[O-11] Senior high school student poster presentations

[O11-P51] The role of humus soil as waterside soil in the upper reaches of river

*Tomoaki Shibata¹, *Shuntaro Watanabe¹, *Nanoka Misima¹, *Yua Makioka¹ (1.Ibaraki Prefectural Hitachi Daiichi High School)

Keywords:humus soil, water retention, Rain disaster, The Siphon Principle

The Miyata River, which flows near the school, had not flooded for a long period of time due to appropriate flood control facilities. However, it was flooded by the 2023 linear precipitation event. The cause was thought to be that the current flood control system had exceeded its capacity, and attention was paid to humus, a riverbank soil, as a new flood control measure. They hypothesized that humus, with its excellent permeability and water retention properties, would prevent flooding even after heavy rainfall, and conducted an experiment. However, when comparing the amount of water added in the experimental method and the method of adding water to the soil with the actual rainfall the amount of water added and the method of rainfall were unrealistic, and the results were not as expected. The objective of this study is to improve these experimental methods by using the siphon principle, and to accurately clarify the permeability and water retention properties of humus. As a first step, this study aims to calculate a formula to determine the amount of water to be added using the siphon principle.