Land Use Based Flood Hazard Analysis for the Mekong Delta

Das Mekong-Delta nimmt für die Republik Vietnam einen sehr hohen Stellenwert in Bezug auf Natur, Wirtschaft, Politik, Menschen, Landwirtschaft, Fischerei, Geopolitik und vielen anderen Bereichen ein. Der sogenannte Dreifachreis (auch Herbst-Winter-Ernte oder Third Crop genannt) wurde in den letzten Jahren für das Mekong-Delta in den stark überfluteten Gebiete durch umschlossene Kompartimenten wie Halbdeichstrukturen (zum Schutz der Reisfelder vor Hochwasser (von Juli bis Mitte August) sowie Volldeichmessungen (zum vollständigen Schutz der Reisfelder während der Hochwassersaison) schnell ausgebaut. Der Reisanbau hat daher Auswirkungen auf die Hochwassersituation in den flußabwärts gelegenen Gebieten. Diese Studie zielt darauf ab, die Auswirkungen von Deichmessungen auf Hochwasser in den Mekong-Flüssen zu analysieren, indem das 1D-Hydraulikmodell MIKE11 sowie Fernerkundungsprodukte (MODIS-Satellit) verwendet werden. Um diese Einflüsse umfassend zu erforschen, wurde mit dem Hydraulikmodell MIKE11 die Auswirkungen von mehreren Volldeichkompartimenten auf das Hochwasser entlang der Hauptflüsse basierend auf einem Geographical Impact Factor (GIF) analysiert. Der Autor fand heraus, daß verschiedene geografische Kompartimente unterschiedliche Einflüsse auf das Hochwasserniveau entlang des Mekong haben. Fernerkundungsprodukte wurden eingesetzt, um die Veränderung der Landnutzungsgebiete im Mekong-Delta von 2000 bis 2017 zu analysieren. Außerdem wurde von MODIS Satellitenprodukte eine komplette Datenbank von Hochwasserverteilungskarten (476 Karten) im Mekong-Delta während der Hochwassersaison 2000 bis 2017 interpretiert. Darüber hinaus wurden die Satellitenprodukte einschließlich Landnutzung und Hochwasserkarten in MD zu weiteren Untersuchungen des Mekong Delta für die Öffentlichkeit online zur Verfügung gestellt. Die Simulation funktioniert für ein großes und komplexes Flussnetz, da das Mekong-System viele Anstrengungen und Erfahrungen der Ingenieure erfordert, die nicht leicht zu bewältigen sind. Daher wurde eine einfache Methode zur Interpretation des Hochwasserstandes entlang der Mekong Flüsse entwickelt, um Ingenieuren ein schnelles Werkzeug zur Bewertung der Auswirkungen von Deichkonstruktionen für Landnutzungszwecke auf Hochwasserregime zur Verfügung zu stellen. Im Bereich Hydraulik wurde ebenfalls eine Empfehlung zum Reisanbau in den Gebieten vom Mekong-Delta abgegeben, welche den Anwendern die Möglichkeit bieten soll, die Ausrichtung der landwirtschaftlichen Entwicklung gegenüber dem Hochwassermanagement zu steuern

Datasets of land use change and flood dynamics in the vietnamese mekong delta

This paper compiles the data associated with a research article published in STOTEN [1]. The data set represents figures, tables, and images illustrating the temporal and spatial distribution of land use and flood dynamics from 2000 to 2020 in the Vietnamese Mekong Delta (VMD). The MODIS imageries were freely accessed online via the NASA website [2] and processed to land use and flood maps based on the algorithms by Sakamoto et al. [3,4]. The MODIS products show a high validation with statistical data and radar satellites [1]. The datasets of flood map and land use, therefore, are available to scientists, engineers, and policy-makers in agricultural management associated with flood management in the VMD. They could be used for policy settings, household livelihood assessment as well as other economic analyses for the VMD region due to the change of land use and flooding dynamics

Sand Spit Morphology at an Inlet on Phu Quoc Island, Vietnam

Tidal inlets with attached sand spits are a very common coastal landform. Since the evolution of sand spits along coastlines influence the social-economic development of local coastal areas, sand spits have become the objects of numerous studies. However, previous studies have mainly focused on sand spits that are usually in the scale of hundreds of meters in width, whilst knowledge about the evolution of smaller-scale sand spits still remains limited. Therefore, in this study, the morphological change of a small and unexplored sand spit in front of Song Tranh Inlet on the west coast of Phu Quoc Island, Vietnam is investigated. Satellite images are first used to observe the morphological change of the sand spit and calculate the longshore sediment transport rates (LSTR) along the sand spit. Waves and beach sediments are collected at the study site to calculate the longshore sediment transport rate using the CERC formula. It is found that there is a seasonal variation in the evolution of the sand spit at Song Tranh Inlet. The longshore sediment transport rates along the spit calculated by image analysis are 39,000 m$^3$/year, 66,000 m$^3$/year, and 40,000 m$^3$/year, whilst the longshore sediment transport rate calculated by the CERC formula is 72,000 m$^3$/year. This study aims to contribute to the methodology for investigating the evolutions of small sand spits and, specifically, sustainable coastal management for Phu Quoc Island, which is well-known as the Pearl Island of Vietnam

Expansion of KPC-producing Enterobacterales in four large hospitals in Hanoi, Vietnam

Objectives : The incidence of carbapenem resistance among nosocomial Gram-negative bacteria in Vietnam is high and increasing, including among Enterobacterales. In this study, we assessed the presence of one of the main carbapenemase genes, blaKPC, among carbapenem-resistant Enterobacterales (CRE) from four large hospitals in Hanoi, Vietnam, between 2010 and 2015, and described their key molecular characteristics. Methods : KPC-producing Enterobacterales were detected using conventional PCR and were further analysed using S1 nuclease pulsed-field gel electrophoresis (S1-PFGE), Southern blotting and whole-genome sequencing (WGS) for sequence typing and genetic characterisation. Results : blaKPC genes were detected in 122 (20.4%) of 599 CRE isolates. blaKPC-carrying plasmids were diverse in size. Klebsiella pneumoniae harbouring blaKPC genes belonged to ST15 and ST11, whereas KPC-producing Escherichia coli showed more diverse sequence types including ST3580, ST448, ST709 and ST405. Genotypic relationships supported the hypothesis of circulation of a population of ‘resident’ resistant bacteria in one hospital through the years and of transmission among these hospitals via patient transfer. WGS results revealed co-carriage of several other antimicrobial resistance genes and three different genetic contexts of blaKPC-2. Among these, the combination of ISEcp1–blaCTX-M and ISKpn27–blaKPC–ΔISKpn6 on the same plasmid is reported for the first time. Conclusion : We describe the dissemination of blaKPC-expressing Enterobacterales in four large hospitals in Hanoi, Vietnam, since 2010, which may have started earlier, along with their resistance patterns, sequence types, genotypic relationship, plasmid sizes and genetic context, thereby contributing to the overall picture of the antimicrobial resistance situation in Enterobacterales in Vietnam

Mapping for engagement: setting up a community based participatory research project to reach underserved communities at risk for Hepatitis C in Ho Chi Minh City, Vietnam

Background: Approximately 1. 07 million people in Vietnam are infected with hepatitis C virus (HCV). To address this epidemic, the South East Asian Research Collaborative in Hepatitis (SEARCH) launched a 600-patient cohort study and two clinical trials, both investigating shortened treatment strategies for chronic HCV infection with direct-acting antiviral drugs. We conducted ethnographic research with a subset of trial participants and found that the majority were aware of HCV infection and its implications and were motivated to seek treatment. However, people who inject drugs (PWID), and other groups at risk for HCV were under-represented, although injecting drug use is associated with high rates of HCV. Material and Methods: We designed a community-based participatory research (CBPR) study to engage in dialogues surrounding HCV and other community-prioritized health issues with underserved groups at risk for HCV in Ho Chi Minh City. The project consists of three phases: situation analysis, CBPR implementation, and dissemination. In this paper, we describe the results of the first phase (i.e., the situation analysis) in which we conducted desk research and organized stakeholder mapping meetings with representatives from local non-government and community-based organizations where we used participatory research methods to identify and analyze key stakeholders working with underserved populations. Results: Twenty six institutions or groups working with the key underserved populations were identified. Insights about the challenges and dynamics of underserved communities were also gathered. Two working groups made up of representatives from the NGO and CBO level were formed. Discussion: Using the information provided by local key stakeholders to shape the project has helped us to build solid relationships, give the groups a sense of ownership from the early stages, and made the project more context specific. These steps are not only important preliminary steps for participatory studies but also for other research that takes place within the communities

Quantifying the Emergence of Dengue in Hanoi, Vietnam: 1998–2009

Dengue is the most common vector-borne viral disease of humans, causing an estimated 50 million cases per year. The number of countries affected by dengue has increased dramatically in the last 50 years and dengue is now a major public health problem in large parts of the tropical and subtropical world. It is of considerable importance to understand the factors that determine how dengue becomes newly established in areas where the risk of dengue was previously small. Hanoi in North Vietnam is a large city where dengue appears to be emerging. We analyzed 12 years of dengue surveillance data in order to characterize the temporal and spatial epidemiology of dengue in Hanoi and to establish if dengue incidence has been increasing. After excluding the two major outbreak years of 1998 and 2009 and correcting for changes in population age structure over time, we found there was a significant annual increase in the incidence of notified dengue cases over the period 1999–2008. Dengue cases were concentrated in young adults in the highly urban central areas of Hanoi. This study indicates that dengue transmission is increasing in Hanoi and provides a platform for further studies of the underlying drivers of this emergence