscape, negatively affecting the cultural values of the village, as well as the goal of sustainable rural development in Vietnam. This paper highlights the experiences in restoring and conserving traditional landscape of some countries around the world and lessons for Vietnam.
Building a reasonable irrigation with fertilizing process for Hung Yen orange trees in Phu Cu district, Hung Yen province
Hung Yen orange trees, a type of orange that come from “Vinh oranges”, which was cultivated in Hung Yen province, is one of the key fruit crops that is researched, planned and developed in priority by the government of Hung Yen province with purpose to become the brand name "Hung Yen oranges". Currently, the Hung Yen orange trees is cultivated in 8 of 10 districts/cities in the province grown most in Phu Cu district. Cultivation techniques of farmer (irrigation, fertilizing, etc.) for Hung Yen orange trees are mainly implemented by their experience then the productivity and quality of Hung Yen orange are affected. In the context reasonable irrigation with fertilizing process has been applied successfully in concentrated orange cultivation areas in the Northern Mountainous, North Central, Southeast regions… in Vietnam, the research on building a reasonable irrigation with fertilizing process for Hung Yen orange trees to solved mentioned above problems has very high practical significance. This paper presents the results of research on building a reasonable irrigation with fertilizing process for Hung Yen orange trees in its business period. The results show that with irrigation rates of 50¸60 (liters/tree/times) and 35¸40 times /year, using irrigation technique with fertilizing, orange productivity increases by at least 20%, reduction of fertilizer by 15%¸20%, saving labor and electricity costs... in comparation with traditional methods. The process has been approved by the Department of Science and Technology of Hung Yen province and is recommended for application for Hung Yen orange cultivation throughout the province.
Research on the characteristics and appropriate irrigation requirement for the growth stages of banana
Banana is a fruit crop, characterized by a soft, cylindrical stem; the foliage is long, translucent, green, and smooth, cluster roots that go deep underground and grow over time. In Vietnam, banana trees are listed as the main crops and bring high economic value. Like some other fruit crops, bananas have growth characteristics divided into four main periods. Depending on each stage of development, bananas have different irrigation requirements. Currently, the demand for banana products in the world is very high; the potential for banana export is an opportunity to develop the agricultural economy in particular and the country's economic development in general. However, the productivity and quality of banana crop depends on many factors, some of which are the main factors such as soil, seedling quality, pests and diseases, and especially an appropriate irrigation requirement for the growth stages of banana. Therefore, in this study, we focused on determining the appropriate irrigation regime for the growth stages of banana crops to improve yield and product quality. The research results determined that on one hectare of bananas with 2,000 trees, the amount of water required for the entire period is 1.578,67 m3/ha. Besides, the results also showed that the water demand for each growth stage is different; that is the highest water demand at the stage of banana flowering and fruit raising with an irrigation requirement of up to 18.62 liters/tree/time, while the young tree stage has the lowest water demand with an irrigation requirement of only 4.3 liters/tree/time.
Innovation in Bac Nam Ha hydraulic works exploitation single-member limited liability company
Bac Nam Ha Hydraulic Works Exploitation single-member limited liability company has managed and exploited one of the largest hydraulic work systems in the Red River Delta region. In recent years, the company has boldly innovated the way of project management and exploitation, water management and financial management. Subsequently, it effectively serves agricultural production, people's lives and the environment deserving to be the industry leader.
Review of regulations and policy for circular economics application in water and sanitation management for climate resilience in Vietnam
An essential responsibility in achieving the goals of water resource security strategies is efficient management, water-saving use, and water resource protection. In rural areas, the main issues were the high rate of inefficient water supply systems and water losses, as well as the fact that domestic water waste management is still out of control and water resources are contaminated. One of the causes was the absence of appropriate economic models that might guide the development of the water supply in a sustainable and effective manner. This essay discussed how circular economics could be used to manage rural water supplies. Reviews of the literature on policies, circular economics applications worldwide, and its adaptation in water supply management suggested potential circular economics principles for the water supply sector. They were 3R, which stood for Reduce, Re-use, and Recover. The incentive policy mechanisms for circular economics in water supply in Vietnam were not synchronized, and they were regulated in many relevant law documents. As a result, it was required to put forward a plan for rural water supply management based on the principles of the circular economy, which included developing scientific research, establishing regulations, and defining indicators for reducing, reusing, and recovering water resources.
Several features of dam break wave dynamics at the reservoir upstream in case of a concrete dam break
When a concrete dam failure occurs, negative reverse waves often appear at upstream and positive forward waves appear at downstream. This article presents several hydrodynamic characteristics of dam break wave dynamics at the reservoir upstream in case of a concrete dam breaks. Results obtained from computational research using 3D mathematical models with the RNG k-ε turbulence flow model, show that at upstream there is a pair of negative reverse waves in front and positive waves behind
Mechanism and policy to support the installation of low-cost equipment on water storage, treatment and supply for rural domestic water for small household and residential clusters in the coastal provinces of the Mekong Delta
Ensuring domestic water sources for thousands of households in the Mekong Delta is one of the urgent needs. There are many people in coastal areas still have to directly use the canal water and underground water of poor quality for daily activities, especially during periods of drought, water shortage and salinity intrusion. There are a number of domestic water treatment technologies are products of scientific research that basically meet criteria such as investment cost, low operating costs, easy management, and simple maintenance. However, for those technologies to be put into practice, suitable for the living, economic and social conditions of the coastal provinces in Mekong delta and capable of being replicated, it is necessary to have specific mechanisms and policies. Based on a review of existing mechanisms and policies, this article has analyzed and proposed a number of policies to support the construction and installation of rain and surface water collection, storage and treatment equipment to proactively supply water for rural households and small residential clusters during periods of drought, water shortage, and salinity intrusion in the coastal provinces of the Mekong Delta.
Basis for dam safety level assessment in Hanoi city based on current data status of earth dam monitoring
According to general assessments in the world as well as in Vietnam, one of the main causes of dam failures is seepage and structural instability. Monitoring equipment arranged in the dam body plays an important role in providing information to help operations managers early identify risks and have timely treatment plans. However, dams in Hanoi city have only installed water level monitoring equipment and a few reservoirs have installed saturation line monitoring equipment in the dam body. To make the most of existing monitoring data, the article presents the results of assessing the level of dam safety in the city according to the current status of earth dam monitoring data for 2 typical cases, including: (i) The project is installed with water level monitoring equipment. Through dam inspection, seepage appears on the downstream slope of the dam, outside the drainage equipment; (ii) The project is synchronously installed with water level monitoring equipment and saturation line monitoring equipment in the dam body.
The Mekong river training alternatives from environmental friendly solutions
Due to the presence of a big river and alluvial geological conditions, the Vietnam Mekong delta (VMD) is prone to landslides, resulting in numerous vulnerable areas where erosion and land subsidence can occur frequently. In addition, the concentration of major cities and densely populated areas (such as Long Xuyen, Cao Lanh, Can Tho, Vinh Long, My Tho, Ben Tre) along rivers, which is often preferred due to their historical, economic significance, may pose a notable risk of riverbank collapse. Based on statistical data from 2019, approximately 393 areas in the VMD have been impacted by riverbank erosion, this has resulted in significant damages to both the economy and threatening human lives in the areas. Various river training alternatives for the Vietnam Mekong delta have been progressively implemented, starting with basic studies and the development of plans aimed at stabilizing river morphology. These efforts are geared towards ensuring river flow stabilization and promoting social-economic development. Among the interventions including both hard and soft solutions for river training in VMD, the article introduces a number of possible environmentally friendly solutions, such as, directing the flow, flow voltex solutions to adjust the sediment transport and riverbank protection measures. Each solution is accompanied by calculations and cost estimates, indicating their feasibility and potential for implementation
Institutional arrangements and stakeholder engagement in irrigation service pricing in Vietnam
Institutional arrangements and stakeholder engagement play an important role in the enforcement and effectiveness of irrigation service pricing policy. Recently, the irrigation service price policy in Vietnam has changed significantly in terms of content as well as application form, especially since the promulgation of the Law on Hydraulic Works. This change has greatly affected the participation of stakeholders in the setting and implementation of the irrigation service pricing policy. This study assesses the exsiting of institutional settings and stakeholder engagement in the eenforcement of the irrigation service price policy in Vietnam. Based on key findings, improvements are recommended for institutional arrangements and stakeholder engagement in irrigation service pricing policy in Vietnam.
Assess the applicability of anti-overtopping barrier for river dyke by foam-core composite panel (VTC.FC.3020) in Viet nam
Mobile overtopping prevention technology for rivers due to floods has been applied in many countries around the world. However, it is not yet popular in developing countries like Vietnam due to the high cost and we have not yet mastered this technology. This paper introduces a new technology by using barriers with composite-coated foam panels. The structure has been completely fabricated, tested with real-life flood scenarios and deployed in the field. The results show that the structure completely meets the technical requirements and has many outstanding advantages. compared to traditional solutions (using sandbgas or reinforced concrete panels).
Assessment of the impacts of planning traffic bridges system across red river on Ha noi reach to the river bank erosion and river bed changes for period from 2020 to 2030
The article presents some results of research and evaluation about the influence of planning traffic bridges system across Red River on Ha Noi reach to the river bank erosion and river bed changes for period from 2020 to 2030. On the basis of simulation results on hydraulic models, MIKE 21FM HD-ST two-dimensional morphology simulated for the Red River section from Son Tay to Hung Yen and Duong River to Thuong Cat. Bridge piers are simulated in the model using a combination of both meshing and pier simulations. The evaluation results include topographic changes in the cross-section, longitudinal section, changes in the riverbank, and deep creeks on the studied river section before and after the construction of the bridge.
Using artificial intelligence approach in predicting chloride content in concrete exposed to chloride solution
Structural corrosion due to chloride ingress is considered to be the greatest threat to buildings. Structures such as bridges, roads, infrastructure, and harbors are exposed to chloride-rich environments, either through anti-freeze salting or from the natural environment. In the marine environment, tidal and wave areas are considered to be at high risk of corrosion. The corrosion process is highly dependent on the chloride concentration in the concrete structure. Therefore, the determination of chloride concentration in concrete is meaningful and reliable. In this study, a Gradient Boosting (GB) machine learning model is proposed to predict chloride content in concrete. A dataset of 325 experimental results was collected from international literature. The results of the model are programmed and run in the Python platform, the authors use the tool of the Gradient Boosting model to predict the output parameters of chloride content in concrete. The results show that the proposed model can predict the chloride content in concrete simply and quickly, helping design engineers to predict the chloride content in advance based on the input parameters
Reasonable number of anaerobic chambers on waste treatment plant from pig raising sector
The pig raising industry in Vietnam currently tends to shift from a small scale to a concentrated raising with different farm-scales. Along with that trend, the problem of environmental pollution from livestock production in rural areas is becoming more and more serious due to the high density of livestock in one location while waste treatment methods are still simple (mainly biogas) and can not fully treat the pollution problem. Currently, there are many technologies applicable for waste and wastewater treatment in pig-rising sector, including: (i) natural treatment solution which is cheap but requires a lot of space (ponds, lakes, wetland, etc.); (ii) high treatment efficiency (Aerotank, MBR, JOHKASOU) using less space requirement but expensive; and (iii) semi-natural treatment technologies that combines two biological treatment processes (anaerobic, aerobic) to limit the disadvantages and take advantages of the two above mentioned technologies. This paper presents the results of research on selection of a reasonable number of anaerobic treatment modules, including: Anaerobic Baffle Reactor (ABR) and Anaerobic Filter (AF) of the wastewater treatment plan in pig-farm raising sector as a basis for standardizing the technological solution of wastewater treatment for small and medium-scaled in the North Central Region in Vietnam
Sustainable finance policy for management and operation of irrigation systems: International experience and lessons for Vietnam
So far, the management of irrigation systems have basically met the actual requirements because of fundamental reforms in institutions and policies, especially since the promulgation of the Law on hydraulic works in 2017. However, limitations in the management have been remained as the current financial policy still supports farmers in the indirect form through enterprises and water user organizations. This leads to unguaranteed financial sustainability of these organizations. Therefore, it is necessary to develop a sustainable financial policy so that operational organizations of irrigation systems can afford their activities. This article analyzes and synthesizes international experiences in the development and application of sustainable finance policies in irrigation management. Principles and approaches to sustainable financing learnt from international experience are recommended to Vietnam
The management of biosphere reserves in Vietnam: Opportunities and challenges
Biosphere reserves (BR) are areas of terrestrial and coastal ecosystem which promote solutions that reconcile the conservation of biodiversity with its sustainable use. Biosphere reserves serve in some ways as "living laboratories" for testing and demonstrating integrated management of land, water and biodiversity. BR is internationally recognized within the framework of UNESCO’s Man and Biosphere (MAB) Program. The MAB Program aims at solving one of the most important practical problems that people are facing today: how to strike a balance between biodiversity conservation, natural resources exploitation and socio-economic development that maintaining traditional cultural values to meet the increasing needs of people. It combines the natural and social sciences with a view to improving human livelihoods and safeguarding natural and ecosystems, thus promoting innovative approaches to economic development that are socially and culturally appropriate and environmentally sustainable. Vietnam currently has 11 BRs scattered across the length of the country and contains an important set of typical ecological, cultural and economic diversity of Vietnam. This article presents the current status of management of Vietnam's BRs, opportunities, challenges, and some recommendations on effective management of these areas
Water security: Global context and lessons learnt for Vietnam
Water is a finite renewable resource and it is facing high stress across the globe. More than one third of the world nations now experience water shortage. This situation is getting worst and a low level of water security will pose a growing threat to societies. Water security has many different aspects and there are different approaches to enhance water security. However, they vary from definitions to practices and from nation to nation. This paper efforts to present a quick overview of water security under the global context and lessons learnt for Vietnam. Findings and recommendations are considered a good reference to inform decision makers in order to enhance the national water security.
Application of genetic algorithm and artificial neural network for predicting the slump and compressive strength of Alkali-activated fly ash - ground granulated blast furnace slag concrete
This study presents the development of models for predicting the slump and compressive strength of Alkali-Activated Fly Ash-Ground Granulated Blast Furnace Slag (AAFS) concrete, utilizing genetic algorithm (GA) and artificial neural network (ANN) techniques. The models are based on four input parameters, include %Na2O, %GGBS, W/S, and tpaste, and a total of 178 experiments were conducted to determine the slump and compressive strength of AAFS concrete. GA was used to optimize the hyperparameters of the ANN models, and to build the Mathematic model. The ANN models achieved R-squared values of 0.93 and 0.97 for slump and compressive strength, respectively, while the Mathematic model obtained R-squared values of 0.88 and 0.95 for slump and compressive strength, respectively. The results indicate that the compressive strength of AAFS concrete is significantly affected by %GGBS, %Na2O, and W/S, while the slump is most influenced by tpaste and W/S. Furthermore, each tpaste value corresponds to two threshold values of W/S, with a slight change in W/S between the two thresholds resulting in a significant change in the slump. Similarly, each W/S value corresponds to two threshold values of tpaste, where a low tpaste value initially leads to a very low slump. However, beyond a certain threshold, the slump increases rapidly until it reaches an upper threshold value.
Numerical study on the effect of perforations on the wave dissipation characteristics of “Horse-hoof-shaped hollow piles breakwaters”
This paper investigates the effect of perforations on the wave dissipation characteristics of Horse-hoof-shaped hollow pile breakwaters (HHPBs) using the Flow3D model. The results indicate that, with varying wave parameters and sea water levels, the wave dissipation coefficient (Kl) varies between 0.59 and 0.82, the transmission coefficient (Kt) varies between 0.24 and 0.63, and the reflection coefficient (Kr) ranges from 0.33 to 0.6, as the perforated ratio on the front side changes from 9.6% to 14%, while the perforated ratio on the rear side remains constant at 11.31%. In particular, the maximum wave energy dissipation (67%) occurs when the front-rear side ratio is 12% - 11.31% and the ratio of water depth to wave height (d/H) is 0.8.
Initiatives on engineering solutions for Cua Tung and the northern beach of the estuary in Quang Tri province
Cua Tung estuary is one of the largest estuaries of Quang Trị province in Central Vietnam. The beach here is beautiful and well-known for tourist in the past. But it has been eroded thus reducing tourist attraction. Cua Tung estuary serves as an important waterway, flushing out floodwater from Ben Hai river to the sea. The complexity of hydrodynamic regime in Cua Tung estuary and vicinity area is a main driver to cause high variation on erosion and sedimentation. Erosion occurs in the north beach area leading to reduction of open space for tourist, meanwhile deposition accumulates in the south beach area of the Cua Tung estuary. The paper provides some initiatives on engineering solutions for Cua Tung estuary area and rehabilitating measures in the northern tourism beach of the estuary
Simulation methododlogy of sediment imbalance in calculation and forecast morphological changes at downstream of Thai Binh river
Hydraulic regime and morphology of a river section is in equilibrium if there is no human impact. However, under the human action impacts, the hydraulic regime and morphology of a river section have changed. The sediment imbalance in the river is usually caused by two factors, including the decline of sediment discharge from upstream when reservoirs were built and the sand mining. In particular, the sand mining process has a significant influence on the internal morphological changes as well as the river morphology at downstream section. In this article, a method of simulating the sand mining process on a mathematical model is presented and some results of morphological river prediction for the Thai Binh river are also shown in case of existing sand mining activities at the river upstream parts.
Studying into solutions for flood and inundation control in Bui basin and its vicinity
Bui river is a tributary of the Day river that flows in the territory of Hanoi city and Hoa Binh province. The downstream part of the Bui river, located in the districts of Chuong My and Quoc Oai of Hanoi, is where heavy rains often occur, causing serious impacts on people, especially the floods in 2008, 2017, and 2018. This study used the MIKE hydraulic model, ArcGIS software, and Google Earth to build inundation maps and evaluate effectiveness of flood defense solutions. Options have been proposed to prevent and control flooding and inundation for the Bui river basin and its vicinity, including Restoration of the Tich, Bui and Day rivers; Upgrading and building new reservoirs; Building channels to isolate mountain floods; Upgrading and building new dikes; Upgrading and building new drainage pumping stations, detention basins, and relocation in vulnerable areas. In addition, the study also estimated the number of households to be relocated and the required costs to implement these solutions
Calculation of flood discharge and storage capacity by climate change scenarios in Rach Bau Ha, Tuy Hoa city using the mike model
The climate and topography characteristics of Tuy Hoa city, Phu Yen province are quite complicated and being affected by most types of natural disasters, in which storms and floods frequently occur in the downstream of rivers. Huge amount of water from upstream in combination with local downpour have caused numerous flash floods. Rach Bau Ha, the main flood-discharge of the city, is a low-lying area and often being submerged during rainstorms. This article aims to apply MIKE model in forecasting the flood discharge and storage capacity of Rach Bau Ha response to climate change scenarios and proposing appropriate alternatives for the purpose of minimizing flood in the research area. Collected hydro-meteorological, topographical and geological data, previous research results, synthesis, analysis and calculation of designed hydro-meteorological characteristics will be used as input for the MIKE model. The results show that the cross-sectional area and lake area of Rach Bau Ha according to a scenario (lake surface area F = 12.50 ha) completely ensure the flood discharge and storage of Rach Bau Ha, without much increase of the maximum water level and inundation duration, ensure that the water levels of the canal shall not affect inhabitants and infrastructure of the vicinity
A model for simulation of acid water in canals and linkage to acid sulphate soil model
It is given in this paper an attempt to consider the problem of canal acid water in linkage to the ground acid water with the presence of the alunite and jurbanite in the soil. 1D model is applied for canals while 2D depth-average model is used to simulate the processes occurred in the soil. Data of 1995 collected at Tan Thanh farm, in the Plain of Reeds of the Mekong Delta in Vietnam, are used as a case study.
Prediction of pile capacity using artificial neural network with two hidden
The bearing capacity of the pile is an important factor in the design of the pile foundation. Determining the bearing capacity of piles through in situ load testing is costly and time consuming. The purpose of this study is to show the applicability of artificial neural network (ANN) to predict the axial load capacity of piles. The data set used to build and verify the ANN simulation tool includes 100 data of test results of pile load testing in Dong Van industrial zone - Ha Nam. After conducting trial and error, the structure of the selected ANN includes 10 input parameters, two hidden layers with the number of neurons in the two layers of 12 and 10 neurons, respectively. Programmed and run in the Python platform, the authors use the ANN model to predict the axial load capacity of the pile. The results show that ANN has good potential to be used as a pile bearing capacity prediction tool to help design engineers predict pile load capacity for minimizing the time experimental and expensive
Some research results using the cement, fly ash, ground blast furnace slag and magnesium oxide to improve the mechanical characteristics of the dredging mud in Ca Mau province
The article presents a study of stabilized dredged mud in brackish water in Ca Mau province. A method using a mixture of cement, finely crushed blast furnace slag, fly ash and magnesium oxide to improve the mechanical and physical properties of the dredged mud material. The dredged mud is used to replace sand leveling materials, embankment structures surrounding irrigation works. The results also show that using magnesium oxide in different proportions in the mixture of cement, finely crushed blast furnace slag and fly ash significantly improves the mechanical and mechanical properties of the hardened sludge, especially the compressive strength. This is a useful solution to reuse the dredged mud besides other solutions being used.