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  • 1995 Volume 15 Issue 4
    Published: 20 July 1995
      

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  • Huang Chenglin
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    From the point of view of culturel ecology, this paper discusses preliminarily the geography background of the formation and development of Huizhou Culture, the influence of Huizhou geographical conditions upon its cultural phenomena, and the relation between Huizhou Culture and its natural environment. The paper puts forward some views as follows: 1. The geographical position and natural environment of Huizhou is an important prerequisite of the formation and development of Huizhou Culture. 2. Huizhou geographical environment influences directly its material culture, and affects indirectly its mental culture. 3. Huizhou Chulture is in harmony with its natural conditions. The relation between Huizhou Culture and Huizhou natrual environment embraces four aspects: restriction, adaptation, reappearance and selection.
  • Yang Shilun, Chen Jiyu
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    Flood is the prime natural disaster in the Taihu Lake drainage area. Based on the data of climate, relief, human activity and disaster records, this article mainly deals with the factors which control the formation and evolution of flood.The formative factors include rainfall and relief. The peak rainfall can reach to 203 mm/h, 582 mm/d and 2356 mm/a at individual station. Three-fourths of the drainage area is plain, half of which is below high tide level. Permanent waters (lakes, rivers and ponds) and paddy fields together cover 55% of the drainnage area (36500 km2) in summer, the main flood season. The gradient of water surface in the major discharge waterway, the Huangpu River, is 6.5?10-6 in average and is even negative at high tide.The frequency of flood has been increasing in the past two thousand years. The major causes are:(1) the crust of this area has been sinking at the rate of 1.2 mm/a; (2) the coastline of the Changjiang River delta has been continuously moving toward the East China Sea; (3) as a result of (1) and (2), the gradient of the discharge waterway has remarkably decreased to 1/3; (4) the population density has increased from 6/km2 to 900/km2.In the 21st century, the rainfall of the drainage will increase by 40%-50% due to the global warming climate, the sea level of the Changjiang Estuary will rise about 40 cm-60 cm. Consequently, the threat of flood will be aggravated in the next century.
  • Zhao Wenzhi, Li Kerang, He Xindong
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    According to the results which use PCA and hierachical clustering to analyse salt content of drifting sand, 12 sandlands (sandy deserts) of our country are devided into 4 types of salt leaching sandland, i.e. strong leaching, leaching, weak leaching and non-leaching. Analysis shows that the ratio of evaporation to precipitation is a key factor that affect the salt status of sandland, rather than air temperatrue. Existence of vegetation can weaken salt leaching to different extent in each natural zone.
  • Wang Jian, Yang Huairen
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    Five transfer functions (depth/foraminifera percentage) are established in terms of the calculation of modern foraminifera data which are derived from 77 sea-bed surface samples of the South Yellow Sea. After adaptability analysis, D=35.60-0.95 PAm.bec+0.864 PAm.keli (R=0.911, ε=9.7 m) is selected and used to estimate the depth changes of the South Yellow Sea for the last 130000 years.In the past 130000 years, relative deeper sea appeared in 120, 100, 80 ka B. P. and nowadays, relative shallower sea appeared in 110, 90, 70-50, 20-15 ka B. P. In general speaking, the changes of sea depth indicate the changes of glacial-eustatic changes. The greatest depth during the last interglacial was 5-10 meters greater than that at present. This suggests that the highest sea level during the last Interglacial might be 5-10 meters higher than that at present.
  • Shuai Jiangping
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    Based on the analysis of the development advantages and the evaluation of market potentials, the author concluded that the development of export-oriented agriculture in the southeastern region of China is possible. The drive for the growth of export-oriented agriculture in the region is the overseas market, which stimulate the development of high-efficency agricultural production and then enhance the change of regional agriculture to "high-productivity, high quality and high-efficiency."The further development of export-oriented agriculture in the region should be sustainable and coordinated with the regional agriculture, adapt to the international market and competition. The cooperation with the agricultural production and capitals are very important. In addition, reformation on system, trade and organization are also necessary.The foreign investment and ventures have played an important role in the development of export-oriented agriculture in the region, for they increased the export, utilized the advantages and became one of the source of expanding reproduction investement. To guide the foreign investment ventures, three different investment districts of local fine agricultural varieties, closed special development zones and new agricultural varieties introduction areas can be built.
  • Jie Dongmei, Lu Jinfu
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    Songnen sandland lying in the middle of northeast China is in the continental monsoon climatic region of transitional belt between semi-humid and semi-arid temperate zone. It is the first-grade susceptible belt of environmental evolution in China.Since the last glacial age, the nature environment of Songnen sandland have undergone complex evolution process. Based on the principle that vegetation is related to precipitation and aridity degree, using pluralistic linear regression analysis, the authors calculated quantitatively the precipitetion and aridity degree of Songnen sandland since the last glacial age, and drew the change curves of precipitation and aridity degree in different periods, and 1.1-1.2 isogram of aridity degree. Since the last glacial age Songnen sandland underwent 5 periods of high precipitation and low aridity degree. And the east boundary of the sandland in different periods have also been estimeted.
  • Zhao Jingbo
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    According to the study on the illuvial depth of CaCO3, CaCO3 content and leached cracks, it is determined that moving depth of CaCO3 illuvial horizon represents the permeated depth of gravitative water, and the distance from the top of paleosol to the bottom of CaCO3 illuvial horizon is the thickness for the permeated zone for gravitative water.The permeated depth of gravitative water can reliably reflect the precipitation and can be used as the basis for determining the depth of film water zone and groundwater level. In general, groundwater can be classified into the gravitative water zone and the film water zone, but the gravitative water may stretch down to the groundwater level and film water zone is lacking in the area with rich rainfall.The precipitation during the development of the paleosols from 1st to 7th layer was between 600 and 1000 mm, with maximum difference less than one time. However the permeated depth for gravitative water of seven layers of paleosol is between 7.4 and 0.7 m, with maximum difference more than ten times, which demonstrates that the rainfall during warm and moist periods of Pleistocene was uneven, rain season and dry season were obvious, that increased rainfall mainly concentrated in rain season, and the difference in rainfall between dry period and moist pertod was great in rain season and little in dry season.
  • Yu Zhiliang, Sun Xufu
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    Inland encroachment by salt seawater over Laizhou Bay area makes serious endan-germents. Scientific calculation resulting from a great quantity of meteorological dada sets have shown that about 15 billion tons of cloud water resource can be used for precipitation enhancement from March to October every year over Laizhou Bay area. For example, more than 0.9-1.2 billion tons of cloud water resource can be increased by artificial enhancement for stratus clouds and 7. 5 billion tons for cumulus cloud. So, the cloud water resource is considered to be rich over Laizhou Bay area. Precipitation enhancement by cloud seeding is a very significant and efficient way to increase the surface precipitation, to raise the subterranean water level, and to keep salt seawater from intrusion.
  • Liu Shengjia
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    Sustainable development can be summarized as the establishment and development of the coordinated relationship among population, resources, environments and development. Excessive population growth, lack of natural resources, aggravated environment problems have seriously hampered the sustainable development of human society of the 21st century. In this thesis, the author thinks that the main problem of the sustainable development and the coordinated relationship is the unbalanced distribution of population, resources, environments and development in the material world, while the unbalanced development of human society intensifies the unbalanced distribution of the material world, therefore, it brings about the uncoordinated relatonship under the unbalanced conditions. Besides the controlling of excessive growth of population, the key point to resolve this problem is to promote the all-round development of human society, especially to quicken the development of the developing countries and strengthen the reasonable flow of population, energy, material and information, so that it can establish a scientific intelligent adjusting system.Geography always takes the coordinated relationship among population, resources, environments and development, that is, the relationship between the development of human society and geography conditions as one of the most concerned study fields. Facing the sustainable development problems which the whole world concerns, geography must unify the regional difference law with the material unbalanced distribution law, and reveal the movement developing law of the coordinated relationship among population, resources, environments and development by the space system which is consisted of flow, network and boundry line, and take the construction of flow-geographic construction as a stage where it will serve the sustainable development of human society, so geography will serve the sustainable development of human society, and achieve a revolutionized development.
  • Ye Yuguang, Diao Guangbo, He Jie, Gao Juncheng, Lei Xiangyi
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    The ages of palaeo-accumulation of mud-rock flow in Dongchuan, Yunnan are ob-tained by ESR dating technique, they are consistent with 14C ages. The ESR ages show that the palaeo-accumulation of mud-rock flow is the product during the humid periods of the Late Pleistocene. The simulative experiments and analyses under SEM show that the reset mechanism of Ge center in quartz is most likely attributed to the collisions between quartz grains during the periods of quick transportation of mud-rock flow, besides the bleaching exposed to the sun.
  • Liu Yinliang, Yan Minhua, Meng Xianmin, Zhang Wenfen
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    In this paper, we have researched the changes of swamp soil after the great fire event occurred on 6 May, 1987 in the Da Hinggan Mountain. It is revealed that the fire had severely effected the soil profile by burning away the organic matter in topsoil. Soil thermal situation has been changed, and soil temperature rise. Soil water content has been altered because the water reservation condition has been changed by the fire. Soil pH and the content of P2O5, K2O, CaO, MgO increase after the fire, on the contrary, the organic matter content and N content decrease, the quantity of microorganism greatly increased after the fire. It is considered that the fire is beneficial to the development and genesis of swamp soil in this area.
  • Zhang Bai, Sun Baida, Wang Qichun
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    The paper mainly analyses the distribution and change of reed resources in the lower reaches of the Huihe River in Hulun Buir grassland of China on the basis of remote sensing information and specimen spot data. In order to preserve and use effectively reed resources, a proposal is also put forward. 1) Though the area belongs to semi-dry grassland zone, the climate is not suitable to reed growing, which need a lot of water, there are many wetlands caused by the winding course of swamp stream on the smooth grasslands (gradient is about 1:2500), they provide fine natural conditions for reed growing, so that in the wetlands the reed comnunity covers an area of more than 300 km2. 2) The moisture difference, caused by the geomorphologic difference results in the difference of reed growth. The reed there can be divided into three degrees according to the qualitative features (height, major diameter, density), grantiative feature (weight per unit) and remote sensing images (colour, tone, etc.). 3) Compared with the historical data it is shown that the reed in the area has been already degenerated. The major reasons are climatic changes and improper utilization. In order to preserve and use the read resources most properly, it is necessary to build irrigation works and improve production management.
  • Ding Weixin
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    The paper deals with the effect of bioclimatic zone on the morphology and availability of manganese in soils of China by using a sequential extraction method. The distribution of manganese in soil fractions varies with bioclimatic zone. The ratios of exchangeable Mn, amorphous iron oxides bound Mn and crystalline iron oxides bound Mn to total Mn in soils in China decrease slowly, however the ratio of Mn oxides to total Mn increases from tropical zone, subtropical zone to warm-temperate zone, temperate zone. the rate of organical bound Mn to total Mn shows another model, i. e. increase from tropical zone to subtropical zone and then decrease from subtropical zone to warm-temperate zone and temperate zone. The variation of available Mn in soils is the same as that of exchangeable Mn. The available Mn in acid soils in South China comes from ex-changeable Mn and organical bound Mn and mainly from Mn oxides and exchangeable Mn in alkaline soils of North Chian.