检索结果-南通市图书馆

Aerosol retrieval over land by exploiting the synergy of TERRA and AQUA MODIS DATA

在线全文

学校读者我要写书评

暂无评论

Science China Earth sciences 2006年第6期49卷 641-649页

作者： TANG Jiakui1, XUE Yong1,2. YU Tong3. GUAN Yanning1, CAI Guoyin1 & HU Yincui1 1. State Key Laboratory of Remote Sensing Science, Jointly Sponsored by the Institute of Remote Sensing Applications of Chinese Academy of sciences and {2. Normal {2., {2. 100101, China 2. department of Computing, London Metropolitan {2., 166-2.0 Holloway Road, London N7 8DB, UK 3. {2. environmental Monitor Center, {2. 100044, China 1. State Key Laboratory of Remote Sensing Science Jointly Sponsored by the Institute of Remote Sensing Applications of Chinese Academy of Sciences and Beijing Normal University Beijing 100101 China 2. department of Computing London Metropolitan University 166-220 Holloway Road London N7 8DB UK 3. beijing {2. Monitor Center Beijing 100044 China

Aerosol retrieval over land from satellite remotely sensed data remains internationally a difficult task. By using MODIS data, the Dark Dense Vegetation (DDV) algorithm aerosol distribution and properties retrieval over land has shown excellent competence. However, this algorithm is re-stricted to lower surface reflectance such as water bodies and dense vegetation, which limits its actual application, and is unable to be used for high reflective surface such as over urban areas. In this paper, we introduce a new aerosol retrieval model by exploiting the Synergy of TERRA and AQUA MODIS data (SYNTAM), which can be used for various ground surfaces, including for high reflective surface. Preliminary validations have been carried out by comparing with AERONET measured data, which shows good accuracy and promising potential. Further research work is undergoing.

关键词： aerosol retrieval, aerosol optical thickness, MODIS, TERRA, AQUA.

Ecological rebuilding and land reclamation in surface mines in Shanxi Province, China

在线全文

学校读者我要写书评

暂无评论

Journal of environmental sciences 2000年第4期12卷 486-497页

作者： MIAO Ze wei 1, BAI Zhong ke 2. GAO Lin 1 (1. Research Center for Eco environmental sciences, Chinese Academy of sciences, {3. 100085, China E\|mail: miaozewei@*** 2. department of Soil Science, Shanxi Agricultural university Taigu, 03 中科院生态环境研究中心北京 1 0 0 0 85 山西师范大学山西临汾 0 3 0 80 1

It is well known that the mining industry produces a large amount of derelict land, and causes pollution of water loss and soil erosion as well as other environmental damage in China. As land is under pressure in China, it is now policy to restore or reclaim land despoiled by mining, the aim being to develop sustainable and healthy arable land ecosystems. This paper outlines the principles and approaches of ecological restoration, which have been adopted in Shanxi Province with reference to three typical surface mines. In the research, the principles of ecological engineering and ecological succession are considered as the critical theories of ecological restoration in mine degraded land. Meanwhile, the paper made a comparative research on main links of ecological rebuilding in three surface mines in Shanxi Province, which include new land construction, treatment of toxic substances, control of soil erosion, fertility management, irrigation, ecological planning and the establishment of legislation systems. As the research demonstrated, for successful restoration, new land construction is the fundamental framework, but it must be integrated with ecological engineering including ecological planning, the control of soil erosion and vegetation establishment and ecosystem creation in order to optimise land productivity and soil fertility. In addition, the establishment of the legislation systems and organization of administration are also indispensable aspects of ecological rebuilding in mined land.

关键词： ecological restoration land reclamation open-pit mine

Human impacts on the terrestrial ecosystem of Fildes Peninsula of King George Island, Antarctica

在线全文

学校读者我要写书评

暂无评论

Journal of environmental sciences 2000年第1期12卷 14-19页

作者： ZHAO Ye\+1, XU Cui\|hua\+2.(1. Institute of Resource and environmental sciences, {2. Normal {3., {2. 100875, China 2. Laboratory of Industrial Hygiene, Ministry of public health, {2. 100088, China) Foundation item: National Natur

Antarctic environment has valuable baseline information for understanding the global change. The objectives of this study were to investigate the impacts of human activities on Antarctic terrestrial ecosystem. Based on the investigation results and the sampling analysis of the environment of Fildes Peninsula, King George Island, Antarctica, it was shown that there are some artificial radioactive elements—? ? 13. Cs in Antarctic environment: the radioactivity of 13. Cs in the surface soil, the surface moss, the fruticose lichen and the crustaceous lichen are 6 00—14 80, 2. 07, 2. 04 and 58 07 Bq/kg separately; i.e. the sequence of 13. Cs specific activity is as follows: crustaceous lichen>fruticose lichen>surface moss>surface soil, which demonstrates that the crustaceous lichen is one of the most sensitive monitor ways for the effect of the long term diffusion of 13. Cs. The impacts of the scientific research activities on the partial ecosystem of Fildes Peninsula include: the changes of the landscape and the soil material have made a strong freezing thawing process, which decreases the stability of the ground surface, causes the degradation of the vegetation in the some small areas; some small lakes, runoff and lichens in middle areas of Fildes Peninsula have been affected by the wastes of the stations, in the surrounding areas of the expedition stations, the concentration of Cr, Cu, Ni, Pb and Zn in the lichen and the water are higher than that of the contrasting area. Fildes Peninsula is one of the most crowded areas of expedition stations, at some extent, the environment and terrestrial ecosystem have been affected by the human activities. The conservation of the environment and ecosystem should be an important aspect of Antarctic environmental sciences.

关键词： Antarctica Fildes Peninsula terrestrial ecosystem human impacts CLC number: X2. Document code: A

A comparative study on Canadian and Chinese river basin planning

在线全文

学校读者我要写书评

暂无评论

Journal of environmental sciences 1994年第2期6卷 224-233页

作者： Guo Huaicheng (Center of environmental sciences,{2. {3., beijing 100871,China)G. Beanlands ( school for Resource & environmental Studies,Dalhousie {3., Halifax, Canada B3. 3.2.

The paper tries to summarize basic approaches to river basin planning in Canada andin China, and makes a comparative analysis taking the Saint John River in Canada and the TaiziRiver in China as examples. The analytical results indicated that policy and management are the ma-jor features of the river basin planning study in Canada; control and treatment of water pollutionhave been generally treated in China; lack of implementation is a common problem in bothcountries.

关键词： river basin planning public participation water pollution.

Efficiency of sediment transport by flood and its control in the Lower Yellow River

在线全文

学校读者我要写书评

暂无评论

Science China(Technological sciences) 2004年第z1期47卷 173-185页

作者： NI Jinren1, LIU Xiaoyong2. LI Tianhong1, ZHAO Ye’an3.& JIN Ling1 1. department of {2. Engineering,{2. The Key Laboratory of Water and Sedi- ment {3., Ministry of Education, beijing 100871, China 2. General Institute of Water Resources and Hydropower Planning and Design, Ministry of Water Re- sources, beijing 100011, China 3. The Yellow River Conservancy Commission, Zhengzhou 450003. China 1. department of environmental Engineering Peking University 100871 Beijing China 2. The Key Laboratory of Water and Sediment sciences Ministry of Education 100871 Beijing China 3. General Institute of Water Resources and Hydropower Planning and Design Ministry of Water Resources 100011 Beijing China 4. The Yellow River Conservancy Commission 450003 Zhengzhou China

This paper presents the characteristics of sediment transport by flood in the Lower Yellow River with the reach from Huayuankou to Gaocun, which is regarded as a typical braided pattern. The Artificial Neural Network Model on Water Use for Sediment Transport (WUST) by flood was established based on the measured data from 1980 to 1998. Consequently, simulations of controlling process of sediment transport by flood were made in terms of the control theory under different scenarios. According to the situation of sediment transport by flood in the Lower Yellow River, Open-Loop control system and feedback control system were adopted in system design. In the Open-Loop control system, numerical simulations were made to reveal the relationship between average discharge of flood and the WUST with varying sediment concentrations. The results demonstrate that sediment concentration has significant influence on the controlling process of flood flow to WUST. It is practical and efficient to control WUST if sediment concentration is less than 2. kg/m3. In the feedback control system, controlling processes of sediment concentration and flood discharge for sediment transport were simulated respectively under given conditions, and it was found that sediment transport process could be controlled completely by sediment concentration and discharge at the inlet of the reach from Huayuankou to Gaocun. Using the same method, controlling processes of sediment transport by flood in other reaches in the Lower Yellow River were also simulated. For the case of sediment concentration being 2. kg/m3. the optimized controlling discharge ranges from 2.0}0 to 2.00 m3.s in the lower reach of Huayuankou. This study is also of significance to flood control and flushing sediment in the Lower Yellow River with proper operation modes of Xiaolangdi Reservoir.

关键词： the Lower Yellow River, flood, sediment transport, efficiency, simulation, control.

Test of magnetic susceptibility and grain-size age models of loess

在线全文

学校读者我要写书评

暂无评论

Progress in Natural Science:Materials International 2007年第11期17卷 1312-1317页

作者： Chen Yimeng1,2.3. Feng Zhaodong4 and Gong Huili1,2.1. MOE and Key Laboratory of Resources Environment and GIS of beijing, beijing 10003., China 2. Key Laboratory of 3. information Acquisition and Application, The Capital Normal {2., beijing 10003., China 3. department of Economics & Management of Huizhou {2., Huizhou 516007, China 4. Key Laboratory of Western China’s environmental Systems, Ministry of Education, Lanzhou {2., Lanzhou 73.000, China) MOE and Key Laboratory of Resources Environment and GIS of beijing Beijing 100037 China Key Laboratory of 3. information Acquisition and Application The Capital Normal University Beijing 100037 China department of Economics & Management of Huizhou university Huizhou 516007 China Key Laboratory of Western China’s environmental Systems Ministry of Education Lanzhou University Lanzhou 730000 China

Ages of the stratigraphic boundary MIS1/2.and MIS3.4 of the Yuanbu loess section in Linxia are used as the basis of the nodal control age. The age of MIS1/2.and MIS3.4 are obtained from the latest international research result—the climatic events recorded in the stalagmite in the Hulu Cave in Nanjing, that MIS1/2.is 11.5 kaB.P. and MIS3.4 is 59.8 kaB.P.. The ages of the two climatic events contain three nodal age control models (Model 1: 0 kaB.P.—59.8 kaB.P.; Model 2. 0 kaB.P.—11.5 kaB.P. and 11.5 kaB.P.—59.8 kaB.P.; Model 3. 11.5 kaB.P.—59.8 kaB.P.), which are used as the nodal control age separately. The deposition times of various stratigraphic horizons are calculated by using the magnetic susceptibility age model and grain-size age model, and then compared with each other. In addition, the AMS14C age, OSL age and the ages of YD and H events are compared with the ages of the corresponding horizons calculated by the three models of nodal control ages. From the analyses of lithologic characters and climatic stages it has been found that both the magnetic susceptibility age model and the grain-size age model have some defects. Because the accurate control ages are selected as the nodal points of the glacial period or interglacial period, the stratigraphic deposition times determined by the high resolution of magnetic susceptibility age model and grain-size age model approximate to the actual ages. As for the relative accuracy of the two age models, the magnetic susceptibility age model is more accurate than the grain-size age model.

关键词： loess nodal control age magnetic susceptibility age model grain-size age model test

Mixed uncertainty analysis of polycyclic aromatic hydrocarbon inhalation and risk assessment in ambient air of beijing

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of environmental sciences 2008年第4期20卷 505-512页

作者： College of environmental sciences and Engineering,{2., {3. 100871, China GUO Huaicheng LIU Yong HUANG Kai WANG Zhen ZHAN Xinye 不详 school of Natural Resources and Environment University of Michigan Ann Arbor 48109 USA department of Civil and Resource Engineering Dalhousie University Halifax NS B3JIZ1 Canada

This article presents the application of an integrated method that estimates the dispersion of polycyclic aromatic hydrocarbons （PAHs） in air, and assesses the human health risk associated with PAHs inhalation. An uncertainty analysis method consisting of three components were applied in this study, where the three components include a bootstrapping method for analyzing the whole process associated uncertainty, an inhalation rate （IR） representation for evaluating the total PAH inhalation risk for human health, and a normally distributed absorption fraction （AF） ranging from 0% to 100% to represent the absorption capability of PAHs in human body. Using this method, an integrated process was employed to assess the health risk of the residents in {3., China, from inhaling PAHs in the air. The results indicate that the ambient air PAHs in {3. is an important contributor to human health impairment, although over 68% of residents seem to be safe from daily PAH carcinogenic inhalation. In general, the accumulated daily inhalation amount is relatively higher for male and children at 10 years old of age than for female and children at 6 years old. In 1997, about 1.73. cancer sufferers in {3. were more or less related to ambient air PAHs inhalation. At 95% confidence interval, approximately 2.2.3.9 individual cancer incidences can be attributed to PAHs pollution in the air. The probability of greater than 500 cancer occurrence is 15.3.. While the inhalation of ambient air PAHs was shown to be an important factor responsible for higher cancer occurrence in {3., while the contribution might not be the most significant one.

关键词： polycyclic aromatic hydrocarbons (PAHs) uncertainty analysis human health risk

Above-and belowground biomass in relation to envi- ronmental factors in temperate grasslands, Inner Mongolia

在线全文

学校读者我要写书评

暂无评论

Science China(Life sciences) 2008年第3期51卷 263-270页

作者： MA WenHong1,2. YANG YuanHe1, HE JinSheng1, ZENG Hui1,2.& FANG JingYun1 1 department of Ecology, College of Urban and environmental {2.,{3., beijing 100871, China 2.school of Environment & Urban Study,{3. Shenzhen Graduate school, Shenzhen 518055, China 1. department of Ecology College of Urban and Environmental Sciences Peking University Beijing 100871 China 2. school of Environment & Urban Study Peking University Shenzhen Graduate School Shenzhen 518055 China

Above- and belowground biomasses of grasslands are important parameters for characterizing re- gional and global carbon cycles in grassland ecosystems. Compared with the relatively detailed in- formation for aboveground biomass (AGB), belowground biomass (BGB) is poorly reported at the re- gional scales. The present study, based on a total of 113.sampling sites in temperate grassland of the Inner Mongolia, investigated regional distribution patterns of AGB, BGB, vertical distribution of roots, and their relationships with environmental factors. AGB and BGB increased from the southwest to the northeast of the study region. The largest biomass occurred in meadow steppe, with mean AGB and BGB of 196.7 and 13.5.2.g/m2. respectively; while the lowest biomass occurred in desert steppe, with an AGB of 56.6 g/m2.and a BGB of 3.1.0 g/m2. In addition, about 47% of root biomass was distributed in the top 10 cm soil. Further statistical analysis indicated that precipitation was the primary determinant factor in shaping these distribution patterns. Vertical distribution of roots was significantly affected by precipitation, while the effects of soil texture and grassland types were weak.

关键词： temperate grasslands aboveground biomass (AGB) belowground biomass (BGB) spatial pattern vertical distribution precipitation

Contribution of Root and Microbial Respiration to Soil CO_2.Efflux and Their environmental Controls in a Humid Temperate Grassland of Japan

在线全文

学校读者我要写书评

暂无评论

Pedosphere 2009年第1期19卷 31-39页

作者： WANG Wei FENG Jiang T. OIKAWA department of Ecology College of Urban and Environmental Sciences and Key Laboratory for Earth Surface Processes of the Ministry of Education Peking University Beijing 100871 （China） school of Urban and environmental {2. Northeast Normal University Changchun 130024 （China） Institute of Biological sciences University of Tsukuba Tsukuba Ibaraki 305-8572 （Japan）

Soil CO2.efflux, root mass, and root production were investigated in a humid temperate grassland of Japan over a growing season （Apr. to Sep.） of 2.05 to reveal seasonal changes of soil CO2.efflux, to separate the respective contributions of root and microbial respiration to the total soil CO2.efttux, and to determine the environmental factors that control soil respiration. Minimal microbial respiration rate was estimated based on the linear regression equations between soil CO2.effiux and root mass at different experimental sites. Soil CO2.efflux, ranging from 4.99 to 16.2. μmol CO2.m^-2.s^-1, depended on the seasonal changes in soil temperature. The root mass at 0-10 cm soil depth was 0.82.and 1.2. kg m^-2.in Apr. and Sep., respectively. The root mass at 0-10 cm soil depth comprised 60% of the total root mass at 0-50 cm soil depth. The root productivity at 0-3. cm depth varied from 8 to 180 g m^-2.month^-1. Microbial and root respiration rates ranged from 1.3. to 5.51 and 2.72.to 12.06μmol CO2.m^-2.s^-1, respectively. The contribution of root respiration to the total soil CO2.efflux averaged 53., ranging from 3.% to 72.. The microbial respiration rate was exponentially related to soil temperature at 10 cm depth （R^2.= 0.9400, P = 0.002. n = 6）, and the root respiration rate was linearly related to the root production at 0-3. cm depth （R2.= 0.6561, P = 0.042. n = 6）.

关键词： grasslands microbial respiration root production root respiration