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Search Results: 1 - 10 of 117804 matches for " LIU Chang-Ming "
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On the importance of rainwater utilization and agricultural water supply
论雨水利用及其农业供水的意义

Liu Chang-ming,
刘昌明

中国生态农业学报 , 1999,
Abstract: Certain theory problems concerned with evaluation and utilization of water resources in China are discussed from the view of agricultural water supply.Rainwater utilization is probed into in combination of agriculture and rural water supply,and some suggestions are put forward for fully rainwater utilization.
Asynchronism-synchronism of regional precipitation in South-to-North Water Transfer planned areas

ZHENG Hong-xing,LIU Chang-ming,

地理学报 , 2001,
Abstract: This paper proposes a method on analyzing the asynchronism-synchronism of precipitation of different hydrological regions regarding the S-to-N water transfer areas of eastern China. The general process of the analysis includes three steps. Firstly, we created the rainfall series of the region concerned by calculating the regional average rainfall of the stations in the area with the help of the classical Thiessen Polygon method. Secondly, the standards of assessment indices for wetness or dryness are set according to Gamma distribution function with a certain probability P 37.5% or 62.5% given respectively. Finally, the frequency of nine combinations are counted as the quantitative feature of asynchronism and synchronism in three time scales, that is the yearly, seasonal and monthly scales. The asynchronism-synchronism of two region pairs has been estimated. The results show that the frequency of precipitation asynchronism in 1957-1998 is larger than the synchronism frequency for both the North China-middle and lower Yangtze River pair and for the North China-upper Hanjiang River pair. As for the synchronism phenomena, the frequency of Nd-Sd is rather low. As the combinations that are suitable for water transfers are Nd-Sw, Nn-Sw, Nd-Sn and Nn-Sn, the total frequency of these combinations for North China-middle and lower Yangtze River is 40% on an annual basis, but only 28% in spring when water shortages are most likely to occur. The total frequency of these combinations for North China-upper Hanjiang River is about 24% on an annual basis, but 35% in spring and winter. It should be noted that if future precipitation patterns are similar to that of the period 1957-1998, it is very important to change the natural character of asynchronism-synchronism by enhancing the capability of hydro-projects regulation and improving management of the water transfer project.
Asynchronism-synchronism of regional precipitation in South-to-North Water Transfer planned areas
Zheng Hong-xing,Liu Chang-ming,
ZHENG Hong-xing
,LIU Chang-ming

地理学报(英文版) , 2001,
Abstract: This paper proposes a method on analyzing the asynchronism-synchronism of precipitation of different hydrological regions regarding the S-to-N water transfer areas of eastern China. The general process of the analysis includes three steps. Firstly, we created the rainfall series of the region concerned by calculating the regional average rainfall of the stations in the area with the help of the classical Thiessen Polygon method. Secondly, the standards of assessment indices for wetness or dryness are set according to Gamma distribution function with a certain probability P 37.5% or 62.5% given respectively. Finally, the frequency of nine combinations are counted as the quantitative feature of asynchronism and synchronism in three time scales, that is the yearly, seasonal and monthly scales. The asynchronism-synchronism of two region pairs has been estimated. The results show that the frequency of precipitation asynchronism in 1957-1998 is larger than the synchronism frequency for both the North China-middle and lower Yangtze River pair and for the North China-upper Hanjiang River pair. As for the synchronism phenomena, the frequency of Nd-Sd is rather low. As the combinations that are suitable for water transfers are Nd-Sw, Nn-Sw, Nd-Sn and Nn-Sn, the total frequency of these combinations for North China-middle and lower Yangtze River is 40% on an annual basis, but only 28% in spring when water shortages are most likely to occur. The total frequency of these combinations for North China-upper Hanjiang River is about 24% on an annual basis, but 35% in spring and winter. It should be noted that if future precipitation patterns are similar to that of the period 1957-1998, it is very important to change the natural character of asynchronism-synchronism by enhancing the capability of hydro-projects regulation and improving management of the water transfer project.
The Analysis about Water Resource Utilization, Ecological and Environmental Problems in Northeast China
东北地区水资源利用与生态和环境问题分析

LIU Zhuo,LIU Chang-ming,
刘卓
,刘昌明

自然资源学报 , 2006,
Abstract: 东北地区是我国著名的老工业基地,50年来,在工农业持续发展的同时,地区水土资源开发利用规模不断扩大,由此引发了一系列与水相关的生态和环境问题,解决该地区水资源利用与生态和环境问题势在必行。文章在分析东北地区水资源利用现状与问题的基础上,具体论述了水污染严重、河道断流、地下水超采、湿地大面积缩小以及西部地区土地荒漠化加剧等与水相关的生态和环境问题,提出了解决问题的具体对策与建议。合理利用地区水资源,量水而行、适水发展,节约与高效并举,建设资源节约、环境友好型社会是实现东北地区可持续发展的必然选择。
Research on the deterministic complex network model based on the Sierpinski network
基于Sierpinski分形垫的确定性复杂网络演化模型研究

Xing Chang-Ming,Liu Fang-Ai,
邢长明
,刘方爱

物理学报 , 2010,
Abstract: 近年来,人们发现大量真实网络都表现出小世界和无尺度的特性,由此复杂网络演化模型成为学术界研究的热点问题. 本文基于Sierpinski分形垫,通过迭代的方式构造了两个确定性增长的复杂网络模型,即小世界网络模型(S-DSWN)和无尺度网络模型(S-DSFN);其次,给出了确定性网络模型的迭代生成算法,解析计算了其主要拓扑特性,结果表明两个网络模型在度分布、集聚系数和网络直径等结构特性方面与许多现实网络相符合;最后,提出了一个确定性的统一模型(S-DUM),将S-DSWN与S-DSFN纳入到一个框架之下,为复
Trend analysis of hydrological components in the Yellow River basin
黄河流域水循环要素变化趋势分析

LIU Chang-ming,ZHENG Hong-xing,
刘昌明
,郑红星

自然资源学报 , 2003,
Abstract: This paper attempts to detect the trends of hydrologic cycle components in the concerned region.The hydrologic components are separated from monthly precipitation and natural runoff series based on the schemes proposed herein.Mann-Kendall method has been applied to detect the trends of the hydrologic components.For the Lanzhou station,only surface runoff(RS)showed a decreasing trend.As for the Huayuankou station,the results showed that RN,RS and RG have a strong decreasing trend,while the decreasing trend of the other components is not significant enough.Furthermore,impacts of human activities,climatic changes and annual runoff coefficient change on hydrologic cycle components have been discussed.The study suggests that increasing water resources development and utilization may be the most important factors for the frequent drying-up in the main course of the Yellow River.Moreover,the similarities of the trends in precipitation and natural runoff suggest a linkage exists between climatic change and hydrologic cycle change.With regard to intensified human activities and climatic change,knowledge about the regional hydrologic cycle change should be seen as the base for searching for an adaptation strategy in water resources use.The Yellow River basin,located in the semi-humid,semi-arid and arid climatic zones,is characterized by vertical hydrological cycle,which means a strong evapotranspiration.Thus,it is important to control that part of water consumption through adjustment of water utilization.Water-saving agriculture must be one of the most important ways to alleviate water resources deficit in the region.Therefore,industrial structure adjustment should also be under consideration for sustainable development in the basin.
An analysis of the relationship between water resources and population-economy-society-environment
浅析水资源与人口、经济和社会环境的关系

LIU Chang-ming,WANG Hong-rui,
刘昌明
,王红瑞

自然资源学报 , 2003,
Abstract: Water resources serve as the material base of the existence and development of human beings.It is a huge complicated system involving population,economy,society and environment.Water resources and water cycle are the keys in the system.Based on the summarization of the water resources concept and its attribute of nature,economy and society,this paper discusses the relationships between water resources and water cycle,water-balance structure,population,economy,society and environment in details.The paper also emphasizes the interactions of water cycle and water balance,water resources utilization and evaluation,economic activity,and water resources carrying capacity.Given an example of the Yellow River valley,the paper states that there is a closer relationship between water resources,population,economy,society and environment.The author gives a definite concept and connotation of water resources carrying capacity on the base of summing up the former studies.Summarizing the model system of water resources carrying capacity,the author also points out that it is very essential to use the system to depict the complex relationship between water resources and other four aspects,namely population,economy,society and environment.Considering the problem from the viewpoint of the regional sustainable development and alleviating the benefit conflict of distribution of water resources,we should clarify the following aspects:water demands for ecological environment,including rivers,animals,plants and land;water demands for population and social-economic development;and water environment capacity that can tolerate certain amount of pollutants.So,in order to promote the sustainable development of population,economy,society and environment,it is of great significance to simulate and predict the evolvement of the huge complex system with the combination of remote sensing,GIS and modern math theory,seek a reasonable allocation of water resources carrying capacity,and study the enhanced module of water resources carrying capacity.
Agro-ecosystems water cycles of the typical irrigated farmland in the North China Plain
华北平原典型井灌区农田水循环过程研究回顾

SHEN Yan-Jun,LIU Chang-Ming,
沈彦俊
,刘昌明

中国生态农业学报 , 2011,
Abstract: This paper reviewed the research progresses on hydrological cycles and water transformation studies at Luancheng Agro-Ecosystem Experimental Station, Chinese Academy of Sciences (simplified as Luancheng Station) during the past 30 years. As a mostly achieved progress, the evapotranspiration (ET) and its partitioning over irrigated winter wheat-summer maize cropland, which is the most common cultivation pattern in North China Plain, are clarified through multi-years observations using weighing lysimeter, micrometeorological measurements, and isotopic analysis. The annual ET of the irrigated wheat-maize field can reach to 870 mm·a-1, which exceeds the annual precipitation by around 350 mm at an average level. This gap between annual ET and precipitation is bridged by groundwater pumpage. As a matter of long-term over exploitation, the groundwater over the North China Plain experienced rapid depletion and caused wide concerns on sustainability. The study at Luancheng Station suggests that the soil evaporation shares about 1/3 of the total water consumption and the evaporation depth can reach deep to 20 cm under land surface through a isotopic method. Moreover, wheat transpiration is mainly dependent on the soil moisture in the depth of 0~40 cm soil layer, which is largely shallower than the generally used "planing wetting depth", i.e. 100 cm. As for the deep percolation or drainage of the soil water and the vertical recharge rate of groundwater, there exists large range among different studies with different method, such as soil water balance modeling, rainfall-infiltration experiment, etc. It is urgently needed to go to the details of water cycles over different agricultural land uses and soil properties, and to address the spatial heterogeneities in evapotranspiration, infiltration, and soil water balancing, over the plain.
Rainwater Resource And Its Utilization in Eco-agriculture
雨水资源以及在农业生态中的应用

LIU Chang-ming,MOU Hai-sheng,
刘昌明
,牟海省

中国生态农业学报 , 1993,
Abstract: Based on the recent progress in international rainwater studies and the theory of five-water interaction,the authors analysed a context of rainwater resource and its utilization.A case study from the North China was given to indicate the importance and function of rainwater in eco-agriculture.Rainwater can be used by direct and indirect ways.For ecological agriculture the direct user of rainfall is of great significance in building up a retention capacity of a soil layer where the crop root system are active.On basis of effectiveness of rainwater use,authors laid emphasis on a coupling system of rainwater catchment and soil reservoir.In addition to this,the authors also suggested controlling the rainwater through soil water regulation indexes.Finally,an example of rainwater regulation taken from Yucheng comprehensive experimental station was given in the present paper.
Supply and demand of water resources and analysis of crop water use efficiency in the North China Plain
华北平原水资源供需与作物水分利用效率指征分析

Wang Hui-,xiao,Liu Chang-ming,
王会肖
,刘昌明

中国生态农业学报 , 1999,
Abstract: 水资源短缺,地下水位大面积下降,是限制华北平原农业可持续发展的重要原因。分析研究了可 持续农业水资源利用的内涵、农田水分利用效率的指征和调控指标等方面内容,为华北平原地区农业水资源高效利用及其可持续管理提供科学依据。
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