Research Topics

Research Topics
Comprehensive Probabilistic Tsunami Hazard Assessment in the Makran Subduction Zone

Although earthquakes in the Makran subduction zone (MSZ) can cause tsunamis along the southern coast of Iran, little research has been done because of ethnic minority settlements and undeveloped areas. Chabahar is an important port city in this region and some areas are considered to be an important coastal zone in Iran as a free trade zone. In this study, a probabilistic tsunami hazard analysis (PTHA) method is proposed to apply to the source and coastal areas where information is scarce, and the probability of tsunami height exceedance for different recurrence periods (50, 100, 250, 500, and 1000 years) is presented for several areas along the southern coast of Iran. […]

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Knowledge, awareness, and attitudes toward tsunamis: A local survey in the southern coast of Iran

Research Overview The southern coast of Iran (mainly the coastal area facing the Gulf of Oman) is a potential tsunami and storm surge disaster area, but since it is the least developed area in Iran, little work has been done to prevent such disasters. In recent years, the Iranian government has moved to designate this area as a free trade zone, and it is being positioned as an important area. In addition, there are many ethnic minorities living in the area, and religious influences are significant, so it was assumed that ordinary disaster mitigation measures would not work well. In this study, a questionnaire survey, interviews, and focus group discussions […]

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Assessing the natural recovery of mangroves after human disturbance using neural network classification and Sentinel-2 imagery

Research Overview llegal cultivation of shrimp ponds and rice paddies was carried out in the Wumbaik Reserved Mangrove Forest in Rakhine State, Myanmar; many of them have been abandoned under administrative guidance. Although mangrove reforestation has often been carried out around the world, it is costly and tends to be biased toward specific tree species, resulting in a state that differs from the natural state. This study focuses on how abandoned sites can be regenerated in a natural state without human intervention. AS abandoned areas are generally small in size and low-cost method is required especially in developing countries, we adopted Senitnel-2 imagery, which has relatively high resolution and can […]

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On the status and mechanisms of coastal erosion in Marawila Beach, Sri Lanka

Research contents Coastal erosion has been a serious threat to the properties and livelihoods of coastal communities on the western coast of Sri Lanka. Since the cause of the erosion was not fully investigated, there were arguments over the selection of countermeasures among beach users. This study found that a decrease in sand supply from rivers was a main reason for the initiation of erosion in the 1980s. An increase in wave energy has become a main cause of coastal erosion since the 2010s. This study suggests the significance of integrated coastal erosion management for the sustainability of the coast and its users. Publication Ratnayakage, S. M. S., Sasaki, J., […]

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Groundwater salinization and associated co-contamination risk increase severe drinking water vulnerabilities in the southwestern coast of Bangladesh

Bangladesh is one of the most vulnerable deltas to climate change, sea level rise, inundation, and salt water intrusions. Freshwater salinization is becoming a serious threat to household water security among coastal communities. Our study found that groundwater is severely contaminated with salinity intrusions while co-contaminants were found to be in high concentrations compare with different drinking water standard values, which is completely unsuitable for drinking purposes. In Bangladesh, almost all the people used to drink groundwater as a principal source of water as well as household purposes. Now, it is a great concern to the future sustainable drinking water security and public health problems. Publication Rakib, M.A., Sasaki, J., […]

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Hybrid methods combining atmospheric reanalysis data and a parametric typhoon model to hindcast storm surges in Tokyo Bay

Reanalysis data and a parametric typhoon model formula are often used to prepare wind and pressure fields for storm surge hindcasting. However, their optimum selection and usage have not been well established. To enhance the accuracy of wind and pressure fields, two hybrid methods were proposed by applying a parametric typhoon model of Mitsuta–Fujii’s formula, which is determined from the typhoon center to a certain radius of Rb, and then switching to the reanalysis data of ERA-Interim in the outer region through the interpolated transition bandwidth of Wb. In hybrid model I, Rb and Wb were fixed because the time-varying radius of the maximum wind speed was determined by the […]

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2019.7.8 iSymWater2019 in Beijing, China

Dr. Sasaki delivered a keynote talk in the international symposium, iSymWater2019, held at Xijiao Hotel in Beijing, entitled "Sustainable Marine Environment and Coastal Disaster Mitigation in Tokyo Bay." One of the organizers of this symposium is School of Environment, Beijing Normal University, with which Graduate School of Frontier Sciences, the University of Tokyo has concluded Memorandum of Understanding (MOU) since May, 2019. This symposium was also reported by China Daily.

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Severe salinity contamination in drinking water and associated human health hazards increase migration risk in the southwestern coastal part of Bangladesh

Bangladesh is a deltaic country and it is highly vulnerable to climate change and sea level rise. The southwestern part of this country is repeatedly devastated by cyclonic storm surges which create long-term waterlogging, flooding’s, and salinity problems. After the cyclone Sidr in 2007 and Aila in 2009, salinity problems in groundwater have significantly increased where groundwater is a principal source of drinking water in the coastal community. After the continuing consequences of salinity contamination and consumption of those types of water, local peoples are suffering from several types of health diseases. Average household health expenditure is significantly increased and it exerts more pressure on their vulnerable household economy. Thus, […]

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ENPC-UTokyo Joint Workshop

ENPC-UTokyo Joint Workshop was held on December 3, 2018, at the University of Tokyo. ENPC or Ecole des Ponts ParisTech is the best university or graduate level school in France. One of the major topics is about water quality problems in Odaiba Seashore Park, Tokyo Port in Tokyo Bay, where long-distance swimming games and triathlon games are going to be performed in the 2020 Olympic-Paralympic games. This is also a common topic in Seine river in Paris where the 2024 Olympic-Paralympic games are going to be held. In Sasaki's lab, collaborating with ENPC, countermeasures against the water quality problem in Odaiba Seashore Park will be studied by employing numerical computation […]

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Presentation at 20th Anniversary Symposium of our graduate school

Mr. Endo, Ph.D. candidate, presented a poster and gave a flash talk at 20th Anniversary Symposium of Graduate School of Frontier Sciences, the University of Tokyo on October 31, 2018. The title is Inluence of Blue Tide on Fishing Ground and its Mitigation Measures in Tokyo Bay

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