1995 Vol. 5, No. 4

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Articles
RELATION BETWEEN δ18O IN ATMOSPHERIC PRECIPITATION AND TEMPERATURE AND PRECIPITATION
Zhang Xinping, Shi Yafeng, Yao Tandong
1995, 5(4): 289-299.
Abstract:
The paper analyzes the relation between δ18O and temperature and precipitation in different regions of the world on the basis of the data from the global observational network set by the International Atomic Energy Agency (I-AEA) and the World Meteorological Organization (WMO). The results show that there is the marked positive correlation between δ18O and temperature in the mid-high latitude continent regions, and the marked negative correlation between δ18O and precipitation in the mid-low-latitude ocean and coast stations.
STATISTICAL ANALYSIS OF TEMPERATURES ON BOTH THE UPPER AND LOWER BOUNDARIES OF SUB-ALPINE DARK CONIFER FORESTS IN CHINA
Wang Jian, Xu Xiaobin
1995, 5(4): 300-315.
Abstract:
Temperature of every month on both the upper and lower boundaries of sub-alpine dark conifer forests at various sites in China are estimated in terms of their distributions and temperature records. Based on these estimated data, the heat factors to influence and control the distribution and growth of subalpine dark conifer forests in China are discussed. It is found that the most important heat index to influence and control the distribution and growth of subalpine dark conifer forests is neither the mean temperature in the warmest month, nor the maximum or minimum temperatures, but monthly accumulated temperature of>0℃ or monthly effective accumulated temperature of>5℃.When monthly accumulated temperature of>0℃ is more than 40℃, or monthly effective accumulated temperature of>5℃ is over 50℃, sub-alpine dark conifer forests cannot grow well. When monthly accumulated temperature of>5℃ is less than 60℃, sub-alpine dark conifer forests can not grow at all. When monthly effective accumulated temperature of>5℃ is in the range 15℃-45℃, subalpine dark conifer forests in China can grow well. The ecological significance of temperature in May and September, and in summer half year are discussed.
DISTRIBUTIVE TENDENCY OF ELEMENT CONCENTRATIONS IN LIMESTONE SOILS IN EASTERN CHINA
Wen Yanmao, Zeng Shuiquan, Pan Shurong, Luo Yuzhen
1995, 5(4): 316-324.
Abstract:
Twenty-eight soil profiles studied were collected from the eastern China. They belong to brown soil, drab soil, yellow brown soil, brown limestone soil and red limestone soil. The concentrations of Ca and Mg in soils decrease and the concentrations of Fe, Al,Zn,Pb,Cd,and Hg increase from north to south. There is no significant correlation between the element concentrations and soil organic matter contents. Statistically there is a most significant positive correlation between the concentrations of Ca and Mg, and pH, while there is a most significant negative correlation between the concentrations of Fe, Zn and Cd, and pH, and a significant negative correlation between Al concentration and pH.There is a most significant negative correlation between concentrations of Ca and Mg, and clay content, and a most significant positive correlation between Fe,Al,pb, Cd, Hg and clay content. The concentrations of Ca and Mg decrease, and those of Fe, Al,Zn,Pb,Cd and Hg increase in the processes of acidification and clayization with the increase in temperature and rainfall.
WATER RESOURCES TRANSFORMATION AND WATER QUALITY VARIATION IN THE URUMQI RIVER BASIN
Qu Yaoguang, Luo Hongzhen
1995, 5(4): 325-335.
Abstract:
Like other inland basins in arid regions, the natural vertical zones create special conditions for water resources transformation in the Urumqi River Basin. In the course of water resources transformation and utilization, the chemical composition and degree of mineralization are influenced by both geographic conditions and human activities. Although the Urumqi River is rather small in runoff and rather short in flow distance, the water quality changes substantially along the river. However, ion concentrations of surface and ground water in the whole basin are relatively low, generally less than 1 g/L. Therefore, the basin is good at providing low-mineralized water. The pollution is not so serious and the water impurity does not surpass the national standard for drinking. As long as people are conscious with protecting water quality and reducing the further water pollution, it is possible for harm of the slight pollution to be eliminated.
THE CHARACTER AND CHANGE TENDENCY OF AGRICULTURAL LAND USE IN THE ZHUJIANG DELTA-A CASE STUDY OF SHUNDE CITY
Zhang Luocheng
1995, 5(4): 336-343.
Abstract:
In this paper, Shunde City is selected as a typical region standing for the Zhujiang Delta because of its excellent location and dike-pond system.There are three main characters of agricultural land use in this region. First, the most typical land use form is dike-pond system. It is a special form of artificial ecosystem of land-water interaction. Second, sandy field is also an important land type in this region. Third, land use is greatly influenced by export-oriented economy. Recently, with economic reforming and the opening up of the Zhujiang Delta, the structure of agricultural land use has been changed greatly. The area of mulberry dike has decreased and a variety of planting crops has increased.Various structure of dike-pond farming has emerged in the Zhujiang Delta such as "fruit dike-fish pond", "flower dike-fish pond", "grass dike-fish pond", "vegetable dike-fish pond". The area of water has slightly increased and its development tends to modernization due to the use of modern equipment and advanced breeding ways. The area for "three high"(high yield, high quality and high efficiency) agriculture has increased greatly.
STUDIES ON WATER STAGE FLUCTUATION OF YAMZHO LAKE IN XIZANG
Liu Tianchou
1995, 5(4): 344-354.
Abstract:
Yamzho Lake, with a drainage area of 6, 100km2, is the largest closed interior lake in the southern part of the Qinghai-Xizang Plateau. The elevation of the lake stage is 4440m, lake storage is about 16 billion m3. Water recharge mainly depends on rainfall, melting water from glacier area, taking up 16%. In the drainage basin about 2% of the area is covered with glacier. Seasonal range of variation in the lake stage is small, usually less than 0.6m. The biggest water level in a year appears in September or October, not in July or August of the rainfall concentrated period, because of the lake's self-adjustment.The lowest lake level occurs in May, June or July. In wet years the stage fluctuation has clear periodicity, in dry years the lake level tends to fall down around the year. There is a close correlation between rainfall and water level variation.Based on the analysis of the patterns of the lake level fluctuation during the recent 100 years, according to the measuring and investigation data, the fluctuation range of the lake level varied at 4 to 5 meters, and the water level has been gently descending at the rate of 0.6m/100 years.
THE CAUSES AND DEVELOPMENTAL TREND OF DESERTIFICATION IN THE MIDDLE REACHES OF THE YARLUNG ZANGBO RIVER AND ITS TWO TRIBUTARIES IN XIZANG
Dong Guangrong, Dong Yuxiang, Li Sen, Jin Jiong, Jin Heling, Liu Yuzhang
1995, 5(4): 355-364.
Abstract:
The middle reaches of the Yarlung Zangbo River and its two tributaries are an important development and construction region in Xizang(Tibet) in recent years, but the fast development of desertification has caused immense damages to its social and economic development, so the study on desertification in this region is significant. The paper studies the causes and development trend of desertification in this region through analysis of natural and human factors as well as their relationship. It can be concluded that desertification in the study area is one process which is accelerated and intensified by human activities on the basis of the slow natural desertification process. It is resulted from the dislocation of irrational and intensive human activities, fragile eec-environment and meagre natural resources, and tends to become more wide and severe.
AN ANALYSIS OF WATER RESOURCE CHARACTERISTICS OF THE RIVERS IN THE NORTHERN SLOPE OF THE KUNLUN MOUNTAINS
Xu Youpeng, Gao Yunjue
1995, 5(4): 365-373.
Abstract:
There are 43 rivers of varying sizes in the northern slope of the Kunlun Mountains, all of which originate from the Kunlun Mountains. Supplied by precipitation and melting water of glacier, the total runoff amounts to 87×108m3. The analysis shows that water quantity distribution of the rivers in the area is more in the west, and less in the east. While in the west, the water quantity of the Hotan River amounts to more than half of the total, in th eeast, most rivers are seasonal rivers except the Keriya River and the Qarqan River, which have relatively large amount of waters. From the analysis of inner structures of the runoff series of the major rivers, we can see that the annual runoff series of all rivers are mainly stable independent random series. Such characteristics of the time series are determined by the supply characteristics of the rivers. Some measures of rationally using water resources are proposed finally.
NATURAL RESOURCES AND ECO-ENVIRONMENT MAPPING IN HENAN,CHINA
Huang Wanhua, Guo Yuxiao, Li Hongwei
1995, 5(4): 374-382.
Abstract:
The history is briefly looked back of natural resources and eec-environmental mapping in Henan Province. The main achievements are alsosummed up in following aspects: geographical mapping, soil mapping, land resource mapping, hydrothermal resource mapping, biological resource mapping, ecological mapping, design and compilation of natural resource and environment atlas, and study on cartographic theory and method. The basic characterristics are discussed, they include 1) extensive cartographic field and varied-type map; 2) resource and environment mapping being closely connected with resource investigation and environment research; 3) traditional cartographic method being dominant; 4) cooperation of cartographic researchers. Finally, the future tasks are proposed as follows: compiling a series of large-scale maps and renewing obsolete maps; dynamically monitoring and mapping of natural resource and environment system; mapping of eec-environment; and establishing information system of resource and environment.