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24 June 1990, Volume 9 Issue 2   
  • CLIMATIC ANALYSES OF THE PLANETARY BOUNDARY LAYER ATMOSPHERE IN THE HEIHE REGION
  • Cheng Linsheng;Chen Yuchun;Li Suhua;Lü Shihua;Song Jie
  • 1990 Vol. 9 (2): 158-168. 
  • Abstract ( ) PDF (738KB) ( )
  • In this paper, the climate characters of the temperature, humidity and wind fields on the planetary boundary layer (PBL) over the Heihe region and its neighbourhood have been analysed utilizing the multi-year monthly mean data at grided points and some sta tions of the area. The results indicate that the seasonal variations of the temperature and specific humidity on the PBL appear a waveform with basically equivalent value for the peak and valley; the lapse rates of the temperature and specific humidity on the PBL for each month are less and large than those on the free atmosphere, respectively. There is a northwest flow with quasi-nondivergence and weak rotation in the whole PBL. The seasonal variation of wind speed also appears a waveform with a equivalent value for the peak and valley in the surface layer, the wave amplitude increases rapidly with height, however, the phase is just contrary to the waveform of the temperature and specific humidity. The analyses of the monthly mean data at the Zhanye station for 07-and 19-hrs. (BLT) indicate that there is a pronounced climatically diurnal variation for the wind direction, wind speed and stratified stability. The monthly mean stratification only at 19(BLT) in July is true potential instability when the stratification of the temperature and humidity in the PBL was analysed at the same time, in the rest seasons and times are still stable stratification. The briefly analyses of monthly mean fields of the wind, temperature and specific humidity in the PBL of extension domain indicate that the surface layer of the Heihe region in the January, April, October is located at the shallow temperature trough area, however, the region in July is just located at the end of zonal temperature gradient vector; the specific humidity in July in the region is the a highest, the other months are very low; the streamlines on the surface layer in extension domain only in July are something complex, the surface layer over Heihe region is located a weak convergence flow field; the PBL over the Heihe region for rest months are basically controlled by the straight north west flow.
  • A PRELIMINARY RESEARCH OF THE MACROSCOPIC WATER BALANCE OVER THE OASIS ZONE OF HEIHE EXPERIMENTAL AREA IN THE 1987/1988 YEAR
  • Chen Manxiang
  • 1990 Vol. 9 (2): 202-212. 
  • Abstract ( ) PDF (732KB) ( )
  • Heihe experimental region is almost a closed water balance area. The inflow water includes river flow and groundwater runoff which are coming from out of the boundary of the region, and the total precipitation at the same area. The out flow water includes the river runoff and underflow at the Zheng Yi Xia hydrological station, and the total evapotranspiration from the experimental area. The variable of reservoir storage of ground water in the Oasis is without consideration, Because it is neglected. In this paper, the analysis of macroscopic water balance over the Oasis zone of Heihe experimental region in the 1987/1988 year has been made. The results show that: the annual water consumption over the Oasis zone in the year is about 585.3 mm; and over the irrigating and farm land area of the Oasis zone very like the ecology enviroment of annual rainfall of 625 mm over Beijing area. Thus we can say that the evapotranspiration amount of about 600 mm is the existence condition for a good Oasis. Here, the net water consumption is about 358.3m 3/mu in the irrigating and farming land area of the Oasis zone. Although, it is hardly to say that it is the best economic level of the water consumption in the Oasis, it is an important reference standard for the reasonable use of water at the irrigating area in the future.