The first part of article has reviewed the history of economic geographical stud-ing carried on in the Institute of geography, Academia Sinica, During last three decades, summaried successful experiences and existing problems during the tortuous developmental processes, as well showed clearly that the development of econmic geogeraphy in China are in golden age with the view of scientific assignments, social effects, growth of talented persons and international scientific exchanges.The second part of article has put foword programmatic views on future development of economic geography.(1) Adhere to the policies serving for socialist construction.(2) Take integrative studies of regional development as a main researcharea.(3) Strengthen studies on theories and methodologies,(4) Develop a team of researchers with higher scietific levels and rational structure.

Significant advances have been made in adopting the linear systems theory in modeling the rainfall-runoff process since Nash proposed the model with equal reservoirs in series in 1957. Such hydrologic models, known as input-output models, are attempted to establish a causal linkage between two or more observed phenomena without detailed description of the physical process under investigation.Continuous models mayebe handled elegantly with operational mathematics. However,hydrologic data are almost always discrete.Therefore, discrete models are of general interest in practice.The purpose of this paper is to present a discretely coincident form of general linear hybrologic system models, to describe some important properties of discrete, linear, hydrologic system model and to suggest different methods for estimating paramters with numerical examples.

Through analysis of strata structure, lithological chracteristics, ¹⁴C dates and depositing environments, stratigraphical subdivision and comparison of Holocene loess are made in the Weihe River Basin within the Loess Plateau. According to the physico-chemical characteristics and weathering-soilization of the loess, sporo-pollen and vegetation, as well as river-water-level changes and the arid-humid changes of climate reflected hy the location migration of ancient cultural sites, the environmental changes of Holocene is exposed in the Weihe River Basin.That is.Q₄¹:10,500-8500 year B.P., the Northwest Monsoon was prevailing, dust-storm and dustrain occurred often, eolian loess deposi ted(L₁).Mean temperature was 6-10℃, rainfall 300-500 mm, semi-arid chimate of the Temperate zone, drygrassland vegetation.Q₄²:8500-6800 year B.P. the southeast Monscon was prevailing, Burozem formed in valley and Black Loesslike Soil in high plain (So-Lower).Mean temperature was 14-16℃, rainfall 700-900mm, semi-humid climate of the Subtro-pic zone, deciduous broad-leaf forest vegetation.The Cishan-Peiligang Culture arose, people lived in high land because of the threat of flood.Q₄³:6800-3000 year B.P., the Northwest Monsoon was prevailing, dust-storm and dust-rain occurred often, Icess deposited(L_v).Mean temperature was 8-12℃, rainfall 400-600mm, semi-arid climate cf the Temperate Zone, forest-grassland vegetation. The famous Yangshao Culture becmed pecole lived in low land near river Since drought and water shertage.Q₄⁴:5000-3120 year B.P., the Southeast Monsoon was prevailing, Burozem and Black Loesslik Soil fermed (So-upper).Mean temperature was 13-15℃, rainfall 700-800mm, semi-humid climate cf warm Temperate Zone, deciduous broad-leaf forest vegetation. Entering the Luongshan Culture and the early Zhou dynasty, people moved to high land because of the threat of flood.Q₄⁵:3120-1400 year B.P., the Norrhwest Monsoon was prevailing, dust-storm and dust-rain occurred, loess deposited (L₀).Mean temperature was 8-12℃, rainfall 300-500mm, semiarid climate of th Temperate Zone, forest-grassland vegetation.The capital cities of the west Zhou, Qing and west Han dynasties in the area were all established in the low land near river because of water shortage.Q₄⁶:last 1400 years, climate has become warm and humid, modern soil is Brown Soil and Black Loess-ilke Soil (MS).Mean temperature is 10-14℃, ra-infall 600-700mm, deciduous broadleaf forest vegetation. The capital cities of the Suei and Tang dynastest were moved to high terrace because of the threat of flood and the rising of underground water-level in low land.According to this regularity of environmental changes, we can find out that there are three climatic cycles whose periodity is about 3700 years in a changing process of coldarid to warm-humid. Now we are living in the warm-humid stage of the third climatic cycle, the modern climate situation since 580 A.D. will continue for about 500 years.

In the paper precipitation normal data from 1951 to 1980 in the Unitec States are used to make research on mountain precipitation distribution.According to geographical positicn and climatic situation, we selected eleven slopes.The western slope of the Cascades Mts., the western slopes (37N and 39N) of the Sierra Nevada Mts., the southwestern and eastern slopes of the Rocky Mts., thh southern, southwestern and eastern slopes of the Colorado Plateau as well as the western and southeastern slopes of the Appalaching Mts. The conclusions can he drawn as follows.1.The mountain precipitation in the United States does not always Increase with height simply.Their distribution have four patterns. (1) Precipitation increases with height without or with the maximum precipitation height or with the second maximum precipitation height probably. (2) precipitation decreases with height at first, then it increases with height.2.The first maximum precipitation height exists mainly on the windward slopes where elevation above see level is height of more than 1500 meter and its height increases with aridity of climate.3.On the slope higher than 2500m A.S.L. of the western slope (37N)in the Sierra Nevada Mts. the increase of precipitation with height again is observed. It is a result that airflow climbs up the slope twice experiencing ascending-descending-ascending process.4.The increasing (lapse) rates of precipitation with height are not uniform and related to geographical position, exposure of the slope and season. Generally the increase of precipitation with height is the fastest at the lower slope on the windward slopes of westerly airflow, and increments or decrements are much larger in rainy season than in dry season, and seasonal differences of the rate values at each height are larger. On the leeward of the westerly airflow the precipitation almost does not change and even decreases with height at the lower slope and the largest increment of precipitation with height often appears at the upper slope or nearby peak and seasonal differences of the rate values at each height are smaller.5.There are experiment relation between annual precipitation (P_z) and elevation above sea level(Z)on all the selected slopes of the mountains in the United States as follows:P_z=a(b-z)z+c, where a, b and c are determinant cofficients and they change with region.6.Annual maximum precipitation height on the windwaid slopes almost dose not change from year to year, but its annual precipitation has large interannual variation.However, there is a good linear regression correlation between annual precipitation of footfill and maximum precipitation height. The correlation coefficient is very high and regression effect is quite remarkable.

The present paper approaches from the slant of ethnogeography,to yunnan's ethnic groups in their origin and development, their distribution, cultural areas as well as the relationship between the diversity in their sociai development and their geographical settings in Yunnan.Located at the key jnnction of south and East Asia; Yunnan lies on the geographical step of rising and falling greatly between two others of Qinghai-Ti-betan plateau and the pacific littoral belt of Southeast Asia.Such a geographic position and physical conditions have made Yunnan since lemote antiquity an area in which primitive hordes of people converged. During the Neolithic Age, the northern nomadic peoples of Di-Qiang distributed in Northwest Yunnan, a part of southern frigne of Qinghai-Tibetan Plateau while the southern agricultural peoples of Baiyue and Baipu shared central and southern parts of Yunnan which are the bases of southeast Asian highlands. A unit of physical geography plays an evidently significant role in the definition of that of human geography.The distribution of northern and southern peoples that inhabited in different surroundings during the neolithic Age contributes the basic patterns of their later distribution in Yunnan. The plane figure of modern distribution of peoples who share their abodes in terms of larger areas and live in a compact community as an ethnic gtoup in terms of smaller areas is the result of their time-honoured migrations and movements on that basis and because of variows factors.The objective existenie of three steps in Yunnan's topography makes inevitable the macroscopically vertical disribution of Yunnan's ethnic groups, where as the ups and downs of the topomaphy in small areas is the major contributing factor of various types of their microscopically vertical disrribution.Yunnan's complicated natural conditions have not only shaped the special disribution of its ethnic groups, but also governed to a great extent their economies and cultures.This paper divides Yunnan Province into four cultural areas and eight cultural types according to diffterent economic and cultural situations urder different physical conditions.These exists a very sharp difference in the social, economic and cultural development among Yunnan's twenty-six ethnic groups. Generally specking, the farther an ethnic group is away from central Yunnan and the higher it distributes, the less developed it is.There is no doubt that the closedness of grographical enviorment has been the major factor that restrists the development of less developed peoples. The understanding of that is very significant in striving for their development.Yunnan's ethnic geography is far beyong what have been outlined above, but rather includes more fields and richerimplica tions,so it is very necessary to make, more efforts in the study of this discipline.

A review of the geomorphoiogical thoughts in the last one hundred years indicates that modern geomorphology has inherited the rational parts of W.M. Davis'theories and, on the other hand, has experienced a revolution in theory framework. Davis proposed his theory framework of Geomorp-hology, i. e., the interpretative description of landforms by structure, process and time, and developed and perfected his theory of erosion cycles in the viewpoint of geomorphic evolution.His evolution viewpoint and his research method of comining deduction with observation hitherto have their realistic significance, Thanks to the impetus by systems theory and oceanic research, a scientific revolution in Geomorphology took place after Davis during late 1940s to early 1960s.Its hallmarks are,(a)the theoretical core of geomorphology has been transferred as a whole from the trinity of structure-process-time to that of morphology-process-timespace;and (b)the old concepta in Davis have been engiven new meaningss, and the study area of geomorphology has been greatly larged.

The region "Great Bohai Sea"includudes Laoning, Hebei and Shandong Three provinces, Beijing and Tianjin two municipalities.This region is rich with natural resources and has very solid economic strength, However, there exists a series of serious problems concerning the distribution of productive fo rces, the usage of resources and the protection of envirment at the same time. The significance and chiefe schemes about carrying out a study of the integrated exploitation and administration of this region are discussed in this article.

The Wuliang River, located in the northern part of the Hengduan Mountains of Southwestern China, is indicated in different positions on different maps published in china.It is indicated on Some maps as the Wuliang River or the Shuiluo River, and on other maps it is indicated as the Wuliang River or the Litang River.After a lot of textual researches, the writer holds that the Wuliang River is not the Litang River. It is the Shuiluo River and also by the name of the Chongtian River.

A measuring method was proposed to calculate the sequences of shielding angle and azimuth of any point in the shading region, and to eliminate the measuring error of shielding angle caused by the theodolite height, by using the synchronous data of shielding angle and azimuth of two points in the area. Therefore,it is possible to obtain the sunrise time and the day length of any point in the shading region graphically or numerically, with the apparent motion locus of the sun and the above calculation of the corresponding point.

The system of theoretical Geography is divided into 3 series in this paper. The first series is Theoretical Geography in its strict meaning, which indicates general geographical laws; the second series is Werder-meaning Theoretical Geography, which contains strict-meaning Theoretical geography and the theories of physical geography and Human geography; and the third series is Generad Theoretical Geography, which ihvolves applied theories of various, geographic things, besides theoretical geography in wider semse.The theoretical geography contains 3 branches. Regoinal Science, Geographical Environment Science and Geo-system Science. some basic concepts of these branches have been discussed in this paper.

This article introduces and summarizes the research on tourism gravity models done by foreign scholars as well as the research work in recent years pursued by the author on this subject.Former tourism models made by western tourism geographers are drawn from experiences in the region and have poor theorefical basis, so that the model applied in a specific region,whatever formula or methord used, is not available for other regions.In 1986, I wrote a thesis about tourism macroscopic layout in Japan.In that thesis, by considering a tourism attraction mechanism, a more gerneral gravity model was made.Thus, it provide a new way which helps analyze and study tourism layouts and locations. Further, I advances a new concept, Attraction Field of Tourism Layout.It describs and analysises tne distribution and structure of Attraction Field as well as the reciprocal behavior between the each centre source.The tourism attraction is quite complex, which includes multi——factors ofnature, economy and society.It is too difficult to use a simple factor to explain exactly the reason for tourism attraction.In the part of this article, the writer also makes a tentative analysis on the tendency of the development of the gravity models theory, citing some examples such as.1) The overall study on multi-branches of learning. The tourism gravity models may involve economics (tourism competitive models, threshold models and so on.)2) The randomness and f uzziness of tourism gravity models (applied statistics models, Markov chain models and fuzzy models.)3) Study of systematology (the growth and distribution models of dynamics system, etc.)

It has given rize to much controversy about the effects of forest on hydro logy The main issue is the effects of forest on rainfall, annual runoff and evapotranspiration. In order to know the reason causing the controversy, in this paper,a careful review on present research situation of forest hydrology is made according to analyzing a lot of research results in China and other countries. And then the effects of forest on hydrological factors (rainfall, streamflow, evapotranspiration, water aulity and groundwater level) in a watershed are mainly discussed, Besides, the effect of forested and watershed areas on forest hydrological elements including the research method is considered too.The effects of forest on hydrological factors in a watershed can be usually divided into three conditions which are positive, negative and zero effects The concrete result varies with specific conditions, so the effects of forest on hydrology can not be lumped together.The problems lie in the research on forest hydrology are as fallows. 1) to put undue emphasis on the effects of forest hydrology. and to isolatedly analyze each factors influencing forest hydrological process. 2) to study insufficently regulated water function owing to using comparable analysis method.These problems are also the reason for controversy because that the above mentioned issues can make researcher judge only according to the superfical phenomenon.

This paper describes the distribution of the suspended sediment concentration (SSC) in coastal regions of China based on a great number of field observation data on suspended sediments.The SSC decreases gradually southward and northward, respectively, from the Huanghe River mouth and the Changjiang Estuary-Hangzhou Bay, and alternates higher concentration with the lower.This paper also analyzes various factors, such as sediment discharges by runoff and from the sea, tidal currents, waves, coastal types, etc., affecting the SSC in time and space.From the analysis, it is found that sediment discharges by runoff and from the sea are the main factor for the characteristics of the distribution of the suspended sediments in the coastal regions of China, tidal current is the important factor for the daily variation and the monthly variation of the SSC, and the wave is the controlling factor for the seasonal variation of the SSC in the coastal regions, and the seasonal variation of the SSC in the coastal regions, and the seasonal variation of the SSC in the estuarine regions depends on the sediment discharges which are larger during the flood seasons and smaller during the dry seasons.Coastal types also affect the SSC in the local coastal regions.The regions with the higher SSC are mainly situated in the estuarine deltaic areas and the regions with lower SSC are basically located in the rocky and gravel coasts.

Both the W8 and W7 drilling cores in the Weinan area, with 52 to 92 layers in all can be divided into two parts.the upper one is stratum alternating several fossil soil layers; the lower stratum is a set of layers consisting alternately of sand, gravel, clay and silty clay of the river or lake facies.With stratigraphic correlation and comprehensive comparison between the W8 and W7 drilling cores, they have quite similar characters in the stratigraphy and paleontology, such as the features of strata, sporo-pollen and microfossils.But the difference between the altitudes above sea of the well-matched layers in both the W8 and W7 holes can be well over 100m.Consequently, the layers of different ages have been contacted at the same altitude in the holes while the same layers have been fractured.The fracture extends from the stratum of the later age of the Middle Pleistocene down through the stratum of the Neogene system at the bottoms of the holes perhaps into the bedrock.According to those mentioned above,the authors identify that the characteristics of the fracture belong to tensile normal fault, rataer then the result of exogenic force.The underground water-bearing beds in the loess-plateau area and its surrounding areas have been cut off from each other by the structural fault.Therefore, with the decreasing of the rainfall and the rapid increasing of the extraction of the groundwater, the problems of the environmental geology.including the widespread and big descending of the groundwater level, the worsening of the water quality and the occurring of the man-made funnels of the groundwater, have been presented in the loess-plateau area.If the groundwater is extracted continuously and indiscriminately, ground sinking may occur in a large number in the loess-plateau area.The tremendous losses caused by the sinking will be difficult to estimate.For this reason, the authors suggest that the effective measures to exploit and to rationally use new sources of water and to stop extracting the groundwater at the loess-plateau should be taken immediately in order to protect the groundwater resource in this area.

This article approaches to the origin of the silkworm and silk-knit industry in China.From some traditions on historical records, and some archaeological finds, it is proved that the original place of the silkworm and silk-knit in dustry was not only one, but multicentres and multiorigins.Original places were mainly distributed in the regions along the lower reaches of the Changjiang River and the middle and lowerr eaches of the Huanghe Rive.They originated from the Huangdi age in the Neolithic age about 5000 years B.P..By analysing the geographical conditions in the lower reaches of the Changjiang River and the middle and lower reaches of the Huanghe River, it is not accidental that the silkworm and silk-knit industry originated there.

There are varied kinds of the active tectonic landforms in the Changma Fault Zone,including tension fault scarp,pressure fault scarp,landslid, drumlin, earthquake fissure, disintegration deformation of terrace and left slip displacement deformation of mountain ridge and water system and so on.Through analyzing the features of these landforms and comparing with each other, the active kind of Changma Fault Zone can be determined to be left strike slip accompanying with dip slip movement and there have been at least three times of sudden faulting or earthquake events since the later period of the late pleistocene.Those 3 earthquakes resulted in the formation of 3 stages of active tectonic landforms in Changma Fanlt Zone.According to the trench material and the ¹⁴C data, the geolgical dates for the 3 stages of active tectonic land forms are follows.Ⅰ<24450±310yr, 5095±85yr<Ⅱ<Ⅰ, and Ⅲ was produced by the earthquake of 1932.

In this paper, the rainfall data in the late 30 years in East China is analysed.It is found that the variation trend of precipitation between North and South China is marked contrary in the early summer.The trend of North China is above normal in 50's, below normal from 60's to 70's, and with an opposite tendency in the South of Changjiang Valley.By analysing the variation of the sunner monsoon systems in East Asia, a long period of oscillation about 3 to 4 years is also obtained.The interaction between the monsoon oscillation and the variation of sea surfare temperature in east equatorial pacific produce a.feedback couple oscillation.According to the above results, a possible long range weather process model of the sea surface temperature effect on the rainfall distribution in East China through the variation of the summer monsoon systems has been proposed as follows.When the sea surface temperature in East equatorial pacific is higher that normal, the sea surface pressure in the easi equatorial Pacific is lower and the Australian anticycle is stronger, while the walker cell is weakened, the cross equatorial air currents and subtropical anticylones are also strengthened.So the summer monsoon circulation and the middle latitude westerlies in the East Asia are intensified.The precipitation is above normal in North China and below in South China.On the contrary, when the sea surface temperature in east equatorial pacific is cold, the walker cell is intensified and other monsoon systems are all weakened.Then the rainfall is below normal in North China and above normal in South China.

From mathematical model, this paper deals with the characters of sediments transport and deposits of the Lower Yellow River on the average of water and sediments of multiple years and obtains the quantities of sediments reduced when the equilibrium of scour and deposit of sediments is reached in the Lower Yellow River.The results are got as follows.1.It is Possible to use the movable-bed mathematical model of nonequilibrium transport of nonuniform sediment in order to inquire into the characters of sediments transport in the Lower Yellow River.The numerical results conform with the field investigations fundamentally.2.The nonuniformity of longitudinal deposits of sediment in the Lower Yellow River is caused by the nonuniformity of longitudinal deposits of coarse and middle sediments.This conclusion shows that the relationship of contrast of sediments and capacity of sediments transport is different in the sections of river.Generally, sediments conform with the capacity of sediments transport better nearer to the mouth of river.3.The policy of primary and secondary may be taken to bring the Lower Yellow River under control according to the character of sediments deposit.The Coarse and middle sediments are 79.5% in all the sediment deposits, but only 43.3% in the sediments.The river channel has lower ability to transport the coarse and middle sediments.So the coarse and middle sediment must be reduced in the sediments.4.The numerical results show that if the quantities of sediments can be reduced to 42.6%, the equilibrium of scour and deposit of sediments will be readied in the Lower Yellow River.

According to the analyses and studies of the grain-size, sporopollen, vertebrate fossils and stratum sedimentary facies in the upper pleistocene strata of the Salawusu River area, this paper discusses the palaeogeographic environment and its evolution during the late pleistocene.1.The palaeogeographic environment of the fluviolacustrine facies strata of the Salawusu Formation formed in the early stage of the upper pleistocene is warm-hummid forest steppe.2.In the late stage of the late pleistocene, the Chengchuan Formation which mainly consists of aeolian sandy deposits chiefly forms under dry-cold desert, desert steppe and in the meantime, it underwent a series of alternating evolution processes of temperate-cool's shrub steppe,sparse woods steppe and forest steppe with this environment.3.The Malan loess in the area has the same geological age as that of dry cold desert steppe.4.The Salawusu Formation is assigned to the Riss/Wurm intcrglacial age, dating back to 1.1×10⁵-7×10⁴ yrs B.P.,thereas the Chengchuan Formation andthe Malan loess are in the Wurm glacial age with an assumed date of 7×10⁴-1×10⁴ yrs B.P..