普通期晴天日における循環灌漑の窒素・リン差し引き排出負荷削減効果  [in Japanese] Effect of Cyclic Irrigation on Reduction of Net Effluent Loadings of Nitrogen and Phosphorus during Sunny Days in Irrigation Period after Puddling Season  [in Japanese]

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Abstract

本研究は, 琵琶湖岸の水田群での水量, 水質の調査結果をもとに, 普通期晴天日における循環取水率と窒素およびリンの差し引き排出負荷の関係を推定した.その結果, 窒素の差し引き排出負荷は, 必ずしも循環取水率の増加によって単調に減少するわけではないことが示された.これは, 排水の窒素濃度の増加分が流出する水量の減少分を打ち消すためである.一方, リンでは, 循環取水率の増加による差し引き排出負荷の削減効果が現れやすいことが示された.また, 揚水量のうち水田に導水されない余剰な水量の割合が低くなることで, 差し引き排出負荷は循環取水率に関わらず常にマイナスとなることがわかった.

The relations between net effluent loadings of total nitrogen and total phosphorus and cyclic irrigation ratio during sunny days in irrigation period after puddling season was estimated on the basis of measurements of quantity and quality of water in a paddy field district around Lake Biwa. As a result, it was shown that the net effluent loadings of nitrogen for the district did not monotonically decrease as the cyclic irrigation ratio increased because the increment of nitrogen concentration of the drainage water negated the decrease of the amount of the effluent water. In contrast, reduction effect of the cyclic irrigation on the net effluent loadings of phosphorus was high. In addition, it was found that the net effluent loadings were negative to any cyclic irrigation ratio if the ratio of the amount of surplus irrigation water to that of pumped water was low.

Journal

  • Transactions of The Japanese Society of Irrigation, Drainage and Rural Engineering

    Transactions of The Japanese Society of Irrigation, Drainage and Rural Engineering 76(5), 419-425, 2008-10-25

    The Japanese Society of Irrigation, Drainage and Rural Engineering

References:  9

Cited by:  1

Codes

  • NII Article ID (NAID)
    10025640575
  • NII NACSIS-CAT ID (NCID)
    AA12240517
  • Text Lang
    JPN
  • Article Type
    Journal Article
  • ISSN
    18822789
  • NDL Article ID
    9707255
  • NDL Call No.
    Z18-365
  • Data Source
    CJP  CJPref  NDL  J-STAGE 
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