According to the study on nine types of soils, including brown soils, for subtypes of cinnamon soils and other non-zonal soils, this paper discusses the existence state and the differentiation characters of heavy medal Cd, Pb and Cu. It also discusses the relationship between soil properties, such as pH and organic matter, and regional differentiation of heavy medal state. Therefore, this paper shows the law of regional differentiation of heavy medals in the soils in the south and north direction and east and west direction.

According to the geographical cycle theory, drainage landform evolution process is divied into three periods—young, mature and old period. In defferent evolution periods, the relation between gully density and cutting depth is various. However, it is sure that landforms are the most tattered and gully density reaches the maximum in the later young—early mature period. By presuming that the drainage landform is evoluted into hills in the period, the maths equation of the theoretical maximum of gully density was established, which is D=ctgθ^h∫_h0^maxdh/(hctga+c)² (1) where:D: gully density;θ: slope;h: cutting depth;c: gully bed average width;h₀: cutting depth minimum;h_max: cutting depth maximum On the above presuming base, the maths function on relation between gully density and cutting depth were established for the defferent development periods. The maths function shows that:①in the early young period, the gully density and cutting depth increase at the same time; ②in the later young—early mature preiod, gully density reaches the maximum and it decreases as cutting depth imcreases; ③ in the later mature—old preiod, gully density decreases as cutting depth decreases. Two example calculations demonstrate that the maths equation of the theoretical maximum of gully density may be used in practice. It can infer drainage landform evolution period and predict soil erosion developing tendency. It supplements quantitative anslysis on landforms shape elements with drainage landform evolution in defferent periods.

According to each coastal island's sea area, nature condition and resource situation, development level and features of national economy, teritiary industrial constitute of national economy and principles in dividing marine economic region, the frame of coastal-island economic region in China is divided on the base of dividing economic type (or typological region) of these twelve coastal-island counties in CHina. The coastal island counties in the north of China are the main objects of study. The northern coastal economic region and its division system are set up, including two second-class economic regions: Changshan Archipelagoes and Miaodao Archipelagoes. Under them, five sub-economic zones are divided (Fig.3). The characters of each small economic zone are shown in Tab.1. In the study on the development tendency of coastal-islands, natural resource and industrial system are involved, and the analytical hierarchy diagram of its development tendency is drawn up. Finally, the development tendency of the economic regions of coastal-island counties in north-china and its counter measures are put forward.

The ancient Yellow River once took over the course of the Huaih River in the historic period. It forms a closed dune by the sediment from the ancient Yellow River.The region of the ancient Yellow River is a developing area with temperate climate, sandy soil, sufficient sunshine, dense population and limited water resource.As a potential agricultural area, the ancient course of Yellow River has satisfactory conditions for green foods production. Sufficent use of land resources and labour force is the fundament need for the economical development in this region.

On the basis of discissing the environmental significance of magnetic susceptibility of lake sediment, the historical environmental variations have been studied from Daihai DH₃₂ Core with the analysis of granulomtry, sporo-pollen, historical data and diatom determination. It is believed that during the historical periods the higher value of magnetic frequency dependent susceptibility in lake sediments coincided with the wet climate, and the lower value related with the dry climate. The climate change in the past 300 years implicated by magnetic frequency dependent susceptibility from DH₃₂ Core can be divided into seven periods which mostly coresponded with the analysis of granulomtry, sporo-pollen, historical data and diatom determination. The magnetic frequency dependent susceptibility of lacustrine sediment is one of the main environmental indexes for reconstructing historical environmental variations.

Drug-market of Anguo Town was originated in Song Dynasty. It had developed for more than 1000 years, and had never faded away at all. Why could it be developed all-along? There is much experience that can be made use of.This paper takes Drug-industry of Anguo Town as an example to analyze the reason for its development with reference to regional economy and culture.Anguo Town lies at the piedmont plain of the Taihang Mountains. Here the open land abounds with water resources, and the local soil and water conditions are favorable-for crude drug growth. This is why many good varieties of drugs were-first named "Qi" (Angou's old name ) in China. According to statistics, there are-more than 300 species of drugs, and the area for drugs is extensive, being about 20% of the total land area of the town. Drug-market was prosperous owing to the convenient water and land transportation.The temple setting up for a drug-god attracts numerous businessmen all over the country. The extensive drug trade has promoted. So "the temple" has become a center-place for exchanging drugs. Space attraction from "temple of drug-god" brings businessmen together, reduces exchange-cost due to shortening of distance from one place to another.The effects of the three machinisms of Exchange-cost, Network-management and Economic intergrowth, are reflected in the following aspects: 1) to cut down the exchange-cost by reducing relating layers; 2) to offer simple financial ways; and 3) to bring credit and professional personnel which is essential for market operations.Drugs' culture was exhibited by it's handicrafts. A famous saying-goes "there aren't flavor of a drug until it is sold at Qi" in China. Many drugs become even more effective after being technically processed in Anguo Town.In a word, space attraction from the Temple becomes a dependence of drug businessmen in the process of moving towards concentration; complete and orderly layer of exchange-network pledges normal operation of transactions; perfect financial system enables the benign circulation of drug market; credit and human-circumstances serve-as a huge umbrella to guarantee fastest and most reliable source of information; and as a kind of historical culture, it is easier to turn traditional crafts-into a one with distinct features in the process of regional and industrial development.

The construction of the Three Gorge Dam on the Yangzte River will put more pressure on the slopelands in the surrounding area. Sustainability of these lands depends on the successful control of soil and water erosion.A site experiment of the contour hedgerow technology in harnessing erosion and enhancing soil fertility has being carried out in the area since 1993.The initial results of the experiment show that the technology can decrease and slow down surface runoff greatly, reduce soil erosion enormously, and provide a large amount of green manure.Among the 12 species selected for the experiment, Leucaena leucacephala, Coriaria sinica, Vitex negundo, Hemerocallis citrina, Vetiveria zizanioides are well adaptable to the local environment and can be used as hedgerow plants.The first three species can be used as green manure plants.The everage biomass cut from the hedgerows of these plants each year amount to 24 000 kg/ha, 8 400 kg/ha and 31 500 kg/ha respectively.A simulated rainfall test shows that vitex hedgerow can decrease runoff by 70% and sediment over 99%.

Beiqiu Lowland is in a semi-closed area with shallow and saline ground water. Some integrated techniques were introduced to reclaim the area, including transferring water from the outside of the area, irrigation, drainage and conservation with uncovered canals. Therefore, the level of ground water does not go down but the results of reclamation are obvious. The analysis of this phenomenon indicates that irrigation and conservation with uncovered canals ensure the field irrigation and the leaching of salt in the dry season; the cover of crops not only improves the environments of near surface evaporation and salt rising from soil but also effectively controls salt accumulation in root-zone.

罗来兴教授与本人同是1938年考入中山大学地理系的,由于我停学一年,入学时,罗兄已二年级了。我们三载同窗,感情深厚。当上星期施兄雅风来座,告知罗兄上月去世(3月18日),不免心中怅然,好友又少一个,决心写一文以表怀思。

On the basis of reviewing the history and present situation of the study on overland flow and hillslope processes, the author summarized the recent development in following fields—the forming mechanism, hydraulic features and models of overland flow, the processes and models of hillslope evolution. It shows that, with theories and methods of geomorphology, hydrology, hydraulics and sediment movement mechanism, to study the erosion dynamic processes and its critical conditions is one of the current frontiers of overland flow and hillslope processes. Finally, the problems and futures of the researches in these fields were put forward.In Addition, some new ideas about the hydrological factors of the overland flow and the formation mechanism of small erosion holes on the slope were also given in this paper. It shows that critical Flow Reynolds Number (R_e) and Energy Per Unit Section (E_s) can be main critical hydraulic parameters to determine whether rill flow appears; the critical Flow Kinetic Energy (E_v) and Critical Shear Stress(τ_c) can be secondary parameters; the critical Froude Number (F_r)≥1 can be one of the essential conditions for the rill flow generation. It is also found that all of the flow potential energy are transformed into the kinetic energy. And water flow is so thin that rainsplash becomes very severe in the joint between trough of rolling wave and slope surface, where the small erosion holes appear firstly.

由中国地理学会、香港地理学会、香港大学地理与地质系、香港中文大学地理系、逸夫书院、香港浸会大学地理系和中国科学院地理研究所等单位联合发起组织的“21世纪的中国和世界国际地理学术讨论会”于1998年8月13日～15日在香港中文大学举行。

Based on more than 800 measured plots and the inventory data of natural resource survey,the total biomass of natural vegetation was estimated for various counties of Qinghai and Tibet provinces,which was 2.586×10⁸t for Qinghai and 1.282×10⁹t for Tibet.The QZNPP model established here shows that,as temperature rises by degrees,net primary productivity (NPP) increases in the way of "S" curve;the rate of increasing is quickened by more precipitation.The rapidest rate appears when the annual mean air temperature is 0℃～10℃ and the annual precipitation is 400 mm-1 000 mm.When the temperature is over 11℃ and the precipitation is more than 1 100 mm,NPP approaches a maximum of 20 t/ha·a;and in the condition of less than 0℃,with the increasing of precipitation,NPP declines slowly,indicating that temperature is a major limiting factor.A biomass map for the 115 counties in Qinghai and Tibet provinces shows that,the maximum biomass occurs in Motuo County of Tibet,up to 196 539 t/ha;the second is in Chayu,Bomi,Linzhi and Milin counties of Tibet,whichis 115 t/ha～140 t/ha;the value is only 1 t/ha～5 t/ha in the extensive regions in north west Tibetan Plateau.A map of potential NPP for the natural vegetation of the Tibetan Plateau indicates that NPP varies from 0 to 20 t/ha·a;the area weighted average of NPP is 6.03 t/ha·a,less than the value of the global terrestrial vegetation (7 82 t/ha·a).

Land degradation caused by water erosion in South China took place mainly due to the vulnerabilities of its ecological environment,such as thin layer of top soil,poor nutrition and moisture and low erodibility of subsoil as well as a marked summer drought.Depletion of vegetation cover induced by adverse human activities provides a breakthrough point for its initiation,and abundant rainfall and frequent rainstorms and typhoons in summer act as the exogenous agent for its development.Land degradation in South China manifests itself as not only soil degradation but also vegetation degradation and deterioration of land surface.Its development could be considered as a multiple vicious circle of the process:vegetation degradation soil degradation deterioration of land surface.Tentative criteria for land degradation assessment were set up,including vegetation types and cover,types and percentage of surface materials exposed as well as erosional morphology and its percentage.

Sustainable development of regional social and economic system depends on the coordinated degree of system components and the gain coupling with ecosystem.Smitulating and regulating socioeconomic system become a challenging work due to its complexity.The weakness in dealing with diffusely coupling,nonlinear and high order equation makes the traditional methods,such as system dynamics and multiobjective planning analysis,become less important in modeling behavior and dynamic character of socioeconomic system.In this paper,a feed forward artificial neural network (ANN) with back propagation (BP) is tested to simulate structure and function of socio economic system.A BP model established by BP builder consists of input layer,hidden layer and output layer.We choose 12 factors,such as total population,cropping land,forest land,water resource and forest cover rate.as variables of neurons at input layer.At output layer,three neurons stand for the ecological quality index,economic development index and social development index.We generate a set of training data by means of real value of socioeconomic system's components from 1991 to 1995 and then train the BP model.Having served to predict and regulate real socioeconomic system around Bohai area of Hebei province,the BPmodel shows that a goal of coordinated development between ecosystem and socioeconomic system will become true by slowing down the economic development speed,increasing land area for ecological purposes,and reducing capital investment and energy input to the ecosystem.

For years,regional economists and planners in China have stuck to a development logic centered at an increase of industrial output values.As a result,overlapped industrial constructions and capital waste projects have been widely proved throughout the country.Considering the fault of the traditional logic,this paper,based on an analysis of the future industrial development in the Sichuan Chongqing setion along the Yangtze Valley,is trying to find out a new one with a focus on reducing industrial operation costs.

Development of science,technology and social economic requires a basic research correspondent with regional social economic development to comprehensively identify regional characteristics.Integrated zonation,which is further researches on natural zonation,combines natural environment with social economic and serves regional economic development.Integrated zonation meets the requirements of regional economic development.In this paper,based on summary of natural zonation,ideology of resources is introduced for regional division.Specifically,"resources groups" and "resources types" which are closely related to social economic development are used to form the fourth level and fifth level classes,the insufficient researched zonation classes before.This paper takes Chaidam Basin case as an example to establish a regional integrated zonation system for the sustainable regional economic development.

Regional sustainable developments in China need not only to pay attention to the integrated developments in the easterm and western part of China,but also to coasider the coordinating disparity in the southern part and northern part of China.The South North regional economical development has a disparity,which was resulted from the disproportion and compliacty of various facts in nature,economy and social history.For that,the Complementarity of the South North regional economical development should be strengthened,which are the important countermeasures that coordinating development of Chinese regional economy must select.

Landscape ecology is a discipline for application,connecting with tourism development,and we can use the theory of landscape's spatial heterogeneity.The ecological classification of landscape and the landscape's zoning based on landscape ecology are a key problem in regional tourism development.In the paper,with a case study in Anning City,we can set a new idea of tourism development that mainly emphasizes on landscape's study and key developing zones(areas) based on the ecological principles and the function of tourism.

Land desertification and land salinization are popular in West Jilin province,which is the major distribution area of deserted land in semi arid region of China.At present,human economic activities have destroyed the stability of sandy land ecological system.There exists obvious trends of environment degradation,such as drought,wind sand damage,salinization,etc.It is indispensable to conduct landscape ecological construction to resolve these problems.Supported by Geographic Information System (GIS),in this paper,67 landscape types were classified according to some principles and their stability was assessed according to three indexes:ecological relief,human utilization level,and degree of desertification or salinization.Then,combining the about theories of landscape ecology and taking the three indexes of significant value of types,density of patches and average interior to edge ratio,the authors analyzed the landscape spatial structure of these types in the three regions (West Region,Middle Region,and East Region) in West Jilin.It can provide a scientific basis for local landscape ecological construction.

Knowledge economy is a new geographical phenomenon.It will change traditional geographical spatial conception.Knowledge economy has some location tendency and shows some clear areal differential characteristics at both macro to micro areal levels.Aslo,it is different to agriculture economy and industry economy,and has new characteristics in spatial organization.

Yellow River is a river with a large amount of sands in water.The water divevced from it has a great deal of sands and muds.The sand sinking pool can effectively treat muds and sands in water due to its function of sinking coarse sands and draining silt.When sand sinking pools are full and lose efficacy,the method of "digging out sands to wait for deposition" can increase the life of irrigation region.But this method is not as good as that of "pumping up water to sink sands".Considering that the lower reach of Yellow River is an aboveground river,the problem of cultivated land occupation by deposited sands may probably be solved by the foundation of sand sinking pools on the high flood land of Yellow River channel.

The regional development research and decision making are the metasynthetic engineering.According to the idea of Hall for Workshop of Metasynthetic Engineering (HWME) advanced by Qian Xuesen,this article puts forward a framework of HWME for regional sustainable development (HWME RSD).The HWME RSD combines the modern computer technology,decision making technology and traditional system engineering technology.The HWME RSD may be considered from two aspects:(1) As a huge intelligent system,the HWME RSD can be built as a physical system partly or entirely;(2) As a methodology,the HWME RSD is a series of logical processes that organize the researchers and available tools together to solve problems more effectively.The word "HALL" of HWME RSD stands for a computer network supporting environment that can be regarded as a "virtual hall" or a "logical hall".

With a technique of GIS and a method of regression analysis,the spatial patterns of crimes and their correlation with population density in Edmonton,Canada,are analyzed in this paper.The crime statistics for each neighborhood in 1991 is obtained from the Edmonton Journal released by the city police.The crime types selected include thefts,motor vehicle thefts,break and enters,robbery,homicides,sexual assaults,assaults,and abductions.Variables used in the paper include crime density,crime occurrence and crime rate.The results obtained from a map analysis on crime density show that spatial differentiation of crimes occurred in the city is obvious.The general patterns of the distribution for all types of crime accord with the law of distance decay,the nearer to the city center a neighborhood,the higher its crime density.The results of regression analysis indicate that there is a positive relationship between the crime density and population density,which means that the neighborhoods with higher population density bear higher crime density.Analysis of the relationship between land use and crime density shows that commercial districts bear highest crime density among all types of land uses.

This paper researches changes of the lakes on the coastal plain north of the Shandong Peninsular along the Laizhou Bay or the southern rim of the Bohai Sea in North China.According to field investigations,results of archaeo-logical researches and historical records in ancient writings,there were many lakes and marshes on this plain,some lakes were 40 km in length and 20 km in width.They experienced great changes in historical times,some even had their courses migrated,and a number of new lakes appeared in later on.But today almost all of them disa ppeared.The following factors are accountable for the changes of these lakes:changes of coastlines,river course migration and deposition,geo tectonic movements of faults zone,and human activities.The disappearance of these lakes resulted in certain serious environmental problems.And the author put forward suggestions on the construction of some water reservoirs on the positions of the ancient lakes to retain water and to improve the environment.

It is the most important in Floristic Geography to determine floristic region,geographical features of transitional floristic region and evolution of flora by correcting and using the coefficient of similarity.The author has commented the formulas and definitions of different coefficient in floristic research,gives the definition of the coefficient of similarity of Flora,introduces exit problems and solved the way in application of coefficient of similarity to floristic geography in the Paper.It is suggested that adopting a same and scientific mathematical formula S C=2c/(A+B)×100% in the comparison study of floristic Geography in the future.

The paper reviewed the climatic change effects on regional hydrological systems and water resources systems,and forwarded the comments on these researches.Researches on hydrological system response to climatic change focused on four fields:precipitation,evaportranspiration,soil moisture and runoff.Under climatic change,precipitation would be redistributed,with increase in some regions and decrease in others,as well as soil moisture.The potential evaporation would increase due to temperature rising,but the actual evaporation would vary with the different climatic change scenarios.Runoff response to climatic change is the most interested to the researchers.Affected by temperature and precipitation change,runoffs from research results differed greatly from various research methods and regions.But runoff in high latitude zones or ice-cover riverbasins would mostly increase,particularly in the Spring.Research on water resources management under climatic change attracted researchers' much attention in the fields of water supply,water demand and water resources management.But thanks to larger uncertainties in hydrological responses to climatic change research,it is far away to practice positive countermeasures to climatic change.On the other hand,some traditional hydrological analysis methods would hinder smooth adjustment to climatic change.But these researches on climatic change and water resources and hydrology still formulated a research framework and we could get some uncertainties from them.

The integration of worldwide and nationwide economic regions requires sophisticated and integrated methods in Regional Economic Geography (REG) study. The progress of scientific thinking, especially the modern mathematical and systematical thinking, the technical advancement of information collection, transmission, processing and application, make the possibility of methodology construction of REG into reality. Several principles are required to maintain the harmonization among methodology construction, theory development and practice progress. The scientific thinking methods and the technical methods should be connected closely with each other, and both of them should be applied into the concrete aspects of the subject. The detailed methods should be selected, arranged and organized rationally into the flexible system to tackle different problems encountered during REG study. As a result, the subject study method system and the factors involved are outlined to illustrate the mechanism of methodology construction in REG.

After surveying the overall 100 years' evolving course of the overseas regional development planning, this paper puts forward three creating modes (under the system of the nation's "high instruction+constraint intervention", "unitive leading + collectively correspondance" and "no control+policy priority") of it, and considers the localization of the planning, which is an important function of the government in special times and whose destiny is dominated by the transformation of the national political-economical system, is unavoidable. When China is carrying out its regional development planning, it should emphasize the moderate combination of the plan and market, the organic coordination of the public and political participation, constitute wholesome legislation and management system of the planning and pay great attention to the research of social eco-environment and strategic problem of sustainable development.

Prof. HUANG Bing-wei is one of the founders of modern physical geography in China. The paper summarizes his academic achievements and thoughts in the fields of soil environmental protection, soil erosion, land degradation and land use. Under his guidance and instructions, Chinese geographers contribute a great deal to soil environmental protection and agricultural development.

Soil-wheat-atmosphere continuum is conceptualized as the interface between soil and atmosphere in winter wheat field, with canopy and soil surface being top and bottom boundary respectively. The depth of the interface is defined as the function proportional to (green) leaf area index. Based on the experiments conducting at Luancheng Agro-ecologic Experimental Station, Chinese Academy of Sciences, from April to June, 1996, the effects of soil moisture and soil-atmosphere interface on water-heat transfer in winter wheat field are analyzed. Soil moisture plays an important role in latent and sensible heat transfer. The drier the soil, the higher the sensible heat flux and the smaller the latent heat flux, and vice versa. This feature is especially remarkable when soil is wet. When soil is very dry, the depth of the interface dominates the two ransfers. For soil heat transfer at land surface, the depth of the interface is a more prominent influential factor than soil moisture. The analysis shows that the relationship between leaf water potential and atmosphere potential with the soil moisture matric potential at 60 cm depth is closer than the relationship between the two potentials with the soil moisture matric potentials at the other depths of soil. The soil layer of top 60 cm is a good index to study the effects of soil moisture and soil-atmosphere interface on water-heat transfer. It is also shown that the change of soil moisture potential acts as a macroscope of the variation of the water movement within the interface and above the interface.