Pub Date : 2023-05-15DOI: 10.25073/2588-1094/vnuees.4936
Nguyen Quoc Son, Nguyen Cam Linh, L. Quynh, Le Phuong Thu
The Red River system plays an important role in the socio-economic development of the Northern of Vietnam. Therefore, regular monitoring and evaluation of water quality parameters in the Red River system are important in water resources management and protection. However, current monitoring methods are often quite expensive and time-consuming. To predict the downstream water quality, this study uses multiple machine learning algorithms to understand the correlation between environmental parameters measured at upstream and downstream stations of the Red River system. The environmental parameters that are chosen for this study include suspended sediment concentration (SSC), inorganic nitrogen content (total N), phosphorus content (total P), and dissolved silicon (DSi). The results show that machine learning algorithms can estimate the downstream DSi and sediment concentrations based on combining values of three upstream stations with relatively high efficiency (R2 equals 0.75 and 0.66, respectively). Meanwhile, these algorithms have limited performance in estimating total N and P content, due to the influence of many exogenous factors. The study introduces a new direction for applying machine learning algorithms in water quality research in the Red River system with the potential application in other river systems in Vietnam.
{"title":"Application of Machine Learning Algorithms in Studying Water Quality in the Red River System","authors":"Nguyen Quoc Son, Nguyen Cam Linh, L. Quynh, Le Phuong Thu","doi":"10.25073/2588-1094/vnuees.4936","DOIUrl":"https://doi.org/10.25073/2588-1094/vnuees.4936","url":null,"abstract":"The Red River system plays an important role in the socio-economic development of the Northern of Vietnam. Therefore, regular monitoring and evaluation of water quality parameters in the Red River system are important in water resources management and protection. However, current monitoring methods are often quite expensive and time-consuming. To predict the downstream water quality, this study uses multiple machine learning algorithms to understand the correlation between environmental parameters measured at upstream and downstream stations of the Red River system. The environmental parameters that are chosen for this study include suspended sediment concentration (SSC), inorganic nitrogen content (total N), phosphorus content (total P), and dissolved silicon (DSi). The results show that machine learning algorithms can estimate the downstream DSi and sediment concentrations based on combining values of three upstream stations with relatively high efficiency (R2 equals 0.75 and 0.66, respectively). Meanwhile, these algorithms have limited performance in estimating total N and P content, due to the influence of many exogenous factors. The study introduces a new direction for applying machine learning algorithms in water quality research in the Red River system with the potential application in other river systems in Vietnam.","PeriodicalId":247618,"journal":{"name":"VNU Journal of Science: Earth and Environmental Sciences","volume":"147 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124699798","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-05-09DOI: 10.25073/2588-1094/vnuees.4199
Vu Van Phai, N. Liem, Pham Hoang Hai, Vu Thi Thanh Ha, Tran Van Binh, Pham Thi Thanh Nga, Nguyen Thu Nhung
The main objective of this paper is to investigate the mechanism of formation and evolution of a river mouth island in front of Cua Dai - a mouth of Vu Gia - Thu Bon river system. The combination of coastal morphodynamic analysis with remote sensing, mapping and GIS methods has shown that the formation and evolution of this island depends on a long-term and complex interaction between the dynamics of the Vu Gia - Thu Bon river system and the coastal littoral, including the Cu Lao Cham archipelago. This process has three stages: i) The formation of river mouth bar; ii) The formation of island in front of the river mouth; and iii) The deformation of island morphology in front of the river mouth. The materials that formed Cua Dai island are not only carried out by the Vu Gia - Thu Bon river system, but also from longshore sediment due to coastal and estuary erosion, mainly from the northern part of Cua Dai. Based on the interaction between material factors (river and longshore sediments) and energy (sea and river dynamics), the evolution of the river mouth bar in front of the Cua Dai island may follow one of two trends: i) The Cua Dai island will gradually move closer to the north shore of Cua Dai, erodes over time, then disappear, assuming no major flood in the Vu Gia - Thu Bon river system and wave and flow regimes are as normal as in the period before 2016; or ii) The Cua Dai island will continue to exist and change if there is an increase in climate change, especially extreme events such as storms, floods, and sea level rise.
本文的主要目的是研究武家河-图邦河水系夸代河口前河口岛的形成和演化机制。沿海形态动力学分析与遥感、制图和地理信息系统方法相结合表明，该岛的形成和演变取决于Vu Gia - Thu Bon河水系与沿海沿岸(包括古老湛群岛)的长期和复杂的相互作用。这一过程分为三个阶段:河口坝的形成;ii)河口前岛的形成;河口前海岛形态的变形。形成夸代岛的物质除了由武家河-图邦河水系携带外，还由海岸和河口侵蚀形成的沿岸沉积物携带，主要来自夸代北部。基于物质因素之间的交互(河沿岸沉积物)和能源(海洋和河流动力学),河口的演变酒吧前戴Cua岛可以参照两种趋势:1)戴Cua岛将逐渐接近Cua戴的北岸,侵蚀了随着时间的推移,然后消失,假设没有重大洪水Vu吉尔-清华好河流系统和波流政权时期2016年之前一样正常;2)如果气候变化加剧，特别是风暴、洪水和海平面上升等极端事件，瓜岱岛将继续存在和变化。
{"title":"Formation and Evolution of Sandy Island in Front of the Thu Bon River Mouth, Quang Nam Province","authors":"Vu Van Phai, N. Liem, Pham Hoang Hai, Vu Thi Thanh Ha, Tran Van Binh, Pham Thi Thanh Nga, Nguyen Thu Nhung","doi":"10.25073/2588-1094/vnuees.4199","DOIUrl":"https://doi.org/10.25073/2588-1094/vnuees.4199","url":null,"abstract":"The main objective of this paper is to investigate the mechanism of formation and evolution of a river mouth island in front of Cua Dai - a mouth of Vu Gia - Thu Bon river system. The combination of coastal morphodynamic analysis with remote sensing, mapping and GIS methods has shown that the formation and evolution of this island depends on a long-term and complex interaction between the dynamics of the Vu Gia - Thu Bon river system and the coastal littoral, including the Cu Lao Cham archipelago. This process has three stages: i) The formation of river mouth bar; ii) The formation of island in front of the river mouth; and iii) The deformation of island morphology in front of the river mouth. The materials that formed Cua Dai island are not only carried out by the Vu Gia - Thu Bon river system, but also from longshore sediment due to coastal and estuary erosion, mainly from the northern part of Cua Dai. Based on the interaction between material factors (river and longshore sediments) and energy (sea and river dynamics), the evolution of the river mouth bar in front of the Cua Dai island may follow one of two trends: i) The Cua Dai island will gradually move closer to the north shore of Cua Dai, erodes over time, then disappear, assuming no major flood in the Vu Gia - Thu Bon river system and wave and flow regimes are as normal as in the period before 2016; or ii) The Cua Dai island will continue to exist and change if there is an increase in climate change, especially extreme events such as storms, floods, and sea level rise. \u0000 ","PeriodicalId":247618,"journal":{"name":"VNU Journal of Science: Earth and Environmental Sciences","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124630392","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-04-21DOI: 10.25073/2588-1094/vnuees.4934
Ngo Duc Thanh, Bui Thi Khanh Hoa
This study used observed data of maximum daily temperature (Tx) and average daily temperature (T2m) from 48 meteorological stations to investigate hot (SU35, Tx≥35 ºC), severe hot (SU37, Tx≥37 ºC), cold (FD15, T2m≤15 ºC), and severe cold (FD13, T2m≤13 ºC) events in Northern Vietnam from 1961 to 2018. Trends and frequency characteristics of SU35, SU37, FD15, and FD13 were calculated and discussed. Results showed a significant increase in the number of hot and severe hot days, while there was a notable decrease in the number of cold and severe cold days in the northern region of Vietnam. The North Central region experienced the highest increase in the number of severe hot days, ranging from 2 to 5 days per decade. In contrast, the Northwest and Northeast regions had the highest decline in the number of cold days, with a rate of 3.5 to 4.5 days per decade for cold and 1 to 3 days per decade for severe cold days. The return values of Tx for the SU35 and SU37 thresholds for 10-year and 50-year return periods exceeded 41 ºC in the Northern Delta and North Central regions, which was higher than other regions (37–40 ºC). Meanwhile, the return values of T2m for the FD15 and FD13 thresholds were the lowest in the Northeast, typically ranging from 3 to 7 ºC for a 50-year return period. These results highlight the necessity of planning adaptation measures to address changes in hot and cold extreme events, particularly in the key industrial areas of Northern Vietnam, in the context of climate change. Keywords: Climate change, extreme hot and cold events, generalized Pareto distribution, trend analysis.
{"title":"Trends and Return Frequencies of Hot and Cold Extreme Events in Northern Vietnam from 1961–2018","authors":"Ngo Duc Thanh, Bui Thi Khanh Hoa","doi":"10.25073/2588-1094/vnuees.4934","DOIUrl":"https://doi.org/10.25073/2588-1094/vnuees.4934","url":null,"abstract":"This study used observed data of maximum daily temperature (Tx) and average daily temperature (T2m) from 48 meteorological stations to investigate hot (SU35, Tx≥35 ºC), severe hot (SU37, Tx≥37 ºC), cold (FD15, T2m≤15 ºC), and severe cold (FD13, T2m≤13 ºC) events in Northern Vietnam from 1961 to 2018. Trends and frequency characteristics of SU35, SU37, FD15, and FD13 were calculated and discussed. Results showed a significant increase in the number of hot and severe hot days, while there was a notable decrease in the number of cold and severe cold days in the northern region of Vietnam. The North Central region experienced the highest increase in the number of severe hot days, ranging from 2 to 5 days per decade. In contrast, the Northwest and Northeast regions had the highest decline in the number of cold days, with a rate of 3.5 to 4.5 days per decade for cold and 1 to 3 days per decade for severe cold days. The return values of Tx for the SU35 and SU37 thresholds for 10-year and 50-year return periods exceeded 41 ºC in the Northern Delta and North Central regions, which was higher than other regions (37–40 ºC). Meanwhile, the return values of T2m for the FD15 and FD13 thresholds were the lowest in the Northeast, typically ranging from 3 to 7 ºC for a 50-year return period. These results highlight the necessity of planning adaptation measures to address changes in hot and cold extreme events, particularly in the key industrial areas of Northern Vietnam, in the context of climate change. \u0000 Keywords: Climate change, extreme hot and cold events, generalized Pareto distribution, trend analysis. \u0000 \u0000 ","PeriodicalId":247618,"journal":{"name":"VNU Journal of Science: Earth and Environmental Sciences","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114775932","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-04-21DOI: 10.25073/2588-1094/vnuees.4942
T. T. Thu, Dao Thi Trang, Pham Thi My Phuong
The overuse of copper (Cu) fungicides has resulted in an accumulation of Cu in the orange-growing soil in Cao Phong district, Hoa Binh province. In this study, we analyzed the fractionation and accumulation of Cu in soils treated with two types of fungicides: Norshield 86.2WG and Epolists 85WP. Using vetiver grass has been known as a approach to immobilize heavy metals in soil, herein, its effect on the fate of Cu was also considered. The bioavailability of Cu was relatively high for both the tested soils treated with Norshield 86.2WG (~9.82-11.03%) and Epolists 85WP (~8.46-10.79%). Noting that Cu in different fractions increased following the order F1 (water soluble) < F2 (exchange adsorption) < F3 (special adsorption) < F4 (bound with Fe/Al hydroxide) < F5 (bound to organic matter) < F6 (remaining form). The use of vetiver grass resulted in different accumulation levels of Cu between natural soil (9.5 ± 0.53 ppm) and Cu-added soils (from 16.17 ± 1.72 to 27.13 ± 1.31 ppm). The application of Norshield 86.2WG and Epolists 85WP has exacerbated the contamination of soil by Cu, therefore, to manage and enhance soil health in this area, we need to consider reducing the use of fungicides in the orange-growing areas. Keywords: Cao Phong orange, fungicides, Cu pollution, Cu accumulation, Vetiver grass.
{"title":"Grass Vetiveria zizanioides (L.) Nash for Immobilization of Copper in the Orange-growing Soil Contaminated by the Overuse of Fungicides: A Casestudy at Cao Phong, Hoa Binh","authors":"T. T. Thu, Dao Thi Trang, Pham Thi My Phuong","doi":"10.25073/2588-1094/vnuees.4942","DOIUrl":"https://doi.org/10.25073/2588-1094/vnuees.4942","url":null,"abstract":"The overuse of copper (Cu) fungicides has resulted in an accumulation of Cu in the orange-growing soil in Cao Phong district, Hoa Binh province. In this study, we analyzed the fractionation and accumulation of Cu in soils treated with two types of fungicides: Norshield 86.2WG and Epolists 85WP. Using vetiver grass has been known as a approach to immobilize heavy metals in soil, herein, its effect on the fate of Cu was also considered. The bioavailability of Cu was relatively high for both the tested soils treated with Norshield 86.2WG (~9.82-11.03%) and Epolists 85WP (~8.46-10.79%). Noting that Cu in different fractions increased following the order F1 (water soluble) < F2 (exchange adsorption) < F3 (special adsorption) < F4 (bound with Fe/Al hydroxide) < F5 (bound to organic matter) < F6 (remaining form). The use of vetiver grass resulted in different accumulation levels of Cu between natural soil (9.5 ± 0.53 ppm) and Cu-added soils (from 16.17 ± 1.72 to 27.13 ± 1.31 ppm). The application of Norshield 86.2WG and Epolists 85WP has exacerbated the contamination of soil by Cu, therefore, to manage and enhance soil health in this area, we need to consider reducing the use of fungicides in the orange-growing areas. \u0000Keywords: Cao Phong orange, fungicides, Cu pollution, Cu accumulation, Vetiver grass.","PeriodicalId":247618,"journal":{"name":"VNU Journal of Science: Earth and Environmental Sciences","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116986734","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-04-13DOI: 10.25073/2588-1094/vnuees.4931
Nguyen Xuan Tòng, Pham Thi Bich Van, LÊ HÙNG ANH
The sediment is the final environment where heavy metals accumulate and directly impact the health of aquatic systems and humans.Therefore, the study was carried out to determine the total content and forms of heavy metals in the sediments at 13 locations in the Saigon River basin in rain and dry seasons of 2022. In addition, this research also assesses the pollution risk level and the correlation between heavy metals and physicochemical properties in the sediments. Chemical analysis was applied to determine the contributors of heavy metals while the geochemical calculation methods (hazard quotient (HQ), geo-accumulation index (Igeo), pollutant load index (PLI), individual contamination factors (ICF) and global contamination factors (GCF), risk assessment code (RAC)) were used to assess the pollution risk level in river sediments. The results show that Ag, Ba, Mn and Zn were metals with high pollution risks, especially in rain season. The results showed that the total concentration of heavy metals in sediments in rain season ranges from 109.92 to 4591.01 mg.kg–1 (Mn > Zn > Li > Ba > Ag > Cr > Cu > Pb) and in dry season from 0 to 3117.8 mg.kg–1 (Mn > Ag > Zn > Li > Ba > Cr > Cu > Pb). Applying the sequential extraction method, the metal forms of Ba, Cr, Cu and Li in the sediment samples are mainly residues (F5) (up to 76.53%), proving these elements dominated by natural sources. In contrast, the Mn extract composition was strongly influenced by human activity with exchange (F1) (>50%) and carbonate (F2) (>20%) components predominating. For Ag, Pb and Cu were mainly in organic form (F4). In dry season, the river sediments didn’t contain Pb because it didn’t carry away rainwater. In particular, Zn had a strong fluctuation between the extracted forms in rain and dry seasons, showing impacts from nature and humans sources. Besides, the statistical analysis results showed that pH affected Cu and Zn contents with a negative correlation, but did not detect the correlation between heavy metals and sand, clay, electrical conductivity (EC) in Saigon river sediments. The research results are foundational for the implementation and design of effective remediation strategies to prevent risks of river sediments degradation in the future.
沉积物是重金属积累的最终环境，直接影响水生系统和人类的健康。因此，对2022年雨季和旱季西贡河流域13个地点沉积物中重金属的总含量和形态进行了研究。此外，本研究还评估了沉积物的污染风险水平以及重金属与沉积物理化性质的相关性。采用化学分析方法确定重金属的贡献源，采用地球化学计算方法(危害商(HQ)、地质累积指数(Igeo)、污染物负荷指数(PLI)、个体污染因子(ICF)、整体污染因子(GCF)、风险评价代码(RAC))评价河流沉积物的污染风险等级。结果表明，Ag、Ba、Mn和Zn是污染风险较高的金属，特别是在雨季。结果表明:雨季沉积物中重金属总浓度在109.92 ~ 4591.01 mg之间;kg-1 (Mn > Zn > Li > Ba > Ag > Cr > Cu > Pb)，旱季为0 ~ 3117.8 mg。(Mn > Ag > Zn > Li > Ba > Cr > Cu > Pb)。采用顺序萃取法，沉积物样品中Ba、Cr、Cu和Li的金属形态主要为残留物(F5)(高达76.53%)，证明这些元素以自然来源为主。相反，锰提取物的组成受人类活动的影响较大，以交换(F1)(>50%)和碳酸盐(F2)(>20%)组分为主。Ag、Pb、Cu主要以有机形式存在(F4)。在旱季，河流沉积物不含铅，因为它不带走雨水。特别是Zn在雨季和旱季的提取形态波动较大，表现出自然和人为因素的影响。统计分析结果表明，pH对沉积物中Cu、Zn含量的影响呈负相关，但未发现重金属与沉积物中砂、粘土、电导率(EC)的相关性。研究结果为今后实施和设计有效的修复策略，预防河流沉积物退化风险奠定了基础。
{"title":"Assessing the Current Status and Proposing Solutions for Heavy Metal Management in the Saigon River Basin Sediments","authors":"Nguyen Xuan Tòng, Pham Thi Bich Van, LÊ HÙNG ANH","doi":"10.25073/2588-1094/vnuees.4931","DOIUrl":"https://doi.org/10.25073/2588-1094/vnuees.4931","url":null,"abstract":"The sediment is the final environment where heavy metals accumulate and directly impact the health of aquatic systems and humans.Therefore, the study was carried out to determine the total content and forms of heavy metals in the sediments at 13 locations in the Saigon River basin in rain and dry seasons of 2022. In addition, this research also assesses the pollution risk level and the correlation between heavy metals and physicochemical properties in the sediments. Chemical analysis was applied to determine the contributors of heavy metals while the geochemical calculation methods (hazard quotient (HQ), geo-accumulation index (Igeo), pollutant load index (PLI), individual contamination factors (ICF) and global contamination factors (GCF), risk assessment code (RAC)) were used to assess the pollution risk level in river sediments. The results show that Ag, Ba, Mn and Zn were metals with high pollution risks, especially in rain season. The results showed that the total concentration of heavy metals in sediments in rain season ranges from 109.92 to 4591.01 mg.kg–1 (Mn > Zn > Li > Ba > Ag > Cr > Cu > Pb) and in dry season from 0 to 3117.8 mg.kg–1 (Mn > Ag > Zn > Li > Ba > Cr > Cu > Pb). Applying the sequential extraction method, the metal forms of Ba, Cr, Cu and Li in the sediment samples are mainly residues (F5) (up to 76.53%), proving these elements dominated by natural sources. In contrast, the Mn extract composition was strongly influenced by human activity with exchange (F1) (>50%) and carbonate (F2) (>20%) components predominating. For Ag, Pb and Cu were mainly in organic form (F4). In dry season, the river sediments didn’t contain Pb because it didn’t carry away rainwater. In particular, Zn had a strong fluctuation between the extracted forms in rain and dry seasons, showing impacts from nature and humans sources. Besides, the statistical analysis results showed that pH affected Cu and Zn contents with a negative correlation, but did not detect the correlation between heavy metals and sand, clay, electrical conductivity (EC) in Saigon river sediments. The research results are foundational for the implementation and design of effective remediation strategies to prevent risks of river sediments degradation in the future. \u0000 \u0000 ","PeriodicalId":247618,"journal":{"name":"VNU Journal of Science: Earth and Environmental Sciences","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-04-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116545227","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-03-26DOI: 10.25073/2588-1094/vnuees.4894
T. T. Huong, Vu Ngoc Toan, Le Ta Dang Khoi
This study was conducted to assess the toxicity of the sulfur mustard military chemical to the growth and development of zooplankton Daphnia magna. D. magna is a group of crustaceans which have unique features such as virgin reproduction/ parthenogenesis form in a time, easy to identify and so they are usually used as a standard model organism for toxicity testing in aquatic environments. D. magna is exposed to a sulfur mustard stimulant at 0, 0.001, 0.005, 0.01, 0.05, 0.1, and 0.5 ppm. The results showed that sulfur mustard agent affected the growth and development of D. magna during the 24 and 48 h exposure. The highest toxicity was observed at the concentrations of 0.1 and 0.5 ppm with 100% mortality after both 24 and 48 h of exposure. At 0.001 to 0.05 ppm, the mortality rate changed from 6.7 to 30% at 24 h and this ratio increased to 10 and 100% at the concentration of 0.001 and 0.05 ppm after 48h, respectively. The LC50 values recorded at 24 h and 48 h were 0.020 and 0.018 ppm, respectively. The results indicated that sulfur mustard can be toxic to the aquatic ecosystem and we need to take this into account when using this chemical group.
{"title":"Toxicity of Military Chemical Sulfur Mustard on the Growth of Daphnia magna","authors":"T. T. Huong, Vu Ngoc Toan, Le Ta Dang Khoi","doi":"10.25073/2588-1094/vnuees.4894","DOIUrl":"https://doi.org/10.25073/2588-1094/vnuees.4894","url":null,"abstract":"This study was conducted to assess the toxicity of the sulfur mustard military chemical to the growth and development of zooplankton Daphnia magna. D. magna is a group of crustaceans which have unique features such as virgin reproduction/ parthenogenesis form in a time, easy to identify and so they are usually used as a standard model organism for toxicity testing in aquatic environments. D. magna is exposed to a sulfur mustard stimulant at 0, 0.001, 0.005, 0.01, 0.05, 0.1, and 0.5 ppm. The results showed that sulfur mustard agent affected the growth and development of D. magna during the 24 and 48 h exposure. The highest toxicity was observed at the concentrations of 0.1 and 0.5 ppm with 100% mortality after both 24 and 48 h of exposure. At 0.001 to 0.05 ppm, the mortality rate changed from 6.7 to 30% at 24 h and this ratio increased to 10 and 100% at the concentration of 0.001 and 0.05 ppm after 48h, respectively. The LC50 values recorded at 24 h and 48 h were 0.020 and 0.018 ppm, respectively. The results indicated that sulfur mustard can be toxic to the aquatic ecosystem and we need to take this into account when using this chemical group. \u0000 \u0000 \u0000 ","PeriodicalId":247618,"journal":{"name":"VNU Journal of Science: Earth and Environmental Sciences","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115625479","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-03-26DOI: 10.25073/2588-1094/vnuees.4909
Dong Phu Hao, Nguyen Thi Thanh Binh, L.T. Hoang Anh
Abstract: Paddy rice production emits a significant amount of greenhouse gas, particularly methane (CH4). The purpose of this review is to assess the current status of CH4 emissions from paddy rice cultivation in Vietnam and propose solutions for reducing CH4 emissions. CH4 emissions from paddy rice cultivation account for 49.7 million tons of CO2eq (CO2 equivalent) per year in Vietnam. Soil texture, watering regime, and paddy cultivation technique are important in influencing CH4 emissions. Applications of advanced farming techniques such as the System of Rice Intensification (SRI), Alternate Wetting and Drying (AWD), and the use of biochar are among the recommended solutions. In summary, paddy rice production is the main source of CH4 emissions, which causes devastating effects on the global climate. Therefore, solutions that may both reduce GHG emissions and increase economic efficiency should be put into practice.
{"title":"Current Situation and Solutions for Methane (CH4) Emission in Paddy Rice Cultivation in Vietnam","authors":"Dong Phu Hao, Nguyen Thi Thanh Binh, L.T. Hoang Anh","doi":"10.25073/2588-1094/vnuees.4909","DOIUrl":"https://doi.org/10.25073/2588-1094/vnuees.4909","url":null,"abstract":" \u0000Abstract: Paddy rice production emits a significant amount of greenhouse gas, particularly methane (CH4). The purpose of this review is to assess the current status of CH4 emissions from paddy rice cultivation in Vietnam and propose solutions for reducing CH4 emissions. CH4 emissions from paddy rice cultivation account for 49.7 million tons of CO2eq (CO2 equivalent) per year in Vietnam. Soil texture, watering regime, and paddy cultivation technique are important in influencing CH4 emissions. Applications of advanced farming techniques such as the System of Rice Intensification (SRI), Alternate Wetting and Drying (AWD), and the use of biochar are among the recommended solutions. In summary, paddy rice production is the main source of CH4 emissions, which causes devastating effects on the global climate. Therefore, solutions that may both reduce GHG emissions and increase economic efficiency should be put into practice. \u0000 \u0000 \u0000 ","PeriodicalId":247618,"journal":{"name":"VNU Journal of Science: Earth and Environmental Sciences","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132753135","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-03-26DOI: 10.25073/2588-1094/vnuees.4900
Tran Thi Ngoc Mai, Bui Thi Nuong, Vu Quynh Trang
This study aims to better understand the changes in the water usage behaviors of Hanoi communities in the current circumstance of preventing the spread of COVID-19 pandemic and developing the economy. The results of 206 survey responses conducted during April 2022 show that the main changes in the domestic water usage behavior of Hanoi communities come from hand washing, bathing/personal hygiene, house cleaning, and clothes washing. During the pandemic, 77% of the respondents had a habit of washing their hands for 30 seconds as recommended by the Ministry of Health and the frequency of daily hand washing increased 5-7 times compared to before the pandemic. The frequency of housing deep cleaning increased by 33% compared to before the pandemic, besides the frequency of floor mopping also increased about 3.5 times per week. The average frequency of clothes washing also changed from 2.43 times/week to 4.61 times/week. The total estimated moderate water use per person increased by 1.41% compared to its before the pandemic. Therefore, based on the total population of Hanoi city, the amount of domestic water increased by 471.457 m3/day. Statistical results show that there are differences in most of the water usage behaviors between the two groups of people living in apartments and houses.
{"title":"Assessing the Impact of COVID-19 Pandemic on the Domestic Water Usage of Local Communities in Hanoi, Vietnam","authors":"Tran Thi Ngoc Mai, Bui Thi Nuong, Vu Quynh Trang","doi":"10.25073/2588-1094/vnuees.4900","DOIUrl":"https://doi.org/10.25073/2588-1094/vnuees.4900","url":null,"abstract":"This study aims to better understand the changes in the water usage behaviors of Hanoi communities in the current circumstance of preventing the spread of COVID-19 pandemic and developing the economy. The results of 206 survey responses conducted during April 2022 show that the main changes in the domestic water usage behavior of Hanoi communities come from hand washing, bathing/personal hygiene, house cleaning, and clothes washing. During the pandemic, 77% of the respondents had a habit of washing their hands for 30 seconds as recommended by the Ministry of Health and the frequency of daily hand washing increased 5-7 times compared to before the pandemic. The frequency of housing deep cleaning increased by 33% compared to before the pandemic, besides the frequency of floor mopping also increased about 3.5 times per week. The average frequency of clothes washing also changed from 2.43 times/week to 4.61 times/week. The total estimated moderate water use per person increased by 1.41% compared to its before the pandemic. Therefore, based on the total population of Hanoi city, the amount of domestic water increased by 471.457 m3/day. Statistical results show that there are differences in most of the water usage behaviors between the two groups of people living in apartments and houses. \u0000 \u0000 \u0000 \u0000 ","PeriodicalId":247618,"journal":{"name":"VNU Journal of Science: Earth and Environmental Sciences","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116939567","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-03-26DOI: 10.25073/2588-1094/vnuees.4898
N. Tien Thanh, Nguyen Thai Son, Nguyen Duc Mien
More and more extreme weather events are frequently observed in Thua Thien Hue province in recent years, especially in 2020. Only 7 days from October 6-12, 2020, total rainfall measured at Thuong Nhat station is approximately 1900 mm, accounting for more than 50% of the total annual rainfall. So, it is necessary to ensure the effective operation for Ta Trach reservoir, a large reservoir with a basin area of 717 km2 in Thua Thien Hue. This study is initially to clarify the performance of hourly rainfall simulations and streamflow to Ta Trach reservoir using WRF and HEC-HMS hydro-meteorological models during the 2020 flood season, respectively. The results showed that on the scale of daily, the correlation between simulated and measured rainfall is quite good, most of the stations could be reached about 0,8. On the scale of hourly, these figures are about 0,5 and the trend of cumulative hourly rainfall simulated is consistent with measured values. Especially, the trend of simulated streamflow using directly hourly rainfall from WRF model to Ta Trach reservoir is consistent with the measurement streamflow although the errors are still seen to extent with the NASH index of about 0,65.
{"title":"Performance of Hourly Rainfall Simulations using WRF Meteorological Model for Calculation of Streamflow to Ta Trach Reservoir During 2020 Flood Season","authors":"N. Tien Thanh, Nguyen Thai Son, Nguyen Duc Mien","doi":"10.25073/2588-1094/vnuees.4898","DOIUrl":"https://doi.org/10.25073/2588-1094/vnuees.4898","url":null,"abstract":" More and more extreme weather events are frequently observed in Thua Thien Hue province in recent years, especially in 2020. Only 7 days from October 6-12, 2020, total rainfall measured at Thuong Nhat station is approximately 1900 mm, accounting for more than 50% of the total annual rainfall. So, it is necessary to ensure the effective operation for Ta Trach reservoir, a large reservoir with a basin area of 717 km2 in Thua Thien Hue. This study is initially to clarify the performance of hourly rainfall simulations and streamflow to Ta Trach reservoir using WRF and HEC-HMS hydro-meteorological models during the 2020 flood season, respectively. The results showed that on the scale of daily, the correlation between simulated and measured rainfall is quite good, most of the stations could be reached about 0,8. On the scale of hourly, these figures are about 0,5 and the trend of cumulative hourly rainfall simulated is consistent with measured values. Especially, the trend of simulated streamflow using directly hourly rainfall from WRF model to Ta Trach reservoir is consistent with the measurement streamflow although the errors are still seen to extent with the NASH index of about 0,65. \u0000 ","PeriodicalId":247618,"journal":{"name":"VNU Journal of Science: Earth and Environmental Sciences","volume":"162 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127926746","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-03-26DOI: 10.25073/2588-1094/vnuees.4888
Vũ Anh Tài, Ngo Thi Bich Hong, Tran Thi Thuy Van, Le Thi Kim Thoa
The biodiversity of Ba Vi National Park has been faced with some passive impacts, one of them is alien species, that habitats for the native species is narrowed by increasing of invasive population expanding, it is necessary to conducted a research on the impacts of the invasive plants there and then giving the basis for better management of the national park. After field surveys in recently years (2018-2022), 47 alliance species recorded at the National Park were evaluated according to guidance and data provided by Invasive Species Specialist Group (ISSG) and Centre for Agriculture and Biosciences International (CABI) developed Invasive Species Compendium (ISC) and also Circular 35/2018/TT-BTNMT. Result showed that 29 species were invaders and especially 11 species of them are detailly evaluated in 10 habitats. 2 species as Mexican sunflower (Tithonia diversifolia) and Lantana (Lantana camara) are evaluated as High risk for both areas while 3 other ones are evaluated as High risk for buffer zone only, including Giant sensitive tree), Leucaena (Leucaena leucocephala) and Giant sensitive plant (Mimosa diplotricha). The other ones have been evaluated as Medium risk (at buffer zone) to Low risk (at core area) are Blackjack (Bidens pilosa), Siam weed (Chromolaena odorata), Bay Biscayne creeping-oxeye (Sphagneticola trilobata), Jamaica cherry (Muntingia calabura), Jamaica vervain (Stachytarpheta jamaicensis) and Coast morning glory (Ipomoea cairica). By this evaluation, Mexican sunflower (Tithonia diversifolia), Blackjack (Bidens pilosa), Jamaica cherry (Muntingia calabura), Jamaica vervain (Stachytarpheta jamaicensis) and Coast morning glory (Ipomoea cairica) are suggested to include to the list of invasive organisms of the nation. Besides that, it is necessary to strengthen control of Mexican sunflower (Tithonia diversifolia) inside the core area of the NP in particular and in Ba Vi district in general, especially at the tourist place where the festival of Mexican sunflower has been yearly organized.
{"title":"Results of Survey and Evaluation of Invasive Plants in Ba Vi National Park, Vietnam","authors":"Vũ Anh Tài, Ngo Thi Bich Hong, Tran Thi Thuy Van, Le Thi Kim Thoa","doi":"10.25073/2588-1094/vnuees.4888","DOIUrl":"https://doi.org/10.25073/2588-1094/vnuees.4888","url":null,"abstract":"The biodiversity of Ba Vi National Park has been faced with some passive impacts, one of them is alien species, that habitats for the native species is narrowed by increasing of invasive population expanding, it is necessary to conducted a research on the impacts of the invasive plants there and then giving the basis for better management of the national park. After field surveys in recently years (2018-2022), 47 alliance species recorded at the National Park were evaluated according to guidance and data provided by Invasive Species Specialist Group (ISSG) and Centre for Agriculture and Biosciences International (CABI) developed Invasive Species Compendium (ISC) and also Circular 35/2018/TT-BTNMT. Result showed that 29 species were invaders and especially 11 species of them are detailly evaluated in 10 habitats. 2 species as Mexican sunflower (Tithonia diversifolia) and Lantana (Lantana camara) are evaluated as High risk for both areas while 3 other ones are evaluated as High risk for buffer zone only, including Giant sensitive tree), Leucaena (Leucaena leucocephala) and Giant sensitive plant (Mimosa diplotricha). The other ones have been evaluated as Medium risk (at buffer zone) to Low risk (at core area) are Blackjack (Bidens pilosa), Siam weed (Chromolaena odorata), Bay Biscayne creeping-oxeye (Sphagneticola trilobata), Jamaica cherry (Muntingia calabura), Jamaica vervain (Stachytarpheta jamaicensis) and Coast morning glory (Ipomoea cairica). By this evaluation, Mexican sunflower (Tithonia diversifolia), Blackjack (Bidens pilosa), Jamaica cherry (Muntingia calabura), Jamaica vervain (Stachytarpheta jamaicensis) and Coast morning glory (Ipomoea cairica) are suggested to include to the list of invasive organisms of the nation. Besides that, it is necessary to strengthen control of Mexican sunflower (Tithonia diversifolia) inside the core area of the NP in particular and in Ba Vi district in general, especially at the tourist place where the festival of Mexican sunflower has been yearly organized. \u0000 \u0000 \u0000 ","PeriodicalId":247618,"journal":{"name":"VNU Journal of Science: Earth and Environmental Sciences","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124095647","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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