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    Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    Qian Huaisui
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    egionalization for estimating the wheat yield by using remote sensing data is the foundation of estimating the wheat yield in a large area by using remote sensing data.It is a special applied regionalization.It intends to offer a spatial framework suitable to the system of the estimation of wheat yield, and to provide the scientific bases for the selection of information sources,temporals of remote sensing,information processing,wheat discrimination,and the estimation methods of wheat area and yield.First,this paper puts forward some regionalization principles.They are the principle of combining the integrative analysis with the analysis of leading factors,the principle of combining the regionalization with classification,the principle of combining crop analysis with the condition analysis of remote sensing,the principle of combining the spatial analysis with the process analysis,the principle of combining the analysis of elements with the analysis of their relations, and the principle of keeping the grass roots administrative regions unbroken.Secondly,it analyses the bases of this regionalization which comprise the spatial differences of ground types and combinations, the succession of crop aspects,the relation of wheat yield to vegetation indices and environmental factors,the atmospheric and soil spectral noise the variance of solar elevation,etc.Thirdly,it works out the schemes about the optimum temporal for the estimation of wheat yield by remote sensing, the information sources of space remote sensing and the land use structure. Finally, it divides the country into 14 regions of crop yield estimation using the optimum temporal as a leading index and the total growing period,the ecological type,the climatic yield and the cropping system as reference indices and 32 subregions of yield estimation taking the ratio of farmland area, and the ratio of planting area of wheat as leading indices and the days of clear sky and the days of overcast sky as reference indices.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    Zhuang Dafang, Liu Jiyuan
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    This paper presents an index system and a method for calculating the comprehensive index of land use degree. The latest data from two projects titled “Remote Sensing Macro Investigation and Dynamic Study of National Resources and Environment” and “Resources and Environment Database of China”have been fully applied. In addition, this paper analyzes the regularity of the regional differentiation of land use degree in China and the socioeconomic and physical factors which affect the change of land use degree in China.The“polar” model and the “Longitude Distance” model of land use degree of China are also developed.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    Fu Bojie, Chen Liding, Ma Cheng
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    and sustainable use has become one of important environment issues in the world. It is necessary to have the proper land use technology and an appropriate method for land use evaluation. This paper deals with the development of a new method for land sustainable use evaluation. We attempt to combine the classical land evaluation method with the landscape ecology method. The classical land evaluation method emphasizes the abiotic factors, such as soil, landform,climate and so on, while the landscape ecology method pays more attention to the spatial relation and processes.In the newly proposed evalution system, we select a series of factors as the evalution indices. Some of the factors reflect the quality, attributes and the use process of the land; others are ecologic, economic and social factors that restrain the land sustainable use. At last, a model of land sustainable use evaluation is given.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    Li Mingsen
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    The “YLN” region of Tibet is the center of the politics, economy and culture of Tibet Autonomous Region and the main developmental region in short term. In this region, the agricultural resources are abundant, the production basis is good, and the agricultural development potential is great. This paper mainly reviews the quantity, quality and developmental potential of various land resources and suggests the ways and countermeasures for rational utiliaztion and protection of land resource in order to provide scientific bases and beneficial opinions for the sustained and steady development of agriculture in this region.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    Ni Jinren, Han Peng, Wang Guangqian, Zhang Ren    
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    Following the companion paper on the laws of sediment size distribution which account for the effects of the measures of water and soil conservation as well as the geomorphologic factors, this paper further deals with the sediment reduction effect of conservation measures in different catchments. Not only is the total reduction load inflowing into rivers (including tributaries and the main stream) due to the measures of water and soil conservation discussed,but also the grading portions of reduced sediment load are predicted and verified by the measured data. The grain size corresponding to the maximum reduction of sediment yield in the non uniform suspended sediment particles is accurately predicted by the model, which is of great importance in the benefit analysis of the measures of water and soil conservation in various catchments.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    Ma Yunrui, Zhang Yimin, Miao Jiwen, Wang Jie
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    The return water of irrigation in Ningxia includes the deep seepage water in irrigation farming soil, the tail water of cultivated land,the seepage water of irrigation canals and part of industrial waste water and city sewage. The amount of return water per year is 3~3.5 billion m3 in Ningxia. The appraisal of 20 kinds of substances in the return water which has been heavily polluted and mineralized shows that it belongs to not poisonous but harmful fresh water. There will be no bad effects on crop growth and no threats of soil salinization and alkalization if the return water is mixed with canal water or rotation irrigation of the return water and canal water is adopted for arable land watering. Therefore, the return water should be developed and used with the least hesitation.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    Li Zhibin
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    The Zhoushan Archipelago is the largest archipelago of China. It is situated at the intersection point of the Changjiang economic zone and the coastal economic zone. It also serves as a base for exploiting marine resources. Harbour navigation channel,marine organism, tourism, salt industry, and ocean energy source are the five superior resources of the Zhoushan Archipelago. To make full use of island resources for the development of island economy, some suggestions are put forward in this paper:(a)practise regional comprehensive exploitation according to island conditions; (b)rationally exploite, protect and use the water resource; (c)exploite the deep water coastline resources;(d)continuously develop the marine fishery; (e)build bases of ocean tourism;(f)exploite the ocean energy;(g)steadily develop the salt products and the salt chemical industry.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    Li Xinrong
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    On the basis of the vegetational investigation in Maowusu sandland, the family and genera composition,geographic components, life form and ecological characteristics of the flora of the shrub resource in the area are analysed. The important position and significance of the shrub in this special ecotone of the geographic landscape are analysed too. According to these, we put forward the countermeasures for the protection and restoration of the diversification of the shrub resource.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    Yang Yusheng, He Zongming, Ma Xiangqing, Yu Xintuo
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    ith the area of Chinese fir plantation increasing constantly, the soil fertility degradation of the site of Chinese fir plantation is increasingly serious. Controlled burning is one of the major causes which cause the soil fertility degradation of the site of Chinese fir plantation. On the basis of the achievements of previous related studies, we, in this paper, fully expound the effects of controlled burning on the slashes, soil and water loss, soil fertility and Chinese fir growth at home and abroad, summarize the advantages and disadvantages of controlled burning,and raise some corresponding countermeasures. This is of great significance for changing the traditional culture system of Chinese fir and for the sustainable use of the resources of the mountainous area in South China.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    Xu Songling
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    This paper has studied the problems that are related to the standardization of the concepts and methods in the computation of the economic loss of ecological resources destruction. The problems are: (a) the muliti value character of ecological resources and the value concept system, (b) the two computation structures used to compute the economic loss of ecological resources, (c) the determination of 1. the amount of ecological resources destruction in the computation structure of the resource value type and 2. the unit function value of resources, (d) the determination of the effect weight of the ecological resources destruction to disasters, and (e) the battering effects of the disasters tempted by ecological destruction on the whole economic social system.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    Bai Wanqi, Zhao Shidong
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    his paper gives a comprehensive description of the main models of land use and land cover change (LUCC) in global change studies with particular attention to vegetation models and the models which consider social driving forces. The main trends of LUCC modeling are:(a) Future LUCC models should be able to simulate the major social economic and physical driving forces of land use and land cover change,including the major feedback relations from LUCC to driving force sand global change.(b) The models are geographically explicit.With appropriate spatial resolution they can predict the long period (50-100 years) LUCC and associated biophysical parameters, such as vegetation attributes and resource accumulation and degradation.(c) The models can improve our understanding of the local, regional, and global dynamics and consequences of the relationships between LUCC and its main driving forces,and make us consider the sensitivity of land use and land cover change to exogenous variables ( e.g., policy,technological progress, population growth, economic development, market change, and some cultural factors, such as attitudes and values).(d) New methods of LUCC modeling will be developed, which can link LUCC models with other global change models, especially with climatic models.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    Pang Aiquan, Ian Nuberg
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    The sustainability of China's agricultural and forestry resources is being seriously challenged by changing physical and social economic conditons.Experiences in China suggest that agroforestry complex system can play an important role in the sustainable development of China. Though reviewing the methods of economic evaluation of the agroforestry complex system in China, this paper reveals that at present the economic evaluation of the agroforestry complex system is mainly limited to financial profits. This is necessary, but it shows insufficient when the sustainable development of the agroforestry complex system is considered. Lastly, an exploration is made for the development direction of the economic evaluation of the agroforestry complex system in China.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    Ma Zhongyu, Cheng Shengkui
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    Agricultural production efficiency,crop livestock integration, grain problem, layout of agricultural production and object of the study of sustainable agriculture have been highlighted by scientists and decision makers in China.These problelms play a crucial role not only in correct policy making, but aslo in the direction of agricultural research. There have been, however, some confusions and misunderstandings in the current viewpoints held by some of the scientists and decision makers in China. Pointing at this situation, this paper makes a significant discussion for the sake of finding a correct answer through a profound analysis and statement based on the researches conducted by the authors themselves and a large amount of study results collected at home and abroad.The conclusions are: (a)Sustainable agriculture is an academic term, not a new model for replacing the conventional agriculture, and the study of sustainable agriculture should give priority to developing input reducing technology and increasing farmers income in order to make Chinas agriculture environmentally sound and healthy; (b)The emphasis of researches on crop livestock integration should be shifted to focusing on how to adjust the composition of energy and protein in feed supplied by cropping and consumed by livestock; (c)The main ways for eliminating the increase of grain shortage in China are to put the strategy of grain substitution into practice as soon as possible and to properly restrain food consumption which has been highly speeded up; (d)According to the principle of less external input and higher efficiency, the priority of developing grain production should be placed on the high yield farmland rather than on medium yield farmland; and (e)The energy efficiency in Chians agricultural production has increased from time to time, which is very important for a correct policy making in China's sustainable agriculture.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    Qiu Huamin, Deng Zhenyong, Fang Debiao
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