@article{oai:repository.naro.go.jp:00002390,
 author = {丸山, 篤志 and MARUYAMA, Atsushi and 伊川, 浩樹 and IKAWA, Hiroki},
 journal = {九州沖縄農業研究センター研究資料, Memoirs of the Kyushu Okinawa Agricultural Research Center},
 month = {Mar},
 note = {The 2016 Kumamoto earthquake caused cracks and uneven terrains that potentially resulted in additional water leakage from paddy fields. To investigate how the water loss  occurred according to different damages, we measured the water-table reduction rate（WTR）in paddy fields in three different areas in Kumamoto-Akitsu, Kamirokka, and Kurokawa. The WTR measured in three fields in the Akitsu area where uneven terrains were created in some parts after the earthquake ranged from 25 to 31 mm/day. These values were slightly higher than the WTR standard range（15 to 25 mm/day）according to the guideline of the Ministry  of Agriculture, Forestry, and Fisheries of Japan. The field in Kamirokka, which had a large crack, had a WTR of 38 mm/day. This value was not very high considering the fact that the soil puddling for rice transplanting was not practiced in this field after the earthquake. In contrast, despite the absence of apparent damage on the ground surface, the WTR in the Kurokawa field was extremely high and was estimated to be at least 260 mm/day. The daily water use during the rice-growing period based on the WTR in the Kurokawa field largely exceeded the typical range of peak water requirement during the soil puddling season（80 to 120 mm/day）. The extremely high water leakage in the Kurokawa field suggests that the soil structure under the ground was altered after the earthquake., 平成 28 年熊本地震により亀裂や不陸（凹凸）が生じた水田圃場において，漏水の指標となる減水深の調査を行った。被害の生じた熊本市東区（秋津），嘉島町（上六嘉），阿蘇市（黒川）の水田において減水深を測定し，不陸や亀裂の有無など，地表の外観状況による減水深の違いを評価した。不陸の生じた水田を含む秋津の 3 圃場で計測された減水深は 25 ～ 31mm/
day の範囲であった。これらの値は，土地改良事業計画設計基準における減水深の目標値である 15 ～ 25mm/day をやや上回っていた。亀裂の生じた上六嘉の水田の減水深は 38mm/
day であった。ただし，代かきが実施されていないため，代かき後の減水深は上記の目標値の範囲内になるものと考えられた。黒川の水田は減水深が極端に大きく，少なく見積もった    場合でも 260mm/day に達した。この減水深から算出された水稲栽培期間中の一日あたりの圃場用水量は，6 ～ 9 月の全ての月で代かき期のピーク用水量の一般的な値（80 ～ 120mm/
day）を大きく上回っていた。同水田では，地表には特に外観被害が見られなかったことから，地表面下における土壌の物理構造が地震の影響を受けて変化したことが示唆された。},
 pages = {10--17},
 title = {平成28年熊本地震により亀裂や不陸が生じた水田圃場の減水深の特徴},
 volume = {95},
 year = {2019},
 yomi = {マルヤマ, アツシ and イカワ, ヒロキ}
}