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Relationship between erosion and sediment yield in drainage basins of loess gully-hilly areas

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Journal of geographical sciences 2001年第1期11卷 71-79页

作者： CHEN Hao (institute of geographic {2. and natural {4. research, cas, Beijing 100101, China) institute of geographic {2. and natural {4. research CAS Beijing China

From a long-term point of view, the balance between erosion and sediment yield in a drainage system can basically realize, i.e., the delivery ratio can be close to 1. However, substantial variations among individual rainfall events or between annual delivery ratio exist, causing frequent sediment retaining or re-erosion and re-delivery of the retained sediments in a short period of time. Thus the delivery ratio will be 1. The sediment delivery ratio is closely related to the spatial distribution of rainfall and magnitude of rise and fall of peak flood and that of runoff depth in the drainage system. Delivery ratio of single event in a drainage system and changes of delivery capacity of silt-laden runoff in various classes of gullies can be expressed by transformation mechanism of shear force of a single rainstorm event with flood resulting from increase and decrease of peak flood per unit area.

关键词： delivery ratio interaction flood and geomorphology dynamic mechanism rainstorm flood

Soil erosion and management on the Loess Plateau

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Journal of geographical sciences 2001年第1期11卷 53-70页

作者： CAI Qiang-guo (institute of geographic {2. and natural {4. research, cas, Beijing 100101, China) institute of geographic {2. and natural {4. research CAS Beijing China

The Loess Plateau is well known to the world for its intense soil erosion. The root cause for river sedimentation of Yellow River (Huanghe) and its resultant “hanging river” in certain section is soil and water loss on the Loess Plateau. The Loess Plateau has a long cultivation history, hence population growth, vegetation degeneration and plugging constitute the chief reason for serious soil and water loss on Loess Plateau. This paper analyses several successful cases and failures in soil conservation, presents practical soil conservation technique and related benefit analysis, and discusses some effective methods adopted in China in soil erosion control, research directions and future perspectives on Loess Plateau.

关键词： soil erosion control technique management Loess Plateau

Delineation of boundary between tropical/subtropical in the middle section for eco-geographic system of South China

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Journal of geographical sciences 2001年第1期11卷 80-86页

作者： WU Shao-hong, ZHENG Du (institute of geographic {2. and natural {4. research, cas, Beijing 100101, China) institute of geographic {2. and natural {4. research CAS Beijing China

This paper discusses division on tropical/subtropical boundary of middle section in South China. This discussion results in new understanding on eco-geographic regions and their boundaries, especially on gradual changes of natural conditions between eco-geographic regions. It analyzes results of the same area by other researchers, clarifies differences and causes of the differences for the results. Boundaries of eco-geographic regions cannot be drawn as a line as changes from tropical to subtropical are gradual. Therefore, for an eco-geographic region like tropical zone, definite boundaries must be mapped while gradual changes are considered. Temperature, vegetation and soil are the indexes to divide tropical and subtropical. After indexes of tropical zone are confirmed, data of annual average index reflect general state of the tropical zone. Line from such data is called “tropical boundary”. On the other hand, affected by the monsoon climate, some years are hotter and some are cooler. In hotter years, temperature of north area of tropical boundary reaches tropical state whereas in cooler years, such area moves southward. Boundary of the hottest year is called annual tropical line and that of the coolest year true tropical line. Temperatures in areas south to annual tropical line can probably reach tropical in some years. Temperatures in areas south to real tropical line reach tropical every year. The area from true tropical to annual tropical is called tropical fluctuating zone. Therefore, new concepts of tropical, annual tropical, true tropical and tropical fluctuating zone are formed to understand tropical area from a new point of view in the paper. Based on the indexes of climate, vegetation and soil, boundaries of tropical, annual tropical, true tropical and tropical fluctuating zone of the study area are established. The tropical fluctuating zone explains different locating of different researchers. The paper also puts forward a new method to display boundary

关键词： eco-geographic region tropical annual tropical true tropical tropical fluctuating zone

Structural patterns of land types and optimal allocation of land use in Qinling Mountains

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Journal of geographical sciences 2001年第1期11卷 99-109页

作者： LIU Yan-sui, DENG Xiang-zheng (institute of geographic {2. and natural {4. research, cas, Beijing 100101, China) institute of geographic {2. and natural {4. research CAS Beijing China

The case study based on Qinling Mountains in Shaanxi Province of China, in virtue of the information from TM image, classifies the land types and analyzes their spatial and temporal differential law, and puts forward three structural patterns of land types in mountainous areas, namely, spatial, quantitative and qualitative structures of mountainous land types. Furthermore, it has been noticed that the analysis of structural patterns can disclose the heterogeneity and orderliness of combination of land types, which can lay the theoretic foundation for comprehensively recognizing ecological characteristics and succession law of structure and function of land types. After the all-around comparative analysis, an optimal allocation of land use in Qinling Mountains has been put forward according to the principle of sustainable development and landscape ecology, which can lay the scientific foundation in practice for the structural adjustment and distribution optimization from the macro level to micro level.

关键词： land types succession of land types structural patterns optimal allocation Qinling Mountains

“Greatest lake period” and its palaeo-environment on the Tibetan Plateau

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Journal of geographical sciences 2001年第1期11卷 34-42页

作者： LI Bing-yuan, ZHU Li-ping (institute of geographic {2. and natural {4. research, cas, Beijing 100101, China) institute of geographic {2. and natural {4. research CAS Beijing China

The “greatest lake period” means that the lakes are in the stage of their maximum areas. As the paleo lake shorelines are widely distributed in the lake basins on the Tibetan Plateau, the lake areas during the “greatest lake period” may be inferred by the last highest lake shorelines. They are several, even tens times larger than that at present. According to the analyses of tens of lakes on the Plateau, most dating data fell into the range of 4.-2. ka BP, some lasted to 2. ka BP. It was corresponded to the stage 3 of marine isotope and interstitial of last glaciation. The occurrence of maximum areas of lakes marked the very humid period on the Plateau and was also related to the stronger summer monsoon during that period.

关键词： Tibetan Plateau greatest lake period highest lake levels interstitial of last glaciation paleo-monsoon

Changes in hair arsenic concentration in a population exposed to heavy pollution:Follow-up investigation in Chenzhou City,Hunan Province,Southern China

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Journal of Environmental sciences 2010年第2期22卷 283-289页

作者： Bin Wu,Tongbin Chen Center for Environmental Remediation,institute of geographic {2. and natural {4. research,Chinese Academy of {2.,Beijing 100101,China. [a] Center for Environmental Remediation Institute of Geographic Sciences natural resources {2. Chinese Academy of Sciences Beijing 100101 China

Follow-up investigation on hair arsenic concentration was conducted in an arsenic heavily polluted area of southern China in 2.02.and 2.06. The results showed that the geometric mean of hair arsenic concentration decreased from 2.95 mg/kg in 2.02.to 1.78 mg/kg in 2.06, when the percentage of the population with levels over 1 mg/kg only decreased from 93.4. in 2.02.to 80.5% in 2.06. Over this four-year period, the population with high arsenic concentrations decreased significantly while there was no obvious change in hair arsenic concentration for people who had relatively low concentrations. In terms of age distribution, young and old people had higher hair arsenic concentrations than the middle-aged. All of these results showed that it is difficult to reverse the negative impact of arsenic pollution on human health. Arsenic pollution has a long-term continuous influence on the health of local residents.

关键词： arsenic human health soil contamination hair arsenic

On coordinated development of oasis and environment in arid area

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Journal of geographical sciences 2001年第1期11卷 117-121页

作者： FU Xiao-feng, LI Zhe (institute of geographic {2. and natural {4. research, cas, Beijing 100101, China) institute of geographic {2. and natural {4. research CAS

Based upon the formation and evolution of oasis and the factors restricting the coordinated development of oasis economy and environment, this paper presents a goal of the development in coordination. It suggests that the sustainable survival and development of oasis could be ensured only if the oasis-desert and water source ecology are managed in a combined way to form a macro system. In light with the above mentioned, the approach to the development of economy and environment of oasis in arid area should depend upon the establishment of an oasis ecological and economic system, which suits the arid environment and promotes the efficiency of resource configuration, stabilizes economic increment and benefits ecological development.

关键词： oasis development environment arid area

STUDY ON DEVELOPMENT STRATEGY OF SHIPPING CENTERS AND TRANSPORTATION NETWORKS IN THE YELLOW SEA RIM

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Chinese geographical Science 2003年第2期13卷 97-103页

作者： JIN Feng-jun (institute of geographic {2. and natural {4. research, Chinese Acad emy of {2., Beijing 100101, P.R. China) institute of geographic {2. and natural {4. research Chinese Academy of Sciences Beijing 100101 P. R. China

It is very important to establish cooperative mechanism to guarantee allmembers to develop their e-conomies in the Yellow Sea Rim. In this paper, the development strategiesof shipping centers and transportation network are discussed based on economic globalizationtendency. The results argue that a united transportation network should be built in order to promotethe economic competition of Northeast Asia in the world. As a key component of the economiccooperation, a hierarchical shipping centers network should be established with Hong Kong, Shanghai,Pusan, Kobe, and Tokyo as cores. The authorities of China, Japan, R. 0. Korea and D. P. R. Koreashould make more efforts to build a set of cooperation institutions based on raising thetransportation efficiency.

关键词： the yellow sea rim shipping center transportation network hub-and-spoke system

A study on environmental aridity over northern and southern to Qinling Mountains under climate warming

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Journal of geographical sciences 2001年第2期11卷 193-201页

作者： YAN Jun-ping~1, LIU Yan-sui~2.(1. College of Tourism and Environment, Shaanxi Normal University, Xi’an 710062. China 2. institute of geographic sciences and natural resources research, cas, Beijing {2., China) College of Tourism and Environment Shaanxi Normal University institute of geographic {2. and natural {4. research CAS

Based on the data up to 1999 from hydroclimatological departments, this pape analyzes the climatic divide implications of the Qinling Mountains in regional response to the process of climate warming, due to which the grades of dryness/wetness (GDW) in 100 years show that the northern region has entered a drought period, while the southern is a humid period. In a course of ten years, the D-value of annual average air temperature over southern Shaanxi (the Hanjiang Valley) and the Central Shaanxi Plain (the Guanzhong Plain) has narrowed, i.e., the former with a slight change and the latter with rapid increase in temperature. Both regions were arid with the decrease in precipition D-value, namely the plain became warmer while the south was drier. The Qinling Mountains play a pronounced role in the climatic divide. The runoff coefficient (RC) of the Weihe River decreases synchronously with that of the Hanjiang due to climate warming. The RC of Weihe dropped from 0.2.in the 1950s to less than 0.1 in the 1990s. The Weihe Valley (the Guanzhong Plain) is practically an arid area due to shortage of water. The successive 0.5, 1.0°C temperature anomaly over China marks, perhaps, the improtant transition period in which the environment becomes more vulnerable than before. The study shows the obvious trend of environmental aridity, which is of help to the understanding of regional response to global climate change.

关键词： climate change aridity Qinling Mountains