農業気象
Online ISSN : 1881-0136
Print ISSN : 0021-8588
ISSN-L : 0021-8588
51 巻, 3 号
選択された号の論文の12件中1~12を表示しています
  • 近藤 純正, 徐 健青
    1995 年 51 巻 3 号 p. 219-228
    発行日: 1995/09/10
    公開日: 2010/02/25
    ジャーナル フリー
    A multilayer soil model is presented for estimating daily and annual variations of evaporation, soil water content, and the ground surface temperature. In the model the surface heat budget, the transport of liquid water and the diffusion of water vapor in the soil pores are taken into consideration. This model is verified by observational data obtained at the Ando-soil (volcanic ash soil) field in Tsukuba and at the Tottori sand dune field. At the Ando-soil field the calculation is made for a period of one year of 1983, and the annual evaporation of 774mm y-1 is obtained. At the sand dune field the calculation is made for a period of 41 days in 1983 summer, and the total amount of evaporation of 57mm is estimated. The model calculations agreed well with observations.
  • 真木 太一, 潘 伯榮, 鮫島 良次, 杜 明遠, 川方 俊和
    1995 年 51 巻 3 号 p. 229-238
    発行日: 1995/09/10
    公開日: 2010/02/25
    ジャーナル フリー
    Investigations of microclimatic improvement, sand protection, and growth promotion of a crop by multiple row windbreaks made of several mixed trees were carried out near the Turpan Desert Research Station at Turpan, Xinjiang, China in the middle of June, 1994. The main results are:
    (1) Wind speed was decreased by the first windbreak partially recovered near the second windbreak, but decreased further after it, i.e., the decrease in wind speed was accumulative as the number of windbreak rows increased.
    (2) In summer, excessive increases in air soil temperatures near the windbreak during the daytime had a negative effect on crops. However, there was a positive effect on the temperatures between the first and second windbreaks due to the decrease in radiative cooling.
    (3) The water vapor content in the air was increased by evaporation from the soil and transpiration from windbreaks and crops, in particular in the weak wind at night because of the temperature decrease. Absolute humidity increased at the daytime in summer, but relative humidity generally decreased due to the temperature increase caused by windbreaks.
    (4) Windbreaks promoted the growth and development of young crops, presumably due to the higher temperature and to the decreasing energy exchange accompaning the lower wind speeds. As a result, crop quality and productivity increased.
    (5) Windbreaks made of Ulmus, Elaeagnus and Populus were suitable for an agricultural field in the arid Turpan region and windbreaks made of mixed trees and multiple rows were most suitable for making oases.
  • 杉浦 俊彦, 本條 均, 菅谷 博
    1995 年 51 巻 3 号 p. 239-244
    発行日: 1995/09/10
    公開日: 2010/02/25
    ジャーナル フリー
    人工気象室でニホンナシ‘幸水’に時期を変えて温度処理を行い, 気温が果実の生長・発育におよぼす影響を検討した。
    1. 果実生長が気温の影響を受けるのは幼果期のみで, 8~25℃の範囲では高温ほど幼果期の生長速度は大きかった。生育中後期は影響をほとんど受けなかった。
    2. 果実発育が気温の影響を受けるのも幼果期のみであり, 満開後33日間の気温と満開期から収穫期までの日数は直線関係があった。生育中後期は気温の影響をほとんど受けなかった。
    3. 気温が幼果期の長さを決め, その後収穫までの生育期間の長さは一定であり, かつ生育中後期の生長は日射量に依存するというモデルを作成した。このモデルで10~25℃の範囲のさまざまな気温下での果実の生長が説明できた。
  • 恒川 篤史, 張 新時, 周 广勝, 大政 謙次
    1995 年 51 巻 3 号 p. 245-257
    発行日: 1995/09/10
    公開日: 2010/02/25
    ジャーナル フリー
    二酸化炭素等のいわゆる温室効果ガスの大気中の濃度が人間活動により上昇し, 地表面気温の上昇等の地球規模の気候変化がもたらされるのではないかと憂慮されている。本研究では, このような地球規模の気候変化によって引き起こされる中国における植生分布のシフトを直接転移関数法アプローチによって予測した。植生分布と気候条件との関係を説明するために, 2種類の統計モデル (判別分析モデルおよび多項ロジットモデル) を試みた。その結果, ロジットモデルの方が判別分析モデルよりも良い結果を示した。そこで植生の分布シフトをロボックら (1993) によって提唱された気候変化シナリオにもとづき, このロジットモデルを用いて推定した。
    ロボックらのシナリオは, 大気中の等価二酸化炭素濃度が産業革命前の2倍の水準になる時期の地域的な気候条件を2種類の状況で考えるもので, シナリオAは年平均気温2度上昇, 降水量20%増加, シナリオBは年平均気温4度上昇, 降水量20%増加となっている。
    その結果, 以下のことが予測された。(1) 中国東北部に分布する針葉樹林域は, 最適生息地が北方に移動するのにともない, 中国内では大幅に減少する, (2) 東部に分布する広葉樹林域はシナリオAで約3度, シナリオBで約5度, 北方にシフトする, (3) 西部に分布する砂漠地域が拡大し, ステップおよびサバンナが減少する。とくにシナリオBのとき, このことが顕著である。
  • 山川 修治, 山口 武則
    1995 年 51 巻 3 号 p. 259-268
    発行日: 1995/09/10
    公開日: 2010/02/25
    ジャーナル フリー
    In this paper, strong acid rains are discriminated and analyzed according to atmospheric pressure patterns and atmospheric conditions such as wind system, stable stratification, humidity and so on in the surface air and the upper air. As a result, key clues to the origins of pollution and process of acid rain have been found.
    Pressure patterns producing strongly acid rains are divided into three types. Each characteristic is summarized as follows with Figure 8.
    (1) Type A: Okhotsk-high, south-low type: From NE-ESE winds blow from Kashima-nada through to the Kanto plain for a long period and pollution air from the Kashima industrial area keep being advected inland with “fumigation” (Bierly and Howson, 1962). Over the boundary layer, warm air of SSW-SW advanced in the direction of northern Kanto along with polluted air over the Tokyo metropolitan area. Part of which is blocked by mountainous terrain, mixes with air of the boundary layer and stagnates. The cause for higher intensity of acidity is presumed to lie in long-term continuity of wind system with a large shear.
    (2) Type B: Migratory-high, South-low type: Owing to small pressure gradient, local circulation is caused; the local discontinuity line in the Boso Peninsula tends to be found. North wind springing up from a migratory north high and SW sea breeze with a component of gradient wind from the westside of anticyclone converge. Polluted air that the latter brings from the Tokyo metropolitan area concludes to make strongly acid rain in a Tsukuba area.
    (3) Type C: Japan-Sea-low or cold front type: By means of week S-SW wind of the surface and boundary layer accompanied by small-scale low or a cold front in the Japan Sea, contaminated air over the Tokyo metropolitan area fills the Kanto district. In addition, when SE sea breeze (or gradient wind) from Kashima-nada blows in, contaminated air over Kashima industrial area is advected to Tsukuba. This type registers more stable stratification in the middle level before precipitation so that it tends to result in strongly acid rain.
  • 広田 知良, 福本 昌人, 城岡 竜一, 村松 謙生
    1995 年 51 巻 3 号 p. 269-277
    発行日: 1995/09/10
    公開日: 2010/02/25
    ジャーナル フリー
    A simple model to estimate the daily mean soil temperature using routine meteorological data has been developed. The model is based on a heat budget equation connected with the Force-Restore Model, in which interdiurnal variation of the soil temperature at the surface layer is estimated. The model has some advantages. First, it is not necessary to set up soil thermometric parameters and initial values at the deep soil layer. Second, sensitivities of the soil thermometric parameters are low compared to the case of estimating diurnal variation of soil temperatures. Finally, the boundary condition is easy to determine because annual mean soil temperatures at different depths are nearly equal.
    The model was applied for a bare soil field and verified using the observed data by the heat balance method. Estimated values of daily mean soil temperature agreed well with the observed value, even if the soil thermometric parameters were set as approximated values. To adapt the model for any case, a way to estimate the initial value of soil temperature was examined.
    Although the soil moisture availability was required to estimate the evaporation in the model, the average value of long-time period gave a good result for estimation of soil temperature. In case the value of the actual soil moisture is unavailable, the model gave a good estimation of cumulative evaporation using routine meteorological data and soil temperature at the surface layer. The model could be used to evaluate the soil moisture availability.
  • 海陸風
    日本農業気象学会局地気象研究部会
    1995 年 51 巻 3 号 p. 279-284
    発行日: 1995/09/10
    公開日: 2010/02/25
    ジャーナル フリー
  • 広田 知良
    1995 年 51 巻 3 号 p. 285-288
    発行日: 1995/09/10
    公開日: 2010/02/25
    ジャーナル フリー
  • 近藤 純正
    1995 年 51 巻 3 号 p. 289-292
    発行日: 1995/09/10
    公開日: 2010/02/25
    ジャーナル フリー
  • 王 秀峰, 堀口 郁夫, 町村 尚
    1995 年 51 巻 3 号 p. 292-293
    発行日: 1995/09/10
    公開日: 2010/02/25
    ジャーナル フリー
  • 真木 太一
    1995 年 51 巻 3 号 p. 293-294
    発行日: 1995/09/10
    公開日: 2010/02/25
    ジャーナル フリー
  • 横山 慎司
    1995 年 51 巻 3 号 p. 294
    発行日: 1995/09/10
    公開日: 2010/02/25
    ジャーナル フリー
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