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    Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    Liu Yunfen
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    In order to have a clear idea about the carbon cycle in the agro-ecological system of China,the uptake, emission,fixation and transfer of CO2 by the system in the years 1990 and 2000 are calculated and analysed,and a schematic map of carbon cycle in the agro-ecological system of China is drawn. The results indicate that the percentages occupied by the emission amount,fixation amount and transfer amount are 89. 7% 91.0% and 9.12% of the uptake amount respectively in the year 1990,and they are 7.83%, 1.18% and 1.16% respectively in the year 2000. It can be seen clearly that the CO2 uptake amount of the agro-ecological system of China is greater than the CO2 emission amount,and the system is a"sink"but not a"source"in respect to the atmospheric CO2 concentration in both the current periat and the peried after climatic change.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    Ni Shaoxiang, Jiang Jianjun
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    To draw up a scientific,reasonable and feasible exploitation scheme of a project area for its integrated developmem of agricultural resources is an important task to the integrated development of agricultural resources. Firsty,the project area should be tentatively selected through land evaluation and land productivity potential analysis. Secondly,the project area is finally determined through imput-output analysis and social and ecological benefit analysis.Thirdly,by making up a model of exploitation scheme for the project area and through an analysis of operation results of the medel as well as an appraisal of the exploitation scheme,the exploitation scheme of the project area is properly drawn up.In this paper,the principles and steps for drawing up an exploitation scheme of a project area is explored,taking the Tongnan Gaosha Mil Region in Tai County of Jiarigsu Province as an example.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    Shi Yubo, Zhou Zhihao
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    According to the characteristics of the shallow ground water system,the authors study the ground water system from the angle of the whole hydrological circle which includes the precipitation, surface water and ground water. A stochastic model is used to generate the input factors and boundary conditions of the model,and empiral expressions are suggested for the estimation of water exchange. The governing equation of the ground water flow is solved on the basis of the Integrated Finite Difference Methed. An example of the medel shows that the results are reasonable.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    Qu Yaoguang, Ma Shimin, Liu Jingshi
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    The exploitation and utilization of the water resource can be divided into three stages according to the transformation, development history,current situation and future tendency of the water resource of the piedmont plains in the arid Norhtwest Chiria. They are the exploitation and utilization stage of the surface water,the united exploitation and utilization stage of the underground and surface water as well as the economical use stage of the usable water resource. These stages reflect that the law and process of the use of water resource are related to the social and technical progress. Saving water is a main way in all the stages.However,the content of the economical use of water in the third stage is different from that in the first two stages,especially in respect of irrigation farming. It means a revolution of the traditional concept of water resource in the arid region. The net utilized water in the arid region is only 160×108m3 at present according to investigation. It accounts for only 18% of the total water resource,which shows the exploitation and utilization of water resource is in an insufficient stage. The usable water can increase 91% if the first stage is completed and can increase 216% after the completion of the.second stage.Therefore,the potential is very great.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    Liu Wenyao, Liu Lunhui, Qiu Xuezhong, Zhao Xuenong
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    In the years from 1990 to 1993, we carried out the experimental studies of suitable species selection, land preparation mode, planting technique and management,structure and combination of biological hedge and biological check dam as well as reservioring water system construction in the dry-hot degenerative mountainous area in Nanjian,Yunnan. The results showed that regulating and controlling water was the most important problem in the bioecological project for controlling the debris flow. On the basis of the experimental results and the analysis of the environmental conditions, we consider that the comprehensive biological control which takes the water storage system as the key is the most effective way for restoring the ecosystem in the dry-hot degenerative mountainous area.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    Gan Jianmin, Xue Jingyi, Zhao Hengkang
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    In this paper, the effects of rainfall on nutrient import and export in the broad-leaved evergreen forest in southwest Yunnan Province have been observed. The results show that in the proress of rainfall the nutrient import in rainfall is mainly N and the major elements of nutrient import in throughrain are P,K and Mg. They orcupy 69.85%, 77.33%, 98.19%,and 80.40% of the total nutrient import respectively. Ca occupies about half of the total nutrient import in rainfall and throughrain and the percentages are 45.35% and 54. 38%respectively. The major form of nutrient export is soil percolation. N, P, K, Ca and Mg occupy 96. 52%, 86.79%, 69.13%, 98.17% and 97.21% of the total nutrient export respectively. In nutrient cycle,N, P, K and Ca increase 15. 94kg/ha. a, 0. 353kg/ha. a,3. 83kg/ha. a, 1. 26 kg/ha. a. respectively,but Mg reduces 0. 654 kg/ha. a.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    Xu Xuegong
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    On the basis of analysing the characteristics of the physical geographic environment and natural resources of the Yellow River Delta,this paper studies the integral structure of the environment and resources system of the region with the Interpretation Structure Medel (ISM).This paper chooses 9 environment factors, 7 superior resources and 6 disastrous or restrictive elements to niake the structure matrix separately. And by using the ISM to tidy up the relations among the elements,three system structure graphs are obtained. Then they are integrated into a great environment-resources system of the Yellow River Delta.After analysing the graphs of the system structure, this paper reaches the following conclusions:1. The structure of the environment and resources system is an entirety. It should be studied and perfected with a comprehensive and systematic view. Only when it has the structure function superiority of the entirety it can realize the real superiority of environment and resources.2. In regional development, the resources exploitation often occupies the key position. In the Yellow River Thlta, oil and land resources should be exploited first. These can bring about the comprehensive exploitation of other resources. The reglon will finally be bullt into an oil energy hase, an oil and salt cheniical industrial base and bases of agriculture, animal husbandry and fishery.3. In the temtorial management of the Yellow River Delta, great attention must be paid to the important problem of the root, middle links, results and appearence of the environment change. These include the Yellow River Mouth management of ground water, saline-alkali land and ecological fragllity. The final goal is to transform and overcome the bad conditions to promote a well cycle of the environment and resources system.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    Huang Jing
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    anzhihua is lorated in the southwestern part of Sichuan province and is called generally "the recource treasure-gathering basin and natural green house"of China.Panzhihua is rich in mineral and agricultural resources. It stores 52. 2 percent of vanaium (V)and 75 percent of titanium(Ti) of China and also has a lot of gallium (Ga),scandium (Sc),lead (Pb),coppor (Cu), cobalt (Co), gold (Au), platinium (Pt), etc. The land there can produce many kinds of vegetables and subtropic fruits needed in the northem section of China in winter. The density of waterpower is 41 times the world average,and 4 large water power stations (they are Ertan, Tongzhilin,Guanyingyan and Banbianjie) can be built there. The abundant natural resources can support the development of a comprehensive raw material processing base.The social and economic conditions inside and outside Panzhihua are favourable to the exploitation of those resources. Many of Sichuan's finances and many of China's spoial resources and raw materials come from Panzhihua. Now Panzhihua is not only the head of the industrial zone of the Changjiang River but also one of the economic growth points of the southwestern part of China. So Sichuan province and China give Panzhihua great support in policies,finances and projects and help it to deveiop.To exploit and utilize Panzhihua's natural resources,China should build Panzhihua into an open and developing area of special resources, improve its interrelations with the rest of the country,ameliorate the conditions of production and livelihood and focus more power on devcloping the metallurgical,agricultural, energy, transportation,telecommunication industries and other facilities. Some projects to be built are listed in this paper.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    Liu Naifa
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    This paper reports the resources of species and genetic diversity of gallinacean in Gansu province and evaluates Gansu' s gallinacean resource according to the usable value of the components of diversity. In Gansu. the resources of species and genetic diversity of gallinacean are rich. There are 19 species,of which 9 are endemic species of China and 11 are protected species. Five species diversity into 14 subspecies, among them the pheasant of Gansu subspecies (Phasianu scolchicus strauchi) has many complicate genetic types. The resources of species and genetic diversity of gallinacean in Gansu have remarkable economic,ornamental and scientific research values,especially have vast vistas in the fields of population ecology,molecular ecology,and domestication and genetic breeding.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    Tan Zhiliang
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    In this paper,the present situation of utilizing the cereal straw resource in China and the so-called "Indian Medel"are analysed and the potential and effective ways of the exploitation and utilization of the crop straw are probed. The aim is to relize the reasonable structure of animal husbandry of the "Economical Food Type".
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    Cao Ye, Wang Zhongjian
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    In this paper, on the basis of the objective deniand to establish a socialist market economy system and aiming at the correction of the realistic weakness in the grassland contract resposibility system,a new grassland management mechanism is raised. This is done through the sharing of the property right of grassland, realizing the share cooperation system of grassland management promoting the management cooperation of the grassland animal husbandry, and lastly improving the effects of the utilization and construction of the grassland.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    Cui Duchang
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    There are obvious regional differences in the utilization efficiency of agroclimatic resources for the cereals yield in the world. The comprehensive utilization efficiency for the cereal yield in Europe is the greatest,which is 2. 78. Next it is 1.43 in North America and Oceania, 1.40 in Asia, and 1.12 in South America.In Africa it is the lowest, which is only 0. 61. The relative light energy utilization efficiency (%) is from 0. 03 (in Angola) to 0. 76(in Netherland). The Heat utilization efficiency (kg.℃-. ha-) is from 0. 03 to 2. 03 (in Netherland and Sweden). The precipitation utilization efficiency (kg. mm-1. ha-1 )is from 0. 35 (in Angola) to 8. 71 (in Netherland). The transfer efficiency of cereals is high in regions where the conditions of light,heat and precipitation cooperate relatively well with the crop demand (see Table 1-4). On the other hand,the moisture is easy to exert efficiency in dry and Semi-dry regions.Therefore the potential utilization efficiency of agroclimatic resources in the world is very great. In China,the utilization efficiency of agroclimatic resources is lowrer than that in countries with high yield mainly because of the low utilization efficiency of the unit area preduction. So to rise the utilization efficiency of agroclimatic resources of the unit area preduction will become an important task in the future.