Nitrate nitrogen release from rice paddy fields due to hyporheic exchange

2015 Fiscal Year Final Research Report

• Project/Area Number: 25420532
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Hydraulic engineering
• Research Institution: Oita National College of Technology
• Principal Investigator: HIGASHINO Makoto 大分工業高等専門学校, 都市・環境工学科, 准教授 (90311117)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: 環境水理学 / 水資源 / 水環境

Outline of Final Research Achievements

A model was developed for nitrate nitrogen release from rice paddy fields to the Oita River induced by raindrop impact pressure in the basin. The nitrate nitrogen release rate in the paddy fields is expressed as a function of rainfall intensity. The field measurements at Funai in the river show that nitrate nitrogen concentrations for dry weather were not much different from those for wet weather. Whereas, nitrate nitrogen loadings for wet weather were 3 to 12 times larger than those for dry weather. The modeled dependence of unit nitrate nitrogen release on the rainfall intensity agrees fairly well with observed data, validating the model.

Free Research Field

工学