[A-HW22] Material transportation and cycling at the land-sea interface: from headwaters to the ocean

[AHW22-P13] Estimation of streamflow and material transport in Chikugo river catchment using modeling approach

*Francis Jhun Tin-ao Macalam^1,2, Kunyang Wang¹, Shin-chi Onodera¹, Mitsuyo Saito¹, Yuko Nagano³, Masatoshi Yamazaki⁴ (1.Graduate School of Advanced Science and Engineering, Hiroshima University, 1-7-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8521, Japan, 2.Department of Environmental Science and Technology, College of Science and Mathematics, University of Science and Technology of Southern Philippines, Cagayan de Oro City, 9000, Philippines, 3.Japan Forest Technology Association, Rokubancho, Chiyoda-ku, Tokyo 102-0085, Japan, 4.PASCO Corporation, PASCO Meguro Sakura Bldg, 1-7-1 Shimomeguro, Meguro-ku, Tokyo 153-0064, Japan)

Keywords:Chikugo river, material transport, modeling, streamflow, nutrients

Assessing water balance and predicting pollutant levels are vital aspects of managing watersheds. While directly measuring pollutants and runoff is ideal, it's not always possible when or where needed. This study aims to replicate the intricate water-related processes in the Chikugo River basin by utilizing Geographic Information System (GIS) and the Soil and Water Assessment Tool (SWAT). The approach involves creating and fine-tuning a model that encompasses various data types such as terrain outlines, weather data, land usage, soil characteristics, and water flow metrics to accurately depict how rainfall, runoff, water loss through plants and soil, seepage, and river flow interact.

The main significance of the research is to provide support for understanding the basic hydrological processes of the basin and simulating material transport under realistic conditions. Furthermore, this study will contribute to a broader understanding of river basin dynamics by providing a framework for assessing the complex interrelationships between hydrological events and material transfers in an extremely dynamic environment like chiguo river basin.