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  • 2001 Volume 21 Issue 4
    Published: 20 July 2001
      
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  • Assessment of Land Use and Land Cover Change in a Middle Size Catchment:A Case Study of the Middle Yiluo Area
    LI Xiao-jian, LIU Gang-jun, QIAN Le-xiang, Jim Peterson
    2001, 21(4): 289-296. https://doi.org/10.13249/j.cnki.sgs.2001.04.289
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    Most of sustainable studies have adopted a normative approach.They attempt to employ common value judgements in assessing human-natural relations and in designing future plans.In practice, however, great regional differentiation precludes the fair use of common principles.This paper, while borrowing some ideas from normative studies, presents a positivist based approach to regional sustainable development assessment:(1) the achievement of sustainability in a region should be judged by the changing direction in a time period concerned; (2) the principle of judgement is whether the changes suit the local environment; (3) in terms of land use and land cover (LULC), a hybrid model that integrates ideas from both the physically and the statistically-based model types, was proposed to develop typical suitable site conditions as benchmarks in determining the suitability of a specific land use type; (4) a multivariate technique was used for measuring the difference between benchmarks and the actual situation.By using this approach, as well as GIS and remote sensing techniques, LULC changes in the Middle Yiluo Basin of the Yellow River were investigated in a fine geographical scale.
  • The Moisture Regime of Transitional Areas of Farming and Pasturing in the Northeastern China and Its Effects on Vegetation Distribution
    ZHANG Jun-tao, LI Zhe, ZHENG Du
    2001, 21(4): 297-300. https://doi.org/10.13249/j.cnki.sgs.2001.04.297
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    Moisture regime, which served as a major factor, determines the plant distribution in transitional areas of farming and pasturing of the northeastern China.It is essential to analyze the relationship between the moisture regime and the plant distribution, in order to adjust measures to local conditions and prevent the desertification.The characteristics of moisture regime in the research areas had been analyzed by using the latest data.The spatial pattern of HI was expressed in three dimensions as well.The result of this research shows that the annual aridity increases from the east to west of the research area, although it is affected by contour microclimates.The aridity in summer and fall is less than that in winter and spring.Using the Kira index, HI, and NDVI vegetation index, the relation was shown more clearly.The seasonal change of NDVI values of different vegetation indicates that the correlation between monthly average of NDVI and precipitation is higher than that between monthly average NDVI and temperature.It is, therefore, obvious that the moisture regime is the principle factor for the land cover change in the research areas.
  • Density of Soil Organic Carbon and the Factors Controlling Its Turnover in East China
    LI Zhong, SUN Bo, LIN Xin-xiong
    2001, 21(4): 301-307. https://doi.org/10.13249/j.cnki.sgs.2001.04.301
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    Based on the soil species data from the Second National Soil Survey, the soil organic C (SOC) density and stocks in East China were calculated, and the influnce factors of SOC turnover in cultivated soils were investigated by field and laboratory experiments.The results show that the SOC densities to the profile depth in Northeast China varied from 2.5 to 73.3 kg C/m2 with a mean value of 10.5 kg C/m2.In southeast tropical and subtropical China, the mean SOC densities to the profile depth ranged from 3.9-16.7 kg C/m2 with a mean value of 9.52 kg C/m2.With the increase of lignin content in plant materails and soil clay content, the decompostion rate of plant materails decreased in the cultivated soils.However, the increase of soil temperature, pH and CaCO3 content promoted the decompostion of plant materails.For the same soil, plant materails decomposed faster in upland soils then in waterlogged paddy soils.The effect of climate conditions on the decomposition of plant materials could be sheltered by the comprehensive influnce of the compositon of plant materials and soil pH, and the effect of soil texiture disappeared with the occurrenceof soil free CaCO3.
  • Research on the Construction and Optimization of Container Transportation Network in Northeast China
    HAN Zeng-lin, AN Xiao-peng
    2001, 21(4): 308-314. https://doi.org/10.13249/j.cnki.sgs.2001.04.308
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    Being a new transportation, container transport not only improves the efficiency of transportation, makes the door-to-door come true, but also change the mode of traditional goods organization and system of transportation.It can be reflected not only by the division of container load center and lateral container port but also the construction of network of container transportation.The network, which is made up of container port, channel of transportation and CFS,is changing the the mode of traditional goods organization.The lag of network of container transportation affects the level of containerzation and the efficiency of container transportation.The article discusses the rule of formation and development of the network of container transportation.Base on the theory, the paper deeply analyses the situation and problem of network of container transportation in Northeast China.At the same time, the paper put forword the layout of container transportation in Northeast China.
  • Comments on Krugman’s Edge City Model
    LIU An-guo, YANG Kai-zhong
    2001, 21(4): 315-322. https://doi.org/10.13249/j.cnki.sgs.2001.04.315
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    In the study of the spatial patterning of economy, there was a long tradition according to which the regularity exhibited in the spatial distribution of economic activities was taken for granted.This tradition was evidenced, for example, in the works of von Thunen and those of Christaller and Losch, which lent little insight on how such regularity was evolved.While von Thunen presupposed the existence of an isolated town around which different farming activities took the pattern of concentric rings, Christaller and Losch argued that a hierarchy of central places turned out the outcome of the interaction between individual economic agents who based their location decisions on the trade-off between economies of scale and transportation costs.Admittedly, Central-Place Theory did give an interesting picture of part of the economic landscape.However, its lack of theoretical strength to explain the observed structure in terms of deeper causes made it fall short of a formal economic model.Consequently, research on agglomeration and spatial patterning of economy has long been neglected by mainstream economists just because that they have regarded it as intractable.In 1990s, by applying concepts developed in an interdisciplinary study of self-organizing systems new perspective was introduced into the study of economics, which was elaborated in The Self-Organizing Economy by Paul Krugman.According to Krugman, there is an interdependence between firms in their making of location decision.The desirability of any place as a business location for a firm depends on where the other firms locate in relation to it.Economic activities tend to move from less desirable to more desirable location as time lapses.Krugman proposes that two basic forces exists in the interaction between firms:centripetal force (competition) and centrifugal force (attraction), which correspond to the positive feedback and negative feedback in the study of self-organising systems.On the basis of an analysis of the centripetal and centrifugal forces between firms as well as their interaction, Krugman presented a model of edge city - city of multi-centers, through which he demonstrated the inherent mechanism of the formation of large-scale patterns of regularity in economic space, that is, the principle of order from instability.The dynamic analysis exhibited in Krugman’s Edge City Model holds great potential in the explanation of "circular and cumulative causation" which intrigues both of urban economists and developmental economists.The evolutionary approach to the study of spatial economy makes itself a valuable compliment to those of von Thunen, Christaller and Losch, which are largely static.The concepts of dynamics, self-organizing etc and the evolutionary approach adopted in the establishment of the model lend important theoretical support to the development of the New Economic Geography, which is winning serious attention from the mainstream economists for its extra insight into some common issues encountered in the study of trade theory, the development theory and economic geography.
  • The Problems in Research of Economic Geography and the Solving Ways in China
    FENG Ren-guo
    2001, 21(4): 323-326. https://doi.org/10.13249/j.cnki.sgs.2001.04.323
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    This paper analyses the problems existing in the research of the Chinese economic geography, and makes some suggestions for the future development as follows:carrying out the research on modern natural process and its driving force; promoting the high-level synthesis of sub-disciplines of geography, perfecting and developing the fundamental theory of geography, gradually advancing on international scientific research; carrying out the policy research related to sustainable development in order to meet the need of national macro-policy-making; paying great attention to the research method and way renewal so as to raise the science nature of geographical research; introducing relevant discipline personnel and promoting discipline intersection are the shortcut of economic geography development; according to the demand of society carrying out the research on regional planning and industrial allocation.
  • Study on Surface Albedo Distribution Over Northwest China Using Remote Sensing Technique
    CHEN Yun-hao, LI Xiao-bing, XIE Feng
    2001, 21(4): 327-333. https://doi.org/10.13249/j.cnki.sgs.2001.04.327
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    The different land surface features and land cover conditions cause anisotropy surface albedo distribution.It is a powerful tool to derive large area of regional surface albedo using remote sensing technique.Land cover of study area is classified into five types, snow covered, bare soil, vegetation, desert and water, in first step.And then, based on the land cover classification over Northwest China, the different surface albedo calculation methods are presented accounting differential land cover condition.Integrated of the different surface albedo calculation methods, a model for regional surface albedo estimate over the heterogeneous landscape is derived.This approach provided a reliable estimate of surface albedo over Northwest China.The accuracy of the model for regional surface albedo estimation is checked by observed surface albedo data.The results of comparison show that the maximal relative error is 18.75 percent, and the minimal error is 8.82 percent, and the average relative error is about 15 percent.The result shows a high accuracy of surface albedo calculation.The main feature of surface albedo over Northwest China is that the value of regional surface albedo synthetically reflects distribution of conditions of soil moisture and vegetation coverage, and the variability of surface albedo is huge in this region.At last, the relationships between surface albedo and vegetation index and surface temperature over Northwest China are discussed in this paper, and these features can be make the conclusions as fellows:1) The relationship between regional surface albedo and NDVI can be given as a power function:Y=18.74*(x-0.2)-0.456.2) The relationship between regional surface albedo and surface temperature(Ts)can be written as,y=-72.3+6.45x-0.086x2, over Northwest China in July,1995.There are some errors in deriving the surface temperature form NOAA/AVHRR data, and scale transformations are not solved completely in regional scale surface albedo calculating.In addition, the vegetation-soil interaction needs research further.All of those are factors to restrict the precision of the model for regional surface albedo estimation and the objects to be study in the future.
  • GIS-Based Risk Assessment of the Debris Flows in the Lower Lancang River Watershed
    YAN Man-cun, WANG Guang-qian, LIU Jia-hong
    2001, 21(4): 334-338. https://doi.org/10.13249/j.cnki.sgs.2001.04.334
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    Debris flow hazards are an inherent but dangerous and costly element of mountainous environments in the lower Lancang River watershed.Conventional hazard map provide useful inventories of hazardous sites but provide little insight into the potential area of the hazards, this approach tends to rely heavily on subjective interpretation of the landscape.Assessing and predicting mountainous hazards potential using geographic information systems (GIS) are receiving increasing attention over years.Based on the spatial analysis of driving and triggering factors promoting the occurrence and development of debris flows in the Lancang River watershed a database and repository are constructed for assessing the area susceptible for debris flows in the area.A correlation of the occurrence of debris flows with slope gradient, vegetation cover and rainfall are also presented for providing multivariate statistical data available for assessing risk of the debris flows in the area.Using Arc/Info grid module all data in Arc/Info coverage, including contour, vegetation cover and rainfall are transformed into TIN data and DEM and further into raster gradient, vegetation and rainfall with raster of 100m X 100m .With the repository used for assessing the potential of the occurrence of debris flows, The classification of gradient, vegetation and rainfall with five ranks, in agreement with five risk ranks of debris flows :highest, high, moderate, less and none are implemented on Arc/info platform.A digital environmental model (DEM) to assess the debris flow risk in the lower Lancang river watershed.is employed to implement the processes of spatial algebra overlay.Raster gradient, vegetation and rainfall data with a weight of 0.5, 0.3 and 0.2,respectively are imported into same grid environment with to produce a new map, showing the potential zones of the debris flows with different risk ranks of the lower Lancang river watershed.With the overlay of conventional map of the debris flow hazards in history in the area with assessment result, it can be shown that the highest and high risk zones of assessment results are in agreement with the dense zones of debris flows in history and also indicate that the index selected and methods used for assessing the risk of debris flows in the Lancang river watershed are rational and credible for conducting the debris flow disaster control and mitigation in the area.and for helping mitigate the associated risk.
  • Analysis on Development Characteristics and Process of Gully in Yuanmon Basin on Lower Reaches of Jinsha River
    CHAI Zong-xin, FAN Jian-rong, LIU Shu-zhen
    2001, 21(4): 339-343. https://doi.org/10.13249/j.cnki.sgs.2001.04.339
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    The Low Pleistocene Series Yuanmon Group alternate sand and mud beds are widely distributed and the gullies are developed in yuanmon Basin.It lies on the south bank of Jinsha River, the upper reaches of Changjiang River(Yangtze R.).Some distribution regions of Pliocene-Pleistocene strata were scoured by running water, and formed thousand of gullies and ravines and some stretches of earth columns in the basin.This landscape is the result of gulling.The gullies erode the farmland, forme the erosion bad land (the earth forsest) and breake the landresources.The gully erosion, as a special erosion shape, received attention only recently.The gully erosion in the Yuanmou Basin is formed under the synthetical influence of local varied conditions, such as stratigraphy, tectonism, climate, soil, vegetation, water dynamic condition, etc.The Yuanmou Basin located in subtropical climate beit is controlled by the south-west monsoon of the Indian Ocean in rainy seasons and by the continental air mass of the tyopics in dry seasons.Its foehn effect was obvious.The climate of the basin is dry and hot, ecpecially in dry seasons with in November-April.The annval average temperature in the basin is 21.8℃, with the maximum of 42℃ and minimum of -1℃.The annual averag rainfall is 615mm, 90 per cent of which is concentrated in the rainy seasons within May-October.The annual vaporization capacity is 3-6 times of precipitation.In rainy seasons the running water carried sand gravel in the gully to make its scouring capacity enhanced and to speed up its incision and headward erosion.The lateral erosion of running water was further enhanced to make some loose sand beds below the gully wall and gully head wall become eroded, and the walls of the gully and gully head became convex-shaped on the top of it, and concav-shaped at the bottom of it, and then the walls of gully and gully head could cause eboulement after a rainstorm, some isolated earth shield and pillars remained.The gully continually stretches to platform at the same time.This article discusses following gully characteristics:(1) the gnlly bank is vertical; (2) the headward erosion is fast; (3) the combination form of gully head is varied.Then the development process and influence factors of gully are analysed.The important influence factors of gully development are folowing:(1) the strata is alternation of sand and mud beds; (2) the vertical joint is development in earth body; (3) the clay particle capacity is larger and the crevice is development in surface soil; (4) the climate is dry and hot and distinct dry season and moist season.
  • Evaluation for Some Tropical Crops in Hainan Province by Using Ales Based Upon Haisoter
    ZHANG Xue-lei, ZHANG Gan-lin, GONG Zi-tong
    2001, 21(4): 344-349. https://doi.org/10.13249/j.cnki.sgs.2001.04.344
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    A SOTER-based, automatic procedure for qualitative land evaluation is developed.This procedure was created in the Automated Land Evaluation System.The objective was to design a procedure that allows for a quick separation of potentially suitable from non-suitable SOTER units for the intended land use,indicating constraints to different kinds of land use.Different kinds of land are unequal1y suited to various uses,Land eva1uation is the assessment of the suitability of a tract of land for a specified kind of land use.1n practice this implicates the comparison(matching)between the requirements of a specified land use and the properties of the land.Land evaluation concepts and definitions are treated in the paper.The ALES is a computer program that allows land evaluators to build their own knowledge-based system with which they can compute the physical and economical suitability of map units in accordance with FAO Framework for Land Evaluation.The ALES program works with so called decision trees,being hierarchical multiway keys in which the leaves are results(e.g.severity levels of land qualities),and the interior nodes of the tree are decision criteria(e.g.1and characteristic values).These trees are traversed by the program to compute an evaluation using actual land data for each map unit.SOTAL is a SOTER-based,qualitative model developed in ALES for physical land evaluation in which presently two land utilization types (LUTs)are distinguished,cultivated banana and mango both under different input and technology conditions.These LUTs are characterized by 11 landuse requirements and evaluated by matching the land use requirements with the corresponding land qualities.The paper elaborates on the criteria used in SOTAL for land quality assessment and how a final suitability rating is achieved on the basis of the rated land qualities.Results are visualized through G1S-generated maps as products in response to the specific information and data needs of decision and policy makers.
  • Time Series-Markov Prediction Model for Precipitation in the Course of Evaluation of Groundwater Resources
    QIAN Jia-zhong, ZHU Xue-yu, WU Jian-feng
    2001, 21(4): 350-353. https://doi.org/10.13249/j.cnki.sgs.2001.04.350
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    Prediction accuracy of precipitation has an important influence on evaluation of groundwater resources that is recharged directly or indirectly by the precipitation.In former literature, many authors usually adopted the frequency of precipitation in the past to predict the precipitation in the future, and brought it into the models which evaluated the quantity and/or quality of groundwater.But this method is rather conservative.In this paper, we combine time series method with the dispersed Markov Chains theory of stochastic process, and present a Markov Model based the time series analysis for predicting the precipitation.In the course of modeling, first we select one-dimension nonstationary time series model to predict the precipitation in light of characteristics of the precipitation series.The result shows that the time series prediction is feasible as a whole, but there exists bigger errors when predicting the variables on the tops of the curves.In order to improve the prediction accuracy of the model, especially to the data with stronger fluctuation, we use the method of Markov’s state change probability matrix to fit them again.Then we attain the fitting values.To test the time series-Markov model, we apply it to predict the precipitation in the section of Xuzhou in Jiangsu Province as an example.Results show that the time series-Markov Model is efficient, and it has higher accuracy than that of the single model of time series.It enlarges applied scope of the time series model, and it is of important practical values and theoretical magnificence to the evaluation of groundwater resources that is finally recharged by the precipitation.
  • A Study on Recreational Belt Around Metropolis (ReBAM):Shanghai Case
    WU Bi-hu
    2001, 21(4): 354-359. https://doi.org/10.13249/j.cnki.sgs.2001.04.354
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    This study is the first one among current studies investigating the near distance and suburban tourism in China, which resulted in the conceptual framework of Recreational Belt Around Metropolis, abbreviated thereafter as ReBAM.Taking Shanghai city, the largest metropolis of China, as a case, the study analyzes the location mechanism, formation process, land use patterns, accessibility, tourist behavior and spatial structure of ReBAM.The study reveals that travel cost to tourists and land price to investors determine simultaneously the location of ReBAM, where tourism planners find their favorite sites for city tourism development.Specifically, this study used Shanghai as a case to described the formation of ReBAM and examined the factors that affect such formation.These factors include demand on weekend recreation, investment preferences of developer, and regional development policy of local government.Three types of recreational land use were identified according to the entrance fee structures.These include 1) low-price section:public recreational facilities sanctioned by government, 2) medium-price section:joint ventures between government and private sector, and 3) high-price section:recreational facilities developed and operated by private sector.The results showed that the ReBAM exhibited three unique and elementary spatial features.They are 1) weak linkage network, 2) distance decay of travel behavior, and 3) activity density diffusion.The significance of the study’s findings goes beyond the proposal of ReBAM.It presents practical implications for tourism planning and development.Based on the principles of ReBAM, the author proposed a three ring-shaped spatial structure for tourism development in Beijing, the capital city of China:central, urban fringe and rural outskirts.
  • The Change of Provision Structure of Built Environment and the Transition of Urban Landscape:A Case Study of Metropolitan Nanjing
    WU Qi-yan, ZHEN Feng, ZHANG Jing-xiang, YANG Qing, YANG Qing
    2001, 21(4): 360-367. https://doi.org/10.13249/j.cnki.sgs.2001.04.360
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    In this paper, the authors firstly review relevant articles and works of Neo-economy, Land economy, Neo-Marxism schools and Institutional Analysis which developed the theory of provision structure of built environment.The authors utilize the theoretical framework to study the metropolis of China in order to find the relation between the transition of provision structure of built environment and the transformation landscape.Within analyzing the above relation, the authors show that the properties of landscape of Chinese metropolis under the impact of change of provision structure of built environment are composed by :(1) Special political-economic transformation; (2) the organizational process of sectors within metropolitan area and the land use organization method; (3) the impact of mediation on developing process or the Transformation of urban planning function.Moreover during different time of development, those above relations differentiate to each other.Particularly after the Reformation since 1978, the new provision structure of built environment contribute to the transformation of landscape through:(1) the increase of localization and increase of self-raised found; (2) the property of foreign Investment its impact on urban process; (3) the re-organizational method of land use and urban process; (4) the transformation of urban planning System as the response to the other dynamic factors.At last, the authors choose metropolitan Nanjing as an example to do some research.
  • Core SX97:Climatic and Environmental Changes Since 70000 a B.P. and Drainage Responses
    ZHOU Hou-yun, YU Su-hua, GUO Guo-zhang
    2001, 21(4): 368-372. https://doi.org/10.13249/j.cnki.sgs.2001.04.368
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    Based on a multi-proxies study (including mineralogy, elemental geochemistry and pollen analyses) on Core SX97, which lies on the north flank of the Pearl River estuary, the authors suggest that the climatic and environmental evolution since 7000 a B.P.over the Pearl River Delta area could be divided into five stages.These stages between different climatic and environmental proxies, such as mineralogy, elemental geochemistry and pollen data, correlate very well with each other as well as with the climatic and environmental information over the coastal zone of South China that was recovered previously from the coastal dunes, beach-rocks and marine deposits.Then, the drainage response of the Pearl River to local climatic and environmental variations is explored.Core SX97 shows that the Pearl River drainage response sensitively to local climatic and environmental changes.When the climate over the Pearl River drainage was relatively warm and humid, weathering was relatively strong, relatively more iron was lost from the weathering profile, and better vegetation was developed over the drainage.All these would result in more FeO and Fe2O3, less herbal relative content, less quartz and more clay mineral (such as kaolinite, montmorillonite and illite) mass fractions in the estuary sediments.Contrary to this was the situation when the climate was relatively cold and arid.
  • Reconstruction of Spring Precipitation in the Middle Region of the Qilian Mountains Using Tree-Ring Data
    WANG Ya-jun, CHEN Fa-hu, GOU Xiao-hua
    2001, 21(4): 373-377. https://doi.org/10.13249/j.cnki.sgs.2001.04.373
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    Using tree-ring width Chronology of Picea Crassifolia of the middle region of the Qilian Mountains, we studied the relationship between tree-ring and climate factors, and reconstructed spring precipitation of the middle region of the Qilian Mountains since A.D.1770.Well replicated tree-ring increment cores for Picea Crassifolia were sampled from the middle region of the Qilian Mountains.After carefully cross-dating and measurement of each core, standard chronology was developed according to chronology building procedure.The correlation between the tree-ring index and the mean precipitation and mean air temperature of Sunan station, Qilian station and Yeniugou station was analyzed.The results indicate that there is positive correlation between tree-ring index and spring precipitation.The correlation coefficient R is 0.505.The tree-ring width is limited by spring precipitation, which is beneficial to tree growth.A reasonable interpretation is that when the rainy season has not arrived yet and precipitation is deficient in spring, the soil water becomes the limiting factor to tree-ring growth.Narrow tree-rings are produced when the limited precipitation leads to shortage of soil water.The spring precipitation benefits the tree growth.Associating the study research in Daqingshan Mountain by Liu Yu, et al., we take a conclusion that the tree growth in arid and hemi-arid region is limited by spring precipitation.According to the tree-ring data, we reconstruct spring precipitation for the period A.D.1770 to 1995.Cross-verification testing of the reconstruction produces highly significant sign test and product mean and high positive reduction of error statistics.These prove that reconstruction is reliable.The reconstructed spring precipitation shows four humid and dry periods in the low frequency variations of 11 years moving average since A.D.1770.Humid periods are 1776-1795 A.D., 1819-1857 A.D., 1888-1906 A.D., 1943-1991 A.D..Dry periods are 1796-1818 A.D., 1858-1887 A.D., 1907-1942 A.D., 1992-1995 A.D..The reconstructed spring precipitation indicateds that the middle region of Qilian Mountains was mainly in a humid state since A.D.1770.Seen from the large scale for the last 230 years, there is no obvious humid or dry tendency for spring precipitation, but take on an alternative form.After analyzing periodic characteristics, we find spring precipitation since A.D.1770 has 69 years periods and 21 years periods.Contrasting to the climate change of neighboring area, we find that reconstructed dry periods correspond well with those of the Hengduan Mountains and Huashan Region.They also correspond with the drought disasters occurred in northwest of China.Suggesting that the spring precipitation, especially the abnormal dry change has large region representative, at least records dry humid change of north-west of China and it also indicates that the reconstruction is reliable.The period of the 1900s-1940s which shows low value for spring precipitation are corresponds well with the period of the east region of China and HuaBei Region and HuaiHe River.The period of the 1940s-1960s with high value is similar with that in the change tendency in most of the regions of China.So we take a conclusion that the spring precipitation probably has a closely relationship with the climate change of North Hemisphere or larger scale.
  • A Study on the Representation of Common Pollens in Soils on the Northern Slope of Shennongjia Mountains
    LIU Hui-ping, TANG Xiao-chun, WANG Kai-fa
    2001, 21(4): 378-380. https://doi.org/10.13249/j.cnki.sgs.2001.04.378
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    The representation of common pollens in soils on the northern slope of Shennongjia mountains area is studied in the light of sporo-pollen analysis and plantation sample investigation.Most of broadleaved-tree pollens such as Quercus, Ilex, Fagus, Juglans,Castanea, Carpinus, Corylus, Ulmus, Tilia and Salix, have a under-representation except Betula and Alnus which have a suitable representation.Some main conifer-tree pollens such as Pinus, Abies and Picea, have a over-representation except Cupressaceae and Taxodiaceae which have a under-represeatation.The research shows that the representation of pollen is influenced from pollen character, external pollens, pollen output, distance from pollen sources and landform.
  • The Historical Changes of Ecological Environment and Solutions to Economic Sustainable Development of Meizhou City
    LIANG Jin-mei
    2001, 21(4): 381-383. https://doi.org/10.13249/j.cnki.sgs.2001.04.381
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    This paper analyses the historical changes of eco-environment of Meizhou City.It believes that the conflicts among population, resources, and environment, which resulted in the damage to ecological balance are the main factors to slow down the development in economy of Meizhou.The paper proposed that afforestation should be expanded to improve the ecological environment and the population control and industrial structure adjustment should be made to guarantee the regional economy’s sustainable development.