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  • 1965 Volume 31 Issue 1
    Published: 15 January 1965
      
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  • A PRELIMINARY STUDY ON THE DRY AND WET CLIMATIC REGIONALIZATION OF CHINA
    QION JIH-LIANG, LINE ZI-KUAN
    1965, 31(1): 1-14. https://doi.org/10.11821/xb196501001
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    In this paper, the dry and wet climatic regionalization of China is made on the basis of the data of 286 stations for the years from 1951 to 1960. Aridity is taken as the first index for the regionalization, which shows the annual state of dryness and wetness. Aridity is the ratio of the potential evaporation and the precipitation, in which the poten- tial evaporation is obtained from the H. L. Penman's formula. Then types of dryness and wetness are used as the second index which shows the seasonal changes. On this basis, China is divided into four climatic zones, i.e. wet, semi-wet, semi-dry and dry, which are called "Class I" regionalization. There is good agreement between the natural landscape and the aridity in general. Then we made use of the dry and wet frequency in the analysis of the dry and wet distribution in various seasons. On this basis, 15 dry and wet types are derived, five of which being fundamental dry and wet types. The dry and wet distributions in each season are closely related with the feature of the general circulation. According to Class I and the dry and wet types, China is divided into 25 dry and wet regions, which are called "Class II" regionalization.
  • A STUDY ON THE WET AND DRY PERIODS AND REGIONALIZATION OF CHINA ACCORDING TO ARIDITY
    LU CHI-YAO, WEI LIN, DU CHUNG-PUH, LIN CHEN-YAO
    1965, 31(1): 15-24. https://doi.org/10.11821/xb196501002
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    In this paper, the geographical and seasonal distributions of the wet and dry periods and their influences on the agriculture of China are discussed. By using the meteorological data during 1951-60 of 310 stations, the durations of the wet and dry periods are de- termined by the histogram of the monthly aridity. The results of the calculations (Fig. 3-8) are in good agreement with facts. Based on the indices of aridity, they are distinguished into the moist, humid, arid and dry periods. The indices of aridity(D) are obtained from the following formula: D=Σd/r，where Σd is the sum of the daily saturation deficit(mb) and r the monthly precipitation (mm). The criteria for wet and dry periods are shown in table 1.
  • A PRELIMINARY ANALYSIS ON CERTAIN CHARACTERISTICS OF THE 500 MB CIRCULATION DURING THE DRY AND THE WET MONTHS IN THE YANGTZE VALLEY AND THE HOPEI PLAIN
    CHANG CHIA-CHENG, KUN FU-SUN, SHIN KUNG-WANG
    1965, 31(1): 25-35. https://doi.org/10.11821/xb196501003
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    A comparative analysis is made of the 500 mb mean monthly circulation patterns over Asia during the wet months from May to August in the Yangtze Valley and North China. It is found that the 500 mb circulation patterns and the monthly height anomaly patterns are fundamentally different between the dry and the wet months. Furthermore, the characteristics of the circulation in the wet months are nearly the same as those of the mean circulation in June based on the average for ten years. The 500 mb circulation over North China Plain at the 10-day period of the wet month from July 21 to August 20 is markedly different between dry and wet periods. The circulation characteristics in the 10-day period of the wet months are nearly the same as those of the first 10-day period of August. Based on the result of the above mentioned analysis, the authors sug- gested that from the climatological view, June is the most rainy month in the Yangtze Valley while the first 10-day period of August is the most rainy period for the North- China Plain. The climatic periods during which the occurrence of rain is most frequent are closely related to certain climatic conditions of the general circulation. Only under such favourable circumstances, is it possible for warm and cold air masses to keep continual contact with the result of frequent rain in the afore-mentioned regions. It is apparent that there are close connections between weather and climate, circulation and precipita- tion. These arc of importance for the explanation of the great precipitation anomalies.
  • REMNANTS OF QUATERNARY GLACIATION ON THE TIBETAN PLATEAU
    WANG MING-YE, CHUNG MEIN-PING
    1965, 31(1): 63-72. https://doi.org/10.11821/xb196501005
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    On the Tibetan Plateau, remnants of the quaternary glaciation are of general oc-curence. Cirques, U-shape valleys, glacial-scoured lakers, till plains, terminal moraines, and drift boulders are wide spread features down to 4200 m in altitude. The authors believe that there was once a fairly continuous ice cover on the Tibetan plateau in late pleis-tocene. Here after the snow-line was raised, and the glaciers retreated gradually to their present positions. The reasons are two-fold:(a) a general warming of the world climate, (b) dessication of Tibet due to further uplift. The latter is evidenced by the obvious shrinkage of many lakes on the plateau. By correlating the moraines of this glaciation with the terrace of Zi-Ling Tsangpo and Yamdrok, we reach at the conclusion that this great Ice Cover was of late Pleistocene in age. Since that time the glacier retreated in three recessional stages: 1. forming Yamdrok Lake ................................……4400 m. 2. forming terminal moraines in Cano Chu Valley ............……4650 m. 3. forming moraines on Cano-La Col ........................……4950 m. Respective recessional moraines are also discovered in the valley of Drokar Chu on the northern slope of Chumulanma.