Marine spatial planning methods: A new study in Cua Hoi, Nghe An

SPOT 6 satellite image of Cua Hoi area

The need for marine spatial planning in Cua Hoi

Vietnam is located in the tropical monsoon zone, which is facing challenges from natural disasters such as floods, storms, coastal erosion, river estuary reclamation, and landslides. The frequency and severity of these natural disasters are increasing, causing significant damage to the economy, estimated at 1-1.5% of GDP annually, along with about 400 deaths or disappearances. In addition, climate change and sea level rise pose many challenges for disaster prevention and mitigation.

Cua Hoi is one of the areas heavily affected by natural disasters, a densely - populated area and an important economic role for Nghe An and Ha Tinh provinces. Here, the strong interaction between the river and the sea leads to abnormal fluctuations during the flood season, especially in July and August every year. Many major floods have occurred, such as the flood in August 1973 when the water level rose to 8.04m, causing serious damage. In 2010, heavy rains inundated thousands of homes and millions of hectares of farmland in the city of Vinh and its surroundings, which may indicate the extent of the devastation of the disaster that occurred in the region.

In addition, Cua Hoi is also affected by tides, stormy winds and storm surges, complicating the situation of erosion and reclamation of the coast - estuary, directly affecting people's lives and activities. Therefore, the assessment of natural factors, natural resources and natural disasters is necessary in marine spatial planning. The application of modern technology in natural disaster research will improve the ability to warn, forecast and manage natural disasters, contributing to protecting people's lives and promoting sustainable development for the Cua Hoi area.

In the international cooperation program between Institute of Geography - Vietnam Academy of Science and Technology and Pacific Institute of Geography, Far Eastern Branch - Russian Academy of Sciences, scientists carried out the project: "Research and development of marine spatial planning methods based on territorial approaches for sustainable management of the (case study in the Far East of Russia and Vietnam)" (code: QTRU02.03/21-22). The pilot research in Cua Hoi area, Nghe An province is of both scientific and practical significance, with the goal of finding out the causes and laws of sand sludge transportation, thereby proposing solutions to prevent and control reclamation, stabilize river estuaries, and serve flood drainage and channel clearance. The project was led by Assoc. Prof. Dr. Dao Dinh Cham.

Assoc. Prof. Dr. Dao Dinh Cham and his colleagues work with experts from Institute of Pacific Geography - Far Eastern Branch, Russian Academy of Sciences

Previous research by Assoc. Prof. Dr. Dao Dinh Cham and colleagues of the Institute of Geography have made an important contribution to understanding and evaluating the factors affecting this process in the State-level project of the KC.09/16-20 Program: "Research on the evaluation of hydrodynamic factors affecting the processes of excavation, erosion of estuarine and coastal areas from Quang Nam to Phu Yen in conditions of climate change and sea level rise", implemented from 2016 to 2019. The project used 69 landscapes of Landsat, Sentinel, and Spot (from 1965 to 2018) combined with MIKE and DELFT 3D models to evaluate the rules and find the causes of shoreline fluctuations and bottom topography in Cua Dai, Quang Nam in stages. The combination of mathematical modeling and remote sensing technology, GIS has allowed for a comprehensive assessment of both coastal erosion and river estuary reclamation, thereby proposing appropriate remedial works.

Sustainability research and solutions

Within the framework of the study, the scientists established a process for processing and monitoring the fluctuations of shorelines and estuaries using data from optical satellite imagery (Landsat 1-3 MSS, Landsat 4-5) and radar satellite imagery (Sentinel-1). This data is processed on the Google Earth Engine (GEE) cloud computing platform, which allows to assess the fluctuations of the coast and mouth of the Cua Hoi River from 1965 to 2022, providing an overview of the trend of fluctuations in the study area.

Developments of Cua Hoi estuary in the period 1979-2022 through satellite images

According to information from Assoc. Prof. Dr. Dao Dinh Cham, his team set up the MIKE 21/3 FM model to simulate hydrodynamic processes in the Cua Hoi estuary area, clarifying dynamic factors such as waves and coastal currents. The study has made an important contribution to the assessment of erosion, accretion and flooding here. In particular, the study applied modules from the MIKE model set, such as MIKE FLOOD, MIKE 11HD and MIKE 21 to simulate the major and historical floods that occurred in the Ca River basin. The model has proven to be highly accurate when compared to actual flooding conditions through the analysis of data from satellite imagery.

In addition, the team has initially proposed scientific and technological solutions to mitigate the impact of natural disasters, protect the coast and stabilize estuaries, based on a thorough analysis of natural and man-made factors to identify vulnerable areas. This contributes to building more effective disaster response measures, and at the same time integrating geoinformatics technology into estuary and coastal management in a sustainable way.

Experts are aiming to apply advanced technologies such as artificial intelligence (AI) and machine learning to study coastal natural disasters, such as erosion and flooding. By combining AI with big data from remote sensing imagery and geographic information systems, the research team hopes to clarify the mechanism of natural disasters, and improve forecasting and early warning capabilities, contributing to optimizing the management of marine and coastal resources in the Cua Hoi area.

In addition to the Cua Hoi area, the group is expanding its research scope to other coastal areas of Vietnam, especially the South Central Region. With strengths in estuarine and coastal hydrodynamics research and territorial planning solutions, scientists will focus on solving the challenges of marine spatial planning, creek development and coastal protection. In the future, the group will continue to promote international cooperation with the Institute of Pacific Geography and the Russian Academy of Sciences to develop marine geography and marine science research for the sustainable management of seas and islands.

Translated by Phuong Ha
Link to Vietnamese version