Archive

  • 2001 Volume 21 Issue 3
    Published: 20 May 2001
      

  • Select all
    |
  • CHEN Shu-peng
    Download PDF ( )   Knowledge map   Save
    In the 20th century, the achievement of geo-science was resplendent in China, which established the modern scientific basis. Confronted with chance and challenge to globalization, network and knowledge economy in 21st century, global study need to be emphasized. The earth's surface between ionosphere and Moho surface is the mean layer of information transmission and the most active human civilization, all of these belong to comprehensive research fields of geo-system science. Progress in the earth observation technology system and advancement of temporal and spatial resolution have made global synchronous dynamic monitoring into reality, information source is very profuse. Networkation has strategically exploited some new research areas, such as "Geo-information science" and "Digital Earth"; which has enhanced our reunderstanding to urbanization, resource, ecology and environment; and strengthened the ability of geographical strategy decision and participating in project programming and planning. Geography is comprehensive subject derived from nature and based on human, which always pays attention to exploit temporal law and spatial structure and it's transformation, geographical science must deeply mine profound geo-information resources, accelerate its informalization and modernization, thus it can fully bring whole and traditional predominance into play. With globalization, network and intelligence together, geo-science must have splendent future in the 21st century.
  • LIU Sheng-he, LU Qi
    Download PDF ( )   Knowledge map   Save
    The fundamental characteristics of sustainable knowledge-intensive agriculture are to use more knowledge capital to substitute limited and exhaustible natural resources and material capital and to transform the primary driving force of agricultural growth from the input increase of material capital and natural resources to more knowledge application and consumption. Based on China's basic conditions of huge population and scarce natural resources and the weak economic basis and low modernization degree of agriculture characteristics, this paper argues that the sustainable development of China's agriculture can only choose the model of sustainable knowledge-intensive agriculture, rather than the so-called sustainable material-intensive agriculture mode or the popular western model of sustainable low-input agriculture. This paper is composed of 4parts: Part 1 is the definition and basic characteristics of sustainable knowledge-intensive agriculture. Part 2 substantiates that the model of sustainable knowledge-intensive agriculture is China's only choice and future hope of agricultural development. Part 3 analyzes the causes of low knowledgeable degree of China's agriculture. Part 4 explores the development mechanisms of China's sustainable knowledge-intensive agriculture. In order to facilitate the development of China's sustainable knowledge-intensive agriculture, the following inspiring mechanisms should be established: A market-orientated mechanism for rural population migration and rural land transfer to inspire farmers' inner demands for technologies. A strong and efficient supply mechanism of agricultural technologies which is majored by the state innovative system of agricultural technologies and supplemented with agricultural technology market, through the sustained increase of state investment on agricultural researches. A consolidated mechanism of agricultural technology extension and supporting service network through the introduction of market mechanism. An efficient inspiring mechanism for technological development through the readjustment of agricultural development goals.
  • MENG Qing-min, LI Guo-ping, YANG Kai-zhong
    Download PDF ( )   Knowledge map   Save
    Social development is in the face of globalization and the knowledge-based economy. Based on the knowledge-based economy and learning firms which is lately put forward in geographical science and regional science, the essay summarizes new regional development mode: the conception of learning region. Learning region is a kind of flexible network system under the environment of different challenges and opportunities, which is promoted by all kinds of regional subjects including firms, governments, civil, locals, et al., and based on the regional network and information system. It explores the route of building learning region, including relational network for firms, relational network for regions and relationship network for countries. And the main part is building relationship network for firms, the basic parts are relational network for regions and countries. The connotation of proximity is made up of social proximity, cultural proximity, organization proximity, and space proximity. At last, it puts forward the basic characteristics of learning region, which are learning and innovating progress in the fields of society, culture, organization and institution including all the local subjects of firms, government, the local and civil, in order to exert the activity of learning region and develop the networks' effect of region. And under the environment of globalization, information modernization, network modernization and knowledge modernization, the new regional development strategy is building learning region.
  • CHEN Fu, GE Xiao-ping, CHEN Gang, PENG Bu-zhou
    Download PDF ( )   Knowledge map   Save
    Based on remote sensing images in 1988,1993 and 1998, the Mashan's landscape was conducted through methods of maximum-like and probabilistic relaxation, which revealed the city's spatial process during 11 years. The authors analyzed the relations between landscape changing and human impacting. A spatial variance, human impact index, was raised to express the spatial distribution of human exploiting and using strength. Using this index, mesh sampling method and geostatistics tool, the authors studied the landscape human impact conditions during the past 11 years, and revealed the spatial characteristics of human exploiting and using strength and their relation with the regional social and economic development.The conclusions may be distinguished as follows: (1) The results of the detection are reasonable and it is feasibility to calculate the transfer matrix of landscape to show spatial pattern of landscape distribution as unit of image pixel. (2) The main characteristics of Mashan's landscape changing are obvious reduction of the existing agricultural landscape and subsequent rapid increase of urban landscape along Guzhu road and cycle road which are main developing axes during the recent 5 years. In 1988, agricultural production was the main human impact of Mashan landscape, but in 1998, urban development and so on has be the main human active. The typical agricultural landscape in 1988 transforms to the urban fringe landscape in 1998. (3) The spatial characteristics of human exploiting and using had strong relations with the economic activities in Mashan Town. When agricultural production was the main human active in 1988, the semivariagram of impact index was very low and in short ranges. In 1993 and 1998, non-agricultural land exploitation were the most important type of human disturbance, the semivariagram was high and in long ranges. Because the north-south belt area was the main exploiting region, the semivariagram was anisotropic from 1988 to 1998, but when the northern new developing belt area and cycle road began to be constructed from 1992, it became more and more isotropic.
  • GONG Zi-tong, ZHANG Xue-lei, LUO Guo-bao, ZHANG Gan-lin
    Download PDF ( )   Knowledge map   Save
    The paper presents the brief progress of SOTER related studies all over the world. The SOTER program is a system which can store detailed information on natural response in such a way that these data can be readily accessed, combined and analyzed from the point of view of potential use, in relation to food requirements, environmental impact and conservation. The methodology was created by ISRIC for world land evaluation and management purpose in the late 1980's, then put into wide uses in some developing countries in Africa and South America and came to Asian nations in the late 1990's, including China. Some advantages of this methodology can be seen through the above practice. SOTER provides an orderly arrangement of natural resource information through the creation of a computerized database containing all available attributes on topography, soil, climate, vegetation and landuse, linked to GIS, through which each type of information or combination of attributes can be displayed as a separate layer or overlay, or in tabular form. The national SOTER programs are all carried out by the national soil research organizations. The number of requests for SOTER developments at national level from the developing countries is indicative of the demand for, and importance attached to the land resource database, land evaluation and landuse planning system which SOTER is capable of providing. A good foreground of this methodology for both theoretical and practical purposes can be seen from the discussed above.
  • ZHAO Geng-xing, DOU Yi-xiang, TIAN Wen-xin
    Download PDF ( )   Knowledge map   Save
    Taking a county (city or district) as basic units, using remote sensing image processing software ENVI3.2 and TM data, the automatic abstraction techniques on cultivated land information of seven counties and ten temporal phases were studied. Because of the spectral characteristic difference between cultivated land subtypes, the interactive unsupervised classification method can be used for obtaining a good result. Among supervised classification methods the ENVI Spectral Angle Mapper can reach a better result because of its data purification function to maintain the typicality of training samples. Compared with salty and mountainous regions, the classification precision can be higher in inner plain region where cultivated land has comparatively accordant spectral information. Based on comparison analysis the best temporal phase of cultivated land information abstraction is in spring which is from March to May. In addition the using of non-remote sensed data such as land use map as well as expert experience is also important for promoting the precision of cultivated land acquiring.Selecting spring TM432 band composite images, processed by geometric calibration and enhancing processing, using interactive unsupervised classification method; the average precision of cultivated land classification is up to 98.22%.
  • WULAN Tu-ya, ZHANG Xue-qin
    Download PDF ( )   Knowledge map   Save
    Based on the analysis of the Qing Dynasty polices towards the Inner Mongolian lands and its impacts on the cultivation, and the spatial-temporal characteristics of the organizational system in Horqin region, the cultivation northern limits of Horqin region within different stages in the Qing Dynasty are reconstructed. Analysis indicates that the cultivation northern limit jumped northward twice remarkably in Horqin region in the Qing Dynasty. (1) During the early Qing Dynasty, cultivation still confined in the lower reaches of the Liaohe River, and the "Wicker Frontier Wall" became obviously dividing line between agriculture and animal husbandry. (2) The first leaping of cultivation northern limit occurred within the period from the late 18th Century to the early 20th Century, namely, the period of "Presenting memorial to the Emperor for Cultivation the Inner Mongolian Lands". The northern limit moved northward from the "Wicker Frontier Wall" to Changchun City, Siping City-the southern Aohen and Ongniut counties. As a result, the plain regions of the eastern and southern Horqin region transferred to the transition zone between agriculture and animal husbandry with the animal husbandry as the dominant style. (3) The second leaping of cultivation northern limit happened within approximately decade at the end of the Qing Dynasty. At that time, the Qing Dynasty adopted series of policies by which quantities of population migrated from inland to Inner Mongolia to cultivation. The result was that the cultivation range extended to the hinterland of the Inner Mongolian lands. The cultivation region pushed northward to the lower reaches of the Taoerhe River Valley and both banks of the West Liaohe River. And the cultivation northern limit extended from the Daqing City, across western Baicheng City, northern Tongliao City and Kailu County to Linxi County. Seen from the changes of cultivation northern limit of Horqin region in the Qing Dynasty, it can be concluded that the Qing Dynasty policies towards the Inner Mongolian lands had dominated the direction and amplitude of the change of the northern limit. These policies not only controlled the amount of agricultural population, but also influenced the speed and scale of the agricultural development in the Inner Mongolia, which demonstrated as the appearance and enlargement of migration organizational agencies. In a word, the Qing Dynasty policies concerning the Inner Mongolia were the major driving force for the changes of cultivation northern limit in Horqin region, and were the important human dimensional factor for the formation of modern transition zone between agriculture and animal husbandry.
  • ZHANG Jian-ping
    Download PDF ( )   Knowledge map   Save
    Land degradation is not only a great environmental problem at present, but a great economic and social problem. Land degradation in southwest China is mainly formed by water erosion. This paper, briefly descibed the land degradation status (slight, moderate and severe degraded land area is respectively 188852.5, 48128.81 and 16.393.62 km2, and respectively makes up 14.30%,3.50% and 1.10% of the total area of southwest China)in southwest China, analyzed different land degradation types of 4 choosed areas(Chuxiong City in Yunnan Plateau(degraded area is 1159.44 km2 and makes up 26.17% of the total area), Suining City in hilly area in middle Sichuan Basin(degraded area is 3188.51 km2, makes up 59.93% of the total area), Bijie Prefecture in lime stone area in Guizhou Province(degraded area is 9055.30 km2, makes up 33.70% of the total area) and Yuanmou County in dry-hot valley in Yunnan Province (degraded area below 1350m of altitude is 1006.02 km2, makes up 70.15% of the total area)),discussed land degradation process(The land degradation process is under fragile eco-environment(great height difference, steep slope, frequent heavy rain and rainstorm),human unreasonable social-economic activity (reclaim slope land, cut forest, over grazing, etc.) caused the process of land degradation), proposed ways(prevention and control of land degradation by the law; strictly control population with the N range of the equation: 0.2113K <0.7887 K (K is the environment bearing capacity); strengthen agricultural basic construction and adjust agricultural structure; strengthen forest protection and afforestation; control livestock quantity and grazing intensity) to control and regulate land degradation.
  • YANG Yong-xing, HUANG Xi-chou, WANG Shi-yan, KONG Zhao-chen
    Download PDF ( )   Knowledge map   Save
    This paper makes a preliminary approach to the relationship between mire development and palaeogeographical environment changes since the early period of middle Holocene in the east part of the Xiliaohe Plain by means of dating, X-ray diffraction of clay mineral, analyses of spore-pollen and plant residual, content and translation and transformation of chemical elements, etc. The formation and development of mire located in the ecotone and ecological transition zone are highly sensitive to the environment change. The environment changes have occurred frequently since the early period of middle Holocene which results in cycle change of formation, development, degeneration and death of mire in its development process. The close relationship was found between mire development and palaeogeographical environment change. It can be divided into six periods, i.e. the breeding and germinating development period in the early period of the middle Holocene (6400-5100a B. P.), the vigorous development period in the middle period of middle Holocene (5100-4300 a B. P.), the interruption development in the middle and late period of middle Holocene (4300-3200 a B. P.), the degeneration development period of the late period of middle Holocene (3200-2100 a B. P.), the resuscitation development period of the early period of late period of late Holocene (1100-0a B. P.). The oldest mire was formed in about 5800a B. P. in the east part of the Xiliaohe plain in the Holocene. The mire development follows the model of long period development of eutrophic mire. The Maili bog-section, Horqin Zuoyi Houqi can be considered as one of the standard section of the Holocene in the east part of the Xiliaohe Plain. The peat deposition is characterized with mult-period in this area in the Holocene.
  • CUI Bao-shan, LIU Xing-tu
    Download PDF ( )   Knowledge map   Save
    The paper presents several kinds of ecological character changes of wetands in the Yellow River Delta, including changes in wetland types and areas, changes in water condition and water quality, unsustainable exploitation and use for wetland products. The reasons of ecological changes are analysed, they is nature and man factors that induce wetland changes. Then the paper suggests a strategy about sustainability management for wetland ecosystem in the Yellow River Delta, and three countermeasures of sustainability management are proposed in the paper, they are, from ecological indices, mitigating, restoring and maitaining the function and process of wetland ecosystem; from social indices, solving the problems between wetland development and conservation; and from economical indices, dealing with the relationship between industry, agriculture and wetlands.
  • SHI Qi, CHEN Fa-hu
    Download PDF ( )   Knowledge map   Save
    Northwestern China is the region with high frequent dust storms in the world, and the dust storms have been the serious disaster in the region. It was firstly discovered that deposit records of dust storm during Early Holocene in the investigation into lake sediments in the Hexi Corridor. Yema Lake section located in the terminal area of the Shiyang River Drainage of eastern Hexi Corridor, Northwestern China, recorded rich information of the lake evolution and climatic change since Holocene. Many interlayers of rapid aeolian coarse silt and fine sand were documented in between the lacustrine sediment, and were considered as transport and deposit of rapid dust storms. Furthermore, analysis of grain size, micro-shape of quartz sand, magnetic susceptibility and organic carbon revealed the coarse silt and fine sand layers were same as modern dust storm deposit with rapid short-haul transporting trait, but different from active dune sand deposit.According to interpolation of the 14C ages of different depth, age sequence of Yema Lake section was established, and lake evolution and climatic change in the Shiyang River Drainage were reconstructed. The result showed that dust storm events had occurred with 400a quasiperiod during Early Holocene(10 000-6 700 a B.P.), the wettest climate phase. The dust storm events occurred in the Shiyang River Drainage during Early Holocene were natural phenomenon relating with regional environment of Northwestern China.
  • YUAN Jian-ping, JIANG Ding-sheng
    Download PDF ( )   Knowledge map   Save
    Based on effect factors of transforming from point to area of infiltration rate and crust etc., put forward the formula of changing soil point's infiltration rate to area's rate on small watershed, which is fm=fn譙n/S譨n譩n. Here, fm is the average soil area's infiltration rate(mm/min) on behalf of different land using models and topography and landforms, fn is the average soil point's infiltration rate(mm/min) under different land using models and topography and landforms through many field tests, Sn represents areas of different land using models(hm2), S is Watershed's area(hm2), an means correct coefficient thinking the effect of crust and system mistake etc., bn is the parameter thinking the effect of soil's water content. Comparing the area's infiltration rate between transforming value and observing value, the result showed that relative error was only 2.42 percent., Preliminary gain the equations, which have high precision including single and fixed factors equations between soil area's infiltration rate and different soil control degree, rain quantity. The method is advantageous for seeking rain, runoff, infiltration's changing trend after comprehensive control on small watershed.
  • ZHANG Yun, ZHU Cheng, YU Shi-yong
    Download PDF ( )   Knowledge map   Save
    Palynology and sedimentology research on Zhangjiawan site in Daning valley, the Three Gorges of Changjiang River during East Zhou to Han Dynasties show the relation between environment evolution and human activity in this region over 3000 years. There was warm-humid climate when man dwelled on this place at first. During East Zhou to Han Dynasties there were warm-cold and a little arid climate. After this stage,a transient large-scale deluge took place in this area. After that,human activity became more active, natural plants were destroyed severely, water and soil lost largely, and mountain torrent became frequent which resulted in that there weren't continuous cultural fault after Han dynasty. But a lot of debris talus materials were accumulated resulting from mountain torrent.
  • ZHANG Yi-ping, LI You-rong, PENG Gui-fen, LIU Yu-hong, MA You-xin, WANG Jin-xing
    Download PDF ( )   Knowledge map   Save
    The data roots in the observation of air temperature that those have been effected by city expansion in Kunming City weather station and have been un-effected by urbanization in Taihua Mountain station. The results indicate that with Kunming City area expanding, the indoor and outdoors air temperature rises, the effect is bigger in Jan. to Apr. and that is lesser in May to Dec. The correlativity between effection of city temperature increasing and urban area and urban population is considerable. Urban area increasing has considerable effect on the average air temperature; while urban population increasing obviously affects average air temperature of indoor. This result will reference on studying fundamentals about urbanization effect on urban climate and city planning.
  • XIE Zhong-lei, DONG De-ming, LI Zhong-hua, BAO Guo-zhang, DU Yao-guo, QIU Li-min
    Download PDF ( )   Knowledge map   Save
    Distribution of manganese content in tea leaves, relationships between Mn content in tea leaves/active Mn in soil extracted by 0.02mol/L CaCl2 and soil pH and between Mn content of tea leaves and active Mn in soil extracted by 0.02mol/L CaCl2 for thirteen tea gardens from East China were discussed in the paper. The results showed that: the law of distribution of Mn in tea leaves was old leaf>mature leaf>young leaf; both Mn in the tea leaves and active Mn in soils extracted with 0.02mol/L CaCl2 were nagtively correlated with soil pH, and furthermore Mn in tea leaves was positively correlated with active Mn in soil; the uptake of Mn by tea leaves was best predicated linely by the amounts of 0.02mol/L CaCl2 extractable Mn in soils, consequently, 0.02 mol/L CaCl2 extractable Mn of soils could be regarded as the "tea leaf available Mn".
  • HE Xue-qin, ZHANG Guan-xi, ZHENG Qing-hua, DU Wan-cheng, WEN Wei-ying
    Download PDF ( )   Knowledge map   Save
    The paper presents the results of analysis and assessment of heavy metal content in the benthons in Daya Bay. The results were obtained as follows. (1) The average content of heavy metal contents in fish is Zn>Cu>Pb>Cd, in crustacea and mollusc is Zn>Cu>Cd>Pb. (2) Benthons have not been polluted by heavy metals, but the concentration of Cu and Zn in crustacea and mollusc has potential serious accumulation problems. (3) The content of Cd in crustacea and mollusc has beyond the human consumption. That should be noticed by the concern department.