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SEDIMENT YIELD MODELING FOR SINGLE STORM EVENTS BASED ON HEAVY-DISCHARGE STAGE CHARACTERIZED BY STABLE SEDIMENT CONCENTRATION

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International Journal of Sediment research 2007年第3期22卷 208-217页

作者： Mingguo ZHENG1, Qiangguo CAI2, and Qinjuan CHENG3 1Assistant professor, Key Laboratory of Water Cycle and Related Land Surface Processes, institute of geographic sciences & natural resources research, CAS, beijing 100101,china. 2 Professor, Key Laboratory of Water Cycle and Related Land Surface Processes, institute of geographic sciences & natural resources research, CAS, beijing 100101,china. 3 Doctoral candidate, Key Laboratory of Water Cycle and Related Land Surface Processes, institute of geographic sciences & natural resources research, CAS, beijing 100101,china. Graduate School of the chinese academy of sciences, beijing 100039, china. chinese Acad Sci Inst Geog Sci & Nat Resources Res Key Lab Water Cycle & Related Land Surface Proc Beijing 100101 Peoples R China

The relation between runoff volume and sediment yield for individual events in a given watershed receives little attention compared to the relation between water discharge and sediment yield, though it may underlie the event-based sediment-yield model for large-size watershed. The data observed at 12 experimental subwatersheds in the Dalihe river watershed in hilly areas of Loess Plateau, North china, was selected to develop and validate the relation. The peak flow is often considered as an important factor affecting event sediment yield. However, in the study areas, sediment concentration remains relatively constant when water discharge exceeds a certain critical value, implying that the heavier flow is not accompanied with the higher sediment transport capacity. Hence, only the runoff volume factor was considered in the sediment-yield model. As both the total sediment and runoff discharge were largely produced during the heavy-discharge stage, and the sediment concentration was negligibly variable during this stage, a proportional function can be used to model the relation between event runoff volume and sediment yield for a given subwatershed. The applicability of this model at larger spatial scales was also discussed, and it was found that for the Yaoxinzhuang station at the Puhe River basin, which controls a drainage area of 2264km2, a directly proportional relation between event runoff volume and sediment yield may also exist.

关键词： Sediment yield Peak flow Flow-sediment relation Loess Plateau

Simulating the transfer and fate of hexachlorocyclohexane in recent 50 years in beijing, china

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Science china Earth sciences 2005年第12期48卷 2203-2213页

作者： CAO Hongying1, LIANG Tao1 & TAO Shu2 1. institute of geographical sciences and natural resources research, chinese academy of sciences, beijing 100101, china 2. Laboratory for Earth Surface Processes, Peking University, beijing 100871, china institute of geographical sciences and natural resources research Chinese Academy of Sciences Beijing China Laboratory for Earth Surface Processes Peking University Beijing China

Taking beijing as a study area, a dynamic fugacity model was used to simulate the transfer and fate of technical HCHs according to the physic-chemical properties of the studying environment and HCH isomers. Dynamic changes of the transfer fluxes and concentrations of HCH isomers during 1952―2003 were simulated and the model results suggest good agreement between the calculated and measured concentrations of HCH isomers. During 1952―1983, the average input and output amount of HCHs through agricultural application and degradation are 130 t and 150 t respectively. The dominant transfer processes of HCHs in the study area are air-soil deposition, soil erosion and soil-air diffusion, transfer fluxes of these processes are 80 t?a?1, 16 t?a?1 and 11 t?a?1, which account for 92% of total transfer fluxes of HCHs isomers. There were approximately 253t HCHs in all environmental compartments of the study area during this period and 97% of which existed in soil compartment. Air and water advection became the dominant input sources of HCHs after 1984 when the application of technical HCHs was prohib-ited, concentration of HCHs quickly descended to a quite low level in several years. Total amount of HCHs isomers remaining in the study area environment now is less than 5% that before 1983, and this percentage may descend to 0.5% after 20 years by prediction.

关键词： fugacity model, hexachlorocyclohexane, compartment, transfer flux, fate.

Simulating Hydrologic Changes with Climate Change Scenarios in the Haihe River Basin

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Pedosphere 2005年第5期15卷 53-58页

作者： YUAN Fei 1,2, XIE Zheng-Hui1,* 2, LIU Qian1 and XIA Jun 3 1LASG, institute of Atmospheric Physics, chinese academy of sciences, beijing 100029 (china). 2 College of Water resources and Environment, Hohai University, Nanjing 210098 (china)3 institute of geographical Science & natural resources, chinese academy of sciences, beijing 100101 (china) institute of Atmospheric Physics Chinese Academy of Sciences LASG CAS Beijing 100029 institute of geographical Science & natural resources Chinese Academy of Sciences Beijing 100101

Climate change scenarios, predicted using the regional climate modeling system of PRECIS (providing regional cli-mates for impacts studies), were used to derive three-layer variable infiltration capacity (VIC-3L) land surface model forthe simulation of hydrologic processes at a spatial resolution of 0.25° × 0.25° in the Haihe River Basin. Three climatescenarios were considered in this study: recent climate (1961-1990), future climate A2 (1991-2100) and future climateB2 (1991-2100) with A2 and B2 being two storylines of future emissions developed with the Intergovernmental Panel onClimate Change (IPCC) special report on emissions scenarios. Overall, under future climate scenarios A2 and B2, theHaihe River Basin would experience warmer climate with increased precipitation, evaporation and runoff production ascompared with recent climate, but would be still likely prone to water shortages in the period of 2031-2070. In addition,under future climate A2 and B2, an increase in runoff during the wet season was noticed, indicating a future rise in theflood occurrence possibility in the Haihe River Basin.

关键词： climate change regional climate modeling system runoff VIC-3L model

SYNTHESIS AND CHARACTERIZATION OF NEW STABILIZERS WITH OPTIMAL MOLECULAR WEIGHT

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chinese Journal of Polymer Science 2001年第4期19卷 341-350页

作者： Jiang-qing Pan institute of Chemistry chinese academy of sciences, beijing 100080 china 中科院化学所北京

Over 2 x 10(8) tons of polymers are produced every year, and a large portion of polymers faces the degradation problem. There are many effective methods to protect polymers against degradation and the addition of stabilizers to polymer remains the most convenient and effective way of enhancing polymer life and performance. In this article, a series of effective stabilizers with optimal molecular weight (MW), including common, monomeric and polymeric stabilizers (antioxidant and light stabilizer) were synthesized using isocyanation, controlled isocyanation, hydrosilylation, epoxide addition, macroreaction of stabilizing functional compounds and polymerization of monomeric stabilizers. The structure and performance of these new stabilizers were characterized by using IR, NMR, MS, UV-spectra, XPS and elemental analysis. The current development of stabilizer synthesis was also reviewed.

关键词： preparation of stabilizer antioxidant hindered amine light stabilizer isocyanation hydrosilylation

Urban Water Supply Industry Marketization of china in View of Public Water Service and Water Resource Management

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chinese Journal of Population,resources and Environment 2010年第2期8卷 55-60页

作者： Wang Yining 1,2 1.institute of geographic Science and natural resources research,CAS,beijing 100101,china 2.Graduate School of the chinese academy of sciences,beijing 100049,china institute of geographic Science and natural resources research CAS Beijing 100101 China Graduate School of the chinese academy of sciences Beijing 100049 China

Started with the discussions on the value orientation of urban water supply industry marketization,the article points out that the current urban water supply industry marketization reform is inconsistent with the goal of public water service equalization to some *** article also analyzes the problems emerged in urban water supply industry marketization reform and various rea-sons in view of efficiency and *** efficiency and fairness oriented management model is built in this article to illustrate how the government should conciliate interests of various communities involved in the process of marketization reform of the urban water supply industry so as to actualize the coordination of efficiency and *** the end,an assumption on urban water price is put forward to help achieve the public water service equalization.

关键词： urban water supply industry marketization public water service water resource management

Sandstorms and desertification

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Journal of geographical sciences 2000年第3期10卷 99-102页

作者： CHEN Zhi-qing1, ZHU Zhen-da2 (1.institute of geographic sciences and natural resources research, chinese academy of sciences, beijing 100101, china 2. institute of Dsert research, chinese academy of sciences, beijing 100101, china)

Sandstorm is a frequently occurred disastrous weather in northern china. The increasing occurrence frequency recently, especially the much more frequently occurred sandstorms with high intensity in the spring of 2000 have caused great loss to national economy. The combination of strong wind, exposed sandy soil on ground surface and unstable air current constitutes the necessary conditions for the sandstorms. However, the accelerated desertification process resulting from irrational human economic activities is responsible for the accelerated sandstorms. The effective measures to mitigate sandstorm lie in strengthening desertification control and eco-environmental protection.

关键词： sandstorm generating conditions desertification eco-environmental protection

Simulating the impacts of climate variation and land-cover changes on basin hydrology: A case study of the Suomo basin

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Science china Earth sciences 2005年第9期48卷 1501-1509页

作者： CHEN Junfeng1,2, LI Xiubin2 & ZHANG Ming2 1. institute of Remote Sensing & GIS, Peking University, beijing 100871, china 2. institute of geographical sciences and natural resources research, chinese academy of sciences, beijing 100101, china institute of Remote Sensing & GIS Peking University Beijing China institute of geographical sciences and natural resources research Chinese Academy of Sciences Beijing Chin

Impacts of land cover changes on watershed hydrology have been a long-term academic concern with acute dispute. But little attention has been paid to such effects on mesoscale river basins, where the society has a closer link to river hydrology. The present study focuses on a mesoscale river basin, the Suomo Basin that is located on the upper reaches of the Yangtze River. Land covers in the basin in the years 1970, 1986 and 1999 were mapped. A lumped hydrologic model, CHARM, and a distributed hydrologic model, SWAT, were used to model the impacts of both land-cover change and climate variation on river runoff during the past four decades. The results show that the contribution of climate variation to the change of runoff regime makes up 60%―80%, while that of land cover changes only 20%.

关键词： climate variation, land-cover changes, Suomo Basin, CHARM model, SWAT model.

STATISTICAL RELATIONS BETWEEN GEOMORPHIC PARAMETERS——A CASE STUDY OF THE YUNNAN REACH OF THE LANCANGJIANG RIVER IN SOUTHWESTERN china

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International Journal of Sediment research 2007年第2期22卷 131-141页

作者： Suiji WANG1, Shaohong WU2 and Erfu DAI31,3 Key Laboratory of Water Cycle and Related Land Surface Processes, institute of geographical sciences and natural resources research, chinese academy of sciences, beijing, 100101, china, 2 Key Laboratory of Water Cycle and Related Land Surface Processes, institute of geographical sciences and natural resources research, chinese academy of sciences, beijing, 100101, china, chinese Acad Sci Inst Geog Sci & Nat Resources Res Key Lab Water Cycle & Related Land Surface Proc Beijing 100101 Peoples R China

The properties of rivers and their catchments can be expressed by statistical relationships between geomorphic parameters. These statistical relationships may reveal some inherent differences in geomorphic evolution for different reaches or different order tributaries of a river basin. A case study was undertaken of the Yunnan reach of the Langcangjiang River. The catchment area, channel length and gradient of the first-, second- and third-order tributaries all with catchment areas larger than 100 km2 in the Yunnan reach were the main geomorphic parameters evaluated. The correlation between catchment area and channel length as well as between catchment area and channel gradient with respect to the total tributaries, different reach tributaries, and different order tributaries were revealed using statistical methods. In general, the channel length as a function of catchment area, was best expressed by a quadratic function where channel length increases with increasing catchment area (half parabola), while the channel gradient as a function of catchment area is best expressed by an exponential decay function. Comparison of the best-fit formulas revealed the following phenomena: the lower Yunnan reach tributaries and the first-order tributaries have a dominant effect on geomorphic parameters of the total tributaries. In addition, the statistical relationships indicate that the river geomorphic system in the upper and lower Yunnan reaches evolved differently. This study method used to differentiate river characteristics by determining statistical relationships between geomorphic parameters may be extended to other rivers and their catchments.

关键词： River catchment Geomorphic parameter Correlation River characteristics

A GIS-based mapping method on distribution of critical Ecological Situation in china

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Journal of geographical sciences 2000年第3期10卷 72-80页

作者： YE Qing-hua, YANG Qin-ye, LIU Gao-huan (institute of geographic sciences and natural resources research, chinese academy of sciences, beijing 100101, china)

Concerned with the Critical Ecological Situation in china, according to the concept of the critical Environment and Endangerment, a set of indicators of Ecological Critical Situation has been set up. And with the powe... 详细信息

关键词： geographical Information System (GIS) Critical Ecological Situation (ES) human-environmental relationships Eco-environmental Situation