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No.16 (1969/10) >

 
Title :人工降雨による土壌侵食の実験的考察(沖縄における農地保全の基礎的研究(第 2 報))(農業工学科)
Title alternative :Experimental study on soil erosion caused by man-made rainfall (Fundamental studies on farmland conservation in Okinawa, II.) (Department of Agricultural Engineering)
Authors :翁長, 謙良
Authors alternative :Onaga, Kenryo
Issue Date :1-Oct-1969
Abstract :1.著者の行なった実験は, 人工降雨による土壌侵食のモデルテストであり, 土壌の状態, 降雨のあり方など, 自然とは異なるが, 実際農地においても, 降雨強度と, 流亡土量との関係を知る上の1つの目安とすることができよう。2.吉良は実際農耕地においても, 降雨強度(I)と流亡土量(E)との関係を示す実験式E=aI^bなる式が適用されると報告しており, 土壌侵食のfactorは異なるが, 本実験で求めた実験式もある程度それにマッチしている。3.本実験は, 傾斜5°, 裸地という条件で行なったので, Baverの示すE=f(T.V.S.C.H)のC(気候)・T(地形)についての一元的な解析を試みたにすぎない。4.沖縄における最大10分間降雨強度の極値は68年までの観測では23mmであり, 実験の降雨強度において3mm∿23mmを目標にしたが, 初期の目的雨量にすることは困難であった。
A study on soil erosion was made by means of artificialrain. The type of the soil used in this experiment was the same for each of three plots. The depth of the soil for each plot was 9cm, 19cm, and 27cm, respectively. The plots, which were 0.5 square meters, were set with a slope of 7 degrees. The artificial rain was dropped from a place 6 meters high above the ground for 10 minutes. The results are shown as follows : 1. Although the conditions of soil and rain were different from those in natural conditions, it may be of some clue to know the relation between soil loss and rainfall intensity on the natural farmland. 2. The relation between soil loss and rainfall intensity of each plot is shown by an experimental formula E=a I^b when they are plotted on a log-log graph. The value of a, b of each plot is as following : plot I : E=13.915 I_<10>^<1.24> plot II : E=27.767 I_<10>^<1.48> plot III : E=36.150 I_<10>^<1.34> where E : erosion loss g/10m^2 I_<10> : rainfall intensity mm/10min, 3. As the duration of rainfall was limitted to only 10 ninutes, the relation between soil loss and the depth for each plot can not be identical.
Type Local :紀要論文
ISSN :0370-4246
Publisher :琉球大学農学部
URI :http://hdl.handle.net/20.500.12000/4549
Citation :琉球大学農学部学術報告 = The Science Bulletin of the Faculty of Agriculture. University of the Ryukyus no.16 p.188 -195
Appears in Collections:No.16 (1969/10)

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