Environment
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- Ấn phẩmAbundance and sources of plastic debris on beaches in a plastic hotspot, Nha Trang, Viet Nam(2023) Fruergaard, MikkelViet Nam is challenged by extensive marine plastic pollution, however, remediation efforts are hampered by undefined sources to the coastal environment. This study surveyed the abundance, type, and source of beached plastic litter at seven beaches along the coast of Nha Trang, Viet Nam. A total of 4754 beached plastic litter items (>2 cm) yielded a mean abundance of 19.8 ± 19.5 items m− 2 corresponding to 116 ± 226 g DW m− 2 . Our results demonstrate that plastic litter related to fishing and aquaculture constituted at least 62 % of the total by weight and 38 % by number, showing that these two sectors are responsible for a significant part of the plastic pollution along the coast. Hence, we argue that improved management of the fishing and aquaculture sectors could substantially reduce marine plastic pollution along Viet Nam's coast.
- Ấn phẩmApplying an analytic hierarchy process and a geographic information system for assessment of land subsidence risk due to drought: A case study in Ca Mau Peninsula, Vietnam(2024) Doan, Quang TriThe increase in extreme weather events causes secondary hazards that can influence people and the environment enormously. The Ca Mau Peninsula is known as one of the areas most severely affected by drought, and excessive groundwater exploitation is one of the reasons leading to a higher risk of land subsidence. This study uses the Delphi method and the KAMET rule table to analyze and select indicators that affect subsidence. The study uses the analytic hierarchy process (AHP) analytical hierarchy method to evaluate the weights of influencing factors, combined with geographic information system (GIS) technology to overlay the map layers of the main influencing factors and build a subsidence risk warning zoning map of the study area. The influencing factors selected to evaluate the impact on land subsidence in the study area during the drought period included geological structure, soil characteristics, groundwater flow exploitation, water flow in the dry season, current land use status, and evaporation in the dry season. The weights of these factors were evaluated based on the synthesis of relevant documents as well as consultation with experts. The results indicate that nearly two-thirds of the Ca Mau Peninsula area is currently at very low or low risk of subsidence. Meanwhile, 23% of the area is at medium risk, nearly 9% is at high risk, and 0.1% of the study area is at very high risk. Subsidence risk warning zoning maps can provide a visual and general overview of areas with high subsidence risk, supporting managers in making reference plans for socio-economic development in the Ca Mau Peninsula.
- Ấn phẩmImplementation of nature-based solutions in urban water management in Viet Nam, a comparison among European and Asian countries(2024) Huynh, Thi Ngoc ChauClimate change is severely affecting all regions of the world, and urban water management has become a major urban challenge. Although nature-based solutions (NBSs) have been widely implemented in developed countries in the Global North to address stormwater-related challenges in urban areas, implementation of such approaches in Viet Nam and other Asian countries remains limited. In addition, comprehensive and critical reviews of NBS adoption and development processes in Viet Nam are scarce. This study aims to clarify several aspects through a literature-based review: to understand the development of urban water management in Europe and Asia (China and Southeast Asian countries) along with the drivers for NBS implementation in Viet Nam, to explain the barriers to NBS adoption in Viet Nam, to present feasible solutions for promoting NBS adoption, and to explore future perspectives for NBS development in the context of Viet Nam. Although significant barriers exist, opportunities for NBS implementation are evident. The findings of this study can be used to promote NBS in other municipalities in developing countries.
Ấn phẩmCalibration and verification of a coupled model for the coastal and estuaries in the Mekong River Delta, Vietnam(2026) Trinh, Dinh Lai; Nguyen, Viet ThanhThis study focuses on the calibration and verification of a large-scale coupled numerical model to simulate the complex hydrodynamic–wave–sediment transport processes in the coastal and estuarine regions of the Mekong River Delta (MRD), Vietnam. Using the MIKE 21/3 modeling system, the research integrates Hydrodynamics (HD), Spectral Wave (SW), and Mud Transport (MT) modules across a computational domain of 270 × 300 km. The models were rigorously tested using field measurement data from three distinct periods: May 2004 (dry season calibration), September 2017 (first verification), and June 2024 (second verification). The results from the hydrodynamic model demonstrated high accuracy in predicting water levels, with the average Root Mean Square Error (RMSE) values ranging between 4.4% and 5.8%. The wave spectral model showed reliable performance, with the average RMSE values for wave height ranging from 15.1% to 18.0%. Furthermore, the Mud Transport module successfully captured suspended sediment concentrations (SSC), yielding average RMSE values between 26.0% and 32.1% after the fine-tuning of site-specific parameters such as critical shear stress for erosion and deposition. The study highlights the critical importance of utilizing site-specific sedimentological parameters to accurately predict morphological changes in highly dynamic estuarine environments. This validated model provides a robust tool for assessing coastal erosion and developing protection measures in regions that are increasingly vulnerable to climate change and human activities.- Ấn phẩmZero waste approaches in removing arsenic from water environment using iron coated pomelo peel adsorbent: Fixed-bed column scale and management spent adsorbents(2025) Nguyen, Thi HaiThis study presents a sustainable, zero-waste strategy for arsenic (As) removal from aquatic environments. Pomelo peel, as an agricultural by-product, was modified with iron to develop a novel adsorbent (PPCI), which was then applied in fixed-bed column experiments to eliminate both As(III) and As(V). The column system was tested under varying initial As concentrations (0.3 and 0.5 mg/L) and bed heights (50 and 100 mm). Accordingly, PPCI showed significantly higher adsorption efficacy for As(V) compared to As(III) under identical conditions. Notably, the maximum theoretical adsorption capacities, based on the Thomas model, were 8.54 ± 0.46 mg/g for As(V) and 5.83 ± 0.52 mg/g for As(III) at a concentration of 0.5 mg As/L and a bed height of 100 mm. To ensure environmental safety post-treatment, the spent adsorbent was encapsulated via a stabilization/solidification (S/S) process and repurposed as construction materials. A total of 12 concrete brick samples incorporating As-laden PPCI with various cement and lime ratios were fabricated and evaluated. These bricks met the requirements of Vietnamese national standards for compressive strength and water absorption properties. Importantly, the amount of As leaching from the bricks ranged from 0.11 ± 0.010 µg/L – 7.34 ± 0.031 µg/L, which is far below the USEPA threshold of 5 mg/L. Overall, this integrated approach not only effectively removes As from water but also addresses the eco-friendly disposal and valorization of spent adsorbent, offering a promising solution for sustainable water treatment alongside waste reuse in construction applications.
- Ấn phẩmA systematic investigation of flood resilience measures in the Mekong River Basin(2025) Ho, Thanh PhuocThe Mekong River has encountered severe flooding challenges due to increasingly extreme weather conditions. Despite these challenges, residents of the Mekong River Basin (MRB) have developed and demonstrated remarkable flood resilience in various ways, enabling a dynamic and thriving socio-economic system in the floodprone environment. This study presents a systematic review and meta-analysis based on 460 search results from Scopus and Web of Science datasets, covering literature from 1999 to 2024, focused on the MRB. The review aims to investigate the measures developed by people in the MRB to improve their flood resilience, as determined through a comprehensive scoping review of peer-reviewed literature. The review revealed the following findings: (1) A total of 85 measures were identified and categorized into nine measure groups and three approaches based on their characters, (2) statistical analysis indicates a rising trend in stakeholder cooperation, with over 66 % of the total mentioned measures involving coordinated approaches rather than being strictly top-down or bottomup, (3) infrastructure and engineering investments, as well as advancements in agricultural technology, were the dominant measures observed across Mekong River Basin countries, and (4) a Venn diagram illustrates overlapping measures applied across various countries, with Vietnam, Cambodia, and Thailand contributing significant efforts to improving flood resilience. This study provides valuable insights for policymakers and researchers into the flood resilience situation within the region, supporting the development of effective future flood management frameworks and research approaches.