• 全国中文核心期刊
  • 中国科技核心期刊
  • 美国工程索引(EI)收录期刊

1991 Vol. 2, No. 4

Display Method:
Glimatic Warming and Drying Trend and its Impact on Water Resources in Mid Latitude China
Shi Ya-feng, Fan Jian-hua
1991, 2(4): 217-223.
Abstract:
The area of mid latitude China, mainly the zones from semi-humid to ariddesert extending from 35°N to 50°N, accounts for 60% or more of the area of China. Since the end of the Little Ice Age, climatic change has shown obviously warming and drying trend. Especially, more stronger change has occurred since 1960's. Under the impact of climatic change, such phenomenon as shrinkage of glaciers and lakes,decrease of runoff, descent of groundwater table and increase of drought frequency and extent etc,have been caused.With a tendency of global warming, climatic drying would continue. However,if the greenhouse effect could cause the increase of the temperature by 2℃ or morein the next century, the climate of mid latitude China could get humid.
Meteorological Causes for Summer Drought in the North-East Side of the Tibet Plateau and its Long-Range Forecast Research
Lu Ju-zhong, Lin Jing-yu
1991, 2(4): 224-231.
Abstract:
By using the 40 years (1950-1988) data of the monthly sea surface temperature (SST) of north Pacific ocean, monthly south oscillation index (SOI)and 100hPa monthly mean height in the north hemisphere, the influence of them on the summer drought of loess plateau and the information areas of teleconnection are investigated in this paper. The results show as follows:In tropic regions(especially in low latitude regions),there were high teleconnections between the variations of strength of the SST and the summer drought of the north-west part of China and there existed a time-lag relation for about a half year in various information areas.Also,the influence of SST variation in Kuroshio area on the circulation system (south Asia high) of summer drought of the north-west part of China are discussed by the view of energy frequency diffusion. The results indicate that for seasonal forecast of summer drought of the north-west part of China,the SST variatons of the tropic region and south oscillation in late winter and early spring are previous period needs and attach great importance,exclusive of considering the variations of atmosphere circulation of the high and middle latitudes as a rule.
Climatological Analysis of Rainstorm Characteristics in the Arid, Semi-Arid, and Desert Region of Middle-West Inner Mongolia
He Qin, Wu Xiao-dong
1991, 2(4): 232-237.
Abstract:
based on the rainfall data for about 30 years at 51 stations in the middle-west of lnner Mongolia, the temporal and spatial characteristics of rainstorm in the arid, semi-arid, and desert region are analysed. The extremes of rainfall intensity are given. In addition, the effects of circulation situations, synoptic-scale systems.and topography on the genesis and patterns of the rainstorm are discussed.
Recent Lake Changes in the Arid Area of Northwest China
Wang Hong-dao, Zhang Xue-bin
1991, 2(4): 238-243.
Abstract:
Recent lake changes in the arid area of Northwest China are described,and the causes of the changes are discussed.It is found that these changes have some impacts on environment and ecosystems of lakes,including deterioration of climatic conditions,extension of desert area, disappearance of forest,regression of vegetalion cover,and reduction of fishing yield caused by the impeded fishs breeding.Besides,considering the causes of lake changes,some suggestions and measures to prevent further changes of these lakes are proposed.
Water Resources and Their Transformation Model in Urumqi River Basin
Qu Yao-guang, Liu Feng-jing
1991, 2(4): 244-250.
Abstract:
According to the formation,the transformation regularity and the use of water resources in the arid area of Northwest China,a water resources transformation model in the Urumqi River basin is developed by using the plentiful information of surface and ground water,and the geohydrologic condition.The results of the model show that the actual water withdrawal and net water usage exceed the maximum and net water usage at the present condition respectively. Moreover,the net water usage even surpasses the total water resources.The water resources are overexploited obviously.thus,it is ineffective to increase the potential water usage by further improving the utilization rate of canal system at the present situation.A promising way is to set up a new water balance between supply and demand only by means of saving water and increasing the utilization rate of water.
Analysis of Persistence of Hydrological Drought on the Upper Yellow River
Wang Wei-di, Sun Han-xian, Shi Jia-bin
1991, 2(4): 251-257.
Abstract:
Utilizing four kinds of hydrological data from observed,investigated,historical and synthetic series,a comprehensive analysis of drought persistence is made in this article.The results confirm that the persistence of hydrological drought on the upper Yellow River exists,that the 11-year drought from 1922 to 1932 did occur on the upper Yellow River,and that the results of field investigations are reliable.The frequency analysis for yearly runoff of various lengths of persistense has been made with synthetic series.Owing to the extreme severity of the 1922-1932 drought persistence,its recurrence period is far larger than that estimated before.The design of operation of the Longyanaxia Reservoir and Hydropower Project would be more beneficial if the results of this paper were used.
Recurrence Probability of 11-Year Continuous Low Water Period (1922-1932 A. D.) In the Yellow River
Shi Fu-cheng, Wang Guo-an, Gao Zhi-ding, Mu Ping, Ma Gui-an
1991, 2(4): 258-263.
Abstract:
1922-1932 A.D.was a continuous low water period 11 years long in the Yellow River Basin.Based on the measured data of the waterlevel scale at Qingtongxia and Wanjintan from the beginning of the eighteenth century (the Qing Dynasty) and the water regime reports to the Emperor by local officials, this paper estimates high and low water regime for the past 200 years.Combining these estimates with stochastic hydrology calculation,it is concluded that the recurrence period of the continuous low water period (1922-1932) is 200 years at least.The conclusion is rather important to recognizing year-to-year variation of the Yelleow River water resources and to development and use of the Yellow River water resources.
Prediction of Regional Soil Water and Drought
Li Bao-guo
1991, 2(4): 264-270.
Abstract:
A distributive model of soil water balance is developed,which introduces 2-D Cartesian coordinates(x, y)into general soil water balance equation.Thus the dynamic distribution of regional soil water can be predicted.The model has been implemented by using GIS(geographic information system)techniques.Furthermore,the maps of regional soil drought are obtained based on the modcl and the needs of crops on soil water.The method has been applied to the Quzhou,Experimental Area in the Huang-Huai-Hai Plain of China.
An Experimental Study on Vertical Variation of Soil Moisture in the Artificial Sward
Yu You-sen
1991, 2(4): 271-276.
Abstract:
The paper analyzes the annual and vertical variation of soil moisture in the artificial sward by using the experimental data.The results show that the vertical and annual variation of sward soil moisture can be divided:espectively into three layers and three periods:variable layer, transient layer,and stable layer;normal variation period, relative stable period,and most variable period.
Historical Climate Changes of the West China in the Holocene
Xu guo-chang, Yao Hui
1991, 2(4): 277-288.
Abstract:
Based on the results of palaeoclimate studies on glaciers,geology,deserts,lakes,tree rings and historical documents etc,the sequences of climate changes since the holocene in the west China are given in this paper.The main results are as follows:1.The climate changes of the Holocene can be divided into three stages.The transition from the middle Holocene to the late Holocene might occur before 3500 years,which were 500 years earlier than that of the East China.Abrupt changes during the transitional period are also found.2.The climatical oscillations in a thousand-year-scale has experienced six cold stages and five warm stages since the beginning of Holocene,The cold stages were 8700a.B.P, 5900-5400a.B.P,4200-3800a.B.P,3000-2700a.B.P,2000-1400a.B.P,1000a.B.P,the present;and the warm stages were 7500-5900a.B.P,5400-4200a.B.P, 3800-3000a.B.P,2700-2000a.B.P,1400-1000a.B.P respectively.The climatical oscillation had a period of 1000-3000 years in a thousand-year-scale.3.In the recent 1000 years,the temperature change of the climatical oscillations in a hundred-year-scale has experienced six low temperature stages and five high temperature stages.The former were A.D.1100's,1310's,1480's,1830's,1950's.and the later were A.D.1220's, 1390's, 1570's, 1780's, 1990's, respectively.The pcriod of changes was 120-210 years.The coldest stage appeared from the middle 17th century to the early 18th century.For the past 500 years.the drought phase with the highest frequency appeared in A.D.1480-1650,and three most severe drought events 18th century.In the recent 100 years,there is a dry-tendency in the eastern parts of the Northwest China and the North China.
wan zhao-hui
1991, 2(4): 289-290.
Abstract: