| Project/Area Number |
07556054
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| Research Category |
Grant-in-Aid for Scientific Research (A)
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| Allocation Type | Single-year Grants |
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| Section | 展開研究 |
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| Research Field |
Irrigation, drainage and rural engineering/Rural planning
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| Research Institution | TOTTORI UNIVERSITY |
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Principal Investigator |
YAMAMOTO Tahei Tottori University Arid Land Research Center Professor, 乾燥地研究センター, 教授 (00032102)
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| Co-Investigator(Kenkyū-buntansha) |
TORIDE Nobuo Saga University Faculty of Agriculture Associate Professor, 農学部, 助教授 (70212074)
FUJIYAMA Hideyasu Tottori University Faculty of Agriculture Professor, 農学部, 教授 (90108796)
OTSUKI Kyoichi Tottori University Arid Land Research Center Associate Professor, 乾燥地研究センター, 助教授 (80183763)
INOUE Mitsuhiro Tottori University Arid Land Research Center Associate Professor, 乾燥地研究センター, 助教授 (90032309)
KAMICHIKA Makio Tottori University Arid Land Research Center Professor, 乾燥地研究センター, 教授 (20032310)
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| Project Period (FY) |
1995 – 1997
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| Project Status |
Completed (Fiscal Year 1997)
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| Budget Amount *help |
¥13,400,000 (Direct Cost: ¥13,400,000)
Fiscal Year 1997: ¥1,600,000 (Direct Cost: ¥1,600,000)
Fiscal Year 1996: ¥2,800,000 (Direct Cost: ¥2,800,000)
Fiscal Year 1995: ¥9,000,000 (Direct Cost: ¥9,000,000)
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| Keywords | Tank irrigation system / Water harvest / Imaging plate / Dielectric soil moisture probe / Calibration curve / Dispersion coefficient / Remote sensing / Spectral reflectance / バルク法 / 斜面日射量 / 誘電率センサー / 溶質移動 / 点滴灌漑 / 緑化基盤 / 土壌面蒸発ロス / 不均一な溶質移動 / 数値実験 / 放射性核種 / オートラジオグラフィ / 分光センサー / 点滴潅漑 / 二次元土壌モデル / 生産緑地 / 塩類モニタリング / 分散移流式 / 自然放射性核種 / 蒸発散 |
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| Research Abstract |
The aims of this research project are to propose the efficient irrigation schedules and to develope new soil salinity monitoring system, assuming productive green arid land conditions. The results are as follows ; (1) Irrigation scheduling for tank irrigation system was proposed by discussing simulation results estimated under conditions of water harvest efficiency of 80%, daily irrigation interval, design irrigation interval, irrigated areas of 150 - 300m<@D12@>D1 during irrigation periods of 4 - 22 years. (2) The sodium chloride solution containing <@D122@>D1Na was added to barley-grown dune sand in order to trace the movement of Na in the soil and plants. The imaging plate (IP) which has digital information and high sensitivity was used instead of X-ray film. It was found that the IP could trace the movement of Na in the soil and the translocation of Na in plants than the X-ray film. (3) The measuring precision of some dielectric soil moisture probes based on (i) electromagnetic wav
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e, (ii) resonance phenomenon, (iii) complex dielectric constant, (iv) time-domain reflectometry and (v) amplitude domain reflectometry was evaluated using salty sand. The influence of salt concentration on the measurement of soil water content was discussed. A field-type dielectric soil moisture prove with four parallel rods based on amplitude domain reflectometry had the measuring precision within (]SY.+-。[)0.01 cm<@D13@>D1/cm<@D13@>D1 and (]SY.+-。[)0.02 cm<@D13@>D1/cm<@D13@>D1 in the low and high water range, respectively. The gauge had small influence of salt concentration on moisture measurement compared with other soil moisture gauges in the range ()to 30,000 ppm of NaCl solution. (4) In order to monitor solute transport in soil, four-electrode salinity probes were downsized to minimize any disturbances of the transport processes. The dispersion coefficients, D,for a regular Tottori dune sand (2 % clay content) and a washed sand without clay were determined for saturated and unsaturated flows using the four probes. The dispersivity for saturated flow is almost constant (0.1 cm) regardless of the pore water velocity, v, for both sands. For unsaturated flow the dispersivity is greater (>0.3cm) than forsaturated flow. The regular dune sand has greater D than for the washed sand especially for lower water content (> 1cm). (5) New vegetation cover index (VCI) using spectral reflectances was derived from the results of the experiments and field observation. It's applicability was confirmed on the model surfaces which were composed of sand, salt (NaCl) and vegetation (turf). The methods to evaluate the sand cover ratio and salt cover ratio using spectral reflectances were derived in the experiment. The method to diagnose the water and salt stresses of vegetation using spectral reflectances are also proposed. Less
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