Climate and Environment

#Global Warming #Climate Change #Atmospheric Science #Weather Disasters #Weather Forecasting #Transportation Economics

The weather experiences continuous fluctuations on a daily basis and profoundly impacts our livelihoods. As a result of the multifaceted impacts of human activities on the global environment, various weather-related issues, such as global warming and torrential downpours, are emerging. Here, we introduce the research conducted by researchers at the University of Hyogo with the aim of safeguarding our welfare, human existence, and the biodiversity of the global environment.

Evaluation of the potential meteorological hazard due to climate change using a numerical weather prediction model

Yuichiro Oku

Associate Professor, School of Human Science and Environment

(Researcher Information)

Climate change, encompassing global warming, is unquestionably inevitable. Aside from mitigation strategies aimed at reducing emissions of greenhouse gases responsible for global warming, there is an urgent necessity to implement adaptation measures to accommodate the evolving nature of disasters and societal responses to the ongoing effects of global warming. Within the realm of atmospheric science, my expertise lies in scrutinizing the mechanisms underlying meteorological phenomena, spanning from severe weather events like storms to milder climatic conditions, with the aim of forecasting future trends and their ramifications on human existence.

The amount of damage caused by a typhoon depends greatly on its track. Heavy rainfall is related to topographic features such as mountain ranges and also depends on the track and migration speed of a typhoon. In order to determine the worst-case scenario for disaster hazards, we evaluate the potential for typhoon-related hazards, such as heavy rainfall and severe wind, induced by typhoons with controlled track and intensity with the aid of ensemble simulations employing a numerical weather prediction (NWP) model. The NWP model can produce or reproduce physically based predictions for various meteorological phenomena including severe hazards, and an ensemble is a group of NWP model simulations used for typhoon projections. It is hoped that the results of this study will contribute to the planning of adaptation measures by providing a set of scientifically possible examples based on actual typhoons.

Hyogo Prefecture has the largest number of small reservoir ponds in Japan due to its relatively warm and dry climate especially in the southern part of the prefecture. Small reservoir ponds, especially those that are either excavated or which make use of the natural topography, are excellent at storing surface water for various uses, including irrigation and flood prevention. However, the number of such ponds is decreasing by being filled in and repurposed for industrial or residential areas, resulting from the abandonment of farming due to depopulation in rural areas.

On the other hand, due to the difference in the specific heat capacity of the land and the water surface of the pond, there is usually a temperature contrast between the two: the land warms up more strongly than the pond during the day when the sky is clear. The use of the relatively cool breeze from ponds to mitigate heat waves or the urban heat island phenomenon has attracted attention as an adaptation measure.

To evaluate this cooling effect, we compared the temporal variation of the spatial distribution of surface air temperature between a control experiment reproducing real weather and a sensitivity experiment that estimated the effect of replacing the water bodies of ponds with urban residential areas at the lower boundary condition of the control experiment. This research is being conducted in collaboration with researchers specializing in biogeochemistry and hydrology at other universities. We expect to discover the potential of reservoirs in many fields, including agriculture, disaster prevention, and the environment.

Expanding Research

Improving the accuracy of heavy rainfall forecasts and reducing damage from weather-related disasters by understanding the mechanisms of phenomena

Hiroshi Taniguchi

Associate Professor, Graduate School of Disaster Resilience and Governance

(Researcher Information)

My specialty is meteorology, climatology, and geophysical fluid dynamics. I study the mechanisms of atmospheric phenomena from urban to global scales by performing analyses of observational data, numerical simulations, and theoretical calculations. Recently, we have been working on a project with several undergraduate schools and graduate schools within the university to conduct observational research to improve the predictability of heavy rainfall events such as the linear rain band that occurs mainly in the Kinki region. To improve the predictability, it is necessary to obtain data at sub-interval scales not captured by existing observations and to investigate the contribution of these observations to significant phenomena such as heavy rainfall. Therefore, we are conducting radiosonde observations to find the best data collection points, which will improve the accuracy of heavy rainfall forecasts. In the future, we would like to have permanent observation points and use the results of numerical simulations based on the obtained data for a wide range of applications, such as hazard assessment.

Incorporating a meteorological perspective into economics to achieve sustainable transportation

Shinya Koyama

Professor, School of Economics and Management

(Researcher Information)

My area of expertise is transportation economics. For example, public transportation systems such as railroads utilize knowledge from various fields, such as demand forecasting and risk management, to provide optimum services safely. Weather data is one of them. If stable operations are impaired, there is a risk of various losses to society. In the past, operations were restricted when heavy rain or strong winds exceeded specific standards, with the highest priority given to keeping operations running as normally as possible. However, since 2014, planned shutdowns have been introduced. By observing weather data and predicting the possibility of an impact on operations, it is now possible to give advance notice of a suspension. This makes it possible to reduce the impact on society by temporarily halting traffic. The norms of industry change as society changes. We will continue our research on sustainable transportation while appropriately responding to the needs and changes in society.

Focus on Person

Crossing land use data with weather data to understand the effects of urbanization on climate

The theme of my master’s thesis is the urban heat island phenomenon in the city of Akashi. First, to grasp the current temperature distribution, I installed thermo-hydrometers on the thermometer shelters (Hyakuyo-Bako) of nine elementary schools in Akashi. The observed data have revealed how the land use and geographical features affect the micro climate. In addition, using the observed data and a numerical weather prediction model, I conducted a reproducibility test. After verifying the validity of the results against the observed data, I also conducted another experiment by modifying the land use data to the data in 1976 to clarify the impact of land use change on surface air temperature. Based on municipal plans, I will modify the land use into a more built-up one and predict the future environment. I hope this series of research will raise awareness of the urban heat island phenomenon and lead to discussions on mitigation measures.

Crossing land use data with weather data to understand the effects of urbanization on climate

Sou Sakamoto

2nd year master's program student, School of Human Science and Environment

Spreading the concept of disaster mitigation and recovery through flood countermeasures

When designing houses, preparedness for flood damage has yet to be well recognized. I am studying preparing houses for flood damage and easily recovering from such damage, taking a combined approach to disaster mitigation and recovery. I am researching disincentives and ways to promote the flood-proofing of housing. I conducted a questionnaire survey of people who suffered damage in Takeo, Saga, which has experienced large-scale flood damage, and analyzed the issues that emerged from the survey. I hope this research will assist not only countermeasures against floods but also contribute to expanding awareness of the concept of disaster resilience and governance, learning from disasters and applying it to the next stage of disaster prevention.

Spreading the concept of disaster mitigation and recovery through flood countermeasures

Kaho Takahashi

2nd year master's program student, Graduate School of Disaster Resilience and Governance