Water
Duyệt Water theo Nhan đề
- Ấn phẩmA model-based approach for improving surface water quality management in aquaculture using MIKE 11: A case of the Long Xuyen Quadangle, Mekong Delta, Vietnam(2022) Ut, Vu Ngoc; Avtar, Ram; OthersThis study utilized MIKE 11 to quantify the spatio-temporal dynamics of water quality parameters (Biochemical Oxygen Demand (BOD5), Dissolved Oxygen (DO) and temperature) in the Long Xuyen Quadrangle area of the Vietnamese Mekong Delta. Calibrated for the year of 2019 and validated for the year of 2020, the developed model showed a significant agreement between the observed and simulated values of water quality parameters. Locations near to cage culture areas exhibited higher BOD5 values than sites close to pond/lagoon culture areas due to the effects of numerous point sources of pollution, including upstream wastewater and out-fluxes from residential and tourism activities in the surrounding areas, all of which had a direct impact on the quality of the surface water used for aquaculture. Moreover, as aquacultural effluents have intensified and dispersed over time, water quality in the surrounding water bodies has degraded. The findings suggest that the effective planning, assessment and management of rapidly expanding aquaculture sites should be improved, including more rigorous water quality monitoring, to ensure the long-term sustainable expansion and development of the aquacultural sector in the Long Xuyen Quadrangle in particular, and the Vietnamese Mekong Delta as a whole.
- Ấn phẩmA Modern Mine Water Treatment Plant for Removal of Iron, Manganese and Coaldust is put into Operation in Northern Vietnam.Bilek, Felix; Kurtz, Stefan; Brömme, Katrin; Stolpe, Harro; Kochan, Jürgen; Schlenstedt, JörgThe RAME research project started its first activities in Vietnam at the end of 2005. The aim of the BMBF (German Federal Ministry of Education and Research) funded research and development project is to develop methods to reduce the environmental impactsdue to hardcoal mining in Quang Ninh province / Vietnam by selected technical measures and enhancement of the environmental management. Based on a preliminary survey, dump stabilization and recultivation, mine water treatment, dust mitigation and post-mining land use were identified as main research fields which are implemented in several subprojects. This publication highlights the RAME research results on mine water treatment.
- Ấn phẩmAllocating water in the Mekong River basin during the dry season(2019) Yuan, Liang; He, Weijun; Liao, Zaiyi; OthersWith population numbers increasing and anthropogenic climate change, the amount of available fresh water is declining. This scenario can lead to an increase in the occurrence of water conflicts, especially in transboundary river basins. Prevention strategies to avert water conflicts by designing a fair, efficient, and sustainable water allocation framework are needed. Taking into account the socioeconomic and environmental differences among the riparian countries is one of the most important features an allocation scheme should have. In this article, bankruptcy and bargaining games were used to construct a new weighted water allocation model. The proposed method was applied to allocate the contested water capital of the Mekong River during the dry season. The Mekong River originates in China and flows through Myanmar, Laos, Thailand, Cambodia, and Vietnam. The results of the allocation showed that, except for China and Vietnam, all the other riparian countries get their full claim of the water demand from the river. The water allocation payoffs satisfy individual rationality, Pareto optimality, and maximization of the group utility. Therefore, the allocation outputs from the proposed scheme are self-enforceable and sustainable.
- Ấn phẩmAllocating water in the Mekong River basin during the dry season(2019) Yuan, Liang; He, Weijun; Liao, Zaiyi; OthersWith population numbers increasing and anthropogenic climate change, the amount of available fresh water is declining. This scenario can lead to an increase in the occurrence of water conflicts, especially in transboundary river basins. Prevention strategies to avert water conflicts by designing a fair, efficient, and sustainable water allocation framework are needed. Taking into account the socioeconomic and environmental differences among the riparian countries is one of the most important features an allocation scheme should have. In this article, bankruptcy and bargaining games were used to construct a new weighted water allocation model. The proposed method was applied to allocate the contested water capital of the Mekong River during the dry season. The Mekong River originates in China and flows through Myanmar, Laos, Thailand, Cambodia, and Vietnam. The results of the allocation showed that, except for China and Vietnam, all the other riparian countries get their full claim of the water demand from the river. The water allocation payoffs satisfy individual rationality, Pareto optimality, and maximization of the group utility. Therefore, the allocation outputs from the proposed scheme are self-enforceable and sustainable.
- Ấn phẩmAn assessment of groundwater quality for drinking and agricultural purposes in Ca Mau peninsula, Vietnamese Mekong Delta(2022) Van, Le Thi Mai; Le, Vo Phu; OthersGroundwater serves as the major source for drinking water and the only fresh water source in the dry season in Ca Mau province, the Vietnamese Mekong Delta. The study is performed to assess groundwater quality in the area. Groundwater Quality Index (GWQI), magnesium hazard (MH), sodium percentage (Na%), sodium adsorption ratio (SAR), permeability index (PI) combined with geostatistical tools were conducted by using groundwater quality data from 400 samples collected from private wells. GWQI values suggest that 7%, 63%, 28%, 2%, 1% of total samples are classified into excellent, good, poor, very poor and unsuitable for drinking water. High Cl and TDS are the main cause of high GWQI values suggesting that saltwater intrusion deteriorates groundwater quality. For irrigation purposes, 4%, 17%, 36%, 43% of total samples classify into Good, Permissible, Doubtful, Unsuitable respectively by Na% indicator; 55.0%, 30.9%, 11.9%, 2.2% of total samples is Excellent, Good, Doubtful and Unsuitable according to SAR, 54% samples are unsuitable by MH index, and all samples are good by PI. This study provides useful information on groundwater quality for various purposes in Ca Mau province, that could help water management and water users to identify the necessary approach for groundwater protection and water-treatment methods before utilising the groundwater source for specific purposes in the study area.
- Ấn phẩmApplication of remote sensing in detecting and monitoring water stress in forests(2023) Son, Le Thai; Harper, Richard; Dell, BernardIn the context of climate change, the occurrence of water stress in forest ecosystems, which are solely dependent on precipitation, has exhibited a rising trend, even among species that are typically regarded as drought-tolerant. Remote sensing techniques offer an efficient, comprehensive, and timely approach for monitoring forests at local and regional scales. These techniques also enable the development of diverse indicators of plant water status, which can play a critical role in evaluating forest water stress. This review aims to provide an overview of remote sensing applications for monitoring water stress in forests and reveal the potential of remote sensing and geographic information system applications in monitoring water stress for effective forest resource management. It examines the principles and significance of utilizing remote sensing technologies to detect forest stress caused by water deficit. In addition, by a quantitative assessment of remote sensing applications of studies in refereed publications, the review highlights the overall trends and the value of the widely used approach of utilizing visible and near-infrared reflectance data from satellite imagery, in conjunction with classical vegetation indices. Promising areas for future research include the utilization of more adaptable platforms and higher-resolution spectral data, the development of novel remote sensing indices with enhanced sensitivity to forest water stress, and the implementation of modelling techniques for early detection and prediction of stress.
- Ấn phẩmAssessing water resources management and development in Northern VietnamCastelletti, A; Pianosi, F; Quach, X; Sessa, Soncini. RIn many developing countries water is a key renewable resource to complement carbon-emitting energy production and support food security in the face of demand pressure from fast-growing industrial production and urbanization. To cope with undergoing changes, water resources development and management have to be reconsidered by enlarging their scope across sectors and adopting effective tools to analyze current and projected infrastructure potential and operation strategies. In this paper we use system analysis and optimal control to assess the current reservoir operation and planned capacity expansion in the Red River Basin (Northern Vietnam), and to evaluate the potential improvement by the adoption of a more sophisticated information system. Results show that the current operation can only be relatively improved by advanced optimization techniques, while investment should be put into enlarging the system storage capacity and exploiting additional information to inform the operation.
- Ấn phẩmAssessment of surface water quality in a drinking water supply reservoir in Vietnam: a combination of different indicators(6/23/2022) Pham Thanh, Luu; Tran Thanh, Thai; Tran Thi Hoang, YenEutrophication and water pollution have become serious aquatic environmental problems worldwide. In this study, four different water quality indexing methods, the Canadian Council of Ministers of Environment Water Quality Index (CCME WQI), the revised Comprehensive Pollution Index (CPI), the Eutrophication Index (EI), and the Trophic State Index (TSI), were used to investigate water quality and trophic status in the Tri An Reservoir (TAR), Vietnam. Nineteen water variables were monitored bimonthly between February 2018 and December 2019 to calculate these four indices. Although different input data sets were used, all the indices showed similar results in terms of water quality and eutrophic state. The CCME WQI ranged from 32 to 68 (median 36–48), which indicated that the water quality was classified between poor and marginal and was insufficient for domestic purposes. Similarly, the water quality was ranked between slightly polluted and medium polluted based on the revised CPI index, with the median values ranging from 0.72 to 0.94. In the CCME WQI and the CPI, the major parameters that contributed to water pollution in the TAR were turbidity, dissolved oxygen (DO), total suspended solids (TSS), chemical and biological oxygen demand (BOD5), ammonium (NH4+), nitrite (NO2−), iron (Fe), lead (Pb), and coliforms. Regarding the trophic status of water, the EI ranged from 10 to 464, indicating that the reservoir was eutrophic, and the TSI values ranged from 53 to 89, indicating that the water quality was classified between light-eutrophic and hypereutrophic conditions. A temporal variation in water quality was found, with the highest levels of pollution recorded in June during the study period. Our results show that the combination of different water quality indices provides a comprehensive assessment of water quality in the TAR.
- Ấn phẩmAttempting the Production of Public Goods Through Microfinance: The Case of Water and SanitationMader, PhilipThis paper evaluates the attempt to create public goods via microfinance loans. Microfinance loans in the production of goods with public goods characteristics signify an emergent micro-privatisation. As a case study, the production of water and sanitation resources via microfinance loans is examined in India and Vietnam. It is found that microfinance projects for water and sanitation, which are based on individualism and a cost-recovery paradigm, ignore important collective action aspects and underlying distributional problems. Given its questionable effectiveness in other areas, the public goods iteration of microfinance leads not only to insufficient provision for the poor, but also may alienate these citizens from publicly accountable modes of governance and their human right to water.
- Ấn phẩmBasic water requirement and water budget study of Bac Ninh province (Vietnam)(2012-07) Pareta, KuldeepCareful use of the limited fresh water resources is the need of the hour. If sufficient measures are not taken up immediately, we will face a crisis which will be detrimental to the very survival of mankind. The Bac Ninh Province of Vietnam is facing a similar problem of acute shortage of drinking water. The water resources in this study area have been estimated by water balance assessment approach. The water balance study using the Thornthwaite and Mather (TM) models with the help of remote sensing and GIS is very helpful in finding out the moisture deficit and moisture surplus for an entire province. The water balance calculation shows that the maximum annual runoff results from the built-up areas/water body followed by agricultural land, and minimum for the barren land and open forest. The annual deficit in the Bac Ninh Province is 1362.2 mm and the annual surplus is 552.7 mm. The total runoff of Bac Ninh Province was calculated as 564.2 mm from the total precipitation of 1384.2 mm. The annual surface water availability for Bac Ninh Province works out at 564.23 mcm. Deducing 5%, which is usually regarded as natural discharge during non-monsoon months, thus region as 536.02 mcm as surface water availability. The current gross demand as drinking & domestic, irrigation purpose / agricultural used, and industrial used is 347.52 mcm (64.83%). The balance surface water availability for future development in the Bac Ninh Province is 188.50 mcm.
- Ấn phẩmCapacity building for the management, planning and coordination of the sanitation sector at subnational level in Vietnam: summary report.(6/10/2016) Menzies, IainThe combined effects of urbanization and economic growth have created increasing pressure onVietnam’s ageing and inadequate sanitation infrastructure and services. Water pollution by industrial wastewater also causes significant economic damage, impacting the quality and output of aquaculture products. In addition, wastewater from trade villages and aquaculture is causing adverse environmental impacts. In most urban centers up to 50 percent of the urban population are living in ‘deprived’ conditions and the environment is degraded by a number of factors relating to poor sanitation such as uncollected and untreated waste water, polluted surface water (rivers, lakes and coastal waters), polluted ground water, uncollected solid waste, clogged drainage systems, and industrial pollution. Another major challenge in Vietnam’s sanitation sector is the failure to provide satisfactory solid waste management services, which has resulted in air and water resource pollution. Eye, skin, and respiratory diseases are more common in the residential areas neighboring landfills that do not conform to national environmental regulations and standards. The Government has recognized these challenges and the need for an umbrella strategy to address all aspects of environmental sanitation in a comprehensive manner. The concept of a unified sanitation sector strategy came out of a regional water and sanitation meeting in 2005, and since then WSP has facilitated a national-level dialogue leading to the formulation of the Unified Sanitation Sector Strategy and Action Plan (U3SAP) proposal.
- Ấn phẩmChemical composition, radioactive and stable isotopes in several selected thermal waters in North Vietnam(2022) Rusiniak, Piotr; Chau, Nguyen Dinh; OthersThis work presents the chemical composition and concentration of radioactive and stable isotopes in water samples collected from nine well-known therapeutic centers located in north Vietnam. Excluding the Thanh Thuy – Phu Tho waters, which are hosted in Pleistocene sandstone with marble and gravel, the rest of studied waters are hosted in Paleozoic limestone formations. The thermal waters are extracted from 10 to 400 m below the surface, but the Keng Ga Ninh Binh intake is of an artesian nature. The temperature measured in the outlet waters ranges from 39 ◦C to 61 ◦C. The δ18O and δ2 H (δD) vary from − 9.13 to − 5.09 ‰ and − 63.9 to − 34.1 ‰ respectively. All the thermal waters examined originate from infiltration water. This is also confirmed by the values of selected calculated hydrochemical indices. The hydrochemical types of the waters are HCO3-Ca-Mg, HCO3-Na, Cl-Na, SO4-HCO3-Ca-Mg, SO4-Ca-Mg and SO4-Ca. The mineralization of the concerned waters varies from 244 mgL− 1 to more than 11,500 mgL− 1 . The concentrations of uranium and radium in the waters are in the broad interval from about 4 mBqL− 1 to 680 mBqL− 1 for 238U and from below 5 mBqL− 1 (limit of detection - LOD) to above 3400 mBqL− 1 for 226Ra. There is no 228Ra in most of the waters (below 10 mBqL− 1 - LOD), excluding two waters in the Thanh Thuy-Phu Tho district, where 228Ra is present with 18 and 27 mBqL− 1 . In all the waters studied, there is a very low concentration of polonium ( 210Po) which varies from 0.5 mBqL− 1 to 8.2 mBqL− 1 . High mineralization and high radium concentration should be associated with a long residence time in the given geological formation. The linear relationship between the depth of the host water formations and the water temperature suggests that the study waters are mostly heated from the geogradient of heat energy. But the water from the My Lam district is probably heated by intrusive magmatic fluid. From a radiological point of view, the waters used for therapeutic and relaxation purposes are safe, however, there would be some problems if they were to be used for drinking purposes.
- Ấn phẩmChina, an upstream hegemon: A destabilizer for the governance of the Mekong river?(4/10/2017) Han, HeejinTransboundary rivers have remained one of the sources of contention and cooperation among states in international politics. The Mekong is one such river along which China and five Southeast Asian countries have organized their political, economic, and social lives. Studies examining the water politics of this river have argued that the lack of a comprehensive institution to govern this regional common pool resource and the growing power asymmetry between China, an upstream riparian state, and its Southeast Asian neighbors dampen the prospect for an effective governance of the river. Particularly, the economic rise of China and its concomitant increase in demand for energy and water resources has raised concerns about the negative impacts that this would have on the downstream countries. Examination of recent developments regarding the Mekong River suggests, however, that China has adopted a more collaborative approach by engaging in joint development projects and exchanging information and technology via existing sub-regional and regional multilateral bodies since the early 2000s. The study concludes that this growing evidence of cooperation should be taken into consideration for a more comprehensive understanding of China's policy towards the Mekong River
- Ấn phẩmDecision-making for systemic water risks: Insights from a participatory risk assessment process in Vietnam.(3/25/2018) Wyrwoll, Paul R.; Grafton, R. Quentin; Daniell, Katherine A.; Long, Chu Hoang; Ringler, Claudia; Lien, Le Thi Ha; Khoi, Dang Kim; Nam, Do Thang; Tuan, Nguyen Do AnhSystemic threats to food-energy-environment-water systems require national policyresponses. Yet complete control of these complex systems is impossible and attempts to mitigatesystemic risks can generate unexpected feedback effects. Perverse outcomes from national policy canemerge from the diverse responses of decision-makers across different levels and scales of resource gov-ernance. Participatory risk assessment processes can help planners to understand subnational dynamicsand ensure that policies do not undermine the resilience of social-ecological systems and infrastructurenetworks. Researchers can play an important role in participatory processes as both technical special-ists and brokers of stakeholder knowledge on the feedbacks generated by systemic risks and policydecisions. Here, we evaluate the use of causal modeling and participatory risk assessment to developnational policy on systemic water risks. We present an application of the Risks and Options Assessmentfor Decision-Making (ROAD) process to a district of Vietnam where national agricultural water reformsare being piloted. The methods and results of this project provide general insights about how to supportresilient decision-making, including the transfer of knowledge across administrative levels, identificationof feedback effects, and the effective implementation of risk assessment processes
- Ấn phẩmDetermination of seven parabens in surface water samples by UHPLC-MS/MS and solid-phase extraction(2022) Thuy, Quan Cam; Minh, Bui Quang; OthersParabens are considered one of the ideal preservatives in numerous consumer products due to their high antimicrobial properties. Nevertheless, parabens have the following potentially detrimental effects on human health such as adverse effects on male reproductive system, or accelerated skin aging process and breast cancer. Here, ultra-high performance liquid chromatography (UHPLC) coupled with a triple quadrupole mass spectrometry (MS/MS) combined with a solidphase extraction procedure was optimized for measuring seven parabens in surface water and proposed as a modified analytical method. The optimized protocol was validated according to the requirements of European standard SANTE/12682/2019. The limits of detection and quantification of the method obtained were 0.04 and 0.82 ng L-1 , respectively. The validated method was applied to analyzing surface water samples collected in Hanoi, Vietnam, indicating not only the presence of seven targeted parabens but also the prevalence of methylparaben in all water samples.
- Ấn phẩmDetermine the vulnerability of urban surface water resources in Rach Gia City, Vietnam using geographic information system.(2019) Hai, Dinh Tuan; Phin, Trinh ThiRach Gia city is located on the west coast of Mekong Delta, Vietnam. Due to the high salinity intrusion of underground aquifers, urban surface water is the main source of mining. Water retention consists of reservoirs with around 600,000 m3 and 3.2 km length of a canal. These resources are taken from rivers and canals in the area. However, urban surface water in the area is contaminated by human activities such as wastewater discharge and waterway traffic. Furthermore, in dry seasons when water levels in rivers and canals reach low salinity intrusion infiltrate into rivers, affecting water supplies. Therefore, it is necessary to identify the vulnerabilities of pollution on reservoirs and canals. This study employs a spatial analysis model integrating several previously defined parameters such as slope, land use, drainage network density, runoff and salinity levels. They will be prioritized and weighted and then integrated into a geographic information system (GIS). Results indicated drainage network density and land use are majors to cause vulnerability of pollution on an urban surface water resource. Despite the subjectivity involved in the weighing of analytic hierarchy process (AHP), the study determined vulnerability levels as well as factors that cause pollution. These results will support to protect urban surface water resources.
- Ấn phẩmDiagnosing challenges and setting priorities for sustainable water resource management under climate change(2022) Mohammed, Ibrahim Nourein; Bolten, John D.; OthersManaging transboundary river basins requires balancing tradeoffs of sustainable water use and coping with climate uncertainty. We demonstrate an integrated approach to exploring these issues through the lens of a social-ecological system, combining remote and in-situ earth observations, hydrologic and climate models, and social surveys. Specifically, we examine how climate change and dam development could impact the Se Kong, Se San and Sre Pok rivers in the Mekong region. We find that climate change will lead to increased precipitation, necessitating a shift in dam operations, from maintaining low flows to reducing flood hazards. We also find that existing water governance systems in Laos, Vietnam, and Cambodia are ill-prepared to address the problem. We conclude that the solution space for addressing these complex issues will be highly constrained unless major deficiencies in transboundary water governance, strategic planning, financial capacity, information sharing, and law enforcement are remedied in the next decades.
- Ấn phẩmDomestic water qualities of khmer minority communities in the Mekong Delta, Vietnam(2022) Man, Dang Minh; Huy, Nguyen NhatA study on the domestic water quality of Khmer minority communities was carried out in An Giang and Soc Trang provinces in the Mekong Delta, Vietnam. The research revealed that the exploitation and management of domestic water source differed between two provinces. Groundwater and rainwater are major domestic water sources of Khmer communities in Tri Ton and Tinh Bien District of An Giang Province, while rainwater is the most widely used domestic water form of Khmer community in Soc Trang Province. After domestic water quality parameters, including pH, BOD5, COD, total-Fe, arsenic, hardness, E. coli, and total coliforms, were tested, the experimental data showed that the domestic water samples of Khmer communities in the two provinces contaminated by organic matter and microbial infection, which was due to living habits and low cognition about domestic water quality of the Khmer people. Thus, suggestion for the enhancement of domestic water quality is needed to improve living standard for rural Khmer minority communities.
- Ấn phẩmDouble exposures: Future water security across Urban Southeast Asia.(2019) Lorenzo, Theresa E.; Kinzig, Ann P.Southeast Asia is one of the most dynamic regions in the world in terms of economic growth and urbanization. At the same time, the region is also prone to multiple hydro-meteorological disasters, which are projected to be intensified by climate change. This paper analyzes the combined effect of economic development and climate change on the future water security of middle-income Southeast Asian countries using the double exposure framework, focusing on the effects in urban areas. A review of the existing literature reveals unequal water security outcomes across the region as a result of combined climate, economic, and urbanization pressures. The water supply and sanitation infrastructure of upper-middle-income Southeast Asian countries are vulnerable to damage from intensified disasters, potentially decreasing both immediate and longer-term water quality. In lower-middle-income countries, the water quality will be the more important water security challenge in the short-term as opposed to water quantity, mainly due to the fast growth of industries. Lower-middle-income countries, though less vulnerable to disasters, will still have lower future water security compared to upper-middle-income countries, as they have less capacity to address water quality and quantity challenges brought about by both industrial growth and urbanization. Across the region, future water quantity and quality challenges may result in slower economic and urban growth if not planned adequately.
- Ấn phẩmEffects of multi-dike protection systems on surface water quality in the Vietnamese Mekong Delta(2019) Minh, Huynh Vuong Thu; Ty, Tran Van; Dat, Tran Quoc; OthersThe Vietnamese Mekong Delta (VMD) is one of the largest rice-growing areas in Vietnam, and exports a huge amount of rice products to destinations around the world. Multi-dike protection systems have been built to prevent flooding, and have supported agricultural intensification since the early 1990s. Semi-dike and full-dike systems have been used to grow double and triple rice, respectively. Only a small number of studies have been conducted to evaluate the water quality in the VMD. This study aimed to analyze the spatiotemporal variation of water quality inside the dike-protected area. Surface water samples were collected in the dry and wet seasons at 35 locations. We used multivariate statistical analyses to examine various water quality parameters. The mean concentrations of COD, NH4 +, NO3 −, PO4 3−, EC, and turbidity were significantly higher in water samples inside the full-dike system than in water samples from outside the full-dike systems and inside the semi-dike systems in both seasons. High concentrations of PO4 3− were detected in most of the primary canals along which residential, tourist areas and local markets were settled. However, NO3 − was mainly found to be higher in secondary canals, where chemical fertilizers were used for rice intensification inside the dike system. Water control infrastructures are useful for preventing flood hazards. However, this has an adverse effect on maintaining water quality in the study area.
- Ấn phẩmEffects of multi-dike protection systems on surface water quality in the Vietnamese Mekong Delta(2019) Minh, Huynh Vuong Thu; Ty, Tran Van; Dat, Tran Quoc; OthersThe Vietnamese Mekong Delta (VMD) is one of the largest rice-growing areas in Vietnam, and exports a huge amount of rice products to destinations around the world. Multi-dike protection systems have been built to prevent flooding, and have supported agricultural intensification since the early 1990s. Semi-dike and full-dike systems have been used to grow double and triple rice, respectively. Only a small number of studies have been conducted to evaluate the water quality in the VMD. This study aimed to analyze the spatiotemporal variation of water quality inside the dike-protected area. Surface water samples were collected in the dry and wet seasons at 35 locations. We used multivariate statistical analyses to examine various water quality parameters. The mean concentrations of COD, NH4 +, NO3 −, PO4 3−, EC, and turbidity were significantly higher in water samples inside the full-dike system than in water samples from outside the full-dike systems and inside the semi-dike systems in both seasons. High concentrations of PO4 3− were detected in most of the primary canals along which residential, tourist areas and local markets were settled. However, NO3 − was mainly found to be higher in secondary canals, where chemical fertilizers were used for rice intensification inside the dike system. Water control infrastructures are useful for preventing flood hazards. However, this has an adverse effect on maintaining water quality in the study area.
- Ấn phẩmEffects of multi-dike protection systems on surface water quality in the Vietnamese Mekong Delta(2019) Minh, Huynh Vuong Thu; Ty, Tran Van; Dat, Tran Quoc; OthersThe Vietnamese Mekong Delta (VMD) is one of the largest rice-growing areas in Vietnam, and exports a huge amount of rice products to destinations around the world. Multi-dike protection systems have been built to prevent flooding, and have supported agricultural intensification since the early 1990s. Semi-dike and full-dike systems have been used to grow double and triple rice, respectively. Only a small number of studies have been conducted to evaluate the water quality in the VMD. This study aimed to analyze the spatiotemporal variation of water quality inside the dike-protected area. Surface water samples were collected in the dry and wet seasons at 35 locations. We used multivariate statistical analyses to examine various water quality parameters. The mean concentrations of COD, NH4 +, NO3 −, PO4 3−, EC, and turbidity were significantly higher in water samples inside the full-dike system than in water samples from outside the full-dike systems and inside the semi-dike systems in both seasons. High concentrations of PO4 3− were detected in most of the primary canals along which residential, tourist areas and local markets were settled. However, NO3 − was mainly found to be higher in secondary canals, where chemical fertilizers were used for rice intensification inside the dike system. Water control infrastructures are useful for preventing flood hazards. However, this has an adverse effect on maintaining water quality in the study area.
- Ấn phẩmEffects of multi-dike protection systems on surface water quality in the Vietnamese Mekong Delta(2019) Minh, Huynh Vuong Thu; Ty, Tran Van; Dat, Tran Quoc; OthersThe Vietnamese Mekong Delta (VMD) is one of the largest rice-growing areas in Vietnam, and exports a huge amount of rice products to destinations around the world. Multi-dike protection systems have been built to prevent flooding, and have supported agricultural intensification since the early 1990s. Semi-dike and full-dike systems have been used to grow double and triple rice, respectively. Only a small number of studies have been conducted to evaluate the water quality in the VMD. This study aimed to analyze the spatiotemporal variation of water quality inside the dike-protected area. Surface water samples were collected in the dry and wet seasons at 35 locations. We used multivariate statistical analyses to examine various water quality parameters. The mean concentrations of COD, NH4 +, NO3 −, PO4 3−, EC, and turbidity were significantly higher in water samples inside the full-dike system than in water samples from outside the full-dike systems and inside the semi-dike systems in both seasons. High concentrations of PO4 3− were detected in most of the primary canals along which residential, tourist areas and local markets were settled. However, NO3 − was mainly found to be higher in secondary canals, where chemical fertilizers were used for rice intensification inside the dike system. Water control infrastructures are useful for preventing flood hazards. However, this has an adverse effect on maintaining water quality in the study area.
- Ấn phẩmEffects of multi-dike protection systems on surface water quality in the Vietnamese Mekong Delta(2019) Minh, Huynh Vuong Thu; Ty, Tran Van; Dat, Tran Quoc; OthersThe Vietnamese Mekong Delta (VMD) is one of the largest rice-growing areas in Vietnam, and exports a huge amount of rice products to destinations around the world. Multi-dike protection systems have been built to prevent flooding, and have supported agricultural intensification since the early 1990s. Semi-dike and full-dike systems have been used to grow double and triple rice, respectively. Only a small number of studies have been conducted to evaluate the water quality in the VMD. This study aimed to analyze the spatiotemporal variation of water quality inside the dike-protected area. Surface water samples were collected in the dry and wet seasons at 35 locations. We used multivariate statistical analyses to examine various water quality parameters. The mean concentrations of COD, NH4 +, NO3 −, PO4 3−, EC, and turbidity were significantly higher in water samples inside the full-dike system than in water samples from outside the full-dike systems and inside the semi-dike systems in both seasons. High concentrations of PO4 3− were detected in most of the primary canals along which residential, tourist areas and local markets were settled. However, NO3 − was mainly found to be higher in secondary canals, where chemical fertilizers were used for rice intensification inside the dike system. Water control infrastructures are useful for preventing flood hazards. However, this has an adverse effect on maintaining water quality in the study area.