JOURNAL OF JAPAN SOCIETY OF HYDROLOGY AND WATER RESOURCES
Online ISSN : 1349-2853
Print ISSN : 0915-1389
ISSN-L : 0915-1389
Volume 11, Issue 3
Displaying 1-12 of 12 articles from this issue
  • [in Japanese]
    1998 Volume 11 Issue 3 Pages 199-200
    Published: May 05, 1998
    Released on J-STAGE: October 22, 2009
    JOURNAL FREE ACCESS
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  • I:Derivation of Equations of Spatially-Averaged Surface Heat Fluxes and Their Aggretation Criteria
    Tosiyuki NAKAEGAWA, Taikan OKI, Katumi MUSIAKE
    1998 Volume 11 Issue 3 Pages 201-209
    Published: May 05, 1998
    Released on J-STAGE: October 22, 2009
    JOURNAL FREE ACCESS
    This research studys the aggregation of surface heat balance by means of the linear model, and discusses the derivation of an equation of regionally averaged surface heat fluxes and their aggregation criteria. We derive an equation of regionally averaged surface heat fluxes and their aggregation criteria in this paper which is the first part in the two parts, and the following conclusions are obtained; (i) derived equations consist of equations by parameter mean method and, variance and cross moment terms of surface parameters which represent the effect of their distribution, (ii) the aggregation criteria are expressed as the tolerance range of variance and more higher oder moment with a single parameter distributed, (iii) the criteria for the latent heat are more strict than for the sensible one, and it is enough to check the former only, (iv) equations for regional averaged fluxes and their criteria with multiple parameters distributed, are derived, (v) generalized aggregation criteria are the same procedure as the cluster analysis.
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  • II:Aggregation of Surface Heat Fluxes over an Heterogeneous Region
    Tosiyuki NAKAEGAWA, Taikan OKI, Katumi MUSIAKE
    1998 Volume 11 Issue 3 Pages 210-220
    Published: May 05, 1998
    Released on J-STAGE: October 22, 2009
    JOURNAL FREE ACCESS
    This research studys the aggregation of surface heat balance by means of the linear model, and discusses the derivation of an equation of regionally averaged surface heat fluxes and their aggregation criteria. We discuss aggregation of surface heat fluxes over an inhomogeneous region in this paper which is the second part in the two parts, and the following conclusions are obtained; (i)statistical distribution of bulk coefficients in the same land covers can be aggregated by the parameter mean method, (ii)that of evaporation efficiency there can be aggregated for some statistical distributions, not by means of the parameter mean method but the moment method, (iii)the moment method can aggregate the surface heat balance even over an inhomogeneous region with high accuracy, (iv)the dominant land cover method used as the aggregation method in the land process model of many atmospheric models, is not good for the aggregation procedure. (v)the parameter mean method is easy to be implemented in the conventional model, but is not accurate, while the moment method is not easy from the view point of usage but accuracy is good.
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  • Hironori NAKABAYASHI, Nobuyoshi ISHIKAWA, Yuji KODAMA
    1998 Volume 11 Issue 3 Pages 221-228
    Published: May 05, 1998
    Released on J-STAGE: October 22, 2009
    JOURNAL FREE ACCESS
    A forest model based on an all-sky photograph was used to investigate the effects of tree height and distance between trees on the total sky view factor (P), the sun path sky view factor (Q) and the relationships between P and Q of a coniferous forest and a deciduous forest with no leaves. Variations in Q owing to the direction of a forest were also evaluated. P and Q are important factors for discussing the transmission of radiation to the forest floor, because P represents the transmissivity of diffuse radiation and Q represents the transmissivity of direct radiation. For both types of forest, P and Q became larger as the tree height became lower and the distance between trees became larger. Tree height especially affected Q of the coniferous forest, and distance between trees affected P of both coniferous and deciduous forests. The relationships between P and Q varied according to type of forest, and Q of the deciduous forest was smaller than that of the coniferous forest for the same value of P. The value of Q of the coniferous forest depended mainly on the position of the nearest tree to the observation point. Forest direction strongly affected Q of the coniferous forest when P∼0.5 but only affected Q of the deciduous forest.
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  • Adaption of Statistical Reverse Residual Mass-Curve to Dam Planning
    Tatsuhiro KYOSHI, Akira SHIMODA
    1998 Volume 11 Issue 3 Pages 229-239
    Published: May 05, 1998
    Released on J-STAGE: October 22, 2009
    JOURNAL FREE ACCESS
    Validity of the statistical reverse residual mass curve for optimum dam water supply control was confirmed by the past papers I∼III in this reserch. Based on these results, determination of the optimum dam scale is studied corresponding with optimum dam water supply control introducing the theory of capitalized benefit. The statistical residual mass-curve is also proved to be available for dam planning. In addition, this paper explains the optimum control and planning method of extraordinary drought countermeasure dam which is important policy for drought damage mitigation.
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  • Hiroki TANAKA, Yoshihiro FUKUSHIMA, Changhua LI, Jumpei KUBOTA, Takesh ...
    1998 Volume 11 Issue 3 Pages 240-252
    Published: May 05, 1998
    Released on J-STAGE: October 22, 2009
    JOURNAL FREE ACCESS
    In order to numerically evaluate the water discharge property of the Jiulianshan river basin, we applied the hydrologic cycle model (HYCYMODEL) to the discharge response to rainfall observed in the Jiulianshan river basin. The parameters in this model were optimized by trial and error. Monthly potential transpiration rate was computed from observed air temperature, humidity, and solar radiation with Priestly-Taylor equation. The discharge response to the rainfall simulated using HYCYMODEL agreed well with the observed discharge. The estimated parameters and the result of simulation of the discharge response to the rainfall were compared with those reported for the typical Japanese temperate forest river basins. In Jiulianshan, the ratio of the impermeable area is small, and the river basin has a large capacity of water storage. As a result, it was found that the shape of hydrograph of Jiulianshan river basin is different from those of Japanese river basins, although the ratio of total base flow to the total discharge is similar to those of Japanese river basins. In Jiulianshan, the peak of discharge is smaller and the recession hydrograph is more gentle.
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  • Hironori YABUKI, Katsumoto SEKO, Yutaka AGETA
    1998 Volume 11 Issue 3 Pages 253-259
    Published: May 05, 1998
    Released on J-STAGE: October 22, 2009
    JOURNAL FREE ACCESS
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  • Kimpei ICHIYANAGI, Kikuo KATO
    1998 Volume 11 Issue 3 Pages 260-265
    Published: May 05, 1998
    Released on J-STAGE: October 22, 2009
    JOURNAL FREE ACCESS
    The storm hydrograph was separated into “old” and “new” water components using oxygen isotopes (δ18O) of water during a storm event which total rainfall was 4 mm. In the two small forested basins which discharge areas are 53.4ha and 1.6ha, principal component analysis, determination of runoff components and quantitative analyses were calculated. The hydrograph in small basin showed large variations related to the precipitation, but that in large basin showed slowly increase and decrease. Time series of the stormflow agreed well with the change of δ18O compositions in both basins. The results of determination of runoff components indicated that the new water component contributed to the differences of runoff characteristics in two basins. The proportions of new water to total precipitation was 3.4% in large basin and 1.5% in small basin, respectively.
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  • [in Japanese]
    1998 Volume 11 Issue 3 Pages 266-273
    Published: May 05, 1998
    Released on J-STAGE: October 22, 2009
    JOURNAL FREE ACCESS
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  • [in Japanese]
    1998 Volume 11 Issue 3 Pages 274-284
    Published: May 05, 1998
    Released on J-STAGE: October 22, 2009
    JOURNAL FREE ACCESS
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  • [in Japanese]
    1998 Volume 11 Issue 3 Pages 286-287
    Published: May 05, 1998
    Released on J-STAGE: October 22, 2009
    JOURNAL FREE ACCESS
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  • [in Japanese]
    1998 Volume 11 Issue 3 Pages 288
    Published: May 05, 1998
    Released on J-STAGE: October 22, 2009
    JOURNAL FREE ACCESS
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