@article{oai:repository.naro.go.jp:00001181,
 author = {福本, 昌人 and FUKUMOTO, Masato and 進藤, 惣治 and SHINDO, Soji},
 journal = {農研機構研究報告 農村工学研究部門, Bulletin of the NARO, Rural Engineering},
 month = {Mar},
 note = {We examined the characteristics of spatial variation in the water requirement rate, which consists of evapotranspiration and percolation, with data from a water requirement rate survey conducted in 2007 in the Nishikanbara Region of Niigata Prefecture. Data used for the analysis were the averages of three water requirement rate measurements obtained from each of six growth stages of rice plants (hereafter, the averages are called WRR) from 851 survey fields where the subsoil is strongly clayey and the soil type is grey soil. The results obtained were as follows. (1) The variation coefficient of the WRR obtained for all survey fields was 70.6 to 79.4 for each growth stage. (2) The average of the WRR obtained in all survey fields was 11.0 to 17.5 mm/d for each growth stage. (3) The necessary sampling number for interval estimation of the population mean of the WRR within a range of ± 2 mm/d and confidence coefficient of 90% was 46 to 113 for each growth stage. (4) Among the five items (presence of peat layer, elevation of a paddy field, groundwater level, lot area of a paddy field and flooded water level), the item most affecting the WRR was flooded water level for all growth stages. (5) The averages of the WRR obtained in the survey fields located in each of the 12 irrigation water distribution blocks varied largely by block for all growth stages., 減水深は，水田の計画用水量の算定に必要となる水量の一つである。本研究では，新潟県西蒲原地域で行われた減水深調査の資料を用い，減水深の広域的なばらつきの特性を分析した。分析に供したのは，心土の土性が強粘質で，かつ， 土壌タイプがグライ土である，851 枚の調査圃場で得られた水稲生育ステージ別の期別減水深データである。分析の結果，①期別減水深には大きなばらつきが見られること（変動係数 70.6～79.4），②水稲の生育が進むにつれて期別減水深の平均値（11.0mm/d→17.5mm/d）が大きくなること，③期別減水深の母平均を± 2mm/d  の範囲で区間推定（信頼係数90%）するために必要な標本数（調査圃場数）は，46～113 個であること，④計測時の湛水位が期別減水深に大きく影響していること，⑤配水ブロック毎の期別減水深の平均値にブロック間で大きな違いが見られることが明らかになった。},
 pages = {1--12},
 title = {低平地水田における減水深の空間的ばらつき},
 volume = {3},
 year = {2019},
 yomi = {フクモト, マサト and シンドウ, ソウジ}
}