TEXTUAL RESEARCH ON THE MAIN SOURCE OF THE CHANGJIANG RIVER

The Chinese people began to research the main source of the Changjiang (Yangtze) River 2,400 years ago. Limited by the scientific level, they did not discover it.The Tuotuo River was determined as the main source of the Changjiang River in the 1970s. However, this was not correct, because when comparing the length of the Tuotuo River with the Dam River, the glacier length at the headwaters was added to the Tuotuo River, resulting in that the Tuotuo River is 1 km longer than the Dam River, keeping in mind that the glacier can not be regarded as part of the river.In the summer of 1986, we investigated the source of the Changjiang River, we accurately measured the length of both the Tuotuo and Dam rivers, we discovered that the Dam River was 353.1 km long, and the Tuotuo River was 346.3 km long, the Dam River thus being 6.8 km longer than the Tuotuo River. The discharge of the Dam River is 196.18 m3/ sec., 2.6 times as large as that of the Tuotuo River, that of the Tuotuo River is 75.10 m3/sec. The

A Review of Mineral Resources and GIS Applications in Mineral Resource Assessment in Northeast China

Northeast China is one of the regions in China that possesses a great abundance of mineral resources. Coal. petroleum, natural gas, gold, iron, magnesite, graphite, talc, molding sand, glass sand and some others account for large portion in reserves and yields of that in the whole country. The region faced also shortages of copper, molybdenum, oil shale, zirconium, tantalum, rare earth, and beryllium, although they have large reserves, but limited by economical and technical factors. Geological mapping and mineral exploration activities have been intensive. Only the north part of Daxinanling Mountains in the region leaves unexplored. GIS applications in mineral resource assessment in the region start not long. Databases for GIS applications are on the way of construction. Well - trained technical staff and expertise do not meet the demand. This article reviews the situation of mineral resources and GIS applications for mineral resource assessment in the region. Suggestions on multi - lateral cooperation and GIS training are also made.

THE APPLICATION OF REMOTE SENSING TECHNIQUE ON GEOLOGICAL INVESTIGATION OF PLACER DEPOSIT

The practice has proved that it is an economic and effective method to investigate placer gold deposit by using multi-level information sources of remote sensing and multi-variate analysis methods, especially for the area with a sparse population and difficult condition like the Da Hinggan Mountains, China.The information sources used in our work includes Landsat TM, aerial infrared photography and their mosaic image maps and enlarged photos with different scales. According to statistic data, in the study area the gold-bearing rocks are mainly granite, alaskite, granodiorite and some old metamorphic rocks. On gold-bearing geological structures, the fault zones in the four directions (NE, NNE, NW and EW) are obvious, in which NNE and EW are the most key fault zones. On fluvial geomorphology the flow courses stored placer are in the tributaries of the 4th and 5th levels, especially in straight or slight curve reaches. On the basis of analysis the interpretative signs were set up, and the interpretative

THE ECOLOGICAL FEATURES AND ECOLOGICAL CONSTRUCTIONS OF A MIRE IN CHINA

A mire as an ecosystem, usually is considered as an aquatic ecosystem,or a terrestrial ecosystem. The author thinks that mire is a special ecosystem between these two ecosystems, and proposes the new concept that a mire is a natural ecosystem with transitional nature of semi-water and semi-land formed by water and land interaction. The paper discusses the nature of the mire ecosystem, the exploitation and utilization and ecological construction of a mire.

CHANGING FEATURES AND TREND OF LIGHT INDUSTRY DISTRIBUTION IN NORTHEAST CHINA

Modern industry in northeast China started from light industry. From the end of 19th century to 1931 was the phase of initial development of light industry in northeast China. During this period, the development of light industry gave priority to grain processing industry. After occupying northeast China, Japanese vigorously developed heavy industry to meet the needs of munitions and paid more attention to raw materials and semi-finished articles industry for the purpose of the war. Light industry was impeded and developed slowly. After the founding of New China, large-scale economic construction took place in northeast and heavy industry received prior investment and equipment. Northeast region became the first heavy industry base through several five-year plans, the development of light industry made giant strides. The present features of light industry distribution are: difference of light industry distribution, similarity of light industry structure, and imbalance of light industry development.

ON THE INFORMATION OF MIRE DEPOSITIONAL ENVIRONMENT

Mire is the product of the Quaternary. It mostly formed, developed and declined after the postglacial age. Therefore the chemical element analysis, spore-pollen analysis, 14C dating, mire plant determination for mire sediment, and the study on hierarchy relation of mire sediment, can provide a lot of information for restoring paleogeography, paleoclimate and environmental change. So some people called mire sediment-peat as 'database of environment'.

FOR CONSERVATION-THE CONSERVATION ATLAS OF CHINA

I. THE IMPORTANCE AND URGENCY OF NATURAL CONSERVATION Mankind is seeking economic development and utilizing natural resources, which must agree, with limited resources and support of ecosystem while give full consideration for later generations. This is the meaning of conservation. With development of society and technology, the increasing ability of creation and construction of mankind directs the same force of destruction and ravage. In recent decades, as a result of the expanding scale

APPLICATION OF REMOTE SENSING TECHNIQUE TO THE INVESTIGATION ON REED RESOURCES OF BOSTEN LAKE

It is efficient and reliable to investigate the reed resources of Bosten Lake in Xinjiang, characterized by complicated types of reed land and very different reed growth using colour infrared aerial photos, Landsat images and multi band imagery. At first, on the basis of Landsat images and relevant data, we analyzed the ecological environment of the studied area, the characteristics of reed land types and imaging mechanism to determine the program for abstracting remote sensing information and aerial photographic conditions:On the processed Landsat images and aerial photos, we considered typically geographic features and reed land types, preselected ground sampling sections and sites, then determined indexes classifying reed land types according to sampling data and image characteristics, established various interpretation keys, drew distribution maps of reed land types and measured the area of various types of reed land following geometric correction. On the other hand, based on sampling values and

RADIATION BALANCE AND MICROCLIMATIC FEATURES OF MARSH IN THE SANJIANG PLAIN

Radiation balance, soil temperature and the temperature and humidity of air were measured in marshes and reclaimed farmlands of the Sanjing Plain. Soil-heat flux was calculated with two different methods. Through the analysis of a lot of data, the daily variations and the law of vertical distribution of microclimate factors on marsh surface was obtained. It is found that after marshes are reclaimed, radiation balance increases, both soil temperature at different depths and air temperature of various height near ground layer rise, and air humidity decreases obviously. Therefore, one should take the establishment of artificial ecosystem of growing paddy and reed and breeding fish as the main development direction of marshes, at the same time, protect some marshes in order to prevent the environment from getting dry, and maintain regional ecological balance.

WETLANDS IN CHINA: FEATURE, VALUE AND PROTECTION

The estimated total area of wetland in China is more than 25.9 million hectares including about 11.9 million hectares of marshes and bogs, 9.1 million hectares of lake and about 2.2 million hectares of coastal salt marshes and mudflats. The area of wetland is equivalent to 2.7％ of the land surface. China also has 2.7 million hectares of shallow sea water (less 5m in depth at low tide). Marshes and bogs are equivalent 1.3％ of the land surface. Only three provinces(regions)— Qinghai, Xizang (Tibet)and Heilongjiang— have a larger total area of marsh and bog. According to the structure, type and development of wetland in different river basins, wetland can be classified nine main regions. The experiments indicate that the coefficient of the marsh to regulate flood is similar to that of lakes. Wetlands occupy 17.8％ of the Sanjiang Plain area, the annual carbon contribution is 0.78× 104t. Carbon released from marsh soil return into atmosphere is 3.95× 106t/a. At present there is a sharp contradiction between population growth and natural resources shortage, causing wetland to be exerted with huge pressures and serious threats.

A PRIMARY STUDY ON THE HISTORICAL CHANGE OF SONGNEN SANDY LAND

Songnen Sandy Land is situated in the west of the Songnen Plain (Fig. 1 ) and its desertification is more and more serious. For the first time this note studied systematically the dates and the historical changes of Songnen Sandy Land in order to provide theoretic basis for the prediction of desertification development, environmental changes

Comparison Between the Formation of Peatlands and Paleosols of Sandy Land and the Changes of Ari4 Index During Holocene in Northeast China

In Northeast China, peatlands and paleosols have developed very well in the eastern swamps and western sandy lands, respectively. They become an important object of studying the paleoenvironment in this region. Since both of them were formed under humid climate conditions, it is significant to compare their formation and ages for the unification of climatic change divisions and the reconstruction of the

CLUSTER ANALYSIS OF SOME ELEMENTS IN SOILS OF THE MIDDLE PART OF N. E. CHINA PLAIN

Cluster analysis is to determine the similarities and the intimate or distant relations among samples and variations by using mathematical methods based on the multivariant sample data. The different clusters are then divided to reflect the internal relations of the samples of variations objectively.

THE HISTORICAL CHANGE OF STRANDLINE OF XINGKAI LAKE AND DISCOVERY OF ANCIENT RIVERHEAD OF SONG'ACHA RIVER

In the study of scientific and technical key problems of the Sangjiang Plain some new information on the historical chang eof the strandline of the Xingkai Lak(?) were obtained, and the location of three ancient riverheads of the Song’acba Rive was discovered.

A STUDY ON THE PLEISTOCENE STRATA AND THEIR DEPOSITIONAL ENVIRONMENT ON THE SONGLIAO PLAIN OF NORTHEAST CHINA

This paper deals with the Pleistocene strata and their depositional environment on theSongliao Plain of Northeast China by applying determinative and analytic techniques of spore-pollen, magnetic stratigraphy, clay minerals, isotopic dating, sedimentary facies, etc. Resultsshow that the underlying sand gravel layer below 75-80 m in depth in the central plain belongsto the alluvial-lacustrine deposits with a time range of 2.48-1.87 Ma, known as the lowerlimit of the Quaternary. As to the massive clay layer, its lower part, 40-30 m thick, belongsto the middle late period of the early Pleistocene, ranging from 2.01-0.73 Ma, while its upperpart, 25-21 m thick, belongs to the middle Pleistocene, ranging from 0.73-20 Ma, with amean sedimentation rate of 3-4 mm/1000a under the big lake, long-range gentle and steadydepositional environment.

PALAEOGEOGRAPHICAL STUDY ONTHE SONGLIAO PLAIN IN THE MIDDLE QUATERNARY

Songliao Plain is one of the three great plains of China and is considered to be a megalake basin covering an area of 50,000 km^2, formed in the Middle Pleistocene and deposited with a lacustrine clay layer of 30—70 m thick, and then became a clay pan of the regionally confined water.