日本地球惑星科学連合2015年大会

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インターナショナルセッション(口頭発表)

セッション記号 A (大気水圏科学) » A-CG 大気水圏科学複合領域・一般

[A-CG07] Continental-Oceanic Mutual Interaction: Global-scale Material Circulation through River Runoff

2015年5月27日(水) 11:00 〜 12:45 201B (2F)

コンビーナ:*山敷 庸亮(京都大学大学院総合生存学館)、升本 順夫(海洋研究開発機構)、Swadhin Behera(Climate Variation Predictability and Applicability Research Program Research Institute for Global Change/JAMSTEC, 3173-25 Showa-machi, Yokohama 236-0001)、宮澤 泰正(独立行政法人海洋研究開発機構)、山形 俊男(海洋研究開発機構 アプリケーションラボ)、寶 馨(京都大学防災研究所)、座長:山敷 庸亮(京都大学大学院総合生存学館)、宮澤 泰正(独立行政法人海洋研究開発機構)、寶 馨(京都大学防災研究所)

12:15 〜 12:30

[ACG07-11] Landsat-5 TMデータを用いた琵琶湖の沈水植物の影響を除いたクロロフィルa濃度推定

*寺本 智子1山敷 庸亮2小林 剛士3中野 不二男4 (1.京都大学大学院工学研究科、2.京都大学大学院総合生存学館、3.堀場製作所、4.宇宙航空研究開発機構)

キーワード:クロロフィルa, 衛星, リモートセンシング, 湖, 沈水植物

Lake Biwa is freshwater lake that is the source of drinking water of Shiga, Kyoto, Osaka, and Hyogo area. However of expanding blue-green algae or aquatic plant are anxious about the influence of the lake in recent years.
Therefore, various monitoring methodology of those mechanisms is examined. The satellite remote sensing is expected as a leading monitoring tool. The concentration Chlorophyll-a of Lake Biwa is a challenging environment of remote sensing because its concentration is too low and blocked by aquatic plant
The utility of satellite imagery for water quality studies in Lake Biwa is investigated.
The main purposes of this study are to present Chlorophyll-a mapping of Lake Biwa and exclude aquatic plant influence and the accuracy was checked. Moreover, the Chlorophyll-a distribution characteristic in this lake was considered using the proposed algorithm.
The satellite data used is five scenes from 1984,1989,1994,1997 and 2002 The Landsat-5 TM Level 1 product data was downloaded through the Internet site “Earth Explorer.” The value of water observation point of Band1 (0.45 - 0.52 μm), Band2 (0.52 - 0.60 μm), Band3 (0.63 - 0.69 μm), Band4 (0.76 - 0.90 μm), Band5 (1.55 - 1.75 μm) and Band7 (2.08 - 2.35 μm) in these lakes was extracted from the obtained satellite data. On the other hand, the Chlorophyll-a data was obtained from the Water Information System of Ministry of Land, Infrastructure and Transport. And Water quality data are compared to imagery from the Landsat TM data.
The Chlorophyll-a value were compared with Digital Number values of Landsat 5 bands using different band combination of empirical algorithms.
Generally, the results of analysis showed significant correlation between these models and water quality parameters.
Moreover, the value of Digital Number is increasing by 1.3(B1), 0.75(B2), 0.2(B4), 0.2(B5) and 0.55(B7) respectively when the coverage of aquatic plant is decreasing 25%.