检索结果-南通市图书馆

GIS Conceptual Data Model

在线全文

学校读者我要写书评

暂无评论

Geo-Spatial Information Science 2002年第3期5卷 19-25页

作者： XIAO Lebin ZHONG Ershun LIU Jiyuan SONG Guanfuassociate researcher,institute of {2. {3. and Natural resources,Chinese Academy of {3.,3.Datun Road,Anwai,beijing 100101,China. institute of geographic {2. and Natural {3. Chinese Academy of Science

In order to set up a conceptual data model that reflects the real world as accurately as possible,this paper firstly reviews and analyzes the disadvantages of previous conceptual data models used by traditional GIS in simulating geographic space,gives a new explanation to geographic space and analyzes its various essential ***,this paper proposes several detailed key points for designing a new type of GIS data model and gives a simple holistic GIS data model.

关键词： topological relation layer geographic space holistic data model

Dynamics of the Coordination of Economy-Society and Resource-Environment in Shandong Peninsula,China

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Population,resources and Environment 2012年第3期10卷 62-71页

作者： Han Rongqing Zhao Minghua institute of geographic {2. and Natural {3. research CASBeijing 100101China Graduate University of Chinese Academy of sciences Beijing 100049China Population Recourses and Environment College of Shandong Normal UniversityJinan Shandong 250014China

Shandong Peninsula,as a more developed region in Shandong Province even the east coast of China,is facing challenges from resources and environment *** paper tried to track and assess the coordination status and the dynamic between resource-environment and economy-society systems in Shandong Peninsula during 2.01-2.08 in order to provide decision support for regional *** appraisal index system was built including five aspects of harmony degree(A),sustainability degree(B),opening degree(C),stability degree(D) and controllability degree(E).The results showed that:1) The coordination level of resource-environment and economy-society in Shandong Peninsula has continuously grown,and it has undergone three stages:no coordinated degree(2.01-2.02.,weak coordinated degree(2.03.2.06) and basically coordinated degree(2.07-2.08).2. Five indexes of criterion hierarchy also increased overall,but each index showed different *** degree,sustainability degree and opening degree rose all the time,while stability degree and controllability degree alternately rose and *** improvement of controllability degree was the slowest.3. The aggravating trend of environmental pollution was slowing *** economic growth was driven by industrial growth and urbanization typically and investment was still the main force to pull the regional economic *** the same time,technology and education were becoming more and more important for economic *** level of foreign capital utility declined and the geographical advantage of Shandong Peninsula was *** some characteristics of knowledge economy were *** resources become the main constraint factor of fast development in Shandong *** is necessary to further strengthen the coordination ability of government on regional sustainable development.

关键词： dynamics coordination of resource-environment andeconomy-society Shandong Peninsula

Current situation and trend of arable land change in China

在线全文

学校读者我要写书评

暂无评论

Journal of geographical sciences 2000年第3期10卷 28-34页

作者： Received date: 1999-11-02.MENG Xiang-jing1 , JIA Shao-feng 2.(1.institute of Population {3., People’s University of China, {2. 100872. China 2. institute of geographic sciences and Natural resources {3., Chinese Academy of sciences, Beiji 中国人民大学北京中科院地理科学与资源所北京

How to protect arable land in the process of economic development and urbanization is a critical issue in China. In this paper, an attempt is made to analyze the situation of arable land change in China and it's relationship with population growth, economic development and urbanization. In depth analysis is also made in different regions. Forecasting is conducted to show the trend of arable land change in China based on the results of correlation analysis. Some suggestions are put forward for the policy making of reasonable utilization and protection of arable land in the future.

关键词： arable land change population growth economic development urbanization

The significance of lake sediments geochemistry in environmental reconstruction of south Hongshan Lake, northwestern Tibetan Plateau during the past 150 years

在线全文

学校读者我要写书评

暂无评论

Journal of geographical sciences 2000年第3期10卷 65-71页

作者： CHEN Ling, ZHU Li-ping, ZHANG Qing-song (institute of geographic {2. and Natural {3. research, Chinese Academy of {2., beijing 100101, China)

A 107cm piston-core (SHC-2. was drilled at the site with water depth of 5m in South Hongshan Lake, northwest Tibet in 1998. Based upon the 0.72.m/a of modern sedimentary rate that was tested by 2.0Pb method and also calibrated by 13.Cs method as well as the 1cm interval sample cutting level, a lake sedimentary record of 150-yr old and with a resolution of 1.4 yrs was obtained. Ratio of geochemistry contents (TOC, TN, CaCO3. and concentrations of trace elements such as B, Sr, Ba, Ca, Mg, K, Na, Al, Ti, Cu, Zn, Fe, Mn, Ni, Cr, V, Pb, etc were analyzed. The values of TOC, TN, C/N, CaCO3. Sr/Ba and Fe/Mn had clear environmental significance and well reflected the environmental changes. Geochemical multi-proxies of lacustrine sediments from SHC-2.core showed that the environmental changes in this area during the past 150 years could be reconstructed as follows: Stage 1 (1850s-1880s) was a cold period; Stage 2.(1880s-192.s) was a warm period. But the variation of lake water volume was stable in the two periods. Stage 3.(192.s-1950s) was a fluctuant and transitional period in temperature, but there were a short cold period in the 192.s and a warm period in the 193.s. Stage 4 (1950s-) showed a warming tendency, though there existed a cold period from the mid 1970s to the end of the 1980s. In the view of general trend in the past 150 years, South Hongshan Lake was shrinking gradually. It showed that, from the comparison with the Guliya ice core and meteorological records of adjacent weather stations, there is difference in the variations of temperature and precipitation among different regions and altitudes in Tibetan Plateau. It is necessary to search multi-scale and high-resolution records for environmental reconstruction and comparison.

关键词： Kunlun Mts. south Hongshan Lake lake sediments geochemistry environmental changes

On the major proposals for carbon emission reduction and some related issues

在线全文

学校读者我要写书评

暂无评论

Science China Earth sciences 2010年第12期53卷 159-172页

作者： DING ZhongLi1,DUAN XiaoNan2.GE QuanSheng3.& ZHANG ZhiQiang4 1 cas Key Lab of Cenozoic Geology and Environment,institute of Geology and Geophysics,Chinese Academy of {2.,beijing 10002.,China 2.The General Office of Chinese Academy of {2.,beijing 100864,China 3.institute of geographic {2. and Natural resources {13.,Chinese Academy of {2.,beijing 100101,China 4 The Lanzhou Branch of the National Science Library,Scientific Information Center for resources and Environment of cas,Lanzhou 73.000,China 1. cas Key Lab of Cenozoic Geology and Environment Institute of Geology and Geophysics Chinese Academy of Sciences Beijing 100029 China2. The General Office of Chinese Academy of Sciences Beijing 100864 China3. Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 China4. The Lanzhou Branch of the National Science Library Scientific Information Center for Resources and Environment of CAS Lanzhou 730000 China

We evaluated and ran simulations for seven proposals for the reduction of global CO2.emissions (e.g.,those of the Intergovernmental Panel on Climate Change (IPCC),United Nations Development Program,and Organization for Economic Cooperation and Development).All the proposals ignored the fact that the cumulative CO2.emissions per capita for developed countries were 7.54 times those for developing countries in the historical period of *** proposals further deliberately allocate 2.06-2.50 emission quotas to developed countries that are 2.3.6.7 times those to developing *** will seriously violate the development rights of developing *** paper clearly states that proposals such as that of the IPCC are not suitable references for future international climate change negotiations as they violate the fundamentals of fairness and equity in international relationships and the UNFCCC principle of "common but differentiated responsibilities".Comparing estimates of emissions in China in the scenario of rapid development with low-CO2.emission technology in the period 2.06-2.50 with estimates for other countries and groups,we find that China can logically and morally argue for equivalent emission rights even in the case of the strict CO2.concentration target of 450-470 ppmv.

关键词： CO2 emission reduction cumulative CO2 emission per capita emission rights

同方期刊数据库

Study on the changes of water cycle and its impacts in the source region of the 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 142-151页

作者： ZHANG Shifeng1, JIA Shaofeng1, LIU Changming1, CAO Wenbing2. HAO Fanghua3. LIU Jiuyu4 & YAN Huayun5 1. institute of geographic {2. and Natural resources research, Chinese Academy of {2., beijing 100101, China 2. China University of Geo{2., beijing 100083. China 3. beijing Normal University, beijing 100875, China 4. Bureau of Hydrology of Yellow River Conservancy Commission, Zhengzhou 450003. China 5. Bureau of Hydrology and Water Resource Investigation of Qinghai Province, Xining 810001, China 1. institute of geographic {2. and Natural {3. research Chinese Academy of Sciences 100101 Beijing China2. China University of Geosciences 100083 Beijing China3. Beijing Normal University 100875 Beijing China4. Bureau of Hydrology of Yellow River Conservancy Commission 450003 Zhengzhou China5. Bureau of Hydrology and Water Resource Investigation of Qinghai Province 810001 Xining China

The water cycle in the source region of the Yellow River underwent great changes in the 1990s. The major features of the changes are as follows: the gauged runoff declined significantly while the precipitation increased slightly, and the runoff process was more concentrated on the flood season. Water balance analyses indicate that the pondage was kept in the status of negative equilibrium, causing eco-environmental problems. The runoff decrement is due to evaporation increment in this region. Studies show that the runoff process in this region is closely related to that of the other hydrological stations in the upper reaches. When the runoff declines in the source regions, the amount of water also declines in the whole upper reaches of the Yellow River, affecting the balance between water demand and supply. Meanwhile changes will take place in the water cycle of the river course system when the eco-environment deteriorates. The trend of water cycle change in the source region is that the runoff will keep declining with the increment of evaporation caused by temperature rise in the northwest of China in the 2.st century. But the hydraulic engineering in the source region will help to mitigate the deterioration of local eco-environment system, though the impacts to the lower reaches of this project may not be the case.

关键词： source region of the Yellow River, water cycle, evaporation, negative equilibrium.

Effects of Temperature and Water Saturation on CO_2.Production and Nitrogen Mineralization in Alpine Wetland Soils

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 71-77页

作者： GAO Jun-Qin OUYANG Hua XU Xing-Liang ZHOU Cai-Ping ZHANG Feng beijing Forestry University Beijing 100083 （China） institute of geographic {2. and Natural {3. research Chinese Academy of Sciences Beijing 100101 （China） Graduate University of the Chinese Academy of sciences Beijing 100049 （China）

Relationships between carbon (C) production and nitrogen (N) mineralization were investigated in two alpine wetland soils of the Tibetan Plateau using laboratory incubation under different temperatures (5, 15, 2., and 3. ℃) and water saturation (noninundation and inundation). A significant positive relationship was found between CO2.production and N mineralization under increasing temperatures from 5 to 3. ℃ with the same water saturation condition in the marsh soil (r2.> 0.49, P 2.> 0.3., P 2., and a negative relationship with water saturation increasing at the same temperature, especially 2. and 3. ℃, in the marsh soil (r2.> 0.70, P 2.> 0.61, P 3.. In conclusion, temperatures and water saturation could regulate the relationship between CO2.production and net N mineralization in the Tibetan alpine marsh and peat soils.

关键词： CO2.production N mineralization temperature water saturation wetland

Spatial and temporal variation of soil moisture near the interface of high/low stands

在线全文

学校读者我要写书评

暂无评论

Journal of geographical sciences 2000年第4期10卷 109-120页

作者： Liu Su-xia, Mo Xing-guo (institute of geographic {2. and Natural {3. research, Chinese Academy of {2., beijing 100101, P. R. China) 中科院地理科学与资源所北京

In order to explore the spatial variability of soil moisture near the interface of high/low stands, an experiment was conducted at Luancheng Experimental Station, Chinese Academy of sciences, Hebei, China from May to June, 1996. By analyzing the observed soil moisture data, it shows that there exists an obvious turning point of soil moisture pattern from one side of the interface to another. The effect of drier soil closer to the interface in winter wheat field is obvious, which is mainly due to the better ventilation condition near the interface in winter wheat filed than in alfalfa field. The irrigation in large scale is one of the most important factors to control the spatial pattern of soil moisture while the small scale human disturbing activity, such as the stealing event occurred during our observation, does not change the spatial pattern of soil moisture obviously. Latent heat, calculated by Bowen ratio method based on our observed micrometeorological data, is shown larger in alfalfa than that in winter wheat both at earring stage from May 8 to 10 and mature stage from June 11 to 14. This fact, together with the larger ground temperature and a little bit larger wind velocity in lower layer, explains that the soil is drier in alfalfa than in winter wheat from May 8 to 10. While for the period from June 11 to 14, irrigation's effect changes the natural interrelationship of soil moisture with meteorology and ground temperature.

关键词： soil moisture interface of alfalfa/winter wheat field

Differential Hydrological Grey Model (DHGM) with self-memory function and its application to flood forecasting

在线全文

学校读者我要写书评

暂无评论

Science China(Technological sciences) 2009年第4期52卷 1039-1049页

作者： CHEN XiangDong1, XIA Jun1,2.& XU Qian3.1 Key Laboratory of Water Cycle and Related Land Surface Processes, institute of geographic {2. and Natural resources research, Chinese Academy of {2., beijing 100101, China 2.State Key Laboratory of Water resources and Hydropower Engineering Science, Wuhan University, Wuhan 43.072. China 3.School of Hydrology and Water resources, Hohai University, Nanjing 2.0098, China 1. Key Laboratory of Water Cycle and Related Land Surface Processes Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 China 2. State Key Laboratory of Water resources and Hydropower Engineering Science Wuhan University Wuhan 430072 China 3. School of Hydrology and Water resources Hohai University Nanjing 210098 China

This paper addresses a problem of flood forecasting with the self-memory function. Considering flood forecasting’s uncertainty and updating demand, a hybrid hydrological model, namely Differential Hy- drological Grey Model with self-memory function (DHGM-SM), is developed. The model has two fold features. One is to establish a self-memorization equation linked with DHGM, that could extract useful information from past data series and realize updating of hydrological dynamic process. The other is that this model has higher efficiency relative to original hydrological model without self-memory func- tion. This approach was applied to river flow forecasting of two representative basins in Tunxi of South China and Daqinggou of North China. It is shown that this hybrid method has satisfactory forecasting accuracy by examination of both calibration and validation.

关键词： differential grey model the self-memorization principle real-time forecasting faded-memory recursive least square method