1

ASSESSMENT OF WIND ENERGY POTENTIAL IN THE BIEN DONG SEA USING CCMP SATELLITE DATA

 Nguyen Van Thang, Pham Thi Thanh Nga, Vu Van Thang,
Truong Thi Thanh Thuy, Tran Duy Thuc

Viet Nam Institute of Meteorology, Hydrology, and Climate Change

Received: 21 July 2022; Accepted: 30 August 2022

 Abstract: This study assessesed the wind energy potential in the Bien Dong Sea by using the Cross-Calibrated Multi-Platform (CCMP) satellite wind data from 1991 to 2020. The results showed that the wind energy potential at 10 m height above ground is not high in the offshore areas with annual mean wind speeds ranging from 5 to 8 m/s. At heights of 100 m, 150 m, and 200 m, the greatest wind energy potential is found in the offshore areas of the North Bien Dong Sea Region, Binh Dinh – Ninh Thuan, Binh Thuan – Ca Mau, and the central part of the Gulf of Tonkin. Especially, the wind energy is quite high in the Sea of Ninh Thuan to Ba Ria – Vung Tau with annual mean wind speeds of 8 to 10 m/s, and the annual mean wind power density of 500 to 700 W/m2 at a height of 100 m. On the seasonal scale, the wind energy potential of January and October is greater than that of April and July for the orthern offshore areas while the wind energy potential of January is the greatest, followed by July and transition months for the southern offshore areas.

Keywords: Wind energy, potential, high distributions, wind potential, Bien Dong Sea.

DOI: https://doi.org/10.55659/2525-2496/23.75017

APPLICATION OF MIKE FLOOD MODEL FOR INUNDATION SIMULATION IN YEN BAI CITY

Tran Van Tinh⁽¹⁾, Vu Manh Cuong⁽²⁾, Nguyen Thi Bich Ngoc⁽¹⁾,
Tran Thi Tu⁽¹⁾, Tran Thuy Chi⁽¹⁾, Dao Xuan Nam^(2)
(1)Hanoi University of Natural Resources and Environment

⁽²⁾Viet Bac Regional Hydrometeorological Station

 Received: 04 July 2022; Accepted: 02 August 2022

 Abstract: Flood is a natural disaster that can cause loss of life and damage to property. The objective of this study is to create a flood map of Yen Bai city, where flood occurs regularly during heavy rain and Thao River’s water level rises. The study used Mike Flood model based on the connection of 1D and 2D hydrodynamic models. The model parameters were calibrated and validated againts observed water level data of two major flood events in August 2008 and July 2009 which were measured by Bao Ha and Yen Bai hydrological stations, in addition with historical flood survey data in 2008. Flood map was developed corresponding to the alarm levels. The results show that the most affected areas by flood are 4 communes of Au Lau, Hop Minh, Tuy Loc, and Hong Ha wards.

Keywords: Yen Bai City, Inundation maps, Mike Flood, Thao River.

DOI: https://doi.org/10.55659/2525-2496/23.75010

ASSESSMENT OF THE WRF MODEL FOR SOUTHERN REGION OF VIET nAM IN DRY AND RAINY SEASONS

Le Anh Ngoc⁽¹⁾, Vo Thi Nguyen⁽¹⁾, Nguyen Van Hong⁽¹⁾, Bui Chi Nam⁽¹⁾, Le Hong Duong^(2)
(1)Viet Nam Sub-Institute of HydroMeteorology and Cimate Change
⁽²⁾Department of Southern Environmental Protection

Received: 17 July 2022; Accepted: 15 August 2022

 Abstract: This article investigates the capability of the applicability of numerical WRF model to forecast weather at 48 hours for the Southern Region Viet Nam in the rainy and dry seasons in 2021 (12/2020 – 1/2021). The WRF model shows that predicted maximum temperature, minimum temperature and rainfall are lower than measured values. Temperature forecasts are more accurate than rainfall forecasts. Rainfall forecast in the rainy season has a higher error than the rainfall forecast in the dry season, on the contrary, the temperature forecast in the rainy season gives lower error than the temperature forecast in the dry season.

Keywords: WRF, temperature forecast, rainfall, Southern region.

DOI: https://doi.org/10.55659/2525-2496/23.75008

4

USING OBSERVED HAIL TO QUALITY EXTREME HAIL CLIMATE IN VIET NAM. PART I: DATA QUALITY CONTROL AND CLIMATOLOGICAL CHARACTERISTICS OF HAIL

Dam Viet Bac, Nguyen Dang Mau⁽¹⁾, Bui Minh Tuan⁽²⁾, Tran Thanh Thuy⁽¹⁾, Pham Thi Hai Yen⁽¹⁾, Tran Thi Tam⁽¹⁾, Do Van Man⁽¹⁾, Luong Xuan Thai⁽⁴⁾, Nguyen Tung Anh⁽¹⁾, Tran Chan Nam⁽³⁾, Hosam Ali⁽⁵⁾, Muehlbauer Andreas⁽⁵⁾, Osibanjo Olabosipo^(5)
(1)Viet Nam Institute of Meteorology, Hydrology and Climate change, Hanoi, Viet Nam
⁽²⁾Hanoi University of Science, Viet Nam National University, Hanoi, Viet Nam
⁽³⁾Hanoi University of Natural Resources and Environment, Hanoi, Viet Nam
⁽⁴⁾Viet Nam Meteorological and Hydrological Administration, Hanoi, Viet Nam
⁽⁵⁾Center for Property Risk Solutions, Research Division, FM Global, USA

Received: 25 July 2022; Accepted: 18 August 2022

Abstract: In this study, we focus on studying data and calculating climatic features of hail. In this study, a hail dataset was created by combining historic records from 186 meteorological stations for the period 1961 – 2021. The data are obtained from several sources including observations from the Viet Nam Meteorological and Hydrological Administration (VNMHA), annual reports of the Viet Nam Institute of Meteorology, Hydrology and Climate change (IMHEN) and the Viet Nam Disaster Management Authority (VDMA). The data used in this study is defined from the official data sources. Therefore, the data quality control shows that this data may be considered good available data of hail. Research results for 1961 – 2021 show that the highest number of hail events was observed in the Northwest (743 events), and in the Northeast (557 events) subregions; the lowest number of hail events was observed in the South Central (16 events) and the South (27 events) subregions. The higher frequency duration of hail occurs from March to May, with the peak in April. The largest hail diameter, recorded in Vietnam is 12 cm at Bac Ha station on March 27, 2013; the common largest hail diameter size in history at stations is around 3 – 5 cm at the Northern stations and 1 – 3 cm at the southern stations.

Keywords: Climatology, hail, hail size.

DOI: https://doi.org/10.55659/2525-2496/23.75011

5

QUANTIFYING THE RISK OF CLIMATE CHANGE TO WATER RESOURCES IN THE VU GIA – THU BON RIVER BASIN, CENTRAL VIET NAM

Dang Quang Thinh⁽¹⁾, Nguyen Van Dai⁽¹⁾, Huynh Thi Lan Huong⁽²⁾,
Pham Thi Thien^(1)
(1)Viet Nam Institute of Meteorology, Hydrology and Climate Change
⁽²⁾Ha Noi University of Natural Resouces and Environment

Received: 7 July 2022; Accepted: 29 July 2022

Abstract: Climate change is posing serious threat on many different aspects of lives, espcially water resource. Vu Gia – Thu Bon is one of the largest river basins located in the central region of Viet Nam, which is ranked as one of the areas severely affected by climate change. This study aims to assess the level of risk to surface water resources in Vu Gia – Thu Bon river basin in the context of climate change in 03 time slices: The baseline period 1986 – 2005 and the two future periods 2016 – 2035 and 2046 – 2065 under two scenarios RCP4.5 and RCP8.5 using IPCC approach. The results show that the level of risk to surface water resources in both periods of the two scenarios RCP4.5 and RCP8.5 is medium. In which, the Hazard index is at a high level; the Exposure is low; and the Vulnerability is at a medium level. Moreover, the indexes in both future periods of the two scenarios RCP4.5 and RCP8.5 are larger compared to the baseline period. These results are expected to contribute to the basis for decision-making and timely response solutions for relevant sectors and localities in the Vu Gia – Thu Bon river basin.

Keywords: Risk, surface water resources, vulnerable, scenarios.

DOI: https://doi.org/10.55659/2525-2496/23.75012

6

APPLICATION OF GIS AND REMOTE SENSING FOR MAPPING FLASH FLOOD RISE IN HOA BINH PROVINCE UNDER CLIMATE CHANGE CONTEXT

 Nguyen Van Ha, Tran Dang Hung, Doan Tran Anh, Giang Hoang Hiep,
Nguyen Thi Huyen Trang, Doan Ha Phong
Viet Nam Institute of Meteorology, Hydrology and Climate change

Received: 01 August 2022; Accepted: 26 August 2022

Abstract: Hoa Binh is one of the provinces strongly suffering from natural disasters, especially flash floods. High slope mountainous terrains, reduced vegetation cover and unfavorable weather conditions form favorable conditions for flash floods to occur. This article develops a map of flash flood risk zoning in Hoa Binh using remote sensing and GIS technology. First, the factors affecting the risk of flash floods are identified, and each factor is classified based on the level of influence, then proceed to overlay the component maps causing flash floods. Factors affecting flash flood risk include: Slope, soil type, land use type, forest cover density and rain. As a result, areas at risk of flash floods are identified with 3 level: High, medium and low. This information can be used as a basis for forecasting areas at high risk of flash floods in the province.

Keywords: Flash flood, hazard map potential, remote sensing, geographic information system, Hoa Binh.

DOI: https://doi.org/10.55659/2525-2496/23.75013

7

ESTIMATION OF METHANE EMISSIONS FROM DOMESTIC WASTEWATER IN CAU RIVER BASIN BY 2030

Cai Anh Tu⁽¹⁾, Le Van Quy⁽²⁾, Nguyen Duc Toan^(3)
(1)VNU University of Science, Viet Nam National University, Hanoi
⁽²⁾Viet Nam Institute of Meteorology, Hydrology and Climate Change
⁽³⁾Institute of Natural Resources and Environment Training

Received: 8 August 2022; Accepted: 30 August 2022

 Abstract: The Cau River basin has recently raised significant concerns about associated pollution issues and their critical role in socio-economic development. This study aims at assessing and forecasting the impacts of domestic wastewater on the generation of greenhouse gas emissions in Cau River basin in 2030. The main methods have been applied in this study including data collection and analysis, synthesization and inheritance method of research documents. Moreover, the study has calculated the amount of greenhouse gases from wastewater in the Cau River basin basin from the use of septic toilets, other toilets and centralized wastewater treatment plant based upon the guidance of the IPCC (2006). The results show that the CH4 gas is mainly generated from the anaerobic treatment of domestic wastewater with total CH4 emissions for the scenario up to 2030 at 234,337.91 Gg CH4/year (accounting for 95.3%) of the total amount (corresponding to 245,818.59 Gg CH4/total kg of BOD) emitted when applying treatment measures.

Keywords: Methane gas, Domestic waste, Cau River basin.

DOI: https://doi.org/10.55659/2525-2496/23.75014