Pub Date : 2022-03-24DOI: 10.25073/2588-1094/vnuees.4772
Pham Thanh Hà, Phan Van Tan
In this study, a new approach to selecting the Rainy Season Onset Date (hereafter denoted as RSOD) criteria is proposed and applied for Central Highlands and Southern Vietnam based on daily rainfall station data from 1979 to 2015. This approach bases on the similarity between station-based RSODs and regional-scale RSOD signal, obtained by applying Multi variable Principal Component Analysis (MPCA). The results show that these selected criteria can capture reasonably the heterogeneity of the start of the rainy season on both regional- and local-scale. The determined RSODs for the Central Highlands and the South are consistent with previous studies. It suggests the application potential of this approach in objectively determining the suitable RSOD criteria for each station (local-scale) in other regions.
{"title":"Objective Criteria to Determine the Rainy Season Onset Date for the Central Highlands and Southern Vietnam","authors":"Pham Thanh Hà, Phan Van Tan","doi":"10.25073/2588-1094/vnuees.4772","DOIUrl":"https://doi.org/10.25073/2588-1094/vnuees.4772","url":null,"abstract":"In this study, a new approach to selecting the Rainy Season Onset Date (hereafter denoted as RSOD) criteria is proposed and applied for Central Highlands and Southern Vietnam based on daily rainfall station data from 1979 to 2015. This approach bases on the similarity between station-based RSODs and regional-scale RSOD signal, obtained by applying Multi variable Principal Component Analysis (MPCA). The results show that these selected criteria can capture reasonably the heterogeneity of the start of the rainy season on both regional- and local-scale. The determined RSODs for the Central Highlands and the South are consistent with previous studies. It suggests the application potential of this approach in objectively determining the suitable RSOD criteria for each station (local-scale) in other regions. \u0000 ","PeriodicalId":247618,"journal":{"name":"VNU Journal of Science: Earth and Environmental Sciences","volume":"85 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122470843","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 : 2022-03-24DOI: 10.25073/2588-1094/vnuees.4812
Bui Quang Thanh, Vu Van Long, Nguyen Xuan Linh, Phan Van Manh
Machine learning applies predominantly to the classification of the satellite images, aerial photo, unmanned aerial vehicle (UAV) data, point clouds with considerable achievements. However, the dynamic and complex structures of land surface prevent accurate land cover segregation through built-in models, and there is a crucial need to investigate novel ones. This study integrates Catboost into a Convolutional neural network for land cover classification from UAV images, with a case study in Hanoi. The combination of these images and Digital surface model to form the input datasets. The results show that the overall accuracy reaches 91,5%, which is relatively higher than other comparing methods. The proposal model can be used as an alternative method for land cover classification.
{"title":"Combination of UAV Images and DSM for Land Cover Classification using Convolutional Neural Network","authors":"Bui Quang Thanh, Vu Van Long, Nguyen Xuan Linh, Phan Van Manh","doi":"10.25073/2588-1094/vnuees.4812","DOIUrl":"https://doi.org/10.25073/2588-1094/vnuees.4812","url":null,"abstract":"Machine learning applies predominantly to the classification of the satellite images, aerial photo, unmanned aerial vehicle (UAV) data, point clouds with considerable achievements. However, the dynamic and complex structures of land surface prevent accurate land cover segregation through built-in models, and there is a crucial need to investigate novel ones. This study integrates Catboost into a Convolutional neural network for land cover classification from UAV images, with a case study in Hanoi. The combination of these images and Digital surface model to form the input datasets. The results show that the overall accuracy reaches 91,5%, which is relatively higher than other comparing methods. The proposal model can be used as an alternative method for land cover classification. \u0000 ","PeriodicalId":247618,"journal":{"name":"VNU Journal of Science: Earth and Environmental Sciences","volume":"68 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122748140","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 : 2022-03-24DOI: 10.25073/2588-1094/vnuees.4748
B. Loan, Nguyen Huy Hoang, Nguyen Mai Luu, Le Van Nam, Pham Tien Dung, Nguyen Dac Ve, Le Nhu Sieu, Dang Hoai Nhon, Tran Duc Thanh
The sedimentary environment characteristics in Mong Cai coastal area were assessed through pH, Eh, grain sizes, 226Ra, 210Pb, S‰, DO parameters. Mong Cai coastal area is mostly influenced by Ka Long river system that makes changes in the salinity, pH of water, pH and Eh of sediment, grain sizes, and sedimentation rates in the coastal area. There were six sediment types in the coastal area which were coarse sand, medium sand, fine sand, very fine sand, very coarse silt, and coarse silt. Fine sand was common in surface sediments; very fine sand was dominant in sediment core at Ka Long river mount; coarse silt and very coarse silt were common in sediment core at Mui Ngoc. The average sedimentation rate at the Ka Long river mouth (0.72 cm/year) was higher than that at the Mui Ngoc (0.27 cm/year). The sedimentary environment was divided into 3 groups, the first group was marine characteristics higher than the terrigenous characteristic, the second group was terrigenous characteristics higher than marine characteristics, and the third group was marine characteristics. In sediment cores showed 3 stages. In stage 1, distribution fine sand, very fine sand, and very coarse silt, from 52 to 80 cm at the Ka Long river mouth and from 40 to 52 cm at the Mui Ngoc. In stage 2, distribution of very coarse silt, coarse silt, from 38 to 52 cm (1947 - 1877) at Ka Long river mouth with sedimentation rate from 0.08 to 0.31 cm/year, at the Mui Ngoc from 12 to 40 cm (1944 (12 -14 cm)) with sedimentation rate of 0.09 cm/year. In stage 3, distribution very coarse silt, very fine sand, fine sand, from 0 to 38 cm (1919 - 1961) at the Ka Long river mouth with sedimentation rate of 0.34 - 1.62 cm/year, at the Mui Ngoc from 0 to 12 cm (2019 – 1966) with sedimentation rate of 0.07 - 0.51 cm/year.
{"title":"Some Sedimentary Environment Characteristics in the Mong Cai Coastal Area, Quang Ninh Province, Vietnam","authors":"B. Loan, Nguyen Huy Hoang, Nguyen Mai Luu, Le Van Nam, Pham Tien Dung, Nguyen Dac Ve, Le Nhu Sieu, Dang Hoai Nhon, Tran Duc Thanh","doi":"10.25073/2588-1094/vnuees.4748","DOIUrl":"https://doi.org/10.25073/2588-1094/vnuees.4748","url":null,"abstract":"The sedimentary environment characteristics in Mong Cai coastal area were assessed through pH, Eh, grain sizes, 226Ra, 210Pb, S‰, DO parameters. Mong Cai coastal area is mostly influenced by Ka Long river system that makes changes in the salinity, pH of water, pH and Eh of sediment, grain sizes, and sedimentation rates in the coastal area. There were six sediment types in the coastal area which were coarse sand, medium sand, fine sand, very fine sand, very coarse silt, and coarse silt. Fine sand was common in surface sediments; very fine sand was dominant in sediment core at Ka Long river mount; coarse silt and very coarse silt were common in sediment core at Mui Ngoc. The average sedimentation rate at the Ka Long river mouth (0.72 cm/year) was higher than that at the Mui Ngoc (0.27 cm/year). The sedimentary environment was divided into 3 groups, the first group was marine characteristics higher than the terrigenous characteristic, the second group was terrigenous characteristics higher than marine characteristics, and the third group was marine characteristics. In sediment cores showed 3 stages. In stage 1, distribution fine sand, very fine sand, and very coarse silt, from 52 to 80 cm at the Ka Long river mouth and from 40 to 52 cm at the Mui Ngoc. In stage 2, distribution of very coarse silt, coarse silt, from 38 to 52 cm (1947 - 1877) at Ka Long river mouth with sedimentation rate from 0.08 to 0.31 cm/year, at the Mui Ngoc from 12 to 40 cm (1944 (12 -14 cm)) with sedimentation rate of 0.09 cm/year. In stage 3, distribution very coarse silt, very fine sand, fine sand, from 0 to 38 cm (1919 - 1961) at the Ka Long river mouth with sedimentation rate of 0.34 - 1.62 cm/year, at the Mui Ngoc from 0 to 12 cm (2019 – 1966) with sedimentation rate of 0.07 - 0.51 cm/year. \u0000 ","PeriodicalId":247618,"journal":{"name":"VNU Journal of Science: Earth and Environmental Sciences","volume":"266 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117105230","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 : 2022-03-24DOI: 10.25073/2588-1094/vnuees.4781
Trinh Thi Tham, Do Thi Hien, Nguyen Thuy Chung, Ngo Tra Mai
This study aims to assess the pollution level of groundwater in the Holocene aquifer in the Duy Tien district, Ha Nam province, using the groundwater quality index (GWQI). Groundwater samples were collected from 20 wells and dug wells in households in rainy and dry seasons. The results showed that many parameters such as ammonium, nitrite, total hardness, chloride, Fe, Mn, Pb, As exceeded the permitted limits according to QCVN 09-MT: 2015/BTNMT. In particular, the ammonium concentrations at all monitoring wells were higher 2,73 ÷ 28,3 times than permitted values. The GWQI ranged between 84 ÷ 369 in the rainy season and 67 ÷ 290 in the dry season, while the proportion of wells with "very poor water" quality in the rainy and dry season was 50% and 65%, respectively. The GWQI values can be a scientific basis for effective use and protecting groundwater resources.
{"title":"Assessment of Groundwater Quality in the Holocene Aquifer in Duy Tien District, Ha Nam Province using Groundwater Quality Index (GWQI)","authors":"Trinh Thi Tham, Do Thi Hien, Nguyen Thuy Chung, Ngo Tra Mai","doi":"10.25073/2588-1094/vnuees.4781","DOIUrl":"https://doi.org/10.25073/2588-1094/vnuees.4781","url":null,"abstract":"This study aims to assess the pollution level of groundwater in the Holocene aquifer in the Duy Tien district, Ha Nam province, using the groundwater quality index (GWQI). Groundwater samples were collected from 20 wells and dug wells in households in rainy and dry seasons. The results showed that many parameters such as ammonium, nitrite, total hardness, chloride, Fe, Mn, Pb, As exceeded the permitted limits according to QCVN 09-MT: 2015/BTNMT. In particular, the ammonium concentrations at all monitoring wells were higher 2,73 ÷ 28,3 times than permitted values. The GWQI ranged between 84 ÷ 369 in the rainy season and 67 ÷ 290 in the dry season, while the proportion of wells with \"very poor water\" quality in the rainy and dry season was 50% and 65%, respectively. The GWQI values can be a scientific basis for effective use and protecting groundwater resources. \u0000 ","PeriodicalId":247618,"journal":{"name":"VNU Journal of Science: Earth and Environmental Sciences","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126706573","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 : 2022-03-23DOI: 10.25073/2588-1094/vnuees.4696
Nguyen Thi Dung, Nguyen Tien Toan, Cong Thanh
This paper presents a study about identifying parameters of TITAN software applied for Dong Ha and Tam Ky radars to define and monitor thunderstorm cells caused by cold instruction in Central Midle Region of Vietnam. In this study, using radar data of thunderstorm days due to cold instruction in the years from 2014 to 2015 to analyze the evolutions of thunderstorms and make statistics of radio reflect thresholds from which to determine the parameters in TITAN software for 2 radars; the years from 2016 to 2018 are used to evaluate TITAN's ability to track thunderstorms. As a result, a set of parameters for TITAN software was identified, and the ability to identify and monitor the storm drive using TITAN software was also evaluated. Applied TITAN on Dong Ha and Tam Ky dataset give a high accuracy result with 1-hour rainfall forecasting.
{"title":"Application of the TITAN Software for Forecasting the Thunderstorm Over Mid-Central Region of Vietnam","authors":"Nguyen Thi Dung, Nguyen Tien Toan, Cong Thanh","doi":"10.25073/2588-1094/vnuees.4696","DOIUrl":"https://doi.org/10.25073/2588-1094/vnuees.4696","url":null,"abstract":"This paper presents a study about identifying parameters of TITAN software applied for Dong Ha and Tam Ky radars to define and monitor thunderstorm cells caused by cold instruction in Central Midle Region of Vietnam. In this study, using radar data of thunderstorm days due to cold instruction in the years from 2014 to 2015 to analyze the evolutions of thunderstorms and make statistics of radio reflect thresholds from which to determine the parameters in TITAN software for 2 radars; the years from 2016 to 2018 are used to evaluate TITAN's ability to track thunderstorms. As a result, a set of parameters for TITAN software was identified, and the ability to identify and monitor the storm drive using TITAN software was also evaluated. Applied TITAN on Dong Ha and Tam Ky dataset give a high accuracy result with 1-hour rainfall forecasting. \u0000 ","PeriodicalId":247618,"journal":{"name":"VNU Journal of Science: Earth and Environmental Sciences","volume":"180 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-03-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128695483","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 : 2022-03-23DOI: 10.25073/2588-1094/vnuees.4588
Nguyen Huu Cuong
Land valuation is one of many important tasks in land use and management. In order to be objective and scientific in land valuation, it is necessary to identify factors affecting land price and quantify the relationship between land feature factors and land value. The goal of the study is to apply the decision-tree regression model to build mass land pricing models in Vung Tau city. The decision-tree regression model is applied in land valuation by determining the relationship between a combination of land feature factors and corresponding averaged land price. Research on building the land pricing model with independent variables includes business density, area, road types, business activities and road width based on 883 survey samples. The final result of this tree model was categorized into 51 divided groups, and pruned trees included 15 divided groups. The importance of the independent variables, namely, business density, region, road level, business activities and road width are 100%, 83.48%, 78.87%, 58.78% and 10.03% respectively. The interpretation rate of the independent variables to the formation of land price model is 86%. The decision-tree regression model suggests another approach to land valuation theory.
{"title":"Application of Decision Tree Model in Mass Land Valuation: A Case Study in Vung Tau City","authors":"Nguyen Huu Cuong","doi":"10.25073/2588-1094/vnuees.4588","DOIUrl":"https://doi.org/10.25073/2588-1094/vnuees.4588","url":null,"abstract":"Land valuation is one of many important tasks in land use and management. In order to be objective and scientific in land valuation, it is necessary to identify factors affecting land price and quantify the relationship between land feature factors and land value. The goal of the study is to apply the decision-tree regression model to build mass land pricing models in Vung Tau city. The decision-tree regression model is applied in land valuation by determining the relationship between a combination of land feature factors and corresponding averaged land price. Research on building the land pricing model with independent variables includes business density, area, road types, business activities and road width based on 883 survey samples. The final result of this tree model was categorized into 51 divided groups, and pruned trees included 15 divided groups. The importance of the independent variables, namely, business density, region, road level, business activities and road width are 100%, 83.48%, 78.87%, 58.78% and 10.03% respectively. The interpretation rate of the independent variables to the formation of land price model is 86%. The decision-tree regression model suggests another approach to land valuation theory. \u0000 ","PeriodicalId":247618,"journal":{"name":"VNU Journal of Science: Earth and Environmental Sciences","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-03-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121187542","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 : 2021-12-08DOI: 10.25073/2588-1094/vnuees.4693
Phan Nam Long, Nguyen Thi Ngoc Anh, Bui Van The Vinh, Can Thu Van, N.T. Thu Thao, Huynh Thi Thu Thuy
Groundwater quality is vulnerable to various processes. In this study, processes affecting groundwater quality were evaluated in coastal aquifers of Quang Nam - Da Nang (QNDN). A chemical data of 426 groundwater samples from 27 monitoring wells in the period 2011-2018 were analyzed. Principal Components Analysis (PCA) and Base Exchange Indices (BEXD) were applied for the evaluation. The PCA results suggested the influences of natural processes and anthropogenic activities on the groundwater quality. Seawater influence contributed to the dominant ions in groundwater; mineral weathering and dissolution mainly increased the alkalinity, Ca2+, and Mg2+; SO42- reduction explained the low SO42- in the groundwater; and reductive dissolution of Fe (hydroxides) caused Fe exceeding WHO’s drinking standard. Intensive groundwater abstraction generated up coning of saline groundwater; discharge from agricultural practices, industrialization, and urbanization were considered as sources of high NO3- in groundwater. The integration of monitoring data and BEXD gave a better interpretation of salinization and freshening, which can be masked by the memory effects of seawater transgression and regression in history.
{"title":"Evaluation of Processes Affecting the Variation of Groundwater Quality in Quang Nam, Da Nang, Vietnam","authors":"Phan Nam Long, Nguyen Thi Ngoc Anh, Bui Van The Vinh, Can Thu Van, N.T. Thu Thao, Huynh Thi Thu Thuy","doi":"10.25073/2588-1094/vnuees.4693","DOIUrl":"https://doi.org/10.25073/2588-1094/vnuees.4693","url":null,"abstract":"Groundwater quality is vulnerable to various processes. In this study, processes affecting groundwater quality were evaluated in coastal aquifers of Quang Nam - Da Nang (QNDN). A chemical data of 426 groundwater samples from 27 monitoring wells in the period 2011-2018 were analyzed. Principal Components Analysis (PCA) and Base Exchange Indices (BEXD) were applied for the evaluation. The PCA results suggested the influences of natural processes and anthropogenic activities on the groundwater quality. Seawater influence contributed to the dominant ions in groundwater; mineral weathering and dissolution mainly increased the alkalinity, Ca2+, and Mg2+; SO42- reduction explained the low SO42- in the groundwater; and reductive dissolution of Fe (hydroxides) caused Fe exceeding WHO’s drinking standard. Intensive groundwater abstraction generated up coning of saline groundwater; discharge from agricultural practices, industrialization, and urbanization were considered as sources of high NO3- in groundwater. The integration of monitoring data and BEXD gave a better interpretation of salinization and freshening, which can be masked by the memory effects of seawater transgression and regression in history. \u0000 ","PeriodicalId":247618,"journal":{"name":"VNU Journal of Science: Earth and Environmental Sciences","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127926413","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 : 2021-12-08DOI: 10.25073/2588-1094/vnuees.4692
Vu Cong Huu, Dinh Van Uu
In recent years, camera technology has been used in the field of beach variation and beach protection. This study presents the results of processing images of Do Son beach based on images. Camera image processing is calibrated based on real measurements of control points. Camera images are processed to capture shoreline and beach developments for the period from August 2018 to October 2019. The results show that Do Son beach has short term and seasonal fluctuations. Beach geomorphology tends to reach equilibrium form.
{"title":"Assessment of Do Son Beach Changes using Monitoring Camera Images","authors":"Vu Cong Huu, Dinh Van Uu","doi":"10.25073/2588-1094/vnuees.4692","DOIUrl":"https://doi.org/10.25073/2588-1094/vnuees.4692","url":null,"abstract":"In recent years, camera technology has been used in the field of beach variation and beach protection. This study presents the results of processing images of Do Son beach based on images. Camera image processing is calibrated based on real measurements of control points. Camera images are processed to capture shoreline and beach developments for the period from August 2018 to October 2019. The results show that Do Son beach has short term and seasonal fluctuations. Beach geomorphology tends to reach equilibrium form. \u0000 ","PeriodicalId":247618,"journal":{"name":"VNU Journal of Science: Earth and Environmental Sciences","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121162980","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 : 2021-12-08DOI: 10.25073/2588-1094/vnuees.4694
Truong Ba Kien, Vu Van Thang, Tran DuyThuc, Nguyen Quang Trung, Pham Xuan Quan
This study presents an hourly updated assimilation and model forecast system (Rapid Refresh - RAP) designed for rainfall nowcasting at Ho Chi Minh city (named HCM-RAP). The HCM-RAP implemented the Weather Research and Forecasting (WRF) model, driven by Global Forecast System (GFS) data at horizontal resolution of 0.25x0.25 degree, in combination with rapid update of radar data at Nha Be station. The HCM-RAP is evaluated during the heavy rainfall event of 25-26 November 2018 against observation data at 10 stations. Results show the advantage of data assimilation in the improvement of hourly rainfall forecast, in compared with the forecast from the experiment without assimilated data. However, the rainfall forecast amount was still underestimated by the HCM-RAP. This is the first attempt for heavy rainfall forecasting and warning for Ho Chi Minh city. In order to implementing the HCM-RAP for operational forecast, further study is recommended, for instance, more heavy rainfall events and in merger with quantitative precipitation estimation from radar and satellite data.
{"title":"Constructing Rapid Refresh System for Rainfall Nowcasting (0-6 h) at the Ho Chi Minh City","authors":"Truong Ba Kien, Vu Van Thang, Tran DuyThuc, Nguyen Quang Trung, Pham Xuan Quan","doi":"10.25073/2588-1094/vnuees.4694","DOIUrl":"https://doi.org/10.25073/2588-1094/vnuees.4694","url":null,"abstract":"This study presents an hourly updated assimilation and model forecast system (Rapid Refresh - RAP) designed for rainfall nowcasting at Ho Chi Minh city (named HCM-RAP). The HCM-RAP implemented the Weather Research and Forecasting (WRF) model, driven by Global Forecast System (GFS) data at horizontal resolution of 0.25x0.25 degree, in combination with rapid update of radar data at Nha Be station. The HCM-RAP is evaluated during the heavy rainfall event of 25-26 November 2018 against observation data at 10 stations. Results show the advantage of data assimilation in the improvement of hourly rainfall forecast, in compared with the forecast from the experiment without assimilated data. However, the rainfall forecast amount was still underestimated by the HCM-RAP. This is the first attempt for heavy rainfall forecasting and warning for Ho Chi Minh city. In order to implementing the HCM-RAP for operational forecast, further study is recommended, for instance, more heavy rainfall events and in merger with quantitative precipitation estimation from radar and satellite data. \u0000 ","PeriodicalId":247618,"journal":{"name":"VNU Journal of Science: Earth and Environmental Sciences","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115194715","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 : 2021-12-08DOI: 10.25073/2588-1094/vnuees.4811
Nguyen Thi Dieu Linh, Dang Kinh Bac, Vu Thi Phuong, Truong Quang Hai, Hoang Thi Thu Huong
Wetland ecosystems have provided high biological productivity, played an important role in the stability and development of coastal people. The wetland ecosystem service (WES) assessment is an effective tool for calculating direct and indirect benefits that humans obtained from these ecosystems based on monetary valuation. The value of WES in the Tien Yen estuary area has been assessed and calculated using a combination of different methods, including cost-benefit analysis, questionnaire survey, and remote sensing and GIS. The results showed the particular monetary values of 11 WES obtained from 10 wetland ecosystems and total WES value in the study area. The outcome can become the scientific basis to choose the suitable solutions for sustainable use of natural resources in the relationship between preservation and exploitation of wetlands in the future.
{"title":"Assessment of Wetland Ecosystem Services in Tien Yen Estuary, Quang Ninh Province","authors":"Nguyen Thi Dieu Linh, Dang Kinh Bac, Vu Thi Phuong, Truong Quang Hai, Hoang Thi Thu Huong","doi":"10.25073/2588-1094/vnuees.4811","DOIUrl":"https://doi.org/10.25073/2588-1094/vnuees.4811","url":null,"abstract":"Wetland ecosystems have provided high biological productivity, played an important role in the stability and development of coastal people. The wetland ecosystem service (WES) assessment is an effective tool for calculating direct and indirect benefits that humans obtained from these ecosystems based on monetary valuation. The value of WES in the Tien Yen estuary area has been assessed and calculated using a combination of different methods, including cost-benefit analysis, questionnaire survey, and remote sensing and GIS. The results showed the particular monetary values of 11 WES obtained from 10 wetland ecosystems and total WES value in the study area. The outcome can become the scientific basis to choose the suitable solutions for sustainable use of natural resources in the relationship between preservation and exploitation of wetlands in the future. \u0000 \u0000 ","PeriodicalId":247618,"journal":{"name":"VNU Journal of Science: Earth and Environmental Sciences","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115321926","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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