河川水温モデルを用いた河川水温形成に氾濫原が果たす役割の解明  [in Japanese] STUDY OF THE ROLE OF INUNDATION ON RIVER WATER TEMPERATURE WITH A NUMERICAL MODEL  [in Japanese]

Access this Article

Author(s)

Abstract

河川水温は,河川環境や利水と深く関係する物理量であり,また河川の氾濫は,河道と氾濫原にある水を混合することによって河川水温に影響を及ぼすことが明らかになっている.一方で河川の氾濫によって水深の浅い浸水域が広がることで,水面面積や滞留時間が増加し,大気や土壌と交換される熱量の増加や,水深に応じた下向き放射の吸収量の変化による熱収支の寄与割合の変化がもたらされると考えられる.本研究ではこれらの働きを評価するために,水面面積の変化を考慮して熱収支を解く河川水温モデルを開発した.これと河川流下モデルを結合した計算について,タイの観測所における流量,熱収支や河川水温の再現性を検証した上で,氾濫原考慮の有無によって河川水温がどの程度異なるかを算定した.

 River water temperature is one of the major factors in river ecology and water use. Mixture of water between river channels and floodplains affects river water temperature. In addition, the spread of shallow water causes an increase in water covered areas and retention time, which leads to an increase in heat exchange between the atmosphere and soil, and in transmission of radiation, which leads to a change the heat budget. In this study, we developed a river water temperature model by solving the energy balance with consideration of the changes of surface water area in order to evaluate these effects. We combined it with a river flow model and validated river discharge, heat budget and water temperature using in-situ observation data in Thailand. We also assessed the impacts with and without considering inundation area.

Journal

  • Journal of Japan Society of Civil Engineers, Ser. B1 (Hydraulic Engineering)

    Journal of Japan Society of Civil Engineers, Ser. B1 (Hydraulic Engineering) 73(4), I_1213-I_1218, 2017

    Japan Society of Civil Engineers

Codes

Page Top