Japan Geoscience Union Meeting 2021

Presentation information

[E] Poster

A (Atmospheric and Hydrospheric Sciences ) » A-HW Hydrology & Water Environment

[A-HW22] Material transportation and cycling in watershed ecosystems; from headwaters to coastal areas

Fri. Jun 4, 2021 5:15 PM - 6:30 PM Ch.09

convener:Morihiro Maeda(Okayama University), Tomohisa Irino(Faculty of Environmental Earth Science, Hokkaido University), Shin-ichi Onodera(Graduate School of Advanced Science and Engineering, , Hiroshima University), Adina Paytan(University of California Santa Cruz)

5:15 PM - 6:30 PM

[AHW22-P12] Long-term Estimation on Phosphorus flux in a Coastal Catchment Influenced by the Anthropogenic Land Use Change

*Kunyang Wang1, Shin-ichi Onodera1, Mitsuyo Saito2, Yuta Shimizu3 (1.Graduate School of Integrated Arts and Science, Hiroshima University, 2.Faculty of Environmental Science and Technology, Okayama University, 3. National Agriculture and Food Research Organization)

Keywords:Phosphorus discharge, sewerage treatment, non-point source, agriculture impact

Phosphorus is a non-renewable resource and is an important element of the natural material cycle. Phosphorus discharge in coastal catchments not only cause the loss of phosphorus resources, but also cause eutrophication. The quantification of the phosphorus discharge in water were most important indicators of the water environment in coastal area because these processes are related to the transport of large nutrient loads. The phosphorus pollution sources of the surface water environment are divided into point source pollution and non-point source pollution according to the different spatial distribution. Nonpoint source phosphorus pollution from agricultural land is a leading contributor to world water quality impairments.

The Yamato River catchment covers 1077 km2 and has been an important crop production base in Western Japan since the 1600s. The region’s rich groundwater resources were a major factor in its agricultural development. In recent decades, however, agricultural land has gradually given way cities in the course of rapid urbanization and increasing population. These have 5 sewage treatment plant in the watershed, 3 of them are located in Osaka Prefecture and others are in Nara Prefecture. As of 2010s, the overall sewage treatment pipeline in the basin covers more than 90% of buildings.

SWAT model could meet this need and has proven to be an effective tool for assessing nonpoint source pollution for a wide range of scales and environmental conditions, and it supports inputting point source data according to monthly data. This study used the SWAT model to simulate phosphorus fluxes in the Yamato river catchment for more than 50 years, to study anthropogenic impact on phosphorus discharge into the ocean.