检索结果-南通市图书馆

Calculating soil moisture by remote sensing and analyzing hydrologic cycle process in the Yellow River basin

science china(Technological sciences) 2004年第z1期47卷 1-13页

作者： YANG Shengtian1 & LIU Changming1, 2.1. School of Environmental sciences, beijing Normal University, beijing 100875, china 2. institute of Geographic science and natural Resources research, beijing 100101, china beijing Normal Univ Sch Environm Sci Beijing 100875 Peoples R China Inst Geog Sci & Nat Resources Beijing 100101 Peoples R China

Based on the AVHRR pathfinder remote sensing data, soil moisture, precipitation and evaporation during the period of 1982.1998, soil moisture of all layers of soil-profile (0—1 m) in the Yellow River basin over the 17 years are calculated by the remote sensing model of calculating soil water. The Yellow River basin is divided into seven subcatchments as control sections at the location of six hydrologic stations (Lanzhou, Toudaoguai, Longmen, Sanmenxia, Huayuankou and Lijin). After calculating soil moisture and obtaining runoff data and precipitation data, the dynamical features of hydrological cycle in the Yellow River basin are analyzed for the period from 1982.to 1988 using water balance method. The conclusions are as follows: It is feasible to calculate the soil water on the macro-scale, in the soil profile with temporal continuity by means of remote sensing and survey in land. Some values of the key water cycle factors in the Yellow River are obtained, which include the annual precipitation of 4000 km3. the evapotranspiration of 3.00-3.00 km3. and the soil moisture transformation of ?500- 500 km3. Consequently, we analyzed the process of the water cycle in the Yellow River over the 17 years, and the results show that the segment upstream of Lanzhou city is a relatively humid region, and the area of internal waters and the reaches of Shanshan is the most desiccated region. Therefore, the runoff in the depth process is intensive and the runoff-generating process is weak in more arid regions.

关键词： the Yellow River, soil moisture, remote sensing, hydrologic cycle.

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

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

引用

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,{2. 2. institute of Geographic science and natural Resources, Chinese Academy of sciences, beijing 100101,{2. 3. Reconnaissance, Planning, Design and research institute, YRCC, Zhengzhou 450003.{2. beijing Normal Univ Beijing 100875 Peoples R China Chinese Acad Sci Inst Geog Sci & Nat Resources Beijing 100101 Peoples R China YRCC Reconnaissance Planning Design & Res Inst Zhengzhou 450003 Peoples R 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

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

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

引用

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 {3. and {2. Resources research, Chinese Academy of {3.s, beijing 100101, china 2. institute of Environmental {3., beijing Normal University, beijing 100875, china 3. Water Resources Conservation Committee of Yellow River, Zhengzhou 450003. china Chinese Acad Sci Key Lab Water Cycle & Related Land Surface Proc Inst Geog Sci & Nat Resources Res Beijing 100101 Peoples R China beijing Normal Univ Inst Environm Sci Beijing 100875 Peoples R China Water Resources Conservat Comm Yellow River Zhengzhou 450003 Peoples R 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.

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Debris Flow Hazard Assessment Based on Support Vector Machine

引用

Wuhan University Journal of natural sciences 2006年第4期11卷 897-900页

作者： YUAN Lifeng 1, 2., ZHANG Youshui 3. 1. institute of Mountain Hazards and Environment, Chinese Academy of sciences, Chengdu 610041, Sichuan,{2. 2. Graduate University of Chinese Academy of sciences, beijing 100049,{2. 3. institute of Geographical sciences and natural Resources research, Chinese Academy of sciences,{13.,{2. institute of Mountain Hazards Environment Chinese Academy of Sciences 610041 Chengdu Sichuan China Graduate University of Chinese Academy of sciences 100049 Beijing China institute of Geographical sciences natural Resources research Chinese Academy of Sciences 100101 Beijing China

Seven factors, including the maximum volume of once flow , occurrence frequency of debris flow , watershed area , main channel length , watershed relative height difference , valley incision density and the length ratio of sediment supplement are chosen as evaluation factors of debris flow hazard degree. Using support vector machine （SVM） theory, we selected 2.9 basic data of 3. debris flow channels in Yunnan Province as learning samples in this study. We create a debris flow hazard assessment model based on SVM. The model was validated though instance applications and showed encouraging results.

关键词： debris flow hazard assessment support vector machine (SVM)

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

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

引用

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

作者： CHEN Junfeng1,2. LI Xiubin2.& ZHANG Ming2.1. {3. of Remote Sensing & GIS, Peking University, beijing 100871,{2. 2. {3. of Geographical sciences and natural Resources research, Chinese Academy of sciences, beijing 100101,{2. 1. institute of Remote Sensing & GIS Peking University 100871 Beijing China 2. institute of Geographical sciences and {2. Resources research Chinese Academy of Sciences 100101 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 2.%.

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

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Seismic wave propagating in Kelvin-Voigt homogeneous visco-elastic media

引用

science china Earth sciences 2006年第2期49卷 147-153页

作者： YUAN Chunfang1, PENG Suping1, ZHANG Zhongjie2.& LIU Zhenkuan3.1. china University of Mining & Technology, beijing 100083. china 2. institute of Geophysics, Chinese Academy of sciences, beijing 100101, china 3. Exploration and Development research institute of Daqing Oilfield, Daqing 163.12. china 1. china University of Mining & Technology Beijing 100083 China 2. institute of Geophysics Chinese Academy of Sciences Beijing 100101 China 3. Exploration and Development research institute of Daqing Oilfield Daqing 163712 China

This paper studies, under a small disturbance, the responses of seismic transient wave in the visco-elastic media and the analytic solution of the corresponding third-order partial differential equation. A plane wave solution of Kelvin-Voigt homogeneous visco-elastic third-order partial differ-ential equation with a pulse source is obtained. By the principle of pulse stacking of particle vibration, the result is extended to the solution of Kelvin-Voigt homogeneous visco-elastic third-order partial differential equation with any source. The velocities of seismic wave propagating and the attenuation of seismic wave in Kelvin-Voigt homogeneous visco-elastic media are discussed. The velocities of seismic wave propagating and the coefficient of attenuation of seismic wave in Kelvin-Voigt homogeneous visco-elastic media are derived, expressed as functions of density of the media, elastic modulus and visco-elastic coefficient. These results can be applied in inversing lithology parameters in geophysical prospecting.

关键词： Kelvin-Voigt visco-elastic velocity attenuation seismic wave.

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

The mathematical model of wetting angle of heterogeneous nucleation

引用

science china(Technological sciences) 2004年第4期47卷 391-397页

作者： HUANG Cheng1, SONG Bo1, MAO Jinghong2.& ZHAO Pei3.1. School of Metallurgical and Ecological Engineering, University of science and Technology beijing, beijing 100083. china 2. School of Material science, University of science and Technology beijing, beijing 100083. china 3. Central Iron and Steel research institute, beijing 100081, china 1. School of Metallurgical and Ecological Engineering University of Science and Technology Beijing 100083 Beijing China 2. School of Material science University of Science and Technology Beijing 100083 Beijing China 3. Central Iron and Steel research institute 100081 Beijing China

The heterogeneous nucleation has been analyzed in terms of the thermodynamic theory, and the mathematical model of wetting angle of heterogeneous nucleation has been developed based on the dynamic requirements of hetero- and homogeneous nucleation. With the wetting angel model, the wetting angles of different catalysts in liquid iron have been calculated. The result shows that the wetting angle of most catalysts is smaller than 40, and the value of f() is far less than 1. The wetting angles of TiN, TiC and RE2.3.are smaller, while the wetting angle of MnO is bigger among the ordinary nucleation catalysts. The wetting angles calculated by this model are in agreement with the results of other research work.

关键词： heterogeneous nucleation, mathematical model, wetting angle, undercooling.

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

N_2. emissions from agricultural soils in the North china Plain: the effect of chemical nitrogen fertilizer and organic manure

引用

Journal of Environmental sciences 2000年第4期12卷 463-468页

作者： DONG Yun\|she 1,2.3., Dieter Scharffe 2. Manfred Domroes 3. QI Yu chun 1, ZHANG Shen 1 (1. institute of Geographic {3.s and {2. Resources research, Chinese Academy of {3.s, beijing 100101, china E\|mail: dongys@*** 2. M 中科院地理科学与资源所北京 1 0 0 1 0 Max- Planck-institute of Chemistry 德国 Mainz 550 2 0 Mainz University 德国 Mainz 550 99

An enclosed chamber technique was used to measure N 2. emissions from intensively agricultural soils of the North china Plain during the periods of 1995—1996 and 1997—1998, to reflect distinct components of winter wheat and summer maize growing seasons. The results showed that the continuous application of fertilizer in agricultural soils increased N\-2. emissions by a factor of 2..1—2..1, the calculated annual chemical N fertilizer\|transformed N\-2.\|N emissions was 0.67%. Our results indicated that the application of organic manure also had a significant influence on soil N 2. emissions, which combined with the use of chemical N increased about 2.% in a year. It was calculated that there were about 0.11% N of organic manure transformed as N 2. N. Annual mean N 2. emission from our study area of fertilized soils was estimated to be 57.1 μgN 2./(m 2.h). A weak correlation was also found between N 2. emissions and soil available nitrogen content NH + 4.

关键词： N_2. emissions the North china Plain agricultural soils chemical nitrogen organic manure

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Relationships between tree-ring width index and NDVI of grassland in Delingha

引用

Chinese science Bulletin 2006年第9期51卷 1106-1114页

作者： HE Jicheng1,3.& SHAO Xuemei1,2.. institute of Geographical sciences and {2. Resources research, Chinese Academy of sciences, beijing 100101, china 2. institute of Tibetan Plateau research, Chinese Academy of sciences, beijing 100085, china 3. Graduate School of Chinese Academy of sciences, beijing 10003., china institute of Geographical sciences and {2. Resources {3. Chinese Academy of Sciences Beijing China Graduate School of Chinese Academy of sciences Beijing China institute of Tibetan Plateau research Chinese Academy of Sciences Beijing China

Using five well-replicated Qilian juniper (Sabina przewalskii Kom.) tree-ring width index se- ries, monthly normalized difference vegetation index (NDVI) of grassland, and climatic data from 1982.to 2.01, the relationships between tree-ring width index, NDVI of grassland, and climatic data were analyzed firstly. Then, the relationship between tree-ring width index and NDVI of grassland was explored. The re- sults showed that: (1) Temperature and precipitation in June influenced tree-ring width index and NDVI of grassland deeply in Delingha. (2. There were sig- nificant relationships between five tree-ring width index series (DLH1-DLH5) and monthly NDVI of grassland from June to September, with the most significant relationship being between tree-ring width index series and NDVI of grassland in August. (3. The PC1 (the first principal component derived from DLH1-DLH5 series) exhibited good agreement with monthly NDVI of grassland in the grass growth sea- son (from June to September) and the averaged NDVI in the growth season, which was attributed to their common responses to water-supply limit in Delingha. This study may allow an increase in studying the past dynamics of grassland in Delingha in that the variation of grassland NDVI during the last millennium has been reconstructed from PC1.

关键词：圆柏祁连山 NDVI 草原年轮宽度指数

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Interannual variability of Antarctic Oscillation and its influence on East Asian climate during boreal winter and spring

引用

science china Earth sciences 2006年第5期49卷 554-560页

作者： FAN Ke1,2.3.& WANG Huijun2.1. Nansen-Zhu International research Center, {3. of Atmospheric Physics, Chinese Academy of {2.s, beijing 10002., china 2. Department of Atmospheric {2., Yunnan University, Kunming 650091, china 3. Graduate University of the Chinese Academy of {2.s, beijing 100049, china 1. Nansen-Zhu International research Center Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China 2. Department of Atmospheric science Yunnan University Kunming 650091 China 3. Graduate University of the Chinese Academy of sciences Beijing 100049 China

The interannual variability of Antarctic Oscillation (AAO) and its influence on East Asian climate during both boreal winter and spring are addressed. The results show that the positive AAO anomaly decreases the cold activity over East Asia during both boreal winter and spring. AAO-related barotropic meridional teleconnection from Antarctic to Arctic is found through analysis of mean me- ridional circulations. This meridional teleconnection is remarkable over Eurasia during boreal winter and over the Pacific Ocean during boreal spring. The results also show that zonal mean zonal wind at high latitudes in Southern Hemisphere has well positive correlation with that of Eurasia during boreal winter and has negative correlation with Pacific North American teleconnection (PNA) during boreal spring, which again display the meridional teleconnection. Thus, local meridional teleconnection is a possible linkage for interaction of circulations at mid-high latitudes between both hemispheres.

关键词： Antarctic Oscillation, Eurasian west wind, meridional teleconnection, mean meridional circulation.

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：