Journal of Science on Natural Resources and Environment

1. GEOLOGICAL - GEOMORPHOLOGICAL VALUES AND CONSERVATION, THE WORLD'S NATURAL HERITAGE OF HA LONG BAY, QUANG NINH, VIETNAM

Nguyen Quang Minh — 2025-12-31

Ha Long Bay is a World Natural Heritage site of Vietnam, recognized twice by UNESCO in 1994 and 2000 for its outstanding geological and geomorphological values, particularly its unique limestone topography, prominent karst islands, and caves above and below sea level. Currently, some islands and caves have been severely affected by erosion, collapse, and chemical corrosion caused by waves and seawater, which impacts the beauty of this natural heritage. The results presented in this paper provide additional information for managers in support of conservation efforts.

2. USING SENTINEL-1 SAR RADAR IMAGERY TO ASSESS FOREST PROTECTION EFFECTIVENESS IN CUC PHUONG NATIONAL PARK, VIETNAM

Nguyen Thi Thuy Hanh — 2025-12-31

Forest ecosystems in tropical regions face increasing threats from human pressures and climate variability, requiring reliable monitoring approaches to inform conservation and management. This study assesses forest changes in Cuc Phuong National Park, Vietnam, from 2017 to 2025 using Sentinel-1 Synthetic Aperture Radar (SAR) data and the Radar Forest Degradation Index (RFDI). The analysis distinguishes between undisturbed, degraded, and recovered forests across both core and buffer zones, providing additional insights at the commune level. Results reveal that the core zone retains a high proportion of undisturbed forest, demonstrating the effectiveness of strict protection policies, whereas the buffer zone shows more pronounced degradation associated with agricultural expansion, fuelwood extraction, and local livelihood activities. Nevertheless, areas of recovery in several communes point to the positive impacts of reforestation projects and community-based conservation initiatives. The findings highlight the spatial heterogeneity of forest change and underscore the need for tailored management strategies for core and buffer areas.

3. ASSESSMENT OF WATER QUALITY IN DAU TIENG LAKE IRRIGATION SYSTEM IN THE SOUTHEAST REGION, VIETNAM 2024

Nguyen Thi Lam — 2025-12-31

This study was conducted to assess the surface water quality of Dau Tieng reservoir. A total of 32 water samples were collected during the dry season (April 2024) and the rainy season (October 2024) from 16 monitoring sites across the reservoir. Fifteen water quality parameters were analyzed, including pH, BOD₅, COD, DO, TSS, NH₄⁺, NO₂⁻, NO₃⁻, PO₄³⁻, As, Pb, Cd, Cu, Fe, and Coliforms. The results were compared against the national surface water quality standards (QCVN 08:2023/BTNMT) and evaluated using the Water Quality Index (WQI). The findings indicated both seasonal and spatial variations in water quality. Several parameters exceeded permitted limits, particularly during the rainy season, with elevated concentrations of BOD₅, COD, NH₄⁺, Cu, and Fe observed frequently. WQI analysis showed that most water samples fell within the “average” to “good” quality categories, indicating suitability for agricultural irrigation and treated domestic use. However, certain areas, especially during the rainy season, exhibited signs of organic and nutrient pollution, highlighting the need for strengthened water management and pollution control measures.

4. FABRICATION OF A CATION Pb2+ BASED ON MULTI-WALLED CARBON NANOTUBES AND ALUMINUM OXIDE NANOPARTICLES

Do Thi Thuy — 2025-12-31

This study reports the synthesis and characterization of a novel nanocomposite adsorbent based on multi-walled carbon nanotubes functionalized with aluminum oxide nanoparticles (MWCNT_f/Al₂O₃) for the efficient removal of Pb²⁺ ions from aqueous solutions. The structural and morphological properties of the composite were investigated using transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), and thermogravimetric analysis (TGA). Adsorption data were fitted to the Langmuir isotherm model, revealing a maximum adsorption capacity of 81.3 mg/g for Pb²⁺ ions. These findings demonstrate the high potential of MWCNT_f/Al₂O₃ as an effective adsorbent for heavy metal ion removal in water treatment applications.

5. INVESTIGATING THE INTERACTION BETWEEN SURFACE WATER OF THE RED RIVER AND GROUNDWATER IN THE HOLOCENE AQUIFER IN THUONG CAT, HANOI

Tran Thanh Le — 2025-12-31

The interaction between surface water and groundwater is a natural activity and plays a crucial role in the sustainable development of water resources in Vietnam. Meanwhile, few researchers and organizations pay attention to that, so we decided to investigate the interaction between surface water and groundwater in Thuong Cat, Hanoi, Vietnam, in the riverside area of the Red River. In the research, three methods were chosen to investigate surface and groundwater interaction in the study area, including stable isotope analysis (¹⁸O and ²H), riverbank infiltration Lizi meter, and Seepage meter. The correlation coefficients between the ¹⁸O and ²H for the isotope analysis method were above 0.8 for both wet and dry seasons. While the measurement results from the Lizi meter and Seepage meter showed that the interaction is complex and could be impacted easily by external factors, such as infrastructure construction or exploitation of water resources. The results indicated that groundwater contributes to surface water in both dry and wet seasons.

6. FACTORS AFFECTING RESIDENTIAL LAND PRICE IN HA DONG DISTRICT, HA NOI CITY

Duong Dang Khoi — 2025-12-31

The purpose of this study is to evaluate the factors affecting residential land prices in the context of rapid urbanization in Ha Dong district. The study employed the sales data on the website of batdongsam.com to assess the current status of residential land prices in the study area. Then, the AHP-based land price factor analysis was employed to identify the key determinants of the residential land price in the study area. The results show that the location factors are the most important factors affecting residential land price. Economic factors also play important roles, while planning factors have a lower influence level. By observing individual factors within the group, the study reveals that the factors of distance to roads, access to social infrastructure, and GDP growth are the factors that most influence residential land price in the study area. Factors of technical infrastructure planning, industrial park planning, and interest rate have little influence on residential land price in the area. This result provides a practical basis for local land managers to adjust planning and residential land prices, contributing to sustainable urban development in Ha Dong district, Hanoi.

7. PROJECT-BASED LEARNING AND ITS EFFECTIVENESS IN ENHANCING SPEAKING SKILLS OF NON-ENGLISH MAJOR STUDENTS

Vu My Linh — 2025-12-31

This study examines the effectiveness of Project-Based Learning (PBL) in enhancing English speaking skills among non-English major students at Hanoi University of Natural Resources and Environment. A mixed-methods approach was employed with 48 first-year students, utilizing pre- and post-tests, as well as questionnaires. The findings revealed substantial improvement in students’ speaking performance, with noticeable progress in pronunciation, fluency, vocabulary, grammar, and comprehension. In addition, learners reported positive attitudes toward PBL, emphasizing increased motivation, confidence, and reduced anxiety when participating in speaking activities. The results suggest that PBL not only enhances linguistic outcomes but also contributes to affective and collaborative dimensions of language learning. These findings highlight the potential of PBL as an effective pedagogy in the Vietnamese higher education context, carrying important implications for curriculum design, teacher training, and the integration of student-centered learning approaches.

8. RESEARCH ON APPLYING MIKE 11 MODEL TO EVALUATE THE QUALITY OF WATER RECEIVING SOURCE FROM VINH YEN DOMESTIC WASTEWATER TREATMENT PLANT

Mai Quang Tuan — 2025-12-31

This study aims to assess the impact of wastewater discharge from the Vinh Yen 2 wastewater treatment plant on the water quality of the Phan River using the MIKE 11 model. The model simulated the spatial and temporal variations of key pollutants, including BOD₅, ammonium (NH₄⁺), total nitrogen (TN), and total phosphorus (TP), under two scenarios: with and without the operation of the Vinh Yen 2 plant. The results indicate that the operation of the plant significantly reduces pollutant concentrations in the downstream section of the Phan River, particularly for TN and TP, which remain below the limits of column B in QCVN 08:2023/BTNMT. These findings demonstrate the positive role of the new treatment system in improving regional water quality and support the sustainable management of wastewater in Vinh Phuc province.

9. LONG-TERM FIELD EFFECTS OF FRESH AND AGED BIOCHAR ON SOIL MICROBIAL COMMUNITY STRUCTURE

Nguyen Thi Thu Nhan — 2025-12-31

Understanding how soil microbial communities respond to biochar over time is essential for predicting its long-term effects on soil health and nutrient cycling. However, evidence from long-term field studies or repeated applications remains limited. This study examined how microbial communities involved in carbon and nitrogen processes differ between short-term and long-term wood biochar amendments in subtropical grassland soils (rhodic ferralsol). Four field treatments were compared: (i) NPK only (B0), (ii) newly applied biochar in 2019 (B1), (iii) biochar applied in 2010 (B9), and (iv) biochar applied in 2010 with reapplication in 2019 (B9 + 1). Using 16S rRNA gene sequencing, we found that recently applied biochar enhanced bacterial diversity and the abundance of carbon- and nitrogen-transforming taxa, whereas decade-old biochar supported more phototrophic communities, likely linked to higher dissolved organic carbon levels. Variations in microbial composition were primarily driven by soil pH, dissolved organic carbon, and total nitrogen. Notably, reapplication of biochar after long-term use (B9 + 1) did not alter microbial diversity, suggesting that the soil microbial community had stabilized to biochar-derived carbon inputs. These findings highlight that microbial responses to biochar evolve, underscoring the importance of long-term field observations to guide sustainable biochar management in subtropical soils.

10. APPLICATION OF LANDSAT-9 SATELLITE IMAGERY DATA ON THE GOOGLE EARTH ENGINE PLATFORM TO ASSESS THE LEVEL OF LST VARIATION IN THANH HOA CITY

Dang Thanh Tung — 2025-12-31

The phenomenon of Urban Heat Island (UHI) is a significant environmental issue that affects human health, air quality, and the quality of life for urban residents. This study uses Landsat-9 satellite imagery data to analyze the UHI phenomenon in the Thanh Hoa urban area during the Summer and Winter of 2024 - 2025. The Land Surface Temperature (LST) data from Landsat-9 were processed to determine the extent and magnitude of the urban heat island, while also investigating the relationship between factors such as building density, greenery, and land use types on the formation of UHI. The study found that the UHI in summer was 5.28 °C and in winter was 2.92 °C. Additionally, the results show the difference in LSTs between summer and winter. The research findings will provide deep insights into the impact of urbanization on the urban climate environment and propose solutions to mitigate the UHI effect in the Thanh Hoa urban area during the 2024-2025 period.

11. EVALUATION AND SELECTION OF SEA SURFACE TEMPERATURE DATA TO CALCULATE RAINFALL IN HUE CITY

Chinh Kien Nguyen — 2025-12-31

Sea Surface Temperature (SST) plays a crucial role in atmospheric processes such as evaporation and cloud formation. When the SST increases, the amount of water vapor in the atmosphere also rises, enhancing convection and leading to more intense rainfall. In this study, SST data from two sources - the Global Forecast System (GFS) of the National Oceanic and Atmospheric Administration (NOAA) and the Integrated Forecast System (IFS) of the European Centre for Medium-Range Weather Forecasts (ECMWF) - were used to assess their impact on the simulation of 20 rainfall events in Hue City during the period 2015 - 2025 using the WRF model. The simulation results at four rainfall observation stations (A Luoi, Hue, Nam Dong, and Thuong Nhat) indicate that the model's average accuracy improved by 6.25 % when using GFS SST data and by 13.75 % when using IFS SST data. In addition, SST data clearly enhanced simulation accuracy for rainfall events associated with weather systems such as storms, tropical depressions, northeast monsoon winds, easterly disturbances, and their combinations - except for cases influenced by the Intertropical Convergence Zone. Based on these results, the authors recommend using IFS SST data in the WRF model for more accurate rainfall calculation and forecasting in Hue City.

12. DEVELOPING AND TESTING A SET OF EVALUATION CRITERIA FOR LAND PRICE TABLES BASED ON VALUE ZONES AND STANDARD LAND PLOTS: A CASE STUDY IN O MON WARD, CAN THO CITY

Dang Thu Hang — 2025-12-31

This study aims to establish a set of criteria for inspecting and evaluating the process of constructing land price tables based on value zones and standard land parcels. The research methods employed include secondary investigation, primary investigation, and methods for developing a set of criteria to check and evaluate land price table construction, such as Exploratory Factor Analysis (EFA), linear regression, Analytic Hierarchy Process (AHP), and scale-based scoring. A survey was conducted to collect opinions from 150 respondents (including managers, officials from land valuation organizations, and experts). The study collected opinions from 150 respondents, including management officials, staff from land valuation organizations, and experts. The results identified a set of criteria consisting of six groups, which were ranked according to their relative influence and corresponding scores as follows: (1) Development of land price tables based on value zones and standard land parcels (Wi = 0.496 - 50 points); (2) Checking and evaluating amendments and supplements to land price tables (Wi = 0.147 - 15 points); (3) Compliance with principles (Wi = 0.103 - 10 points); (4) Organization and management (Wi = 0.101 - 10 points); (5) Human resources for developing land price tables (Wi = 0.100 - 10 points); and (6) Physical infrastructure (Wi = 0.052 - 5 points). The pilot test conducted in O Mon Ward, Can Tho city showed that the land price table development based on value zones and standard parcels achieved a score of 88 out of 100, classified as “PASS”. However, improvements are still needed in investigation, surveying, information collection, value zone selection, and the selection of standard land parcels.

13. COMPARATIVE PERFORMANCE OF LINEAR REGRESSION AND NEURAL NETWORK IN FORECASTING AIR QUALITY INDEX (AQI) IN HANOI

Tran Canh Duong — 2025-12-31

This study compares the forecasting performance of two machine learning models, namely linear regression and artificial neural networks, in predicting the Air Quality Index in Hanoi based on key pollution indicators, including PM_2.5, NO₂, SO₂, CO, and O₃. The dataset was expanded to improve model training and evaluation. Updated results show that neural networks, when properly optimized, achieve higher accuracy and greater stability compared to linear regression. Model performance was assessed using RMSE, MAE, and R². These findings suggest that nonlinear modeling approaches hold significant potential for environmental forecasting while maintaining a balanced comparison with traditional methods.

14. INVESTIGATING READING STRATEGIES OF ENGLISH MAJOR UNDERGRADUATES AT A PUBLIC UNIVERSITY IN HANOI

Hoang Thi Huong — 2025-12-31

This study examines the use of reading strategies among English major undergraduates at a public university during an academic reading course. The aims were to (a) compare the frequency and types of strategies reported before and after targeted instruction and (b) examine students’ perceptions of strategy usefulness for comprehension. Forty-two participants completed a mixed-methods protocol: quantitative data were collected with an adapted Survey of Reading Strategies, and qualitative insights were obtained from semi-structured interviews. Analysis of quantitative data revealed a significant increase in the application of pre-reading and while-reading strategies once explicit instruction was provided. Post-instruction, most students reported greater strategy awareness, faster reading rate, higher perceived comprehension accuracy, and increased confidence with academic texts. Drawing on these findings, the paper concludes with recommendations for future research directions and emphasizes pedagogical implications, particularly the importance of systematically incorporating appropriate reading strategies into language teaching curricula better to equip learners with effective tools for academic reading success.

15. EMISSION INVENTORY OF PIG HUSBANDRY ACTIVITIES IN LIEN MINH COMMUNE, NINH BINH PROVINCE

Bui Thi Thu Trang — 2025-12-31

The study assessed greenhouse gas (GHG) emissions from a 3,600-pig farm in Lien Minh commune, Ninh Binh province, using IPCC (2006) guidelines. The farm uses industrial feed and treats waste with a biogas system and composting. Results showed total emissions of 706.1 tons CO₂e/year, with CH₄ making up over 95 % due to anaerobic digestion. N₂O emissions came mainly from using post-biogas waste for irrigation or composting. Key emission factors included biogas recovery efficiency, waste treatment methods, and farm management practices.

16. SPATIAL-TEMPORAL VARIATION AND RELATIONSHIP OF PM₂.₅ AND PM₁₀ IN THE NORTHERN KEY ECONOMIC REGION OF VIETNAM

Pham Thi Hong Phuong — 2025-12-31

This study aimed to investigate the spatial-temporal variation and interaction of ambient PM₂.₅ and PM₁₀ in the Northern Key Economic Region of Vietnam, specifically in Hai Phong, Hung Yen, and Quang Ninh provinces. In July and October 2025, two 24-hour sample campaigns were held at traffic, residential, and background sites. PM₁₀ and PM_2.5 were collected during two campaigns in 2025 following the US EPA gravimetric reference methods (40 CFR Part 50, Appendix L and J). For PM₂.₅, the average concentrations were between 15.6 and 59.2 µg/m³, and for PM₁₀, they were between 26.7 and 105.9 µg/m³. Both of these values were higher than the WHO (2021) 24-hour limit. The concentrations consistently followed the order traffic > residential > background. The PM₂.₅/PM₁₀ ratio (0.52 - 0.71) showed that fine particles from combustion and traffic were the most common, and a significant connection (r = 0.9, p < 2.2e - 16) showed that the emissions came from the same places. These findings reveal persistent particulate pollution across northern Vietnam and emphasize the combined influence of anthropogenic activities and meteorological conditions. The study provides essential evidence for developing targeted air quality management and emission control policies under monsoonal climate conditions in Southeast Asia.

17. EVALUATION OF SOIL QUALITY AT PHU MY SPECIES - HABITAT PRESERVATION AREA, GIANG THANH DISTRICT, KIEN GIANG PROVINCE

Huynh Thi Hong Nhien — 2025-12-31

The study aimed to assess soil quality in Phu My Species - Habitat Conservation over the period of 2019 - 2021. Soil quality data were collected at 10 locations in seven habitats in the nature reserve. Soil samples were evaluated by pH, electrical conductivity (EC), salinity (sal), total acidity (TA), soil organic matter (OM), total nitrogen (TN), total phosphorus (TP), available phosphorus (P₂O₅), digestible potassium (K₂O), aluminum ion (Al³⁺), and total iron (Fe_t). The results showed that the pH in the soil was low, the nutrient content was poor, while the aluminum ion and organic matter content in the soil were relatively high. In the period of 2019 - 2021, the pH, EC, Fe_t, and nutrients (TN, K₂O) tended to decrease, while the remaining parameters increased in 2021. The soil quality could limit the diversity of flora and fauna in the conservation area the except for the highly adaptable species. The results provided useful information on soil quality for soil planning management. Future studies should focus on the determination of frequency and location for soil quality monitoring at Phu My Species - Habitat conservation area.

18. FACTORS INFLUENCING SUSTAINABLE CONSUMPTION BEHAVIOR OF STUDENTS IN CAN THO UNIVERSITY

Nguyen Thanh Giao — 2025-12-31

Sustainable consumption is crucial for balancing societal needs with environmental sustainability. While conducting research in Vietnam, studies often focus narrowly on perceptions and attitudes. This study aimed to address this gap by developing and testing an extended model incorporating perceived behavioral control (PBC), belief in environmentally friendly products (BP), consumption attitude for community benefit (ATC), and contextual factors (CF) influencing sustainable consumption behavior among university students. Data were collected via questionnaires from 240 students across four training units at Can Tho University. Regression analysis revealed that ATC (β = 0.385), CF (β = 0.353), BP (β = 0.240), and PBC (β = -0.112) significantly predicted environmental and health protection behaviors (PB), explaining 55.5 % (R² = 0.555) of its variance. Resource and energy saving behaviors (SB) were significantly predicted by CF (β = 0.378), BP (β = 0.153), and PBC (β = 0.151), explaining 44.8 % (R² = 0.448) of its variance. Findings indicate students practice PB more frequently than SB, with significant differences observed across training units and academic years. These results offer valuable insights for designing targeted interventions to promote sustainable consumption among Can Tho University students.

19. IMPROVING SHORT-TERM RESERVOIR INFLOW FORECASTING USING A HYBRID HYPE-ANN FRAMEWORK: A CASE STUDY OF THE PLEIKRONG RESERVOIR

Vu Van Lan — 2025-12-31

Accurate reservoir inflow forecasting is vital for hydropower operation and water resources management in monsoon-driven basins. However, process-based hydrological models often exhibit systematic errors, particularly under high-flow conditions. To address this, we developed a hybrid modeling framework that integrates the HYPE (Hydrological Predictions for the Environment) model with an Artificial Neural Network (ANN) for daily inflow forecasting to the Pleikrong Reservoir in Vietnam. The HYPE model was first calibrated and validated using daily hydrometeorological data from 1994 to 2022. ANN models with different hidden-layer architectures (three, four, and five layers) were then employed to post-process HYPE outputs. Results show that the hybrid HYPE-ANN approach substantially improved forecast accuracy compared to HYPE alone. The four-layer ANN (512 - 256 - 128 - 64 neurons) achieved the best performance, with CC = 0.93, KGE = 0.92, and NSE = 0.87 for one-day-ahead forecasts, while maintaining stable results for two-and three-day lead times. These findings highlight the effectiveness of hybrid process-based and data-driven approaches for short-term inflow prediction using daily data. The proposed framework offers a reliable and computationally efficient tool to support hydropower operation and adaptive water resources management in data-scarce basins.

20. CHANGES IN TYPHOON ACTIVITY OVER THE EAST VIETNAM SEA

Nguyen Binh Phong — 2025-12-31

Typhoons and Tropical Depressions (TDs) are among the natural disasters that cause severe consequences in terms of both human lives and property. Accurately forecasting the intensity, track, and resulting heavy rainfall and strong winds from typhoons and tropical depressions remains a very challenging problem. As is known, during their life cycle (existence, development, and movement), the intensity of typhoons in the East Vietnam Sea changes quite complexly, with periods of weakening and periods of rapid intensification. Upon making landfall, due to friction, typhoons and tropical depressions generally weaken quickly. However, some storms maintain strong intensity and persist for a relatively long duration, causing extensive damage. Understanding the changes in typhoons enables us to implement preventive measures and mitigate damage in the work of disaster prevention and control. In this paper, I will present the change in typhoon activity affecting Vietnam using a statistical method. The paper has collected data on Tropical Cyclones (TCs) operating in the East Vietnam Sea and affecting Vietnam from the National Center for Hydro-Meteorological Forecasting (NCHMF) and the Japan Regional Specialized Meteorological Centre (RSMC) from 1961 to 2024. Statistical analysis of strong typhoons and their damage to our country from 2006 to the present shows that typhoons are tending to become stronger, accompanied by severe losses of life and property. The report has identified the changes in TC activity in recent years, which are positively significant for forecasting and natural disaster risk prevention.