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  • 1997 Volume 52 Issue 1
    Published: 15 January 1997
      
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  • THE BASIC THOUGHT OF REGIONAL DEVELOPMENT PLAN IN NEW PERIOD AND ITS IMPROVING WAY
    Mao Hanying, Fang Chuanglin
    1997, 52(1): 1-9. https://doi.org/10.11821/xb199701001
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    Regional developmental plan is one of the most popular aspects in human geography field in our country. Base on the reviewing it in 1980s the character was revealed, which included following, plans between different types and different spacetime scales. Replenished each other and developed mutually, important breakthrough prefected; metholds were innovated; means were improved. The main problems in current, the first is too large ratio of program in planning: the second is too much macroscopic strategy and poor manipulatableness; the third is soft combination between qualitative analysis and quantitative analysis. To adapt the socialist market economic system, the basic thought of regional development, plan in new period, should be changing plan from program kind to market kind; drawing up flexible plan; changing single goal for economic benefits to multigoal for sustainable development which would coordinate economy, society population, resources and environment; changing economic growth for speed to development for benefits, changing academic research planning to scientific practical planning. In order to promote our regional developmental plan in new period, accomplish those for changings improve the quality and practisal value of plan, market factor research should be stressed in planning, the regional developmental direction, which coordinate PRED should be adhered firmly. Relation between qualitative analysis and quantitative analysis should be dealt correctly, especially, in the later. System analysis, threshold analysis, expart system, decision support system should be advocated and spreaded in quantitative research. Regional developmental policy research should be taken seilously.
  • DISTRIBUTION ON THE MAIN CROP GERMPLASM RESOURCES IN CHINA
    Cao Yongsheng, Zhang Xianzhen, Bai Jianjun, Gong Gaofa
    1997, 52(1): 10-17. https://doi.org/10.11821/xb199701002
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    China is an important center for the origin of crops in the world. Since 1949, researches of exploration, collection, preservation, characterization and evaluation of crop germplasm resources have been done in China. And now 350 000 accessions of crop germplasm have been collected. This paper describes the characteristics and rules of geographical distribution of main crop germplasm resources, totally including 194634 accessions of germplasm of 73 crops. Among them, food crop germplasm have 161574 accessions, making up 83% of the total number. The maps of geographical distribution of main food crop, fibre plants and oil crops are presented. The crop germplasm resources in China are distributed widely in the whole country. With regard to provinces, crop germplasm resources are more bountiful in Shanxi, Guangxi, Sichuan, Shandong, Yunnan, Shaanxi, Hebei, Henan, Guangdong and the total germplasm resources in these provinces are 112185 accessions, making up 57.6% in the whole country. With regard to agricultural regions, crop germplasm resources at the middle and lower reaches of the Yellow River are the most bountiful which have 52325 accessions, making up 26.9% in the whole country. With regard to the cultivated land, there are the richest germplasm resources per million mu (1 hectare=15 mu) of cultivated land in Xizang (2062 accessions), which is much higher than the national average(135 accessions). But there are obvious differences in the whole country. In general, they follow such rules: the more bountiful the heat resources, the more complicated the terrain and the longer the history of agricultural planting, the richer the crop germplasm resources per million mu cultivated land will be.
  • AN ANALYSES ON THE LAND STRUCTURE IN THE YELLOW RIVER DELTA
    Xu Xuegong
    1997, 52(1): 18-26. https://doi.org/10.11821/xb199701003
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    On the basis of land classification and land evaluation, this paper analyses the land structure of the Yellow River delta. The main contents and conclusion are shown as follows: 1. Land type structure reflects the natural character and conditions of the land in the Yellow River delta, as well as the rule of regional differentiation at a middle scale. 2. The analyses of land resources structure comprises two aspects, land quality grade and land suitability. In the Yellow River delta, the general quality of land is lower but its developing potential is high. The suitable utilizaion is farming, animal husbandry and fishery. 3. The analyses of land space structure show that there exist an evident differentiation of land types changing successively in the Yellow River delta, which can form a kind of ideal land use pattern of farming animal husbandry fishery from fan shaped top to the border of the delta. 4. The land succession structure shows the successional rules of the land in the Yellow River delta region. We should master these rules to promote land consequent succession and avoid land degeneration. It is particularly important in the delta because its ecological environment is frail. 5. Current land use structure reflects that the development of the land in the Yellow River delta is at a primary level and there are many land use problems. The current land use structure needs to be regulated. In agricultural development, we should utilize the natural rules gotten from analysing land structure to set up modern and sustainable bases for farming, animal husbandry and fishery in the Yellow River delta region.
  • EFFECTS OF URBANIZATION ON THE ANNUAL MEAN TEMPERATURE OF BEIJING
    Chen Shenbin, Pan Liqing
    1997, 52(1): 27-36. https://doi.org/10.11821/xb199701004
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    The urban heat island is probably the most serious source of systematic error so far identified in land surface climatological measurements (IPPC, 1990). the development of temperature differences between cities and their surrounding rural regions has been well documented (Landsberg, H. E., 1981). the heat storage differences between the materials that are associated with urban and rural surfaces are responsible for the development of observed air temperature differences. the degree of urbanization effects on the annual mean temperature of Beijing has been probed into in this paper. Beijing is the capital of China. Its administrative area is 16 808km2 including suburban districts and counties of outer suburb. There was no any modern industry in Beijing before 1949. the consume of energy is about 3×107 tons of standard coal in 1992. The population (1.1×107) of Beijing in 1992 is more than 2.5 times as many as that in 1949. the population density of Beijing urban districts is 27 629 persons/km2 in 1993 and the highest density is 54 008 persons/km2 in the same period. This paper edscribesa detailed study of trends of the time series (1960-1993) of surface air temperature in Beijing area and the effects of urban heat island. Time series of monthly mean surface temperature of 7 meteorological stations in Beijing area were examined using moving average, and then principal component analysis and trend analysis were used to probe into urbanization effects on the annual mean temperature. The results show that: (1) The first principal component expresses the variation of the annual mean temperature and degree of urbanization effects. The tendencies of the first principal component are negative except beijing and tongxian. The estimated degrees of urbanization effects are about 0.21℃ and 0.19℃/33 years for Beijing observatory and Tongxian station respectively from 1960 to 1993. In the downtown of Beijing, the value of increased temperature by urbanization effects should be more stronger than that in the both stations. The second principal component expresses the quasi cycle of 14 years and the trend of annual mean temperature change in Beijing area. (2) The first eigenvectors are positive, and the amplitudes of variation for Beijing and Tongxian stations are greater than other stations in winter. This, maybe, is caused by stronger urban heat island in winter due to more energy consumed for building warming. The second eigenvectors are the same for all stations in Beijing area. The tendency of warmer winter and cooler summer in Beijing area are showed clearly. (3) It is obvious that temperature records of meteorological station in a city or suburbs are influenced by urbanization or urban heat island. But it is difficult to determine the degree of urbanization effect on temperature records exactly. The author thinks that the method of this paper should be further investigated. (4) Many long term monitoring stations are located in and around the growing urban area, such as Beijing and Tongxian Stations, which can lead to increases of temperature unrelated to global forcing such as the green house effect. So the element of urbanization effects should be paid attention to when we study on regional and global climated change.
  • CHARACTERISTICS OF ENERGY PARTITIONING AND WATER TRANSFER IN WINTER WHEAT FIELD
    Mo Xingguo, Liu Suxia
    1997, 52(1): 37-44. https://doi.org/10.11821/xb199701005
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    In order for the sound management of high water use efficiency agriculture, the characteristics of energy partitioning and water transfer in winter wheat field are explored in detail. Micrometeorological and soil moisture data for the research were collected at Yucheng Experimental Station, Chinese Academy of Sciences from recovering to maturity period in 1992. Bowen ratio is shown much larger before irrigation than after irrigation and its average value in midday (11∶00—15∶00) highly correlates with aerodynamic resistance (ra). The correlative coefficient is 0 72 which is much more notable than that with net radiation and that with soil moisture. Ifrais smaller, the vapour in the crop canopy is easier to be transferred into the atmosphere, which will largely stimulate the water lose processes of crop, and Bowen ratio becomes less and vice versa. Albedo is larger before irrigation than after irrigation. The daily maximum albedo, which is 0 21—0 24, appears at booting period, thereafter gradually going down and reaching 0 15—0 16 at maturity period. And then it turns to slightly increase because of the leaves dying gradually. From recovering to maturity period, that is, from March 20 to May 30, statistically, daily evaporation increases from 3mm/d to 5mm/d, the difference is 2mm/d. Daily net radiation increases from 4 3mm/d to 7 4mm/d. The difference is 3mm/d which is larger than that of daily evaporation. Also from recovering to maturity period, the total evapotranspiration estimated by Bowen ratio energy balance is 297mm. Considering the drainage from irrigation or precipitation to groundwater and evaporation from groundwater to atmosphere through groundwater table variation and groundwater supply capability, the evapotranspiration taken as the residual of water balance equation is 302mm. The minor difference of the two, to a certain degree, shows that it is reliable to use water balance equation to estimate cumulative evapotranspiration. Surface resistance is stable and low at midday while variable and high at dawn and dusk. The difference before and after irrigation is up to 20s/m. Because the meteorological conditions of the two cases are almost the same, this difference is mainly due to soil moisture turning from the deficit to the saturated. The average midday surface resistance is largely dependent on air saturation deficit which is shown to be one of the key factors controlling the opening and closure of stomata. Whether soil surface is fully covered by crop or not is important to the relationship between surface resistance and surface soil water status. There is one irrigation event at March 30 when crop does not fully cover the soil surface and field evaporation mainly comes from soil. It is seen that before irrigation, surface soil is in dry status and evaporation is highly supressed, so surface resistance raises to 80s/m. After irrigation, soil surface is wet, surface resistance then falls down, just 10 to 20s/m. No such obvious changes can be observed after soil surface covered by crop. Generally, surface resistance increases slowly with growth stage which corresponds to the increase of stomatal resistance due to the canopy leaf evolving processes from living to dying.
  • THE DIFFERENTIATIONS IN WINTER CLIMATES OF THE ESTERN PART WESTERN PART AND OF THE TROPICAL CHINA AND THEIR IMPACTS ON THE INTRODUCTIOIN OF RUBBER TREE
    Jiang Ailiang
    1997, 52(1): 45-53. https://doi.org/10.11821/xb199701006
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    Tropicl China were divided into two parts(sub regions)eastern part and western part by Chinese botanists and geographers∶Huge amount of rubber trees(Brasiliensis Hevea)were cultivated in both parts of above mentioned regions in the beginning of 1950’s or 1960’s Remarkable differences in growing conditions of rubber trees in these two parts were found after planting. The rubber trees in the eastern part suffered heavy cold injury frequently during overwintering period and finally diminished and perished completely or almost completely owing to unfavorable winter climate; but the rubber trees in western part have been growing normally, Even though in some cold winters they suffered cold damage but they recovered very soon after ovcrwintcring. And the yicld of latex incrcases year by year, and it is of benefit to the loeal people. A comparison of overwintering climates in these two parts was made. No significant differences in both minimum and mean temperature were found. But great difference in sunshine durations in these two parts was found, Viz, rich sunshine in the western part and poor sunshine in the eastern part. And also the difference in the pattern of temperature drop for these two parts during cold wave outbreak inter, was found the temperature drop in the eastern part is quite abrupt and the temperature drop in the western part is rather gentle. Besides there appears frequently a long spell (several even more than 10 days) of overcast and chilly days during outhreak of cold wave in the eastern part but there appears only a short spell (1 to 3 days) of overcast and chilly days in the western part. Such a long spell of overcast and chilly weather will usually cast the cold injury of rubber trees. The cause of these differences is due to the dynamic effects of Qinghai Xizang plateau. Two aspects should be considered: (1) The position of jet stream in Asia in winter shifts southwards and it hits the western corner of the Qinghai Xinghai Plateau. And somethin like stationary wave is induced, hence the air in certain area (eastern part) moves upwards and the air in some other area (western part) moves downwards. It is knowh in meteorology that fine (sunny)weather is usully connected with downward motion and cloudy or rainy weather is alwys assocaeted with upward motion. The fommer weather will ususally cause the adveetional cold damage of rubber tree. (2) The retarding or blocking effects of the high and huge mass of the Qinghai Xinghai Plateauee to cold air advection in winter make the temperature drop in western part much gentlier in character. And the effects of Qinghai Xinghai Platean also reduce the front activity in the western part, Hence there are much more sunny days in this part. All these effects are of benfitial to the overwintering of rubber tree. But the weathers in eastern part in winter are quite different from those in the western past due to the blocking of high and huge mountais to the north.
  • FORMATION AND EVOLUTION OF THE BAR ON YELLOW RIVER ESTURARY
    Li Zegang
    1997, 52(1): 54-62. https://doi.org/10.11821/xb199701007
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    This paper, based on fields data, deals with the formation and evolution of the bar on Yellow River mouth. The following four substantial aspects are discussed: 1. The characteristic of the bar shape at Yellow River mouth, the distribution and change of the deposition of the bar, as well as the formative conditions of the bar are analyzed. 2. The huge sediment deposition at the place near the dynamic balance position between river and sea (that is the point where the the flow velocity tends to zero) is proved. However, due to the large differce between the discharges during the floods and dry during season in the Yellow River, the position of the dynamic balance point moves up and downward, the reach of the sedimentation increases, thus bar development continues. 3. The important characteristic of bar evolution is that it extends in flood season and eroded in dry season, and the change of the bar occurs in whole tidal flood and ebb processes. 4. Action of wind wave and tidal current on coast is that erosion occurs at upper part of the coast and deposition occurs at the lower part. The water depth of distinction line for erosion and deposition is about 7 5m.
  • THE CHANGE OF THE MAN LAND RELATIONSHIP IN THE NOTHERN YANSHAN MOUNTAIN REGION DURING MEGATHERMAL
    Deng Hui
    1997, 52(1): 63-71. https://doi.org/10.11821/xb199701008
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    The northern Yanshan mountain region is in the eastern part of the semi agriculture and semi pastoral zone in the north China, where the climate is semi arid and sub humid in the northern temperate zone and the eco environment is very sensitive. In this region, both physical landscape and culture landscape have the transitional characteristics. Based on a great deal of materials of archeology, quaternary geology, paleogeography, and palynology, the author of this paper reconstructed the process of the changes in human landuse forms and analysed the impacts of different environmental conditions on this process in Megathermal. Considering the spatial distribution of archeological cultures, the scale and morphology of settlement, and the composition of production tools, the author found that there was a close relationship between the physical environment and the human’s landuse forms. The following conclusions were suggested: During Climatic Optimum (8 000—5 000aBP), the local Neolithic cultures of zigzag patterns, which include Xinglongwa Culture, Zhaobaogou Culture, and Hongshan Culture, developed continuously in a favorable environment. Most of them had large scales and well arranged sedentary settlements. The Xiaoheyan Culture, which existed around 4 500 aBP, represented the ending of the cultures of zigzag patterns. Both quantity and quality of its settlements decreased considerably, and the agricultural production also descended. These changes of the culture were identical with the environmental changes around 5 000aBP. During 4 000—3 000aBP, there were two kinds of Bronze culture in this region, which were the agricultural Xiajiadian Lower Layer Culture and the pastoral Xiajiadian Upper Layer Culture. The first had a great deal of large scale sedentary settlements and high level agricultural production. The later had less sedentary settlements and lower agricultural production. Such a dramatic contrast between the two distinctive Bronze cultures were mainly caused by the environmental changes around 3 000aBP, that marked the close of Megathermal.
  • ECOTYPE EXPLORATION OF POLYNOFLORA FROM ZHALAINOR SINCE THE LATE QUATERNARY
    Tong Guobang, Yang Xiangdong, Wang Sumin,Chong Zhuying, Xia Lianghua
    1997, 52(1): 72-79. https://doi.org/10.11821/xb199701009
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    According to the sporo pollen data of surface samples from Manzheli to Dayangshu, northern of northeast of China, we apply methods of systomolustor, corrosponding analysis, diffcrcntiatic grado (Hs) and isostatic gradc(E), and discuss the polynoflora abundance, species variety and equitability of Zhalainor. It indicates that the ecotype underwent ten ecological periods which belongs to three stages in the region over the past 13.0kaB.P.: (1) Sylvosteppe stage (10.2—2.9kaB.P.), including steppe mixed coniferous forest (3.2—2.9kaB.P.); steppe scattled pinus, Cupressaceae (5.6—3.2kaB.P.); steppe scattled birch, Quercus and other deciduous trees (6.8—5.6kaB.P.); steppe with birch (7.1—6.8kaB.P.); steppe scattled Pinus, Cupressaceae (10.2—7.1kaB.P.). (2) Steppe and tundra stage (12.9—10.2kaB.P.), including bushland with Betula(10.3—10.2kaB.P.); bushland with Betula and Picea (10.6—10.3kaB.P.); tundra with Betula (10.9—10.6kaB.P.); bushland seattled Bctula, Pieea (12.9—10.9kaB.P.). (3) Tundra (20.0—12.9kaB.P.), inciuding only one ecotype which was bushtundra. In the first phase, the content of trees pollen (mainly conifers such as Pinus, Cupressaceae) was 30%—60%, and sometimes that of deciduous trees (mainly Betula, Quercus, Ulmus) was close to of confers. The type of herbs (mainly Compositac and gramincac) was abundancc, but dryresistant and haloxene plant (Chenopodiaceae) rose relatively at some individual strata. The sporo pollen concentration was 350—5642grains/g, the values of Hs (1.6—2.4)and E (0.3—0.6) were more than those of steppe ceotype, indicating the abundant plant species and quantity. In the second phase, it was occupied by pollen of herbs (80%) which was mainly Artemisia and Chenopodiaceae, and the sporo pollen conccntration was 200—6400 grains/g, Hs and E were 1.4—2.4and 0.2—0.6 respectively. The upper limit of all the values was lower than that of sylvosteppe, indicating the lower species abundance and differentiatic grade of steppe. The ecotype of tundra with Betula appeared in particular layers. In the third phase, the value of herbs and ferns sporo pollen was more than 90%, and that of trees pollen was very low (less than 5%). There were mainly Artemisia, Compositae and Gramineae in herbs, Botrychium in ferns and only a small amount of Betula nana and Picea in shurbs and trees. The sporo pollen concentration was 200—700 grains/g, the values of Hs (1.1—2.2) and E (0.3—0.4) were the lowest in the profile, indicating that the vegetation was rare and monotonous, and the ecotype was in the more miserable condition. In the postglacial period, the range and the oscillation of climate were greatly and frequently, the ecotype alternated between bush steppe and tundra with Betula. The climate and environment in this region can be compared with that of the northern Europe. The environmental change in Holocene was mainly influenced by humidity, in the arid period, the ratio of chenopodiaceae of Artemisia added, while the sporo pollen concentration. Hs and E declined and reduced, and vice versa.
  • LAGOON SEDIMENTS GEOCHEMISTRY AND ITS SIGNIFICANCE IN STUDY OF CLIMATIC AND ENVIRONMENTAL CHANGE IN BARROW,ALASKA
    Yang Weili, Wang Guo, Zhang Qingsong
    1997, 52(1): 80-88. https://doi.org/10.11821/xb199701010
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    The paper deals with ass emble feature and distribution of chemical elements in the borehole AB-67 covered a time span of past 450 years from Elson lagoon in Barrow of Arctic Alaska. The correlation between the contents of clay and organic matter and the concentration of chemical elements are described. The analysing data show that the concentrations of major elements(SiO2,Fe2O3),trace elements(Ni,Cu,Zn and Pb)and rare an drare-earth element s(v,Co,Ga,S e,Y,Zr,Li,N b et c.)are qu it e differen t betw een th e upper part(0—20cm in depth)and the lower part(20—60cm in depth)of the borehole AB-67.In the lower part(20—60cm)SiO2,Fe2O3,and A l2O3,account decreases by 76.24%,Fe2O3 and Al2O3 increase up t o 3.39%and 7.21%respectively,in dicat in gastrent hening of chemical weathering which resulted in leaching of SiO2 and enrichment of Al2O3 and Fe2O3.Concen trations of Cu,Pb,Zn and Ni below the depth of 20cm in the coreareless than 15mg/kg,15mg/kg,70mg/kg and 20mg/kg respectively,while abovet hedept hof 20cm in the corethey are roughly double increased. The variation tendency of trace elements are coincided to that of silt and clay as well as the organic matter with a coefficient of correlation of 0.80.An cluster an alysis of chemical elements shows that the rere and rare-earth elements(V,Co,Ga,Se,Y,Zr,Li,Nb etc.)and the trace elements(Cu,Zn,Pb,Ni,Cr)are in a group with close positive linear relationship with a coefficient R=0.95,which shows that the elements are absorbed by clay and colloid and can be carried in sus pended sediments and accumulated together in the lagoon.The trans portation and accumulation of chemical element group infer that the catchment basin in Barrow has been apparently affected by chemical weat hering and biogenic proces ses under relatively a warm climate since 1827. Based on the characters of sed imen tary geochemistry of the borehole AB-67,t he history of climatic and environmental changes in Barrow in the past 450 years can be reconst ructed as follows:(1)A stage with a relatively cold and dry climate and a low sea level occured prior to 1700;(2)It was becoming warm accompanied with a transgression f rom 1700AD to 1827;(3) From 1872 to 1994(eg.0—20cm in depth of the borehole AB-67),it was fluetuated warming accompanied by continuous transgression;in this period relatively cold appeared around 1935 and 1969.This figure coincides with the results obtained from the study of tree-ring in northern Fen noscandinavia and the study of icecore on the Tibet an Plateau.