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  • 1982 Volume 2 Issue 4
    Published: 20 July 1982
      
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  • UPPER LIMITS OF RICE CULTIVATION IN CHINA
    Jiang Ailiang
    1982, 2(4): 291-301. https://doi.org/10.13249/j.cnki.sgs.1982.04.291
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    Rice cultivation may occur in elevations exceeding 2,500 m in Lijiang and adjacent counties in Yunnan and Sichuan Provinces.In the vicinities of the said county,the upper limit of rice lies in the neighbourhood of 2400m,while a cultivar of the crop,heigu,does complete its life cycle every year at a height of 2,660m in Yongning Ba of Ninglang county.Rice is grown above 2500m both in Madeng Ba of Jianchuan county and Pantianguo of Weixi county in Yunnan, and the same is true of Yienyun county of Sichuan Province. Lijiang and adjacent counties constitute a part of the“Region of Transversal Mountain Ranges”.This is probably the region in which rice production has extended to the highest altitudes in China.Eastward or westward from this region, the cultivation of this crop is restricted to considerably lower elevations. For example,to the west of the“Region of Transversal Mountain Ranges”, a farm in Yigong (2250m,30°19′N,94°51′E) of Bomi county in Xizang had conducted experimentation with rice cultivation for six years from 1970 to 1976 and failed.In no year had the crop produced a yield.In some cases,there might be ears each with one to two or a few mature grains. It has been fairly well established that low temperatures over a period of 15 days or longer (from 10 days before florescence to the end of pollination) are critical to yield formation.Air temperature and sunshine seem to function complementarily for reasons not yet definitely known.In general,if maximum air temperature falls below 23℃ in a sunny day,pollinatlon of many cultivars would not proceed normally.If it rises above 25℃ or 27℃,fertilization of most cultivars will not be adversely affected and is likely to pave the way for normal maturity. The impact of minimum air temperature may also be of some importance.With overcast sky,daily mean air temperature below 20℃ or 21℃ usually casts negetive influence to pollination and maturation.To identify a locality suitable for rice cultivation,it is essential to check whether there exists a period of 15 days or more in which mean maximum temperature exceeds 23℃ or 25℃ with fairly ample sunshine.If data of maximum temperature are not available,mean temperature higher than 21℃ or 20℃ may be taken as an approximate equivalent. although this will give less accurate result. With this general idea in view,analyses of the climatic factors governing the upper limits of rice cultivation in South China have been made. The limit for rice-culivation is not high in regions of the world close to the equator.For instance,rice cultivation in the Philippines almost nowhere exceeds 4300 feet (1312m),the crop is non-existing in places like Baguio (1510m). The possible and economic cultivation limits drop still much lower in innertropical reigons of Indonesia where geoecological conditions do not allow any rice-cultivation above 1500m.The upper limits of rice cultivation in Phillipines and Indonesia are much lower than that of Lijiang.Why? The answer probably lies in the absence of a period of sufficient length with a mean maximum temperature above 25℃ or 27℃ with suitable sunshine and rainfall localities above 1500m in the Philippines and Indonesia because of the long cloud cover and high precipitation. Explanation may also be sought from the low temperature tolerance of different strains.Heigu is the known cultivar most resistant to low temperature stress.The lowest temperature it can tolerate during heading and blossoming is about 4 or 5℃ lower than that of the crop in eastern China. The highest upper limits of rice cultivation in the Transversal Ranges is closely correlated with climatic conditions originated under specific geographic environment of the region.The huge barrier,formed of the great QinghaiXizang Plateau in the north and high mountain ranges 2000-3000m or even higher above sea level in the east,has effectively blocked the influence of cold air advection all the year round.Owing to the uplift of the Qinghai-Xizang Plateau and the Transversal Mountain Ranges,most of the areas receive sufficient solar radiation the year round,except the southern and eastern fringes.
  • A STUDY ON RATIONAL LOCATION OF THE COTTON PRODUCTION IN CHINA
    Zhu Zhuo
    1982, 2(4): 302-310. https://doi.org/10.13249/j.cnki.sgs.1982.04.302
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    Cotton is the leading industrial crop and one of the main fibres used as raw materials in the textile industry in China. Cotton producton has made considerable progress in China since the founding of our People’s Republic,but there are great gaps compared with the developing speed and scale of the cotton textile industry and sharp contradictions between its supply and demand,owing to the developing speed of the cotton production is not fast,the field is not stable and its production level is not high. Among the main reasons for creating the situation mentioned above are the reduction of the cotton acreage,the lacking due to the concentration of area of cotton production,the interregional imbalance in the cotton production due to sharp contradiction between production of food crops and that of cotton,the irrational purchasing price for cotton,and overemphasizing of self-support on local supply for civil purposes.Thus,it results in that some old cotton producing zones find themselves difficult to improve their production techniques,and hence their production management remains backward,the unit output drops remarkably,the total yield stagnates and the cotton production as a whole fails to satisfy the needs of the cotton textile industry and cannot meet the requirements for civil purposes. In China,it has favorable conditions for growing cotton.The middle and lower basins of the Yangtze and Yellow Rivers and southern Xingiang in particular have perfectly suitable natural cnvironments and great potentiality for getting better achievements. Therefore it is necessary to carry out the principles of making full use of what is advantageous,While avoiding what is disadvantageous,and applying measures to suit local condition and concentrating production properly,in order to win greater development of cotton production in China.Expressed in a bit more detail,we must actively develop new cotton producing zones in addition to improve and expand the existing cotton producing zones,and firmly contract the acreage with poor cotton cultivating condltions,in order to solve the problem of interre gional imbalance in cotton production.
  • AN ANALYSIS OF THE GEOGRAPHICAL ENVIRONMENTS OF TYPICAL AREAS OF ESOPHAGEAL CANCER IN CHINA
    Guan Shukui, Fa Nailiang
    1982, 2(4): 311-318. https://doi.org/10.13249/j.cnki.sgs.1982.04.311
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    In this paper,we have analysed the factors of the geographical environments, such asgeology,geomorphy,climate,soil,drinking water,and vegetation.The primary results have been obtained as below: In North China,the areas of high incidence rate are located on top of the layer of Permo-carboniferous period.In the coal bed,there is nitrogen which can form nitrosamines,but in the areas of high incedence rate of Sichuan Province, there is no such layer.This is something still should be studied. In the regions of low mountains and hills,and inclined plains,the mortality rates of esophageal cancer are the highest.As one moves away from these regions, the mortality rate will decrease.This variation in mortality rates seems to have some relation with the geomorphic features. These areas of high incidence rate are mostly located at regions of the subarid and subhumid climate which have relatively arid and warm environments (refer to moisture and heat).Taking the northern areas of esophageal cancer in Sichuan Province for instance,it has been found that the farther away from the central region with a high incidence rate of esophageal cancer,the more rainfall and the less arid it is,and the mortality rate of esophageal cancer decreases. In the drinking water and soil in these regions with a high incidence rate, there are nitrites and nitrates which are the precursor compounds of nitrosamines of carcinogenic substance.This phenomenon coincides with the meteorologic conditions of the subarid and subhumid regions and the contents of the trace elements such as molybdenum,copper,manganese,zinc are correspondingly lower than that for areas of low incidence rate.Among these elements,the low content of molybdenum is most obvious. Under the geomorphic features of low mountain and hill regions and the environments of the subarid and subhumid climate,the local masses of these areas of high incidence rate like pickled vegetables ,a local favorite food,This food has been identified that these pickled vegetables cooperated with the action of fungi produce strong carcinogen,
  • THE PALEOCLIMATE RESEARCH OF THE PERIOD OF “PEKING MAN” WITH METHOD OF SEDIMENTOLOGY
    Xie Youyu
    1982, 2(4): 319-326. https://doi.org/10.13249/j.cnki.sgs.1982.04.319
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    It is often feasible to study paleoclimate by sedimentology means.Its advan tage is that a continual sequence of climate changes can be established without limited by the lack of fossils,etc.However,it must be noted that the method of synthetic analysis should be used and also that some special and efficient methods should be chosen according to specified geologic and geomorphic conditions; not all methods are good for use.For instance,in a limestone area the change of content of calcium carbonate in dispersive state is relating to the bedrock rather than dipending on the climate during deposition.Conversely,when cllcium carbonate is present in cemented state,the degree of weathering and recrystallizing of the calcium Carbonate itself as well as the volume and size of the fragmentary limestone in the deposits,and whether they themselves to be solute or cemented, all these can reflect definite climate environment. From results of various analysis for sediments accumulated in the cave of “Peking Man”,(i.e.the existing state of the calcium carbonate,the clay mineral composition,the index of geochemic,the degree of surface corrosion of quartz sand and the mineral characteristics of the debris in the sediments) six different climate stages can be divided for the period of 800,000 Y.B.P.-230,000 Y.B.P,. and they can fully reflect the changes between cold and warm as well as between arid and humid conditions.Besides,this shows that the monsoon climate had been formed in East China in Mid-Pleistocene.And the climate during pleistocene period in North China roughly corresponds to the present climate in the Huaiho River basin,and sometimes corresponds to the warm temperate zone climate in the Yangtze River basin. The general tendency of the climate change during Mid-Pleistocene was changing from semi-humid warm temperate climate to semi-arid temperate climate. There is not arty trace of glaciation to be found from the analytical results of all sediment samples collecting from the whole stratigraphy section in the cave of “Peking Man”.
  • ON THE PROBLEM OF GEOMORPHOLOGICAL CLASSIFICATION IN CHINA
    Qiu Shanwen, Li Fenghua
    1982, 2(4): 327-335. https://doi.org/10.13249/j.cnki.sgs.1982.04.327
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    This article aims at making a comparative study of various schemes of geomorphological classification formulated both at home and abroad.By absorbing their strong points.Such classification is done by means of combining morphology with morphogenesis,taking into account the comprehensive indexes of geomorphological ages.The hierarchy of mountainous relief is classified in accordance with the indexes of the altitude ranging from 5,000m,3,500m to 800m as against the relative height of 200m to 100m.The continental geomorphology of our country is divided into 12 major types or groups and 5 major classes,as shown in the proposed table of geomorphological classification here attached(see Table2),which can be used for geomorphological mapping on different scales.
  • KARST LANDFORMS AND LEAKAGE ANALYSES OF DAHUA RESERVOIR AREA IN GUANGXI
    Zhu Jingjioo, Lin Junshu, Zhang Yaoguang
    1982, 2(4): 337-348. https://doi.org/10.13249/j.cnki.sgs.1982.04.337
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    Dahua Reservoir is cated on the Hongshui River which forms the boundary between Dauan and Mashan Counties.When it has been completed,the reservoir will be the largest hydroelectric station in Guangxi. High temperature,abundant precipitation,massive and pure carbonate rocks, much folding and faulting are the major factors in the karst development of this area.Since the Quaternary Period,the land surface has been uplifted continuously and is now typical of the geomorphological landscape of karst“Fengcong”(peak cluster)and depression. Dolines are widely distributed within the karst depression.Underground water is usually below the level of the cave mouths,although it often emerges from the Caves during the flood season.This phenomenon suggests the possibility that there is an underground river.On the basis of the evidence provided by the distribution of water sinks and the dynamic behaviour of the water level,the water sinks were used to inject fluorescent dyes and coloured lycopodium spores at different times and at possible leakage points.Tracing experiments were conducted six times basically to establish the distribution of flow and the character of the underground river in this area.The results of the observations could be related to the dynamic state of the water level. We concluded that there is no leakage from the reservoir along underground passages as a result of the series of surveys and observations concerning the geological and geomorphological conditions,cave prospecting,long-term observations of underground water slnks,pumping tests,drilling exploration,as well as tracing experiments.This research provided a scientific basis for the construction of the reservoir.
  • PRELIMINARY STUDY ON LANDSCAPE REGIONALIZATION IN CHINA
    Li Wan
    1982, 2(4): 358-367. https://doi.org/10.13249/j.cnki.sgs.1982.04.358
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    The significance of landscape regionalization is essentially to epitomize currently known theory of geographical knowledge in addition to classify scientifically according to geographical law.It can,thus,not only reflect the depth of geographical study and the theoretical level of geography of a certain region,but also expose the problems presented in physical data and theory.It would provide basis for developing agriculture in line with local conditions and accelerate the development of regional physical geography. The principle of landscape regionalization of China is that of zonation,and the zonal principle is based on zonal law.The upper limit of landscape (the natural complex of the earth surface) is the top of the biosphere and its lower limit is the bottom of weathering crust.The latitudinal zones,land-sea zones and vertical zones of its distribution on the earth surface are its concrete appearances.Based on this principle,China may be divided into 2“domains”,12“zones”and 44“regions”,in which the units of each level all have relatively identical potential agricultural productive conditions and productivity.
  • THE VERY UNEXPECTED FLOOD OF THE YANGTZE RIVER IN 1860 AND THE ABNORMAL CLIMATIC PHENOMENA BEFORE RAINSTORM
    Wang Yaofeng
    1982, 2(4): 368-374. https://doi.org/10.13249/j.cnki.sgs.1982.04.368
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    This paper introduces the flood of the Yangtze River in the midsummer of 1860 and the abnormal climatic phenomena of extensive areas,long period,low temperature and cold weather before rainstorm. On the 18th of July,1860,at Yichang hydrological station of the upper reaches occured the 92,500 cubic metres per second peak discharge,which was the fifth high since 1153.According to historical documents and carving records on walls,the flood was divided into three periods:rising period,peak period and dropping period;the progress of flood formation and three peak figures during peak flood period recorded in the publication“Dong Hu Xian Zhi”were introduced and described. In early May,1860,there were some striking abnormal climatic phenomena such as snowing extensively and low temperature lasted for a long time in the middle and lower reaches of the Yangtze River,raining in some local regions in automn after rainstorm in midsummer,early snowing in winter,and exceptionally serious flood.The author describes the relation between low temperature and cold weather before the early May,and rainstorm and flood in midsummer,from the aspects of climate-earth and earth-climate,and also considers that the former in the occurence process of the latter,and it is the forewarning phenomena reflected by the earth surface. As mentioned above,at the Yangtze River region in 1860,there were continuous low temperature and cold weather,much more precipitation,and continuous and frequent catastrophic rainstorm;all these were scarcely recorded on historical flood documents.
  • A STUDY OF THE VEGETATION TYPE IN THE SANJIANG PLAIN
    Yi Fuke, Li Chonghao, Zhao Kuiyi, Zheng Xuangfeng, Ding Shouqin
    1982, 2(4): 375-384. https://doi.org/10.13249/j.cnki.sgs.1982.04.375
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    The Sanjiang Plain is situated in the Northeast China,it’s a low alluvial plain formed by three rivers:Songhuajiang,Helongjiang,Wusulijiang.The plain is one of concentrated distribution areas of marshland and swamp meadows in our country. The vegetation type in the Sangjiang Plain is comprised of forest,meadow and swamp vegetation,in which vegetation of swampy meadow and marshland is dominant,about 74% of natural vegetation.This paper introduced the classification system of vegetation and describes the costituent,construction and distribution of all vegetation types there (figures and photographs of main types),and the formation and succession regularity of swamp vegetation as well,finally comprehensive utilization and necservation of reginal vegetation resources.
  • A STUDY ON POLLUTION CONDITION AND DISTRIBUTION LAW OF TETRAETHYL LEAD IN AMBIENT AIR OF BEIJING AND TIANJIN CITIES
    Meng Ke, Wu Dunhu, Liu Jingshuang
    1982, 2(4): 385-389. https://doi.org/10.13249/j.cnki.sgs.1982.04.385
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    The gaseous tetraethyl lead in ambient air is collected by enrichment in an active carbon adsorption tube.The macerated lead in concentrated nitric acid is determined by anodic stripping voltammetry.The ambient air of urban area of Beijing and Tianjing cities is observed by this approach.The measured concentrations of tetraethyl lead in local ambient air of the refinery industry district is higher.In Beijing and Tianjin cities,the tetraethyl lead concentrations are:0.1～0.3μg/m3 at gasoline station and parking lot,0.01～0.20μg/m3 in city-street, and 0.005～0.030μg/3 in rural area.The distribution of tetraethyl lead in ambient air of urban area shows some regularity.If in an atmosphere at a distance of 320 meters above the earth surface,and at a night without any motor vehicle to be active,the quantity of tetraethyl lead measured is appropriate it indicates that this alkyl lead compound is possible to reside in the atmosp here for longer time.