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Volume 36, Issue 2
Displaying 1-9 of 9 articles from this issue
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I. An Attempt for the Evaluation of Climatic ProductivityYasuyuki SUGIHARA, Juro HANYU1980 Volume 36 Issue 2 Pages 71-79
Published: September 25, 1980
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSA climatic index, YR, which gives the potential quantity of ripening of the paddy rice, was introduced by Hanyu et al. (1966) as follows:
YR=SR{a-b(θR-21.4)2} (1)
where, SR denotes the duration of sunshine, θR the mean temperature during ripening period, and a and b are the empirical constants, respectively. The authors attempted to obtain a climatic productivity index of the paddy rice by improving the above index.
First, YR as a linear function of SR was modified as follows:
YR=ln(1+SR/MO){a-b(θR-θO)2} (2)
where, MO is a parameter modifying the slope of YR increase with the increase in SR, and is estimated to be 10 by the manner described after. The constants a and b were estimated to be 260 and 2.70, respectively, from the upper limiting line in Fig. 2 when MO=10, and θO=21.5°C. Both the constants were estimated for the wide range of MO-values, and then the estimated constants were introduced into Eq. (3) to obtain various M-values. The individual M estimated by the actual yield, Y at each area, is equal to or more than MO estimated by YR.
As is obvious from Eq. (2), YR decreases with the increase in MO, even if the climatic conditions (SR, θR) during ripening period are suitable. Therefore, it is considered that MO is a variable which is inversely proportional to the sink capacity receiving photosynthetic product before and after heading, and so MO may be accepted as a growth index.
Fig. 3 indicates the relationship between the number of grains (N) and M-values obtained by introducing a=260, b=2.70. The limiting curve in Fig. 3 was named MN.
The air temperatures prior to heading time, θV and θH were related to M, as shown in Fig. 6. The lower limiting curves in Fig. 6 show the minimum values of M; MV and MH. The larger value between MV and MH was selected as MG. MG was substituted with Eq. (5′). MG was named the “climatic index of growth”. The minimum value of MG is MO (=10). YP calculated by Eq. (5) gives the climatic productivity,
YP=ln(1+SR/MG){260-2.70(θR-21.5)2} (5)
YP was named the climatic productivity index of paddy rice.
From the relationship (Fig. 10) between MN and θH, another climatic productivity index, Y′P is given by
Y′P=ln(1+SR/M′N){260-2.70(θR-21.5)2} (6)
where, M′N is obtained by Eq. (6′).
The relationship between YP or Y′P and the actual yield, Y (Figs. 8 & 9) was discussed.
The concept on the climatic productivity and its application was previously described by Hanyu et al. (1966).View full abstractDownload PDF (1135K) -
Hiroshi SEINO1980 Volume 36 Issue 2 Pages 81-88
Published: September 25, 1980
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSThe total kinetic energy of a hailfall derived from hailpad is known to be closely related to the degree of crop damage. The hail size distribution (space concentration distribution) is also considered as one of the factors related to crop damage. Hailpad data, however, contain no information on the time of hail. Therefore, the hail size distribution can not be calculated directly from hailpad. In this paper an attempt was made to estimate hailfall duration from hailpad data in the damaged area of approximately 4km width and 8km length suffered by the northern Kanto hailstorm on 9 June 1975. The degree of crop damage had been classified into 5 groups. The hailpad data were classified according to the degrees of crop damage and averaged over each class. The number frequency distribution obtained from hailpad was converted to hail size distribution with the estimated hailfall duration. The characteristics seen in the size distributions were described in relation to crop damage. Furthermore, the size distributions were fitted by the equations of Marshall and Palmer (1948) and Shiotsuki (1975). From the relations of the parameters in these equations to crop damage, it was found that the mean diameter was closely related to crop damage. Thus, as the mean diameter can be derived directly from hailpad, the hailpad observation system is suggested to be useful for the objective assessment of crop-hail damage.View full abstractDownload PDF (1832K) -
Tetsuya HASEBA, Daijiro ITO1980 Volume 36 Issue 2 Pages 89-94
Published: September 25, 1980
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSA fundamental function of the coefficient of heat/mass transfer across a boundary layer on a plant leaf for forced convection was evaluated in relation to the leaf dimension. The average transfer coefficients on a model-leaf were obtained from the measurements of water evaporation from the surface of flat rectangular plates with various lengths and widths from 1 to 32cm. The surface of the model-leaf was set in parallel with the air flow in a wind tunnel.
The average coefficients were proportional to the square root of the wind speed in a laminar region. For plates with relatively small lengths in the direction of the flow, compared to their transverse widths, the observed coefficients were in good agreement with the theoretical ones. For plates with lengths more than a critical value, however, the observed coefficients were larger than the theoretical ones. In a width-fixed model-leaf, the ratio of the observed coefficient to the theoretical one increased with an increase in length, whereas in a length-fixed leaf it decreased with increasing width.
A realistic transfer coefficient for forced convection was formulated as a function of the length and width of model-leaf and wind speed.View full abstractDownload PDF (617K) -
I. On the Dewy Time and Dew Amount in Southwest Area of TaiwanSen-Hsiung HSU, Tsutomu SAKANOUE1980 Volume 36 Issue 2 Pages 95-101
Published: September 25, 1980
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSThe present paper deals with the characters of dew under winter-dry climate in southwest region of Taiwan (represented by Pingtung area). The dew amount was measured by means of weighing method with acrylic plate, and the time of dew formation start and dissipation were recorded by an improved Taylor type dew duration recorder. Records were analyzed for quantity and duration of dew and the dew amount were compared with precipitation and class A-pan evaporation. From November 1977 to May 1978 and October 1978 to May 1979, the observed records of dew were summarized as follows:
(1) From November to May, the total number of dewy days were 149 in 1977 and 155 in 1978, while in the same periods the total dew amount were 25.9mm in 1977 and 26.2mm in 1978. The monthly average frequency of dewy day was 71%.
(2) The maximum dew amount records were 4.2mg cm-2 hr-1, 43mg cm-2 day-1 and 6.57mm cm-2 month-1. The maximum value of duration was 13 hours and the average of that was 8.2 hours.
(3) The daily dew amount can be calculated from the following equation with meteorological data,
Y=9.3304X1+0.2358X2-0.1348X3+0.4167X4-20.3038,
where, Y is the dew amount (mg cm-2 day-1), X1 the nocturnal cooling rate of air temperature in screen (°Chr-1), X2 the nocturnal relative humidity in screen (%), X3 the nocturnal wind speed at 1.5m height (cm s-1) and X4 the total nocturnal net radiation (ly).
The proportion of calculated dew amount from regression equation was 79% to observed dew amount.
(4) During the rainless month in winter season the dew amount was more than precipitation. The monthly average of dew amount was amount to 7% of precipitation and 4% of pan evaporation in normal year. The daily proportion of dew amount to pan evaporation which more than 10% was about 17% in total dewy days during the winter season.View full abstractDownload PDF (2720K) -
Tsutomu SATO, Toshihiko MAITANI, Eiji OHTAKI1980 Volume 36 Issue 2 Pages 103-107
Published: September 25, 1980
Released on J-STAGE: February 25, 2010
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1980 Volume 36 Issue 2 Pages 108
Published: September 25, 1980
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSDownload PDF (169K) -
Hikaru NISHIUCHI1980 Volume 36 Issue 2 Pages 109-111
Published: September 25, 1980
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSDownload PDF (447K) -
Akiyoshi MATSUDA1980 Volume 36 Issue 2 Pages 113-121
Published: September 25, 1980
Released on J-STAGE: February 25, 2010
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1980 Volume 36 Issue 2 Pages 131-144
Published: September 25, 1980
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSDownload PDF (1894K)
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