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., […]
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., […]
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 […]
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.
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, […]
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 […]
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
An investigation of coastal vulnerability and internal consistency of local perceptions under climate change risk in the southwest part of Bangladesh
Bangladesh is one of the most disaster-prone countries, while climate change and its associated hazards such as cyclonic storm surges, inundation, and salinity threats force disruption of coastal communities. Gradually, coastal communities are going to lose their existing livelihoods owing to the regular interruptions of coastal hazards such as high salinity problems in soil and water. In this situation, it is important to secure the coastal lifestyle by investigating the social vulnerabilities and possible policy practices along the coastal belt communities of Bangladesh. Publication Rakib, M. A., Sasaki, J., Palc, S., Md. Asif Newazd, Md. Bodrud-Dozae, Mohammad Amir Hossain Bhuiyan. An investigation of coastal vulnerability and internal consistency of local […]
The 19th Tokyo Bay Symposium (sponsored by National Research Institute for Land and Infrastructure Management, Ministry of Land, Infrastructure, Transport and Tourism) was held at Osanbashi Bridge Hall in Yokohama Port on October 18 (Thu), 2018. Professor Sasaki gave a lecture entitled “Possibility of Blue Carbon and its Social Implementation”, and Mr. Endo, Ph.D. candidate made a poster presentation entitled “Field survey on upwelling of hypoxic water in Sanbanze Shallow Water Area at the head of Tokyo Bay”. It was a great success with about 300 participants.
Beach erosion is a treat to both properties and livelihoods of coastal communities. When the mechanisms of beach erosion are unclear, erosive shorelines are adaptively managed. The success of adaptive management depends on the interpretation of the archived data of each feedback loops. Archived data are limited or difficult to access in developing countries due to lack of budget, technical expertise, institutional coordination etc. Figure 1: Photos of shore next to a tourist hotel after beach nourishment in 2016 December (Photos were taken during my recent field visits) Historical changes in the shoreline and management of Marawila Beach, Sri Lanka, from 1980 to 2017 Coastal management in Sri Lanka is […]