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  • 1986 Volume 6 Issue 1
    Published: 20 January 1986
      

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  • Ren Meie, Shi Yunliang
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    The Yellow River,with annual sediment discharge about 11×108 tons, contributes about 17% of world’s fluvial sediment discharge to ocean.This is because the river,in its middle reaches,flows across the Great Loess Plateau of China.About 70% of its annual sediment discharge comes in July-September and is concentrated in a few strong"spikes"during floods with very high sediment concentration.The amount of its sediment discharge varies greatly during the last 3,000 years. The sediment discharge of the Yellow River has widespread and profound effect on sedimentation of the sea: (1)Remarkable shift of its outlet in 1128-1855 A.D.to the South Yellow sea where it had formed a large subaqueous delta and provided the substrate for an extensive submarine ridge field. (2)Shift of outlet in the modern delta every 10 years is the main reason why with extremely heavy sediment input and a micro-tidal environment,the Yellow River has not succeeded in building a birdfoot delta like the Mississippi. (3)The Yellow River has consistently brought heavy sediment input to sea at least since 0.7my.B.P.Paleochanneils,paleosoils,cheniers and fossils on the sea bottom indicate that the Yellow sea was exposed during late Quaternary glacial low-sea level and the Yllow River had crossed the continental shelf,discharging its sediment to the Okinawa Trough in about 25,000-15,000 years B.C.
  • LIN HUI
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    One of keys related to the existence of GIS is the up-to-date data in its database.Land use and land cover data are the important kind of data in current GIS.The land use and land cover condition often changes due to it is easily affected by the changes of natural condition and the activities of human being.So,the appropriate ways for the data capturing and analyzing are needed.Spaceborne remote sensing,owing to its periodicity,speed,scanning scope and the economic benefit to gain the synthatie information,is becoming the main data source for updating land use and land cover data in the database of GIS. The crux of the updating procedure is to combine the remote sensing system and the GIS by means of the digital image processing system.The accuracies on locating and classifying are considered as the crucial problems in image processing. Author thinks that remote sensing image is a model of a region,which has been compressed in the spatial dimensions and synthesized with its essential factors on surface.So the information from the images evidently has a regional geographic pattern.The GIS just has the basic data and the analysis software for the registration and analysis of the spatial information from remote sensing and other sources.In this paper,author introduces a tentative model experiment on the Dukou regional environment information system after briefly disscusing some related researches at home and abroad.
  • Zheng Daxian, Li Ribang, Tan Jianan
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    The selenium equilibrium in solid-liquid system of soils sampled from different natural zones in China and the Se-uptake of plant in culture experiment are studied, 1.The distribution of selenite-Se in solid-liquid System of soil conforms to the Freundlich equation and to the Langmuir equation in a great extent.The Se-absorption capacity in solid phase of soil(b)relates directly with content of R2O3 in soil and the apparent dissociation constant(Kc)is raised with pH,The distribution of Se effected also by the redox potential (Eh)as a factor influencing the stability or reduction of Fe(OH)3,also as a factor controlling the valence aspects of Se in soil.The lowering of Eh caused by submerged condition may promote the reduction of Fe(OH)3 and the decomposition of Se-R2O3 complex for acid soils,by which Se content in the soil solution is raised,and Se may be reduced for alkaline soils.The result is that Se content in the soil solution is reduced,The effect of organism in soil is complex,but it may be mainly on the proportion of active Self total Se in soil. 2.The significant retationships between Se content in the experimental plant and that in the soil solution,between change of the plant-Se and change of soil solution-Se when culture conditions are changed,which is found in this study,indicate that mass flow is a main way for Se-transport in soil-plant system,but the proportion of Se intercepted by plant roots is raised with quantity of Se uptaked by plant. 3.The uptake of Se reached to roots surface is inhibited by higher pH and indicates that Se-uptake by plant is a initiative procedure depended on the energy metabolism. 4.The culture in submerged condition of soil is advantatgeous to the transport of Se from stems and leaves to grain.
  • Zhu Dakuin
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    Most of 2000 km of intertidal mudflat on the chinese coastline is developed in the mesotidal Bohai sea and Yellow sea,along the great plain of north China and to the north of Hangzhou Bay. The coast slopes are very gentle with gradients of 1:1000 to 1:5000, thus,tidal currents play a major role in shapping the coast.The sediment consists of silt and clay to form extensive intertidal mudflats with the width normally 4 to 6 km,and the mudflats are up to 20km wide at the delta, The mudflats of Jiangsu are divided into four zones.(1)Supratidal zone (grass flats).It is marsh and the location is over the spring high tidal level. The sediment is very thin laimina mud-fine silt and marsh deposit.(2)Mudflat.which is located between spring high tidal level and mean high tidal level,and consists of lamina and thin alternating laimina of silt and mud. (3)Mud-Sand fiats.They are located between mean high tidal level and middle tidal level,and consist of mudium laimina with cross-bedding.They are many.(4)Silt-Sand flats with the wave ripples surface acted by wave action. The mudflats are potential resources of farm land,especially for east part of China where over heavy population is.However,they are also good for developing salt fields,coastal lashing,other aquatic resources,and even there are many locations to be suitable for building harbor.For most part of inner two zone of mudflat,i.e.above mean HTL,and land-ward to the salt marsh can be reclaimated for developing agriculture,the lower two zones of mudflat are ideal ground for accumulating Shell fish such as Meretrix,Cyolina Sinensis etc..It has greater economic value than reclamation. The mudflat coast represents a dynamic balance between wave erosion and deposition of unconsolidated sediment supplied principally by larger river,shch as Yellow River and Yangtze River.Thus,any engineering project related to the coast or river mouth there will cause a series of problems.We do need more regional planning and marine legislation to strengthen the coast management.
  • Wang Tingwu, He Zhenya, Wu Lingyi
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    Using the data of mean monthly precipitation for 1959—1980 close to 200 stations,a harmonic analysis of the precipitation field in China has been made.The characteristics of geographical distribution of relative variance and phase angles of the first three waves and some relationships between these characteristics and general circulation are studied.This analysis is helpful to describe seasonal variation of the precipitation quantitatively.
  • Tang Qicheng
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    According to feature of hydrology in northwest region of China,three paramers α,β and γ can be used to study river runoff distribution,α= W4-8/W7-9 here W4-8—total runoff volume from April to June,W7-9—total runoff volume from July to Sept..α can be explained as a ratio of volume of season snow melt to glacial melt at high mountains and rain volume in total annual runoff.
    β=W4-8/W10-3
    here W4-9—total runoff volume from April to Sept.,W10-3—total run off volume from Oct.to next March..β can be explained as a ratio of flood runoff volume to non flood runoff volume,also a ratio of supply of ground water tototal annual runoff volume. The parameter γ,can be estimated by
    γ=(α-α)/σα
    here α—long term average annual αα—mean square error of α. The paper used the three parameters to make preliminary an approach to the classification of rivers in northwest region of China.
  • Gao Fengqi
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    In areas of the Bohai sea and the north Yellow sea,usually the peat in seashore-perimarine sea zone formed in bay,lagoon and submerged valley at the seaside with mountain and hill during the Middle-Late Holocene.The altitude was almost between five and ten metres.Peat was buried mostly in the underground about ten metres in the marginal plain.The peat of paleo-perimafine sea zone formed mainly in the flood plain and gully-valley out of paleocoast line during the period of high sea level,the altitude was almost between ten and thirty metres.The peat of shallow-sea zone was mainly basal peat following the ingression after the late W黵m-glaciation.It spreads in depth-48--56m of shallow plain of the Yellow sea of getting shallower and shallower toward the seashore.The distributional law of peat in these areas, which can be compared with that of Japan sea,indicated that the fluctuations of sea level in the two areas have been synchronism since the W黵mglaciation.
  • Sun Zhongming
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    For comemorating the 400th anniversary of birthday of Xu Xiake,a great geographer and well known traveller,the paper expounds the contribution of his famous work-"Travel Note for Tracing to River Source" to geography.That is that: (1)the work made a systematic exposition for three river systems, Jin shajiang,Minjiang and Daduhe,and their thread. (2)the work first point out that the Jinshajiang River is a upper reach of the Changiiang River. All of those judgements have exerted a tremendous effect on studing origin of the Changjiang River for successors.
  • Wang Shuyu
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    Based on the climatic condition and level of soil fertility in the Middle region of Jilin and the purpose of high-yield,stableyield,high income,through applying the method of linear programming,the author suggests the best planting structure of main field crop in this paper,inclusive of corn,grain, soybean and sorghum.The best proportion is 65.4 percent for corn,sorghum 0 percent,grain 15.0 percent,and soybean 19.6 percent.The total yield will be increased by 3.53 percent,and the income will be increased by 11.03 percent if according to the this structure. For considering the planting habit,the author suggests also to adopt following proportion,i.e.sorghum 5 percent,corn 59.12 percent,grain 15 percent and soybean 20.84 percent.In this way,the income will be increased by 9,60 percent.
  • Group of the Geomorphological Mapping and Research for Xining Sheet
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    Through mapping of Xining sheet of 1:1,000,000 chinese geomorphic map,three points on the landform coloration can be summarized as follows. 1)A multi-map type,suited by many levels is adapted to explaine a current geomorphic map,because of showing much more geomorphic contents in general.In the Xining sheet of chinese geomorphic map,the two levels are accepted.The first one is that basic form-genetic types in the geomorphic map is explained by landform coloration instead of the technipue of area solid colour.Using different colours present the difference between edogenetic and exogenetic forces in geomorphie formation of the mapping area. As colours are chosen in practic,characters of exogenetie forces are explained by fully using colour pictographs and habits,and then differences between geomorphie types in quantity and degree are shown by different colour steps.When drawing with landform coloration,according to assuming beam light direction a certain colur tone in a certain geomorphic part occurs with dark and bright varying,to show stereo-sense of geomorphology.The second level is that different forms and textures are represented by colour symbols with landform coloration.When drawing the relationships between the two forms and sites should be noted.Comparing with the geomorphic map,expressed by solid colour method,the geomorphic map drawn by landform coloration is much more pitographic and active. 2)Based on what described above,geomorphic analysis about basic types such as,plains,plateforms,hills,low mountain,middle mountain and high mountain,and individual geomorphic subtypes have been executed.Stereo-form drawing method in geomorphic types of all has been also discussed in detail. 3)The print plate with colour-line symbols of landform coloration geomorphic map is drawn by using general mapping techniques and is divided into different printing subplates based upon design requirement.In the mean time,using a more advance electrie color scanner,a geomorphie map by landform coloration is duplicated and a print plate of landform coloration map is completed.Finally,combination of l.ne-drawing plate with landform coloration plate is printed in a suited way,and thus a landform coloration geomorphic map is produced.
  • Wang Zhongyi, Zhang Xuelin, Ren Shufen, Wu Dunhu
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    According to field investigation and data measured by elect-chemistry methods,the paper studies the distribution regularity of different factors in native environments,such as soil,food and drinking water,in Jilin province of China.The results show that Mo content in food and water progressively is reduced from the west part to the east part of this province,and whole Mo and effective Mo contents in soil in the eastern mountains are higher than that in the western plain and terraice area,even then the effective Mo content in soil in a great of area is lower than normal content, therefore it can’t well satisfy growing need of grain crops.In the east mountains the content of Mo in aqueous solution in soil is lower than that in the west part.The paper expounds the regional division of biogeochemistry for microelement of native environment,and gives the regional division map for Mo.Based on Mo content absorbed by human body,Mo contribution in native environment can be divided into two areas,the western plainterraince area with higher Mo content in water and food and the eastern mountaineous area with lowet Mo content in water and food,and 5 subareas.This division is significant for studing environment and health,and factors causing local desease,and for developing agricultural production and environmental protection.