检索结果-南通市图书馆

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

在线全文

学校读者我要写书评

暂无评论

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

The study on Sanmenxia annual flow forecasting in the Yellow River with mix regression model

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 118-126页

作者： JIANG Xiaohui1, LIU Changming1,2, wang Yu3 & wang Hongrui1 1. beijing Normal University, beijing 100875, china 2. institute of geographic science and natural resources, Chinese Academy of sciences, beijing 100101, china 3. Reconnaissance, Planning, Design and research institute, YRCC, Zhengzhou 450003, china beijing Normal University Beijing China institute of geographic science and natural resources Chinese Academy of Sciences Beijing China Reconnaissance Planning Design and Research Institute YRCC Zhengzhou China

This paper established mix regression model for simulating annual flow, in which annual runoff is auto-regression factor, precipitation, air temperature and water consumption are regression factors; we adopted 9 hypothesis climate change schemes to forecast the change of annual flow of Sanmenxia Station. The results show : (1) When temperature is steady, the average annual runoff will increase by 8.3% if precipitation increases by 10%; when precipitation decreases by 10%, the average annual runoff will decrease by 8.2%; when precipitation is steady, the average annual runoff will decrease by 2.4% if temperature increases 1℃; if temperature decreases 1℃, runoff will increase by 1.2%. The mix regression model can well simulate annual runoff. (2) As to 9 different temperature and precipitation scenarios, scenario 9 is the most adverse to the runoff of Sanmenxia Station of Yellow River; i.e. temperature increases 1℃ and precipitation decreases by 10%. Under this condition, the simulated average annual runoff decreases by 10.8%. On the contrary, scenario 1 is the best to the enhancement of runoff; i.e. when temperature decreases 1 ℃ precipitation will increase by 10%, which will make the annual runoff of Sanmenxia increase by 10.6%.

关键词： forecast annual flow, mix regression model, Sanmenxia Station

GIS and ANN model for landslide susceptibility mapping

在线全文

学校读者我要写书评

暂无评论

Journal of geographical sciences 2001年第3期11卷 374-381页

作者： XU Zeng-wang (State Key Laboratory of resources and Environment Information System, institute of geographic sciences and natural resources research, cas, beijing 100101, china) State Key Laboratory of resources and Environment Information System Institute of Geographic Sciences and Natural Resources Research CAS

Landslide hazard is as the probability of occurrence of a potentially damaging landslide phenomenon within specified period of time and within a given area. The susceptibility map provides the relative spatial probability of landslides occurrence. A study is presented of the application of GIS and artificial neural network model to landslide susceptibility mapping, with particular reference to landslides on natural terrain in this paper. The method has been applied to Lantau Island, the largest outlying island within the territory of Hong Kong. A three-level neural network model was constructed and trained by the back-propagate algorithm in the geographical database of the study area. The data in the database includes digital elevation modal and its derivatives, landslides distribution and their attributes, superficial geological maps, vegetation cover, the raingauges distribution and their 14 years 5-minute observation. Based on field inspection and analysis of correlation between terrain variables and landslides frequency, lithology, vegetation cover, slope gradient, slope aspect, slope curvature, elevation, the characteristic value, the rainstorms corresponding to the landslide, and distance to drainage Une are considered to be related to landslide susceptibility in this study. The artificial neural network is then coupled with the ArcView3.2 GIS software to produce the landslide susceptibility map, which classifies the susceptibility into three levels: low, moderate, and high. The results from this study indicate that GIS coupled with artificial neural network model is a flexible and powerful approach to identify the spatial probability of hazards.

关键词： GIS artificial neural network model landslide susceptibility mapping

Straight river: its formation and speciality

在线全文

学校读者我要写书评

暂无评论

Journal of geographical sciences 2002年第1期12卷 72-80页

作者： wang Sui-ji1, NI Jin-ren2 (1. institute of geographic sciences and natural resources research, cas, beijing 100101, china 2. Center for Environmental science, Peking University, beijing 100871, china) institute of geographic sciences and natural resources research CAS 北京 100101 Center for Environmental science Peking University 北京 100871

Straight river is generally regarded as one of the typical river patterns in conventional classifications in terms of their channel plain landforms. However, very few straight patterns were found to be distributed in wider spatial and temporal spans in the self-adjusted fluvial rivers. Thus, the questions occur such as that is it possible for a channel takes on a stable straight pattern? What are the main factors controlling the processes of the river pattern formation and transformation from a straight to other patterns? Various theories and hypotheses including geomorphic threshold hypothesis, the extreme hypothesis on energy dissipation rate, the stability theory, etc. have been developed to explain the aforementioned questions, but none of them is sound for the explanation to the straight-river formation. From the modern fluvial plain patterns, the straight patterns are not as stable as other typical patterns which occurred in nature; from the historic records of the river sedimentation, no apparent evidence was found to support the stable straight river evolution. Based on the analysis of existing theories, observations, evolvement processes of the channel patterns in the experimental results, this paper concluded that the straight pattern should not be included as one of the typical patterns that are self-formed and developed. This study is of importance to understanding of the river pattern formation and transformation.

关键词： straight river formation cause evolvement sedimentation

Reconstruction of precipitation variation from tree rings in recent 1000 years in Delingha, Qinghai

在线全文

学校读者我要写书评

暂无评论

science china Earth sciences 2005年第7期48卷 939-949页

作者： SHAO Xuemei1, HUANG Lei1, LIU Hongbin2, LIANG Eryuan1, FANG Xiuqi3 & wang Lili1 1. institute of geographic sciences and natural resources research, Chinese Academy of sciences, beijing 100101, china 2. National Climate Center, beijing 100081, china 3. beijing Normal University, beijing 100875, china institute of geographic sciences Natural Resources Research Chinese Academy of Sciences Beijing 100101 China National Climate Center Beijing 100081 China beijing Normal University Beijing 100875 China

Using seven well-replicated Qilian juniper (Sabina przewalskii Kom.) ring-width chronologies developed at Zongwulong and Shalike Mts. in the northeastern part of the Qaidam Basin annual precipitation from previous July to current June in the recent 1000 years was re- constructed for Delingha. The reconstruction can capture 63.1% of precipitation variance and the equation was stable over time. For the reconstructed precipitation, wet periods occurred in AD1520—1633 and 1933—2001, whereas dry intervals in 1429—1519 and 1634—1741. In ad- dition, the magnitude in precipitation variation was lower before 1430 with about 15 mm, but it increased to 30 mm during the period of 1430 to 1850. After 1850, the precipitation variance de- creased again. In contrast to the increase in temperature, a decrease in annual precipitation was evident since the 1990s. The agreement in low-frequency variation between the reconstruction and the glacier accumulation and particulate content in Dunde ice cores during the recent several hundred years suggested that the precipitation reconstructed in this study was rather reliable, and represented a regional signal. This 1000-year reconstruction could benefit our understanding of climatic variation in decadal to century-scale in this region, and provide basic data to climate models and to prediction of future climate in the 21st century.

关键词： northeastern part of the Qaidam Basin tree-ring width series of Qilian juniper precipitation reconstruction in 1000 years.

A distributed hydrological model with its application to the Jinghe watershed in the Yellow River Basin

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 60-71页

作者： wang Zhonggen1, ZHENG Hongxing1, LIU Changming1, , WU Xianfeng2 2 & ZHAO Weimin3 1. Key Laboratory of Water Cycle & Related Land Surface Processes, institute of geographic science and natural resources research, Chinese Academy of sciences, beijing 100101, china 2. institute of Environmental science, beijing Normal University, beijing 100875, china 3. Water resources Conservation Committee of Yellow River, Zhengzhou 450003, china Key Laboratory of Water Cyde & Related Land Surface Processes Institute of Geographic Science and Natural Resources Research Chinese Academy of Sciences Beijing China institute of Environmental science Beijing Normal University Beijing China Water resources Conservation Committee of Yellow River Zhengzhou China

For the purpose of water resources management in the Yellow River Basin with highly spatial difference, a daily distributed hydrological model was proposed, of which the determination of spatially-distributed parameters and model inputs processing were performed by means of GIS/RS. In the model, the computation of runoff yield was based on the topography index method and flow routing was modeled by Maskingum method. The operation of the model is followed by means of “command structure” technique based upon the topography of river network. A case study using the model was conducted for the Jinghe watershed, which locates at the middle Yellow River Basin. The simulation of the hydrological processes in 1996 has shown that water quantity balance errors were less than 5% and the Nash-Sutcliffe coefficient arrived at 0.7, indicating that the model structure is justifiable, and the precision of the model can satisfy the purpose of water resources management.

关键词： distributed hydrological model, structure and equation, GIS and RS, Jinghe Basin, Yellow River Basin.

Comparative analysis of temperature and CO2 fluxes for winter wheat in Tibetan Plain and North china Plain using the EMD method

在线全文

学校读者我要写书评

暂无评论

Progress in natural science:Materials International 2006年第10期16卷 1066-1071页

作者： JIANG Zhaoyang, YU Qiang, LEI Shuhe, wang Tianduo, SUN Xiaomin and ZHANG Renhua ( Chinese Academy of Meteorological science, beijing 100081, china institute of geographic sciences and natural resources research, Chinese Academy of sciences, beijing 100101, china Mathematics Department, Ocean University of china, Qingdao 266071, china Shanghai institute of Plant Physiology and Ecology, Chinese Academy of sciences, Shanghai 200032, china) Chinese Academy of Meteorological science Beijing 100081 China institute of geographic sciences and natural resources research Chinese Academy of Sciences Beijing 100101 China Mathematics Department Ocean University of China Qingdao 266071 China Shanghai institute of Plant Physiology and Ecology Chinese Academy of Sciences Shanghai 200032 China

Comparative study of spectral properties of temperature and CO2 fluxes measured by eddy covariance method at Yucheng (36°57'N, 116°36'E, 28 m a.s.l., in the North china Plain) and at Lhasa (29°41'N, 91°20'E, 3688 m a.s. 1., on the Tibetan Plateau) is described using the empirical mode decomposition (EMD) method. The main results are: (1) The intrinsic oscillation modes or intrinsic mode functions (IMFs) were extracted from data of temperature ( T) and CO2 fluxes (F) measured at Yucheng ( T1 and F1) and Lhasa ( T2 and F2) . (2) Hilbert transform was applied to these IMF components, then the Hubert-Huang spectra and the marginal spectra of these data were obtained. (3) Comparison of temperature and CO2 fluxes in North china Plain and on Tibetan Plain illustrated that the characteristic frequencies corresponding to T1, F1, T2 and F2 are 0.05 Hz, 0.03 Hz, 0.014 Hz and 0.005 Hz, respectively.

关键词： empirical mode decomposition (EMD) intrinsic mode function (IMF) flux Hilbert transform wheat Tibet.

Continuous wavelet transform and discrete multi-resolution analysis of surface fluxes and atmospheric stability

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Progress in natural science:Materials International 2006年第4期16卷 403-409页

作者： JIANG Zhaoyang, YU Qiang, wang Tianduo, SUN Xiaomin and ZHANG Renhua Shanghai institute of Plant Physiology and Ecology, Chinese Academy of sciences, Shanghai 200032, china institute of geographic sciences and natural resources research, Chinese Academy of sciences, beijing 100101, china Shanghai institute of Plant Physiology and Ecology Chinese Academy of Sciences Shanghai 200032 China institute of geographic sciences and natural resources research Chinese Academy of Sciences Beijing 100101 China

Variations of land surface fluxes of sensible heat (H), latent heat (LE), and CO2(F-CO2) obtained from the eddy-co-variance measurements above a winter wheat field from March 30 to April 24, 2001 have been studied at scales ranging from 10 minutes to days. Wavelet transform is used in the analysis of land surface fluxes and atmospheric stability (ξ) calculated from the measurements to reveal the changes in land surface fluxes in hours to days scales. The main results are: (1) Concise and compact information about the fluxes, net radiation (Rn), temperature ( T) and ξ in the scale-time domain are extracted from the data by continuous wavelet analysis, and 1 day, 0.5 day and short-period (shorter than 0.5 day) components are revealed. Continuous wavelet coefficients can be used to characterize periodic components of changes in fluxes and ξ. (2) Discrete-time multi-resolution analysis can be used to concentrate total energy variance of time series of the measurements to a small number of coefficients, plotting the relative energy distribution to get several meaningful characteristics of the data. (3) Under neutral atmospheric conditions, the relative energy distributions of the Haar multi-resolution analysis of the three non-dimensional coefficients ( T/T* , q/q * and c/c * ) display clear similarities.

关键词： atmospheric stability flux continuous wavelet transform multi-resolution wavelet analysis.

Origin Distribution Patterns and Floating Population Modeling:Yiwu City as a Destination

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese geographical science 2012年第3期22卷 367-380页

作者： LI Hongsheng wang Yingjie HAN Jiafu State Key Laboratoty of resources and Environmental Information System Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China

Existing quantitative migration studies are mainly at the inter-region or inter-province level for lacking of detailed geo-referenced migration ***,few of them integrate explorative spatial data analysis and spatial regression model into migration *** on aggregated registered floating population data from 2005 to 2008,the phenomena that population floating to Yiwu City in Zhejiang Province is analyzed at the provincial and county *** spatial layout of Yiwu's pull forces is proved as a V-shaped pattern excluding Sichuan Province based on map visualization *** the migration ratio in 2007 as an explanatory variable,two models are compared using ordinary least square,spatial error model and spatial lag model methods for county-level data in Jiangxi and Anhui *** model with migration stock provides an improved fitting over the model without migration stock according to the model fitting *** floating population flocking into Yiwu City from Jiangxi is determined mostly by migration stock while the determinant factors are migration stock and distance to Yiwu City for *** distance-decay effect is true for migration flow from Anhui to Yiwu City while the distance rule is not confirmed in Jiangxi with the best fitting *** correlation between per capita net income of rural labor forces and migration ratio is not significant in Jiangxi and significant but at the 0.1 level only in *** analysis shows that the distance,income and man-land ratio are important factors to explain population floating at earlier ***,as the dynamic population floating process evolves,the determinant factor would be migration stock.

关键词： floating population origin distribution visualization spatial regression model Yiwu City GIS