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    Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    TU Xiang-yang, GAO Xue-ping, HAN Yan-cheng, GUO Qing-ping
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    Tianjin is a big city deficient in water resource,whose most apparent hydrographic features are uneven distribution of annual rainfall and little scarce in non-rainy season.With the booming development of society and economy,the contradiction between water supply and water demand became more and more serious in Tianjin.The conventional flood management measure of leading the floodwater into the sea by non-hazardous principles result in great waste of floodwater resources.Therefore,it is of great theoretical and practical significance to the study of the floodwater resources utilization based on the integrated management strategies of combining engineering measures with non-engineering measures.The focus of this paper is to illustrate the necessity and integrated exploitation mode of flood resource utilization in Tianjin.The conclu-sion,based on the successful utilization of numeric simulation of flood resource impounding into detention basins of the north river network,suggests that flood management in Tianjin should move away from its customary emphasis on heavy engineering towards the softer,natural style of rivers and detention basins rehabilitation. The development trend and reasons for wetlands degradation in Tianjin since last century ware exposited according to the historical hydrographic data and present status of regional water resources,and then the necessity of implementing flood resource utilization storage was discussed.Making use of software of ArcGIS,a 3-D demonstration module for impounding treatment was programmed to meet the demand of real-time calculation on impoundage and impounded area of a detention basin.A comprehensive impounding evaluation system for the detention basins was established which consists of several indexes such as submersion damage,flood preventing benefit,water supply benefit and ecological benefit.Utilizing fuzzy optimizing theory the optimum storing water levels were calculated which contribute to the quantified reference for scheme selection of flood resource utilization.Based on Newton-Raphson interation method and relaxation algorithm,a one-dimensional unsteady channel system hydrodynamics flow model was presented.Coupling with rivers,draw-gates,flood diversion orifices and detention basins,a combined schedule system of hydrographic net was established by applying present water conservancy facilities.Finally,the general implementation strategy of flood resource utilization was discussed which have fundamental significance in releasing water resource crisis and improving water ecological environment in Tianjin.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    LIU Da-qing, XU Shi-guo
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    Zhalong Wetland is a floodplain wetland with an area of 2 100km2.The main source rivers are Wuyur and Shuangyang rivers.The surface of the wetland is very flat except some small ridges.It is composed of a wide central area covered by flush reeds and surrounded by lakes.A root and humus layer of reed with a depth of 1-2m covers a deeply embedded clay layer in the wetland.The maximum depth of water in the central area of the wetland is about 2m.The area of water surface accounts for 70% of the total area of the nature reserve in an average hydr-ological year. Wetlands are now recognized as one of the world's most productive ecosystems which through their functions provide goods and services for the health,safety and welfare of human populations.These functions include groundwater discharge and recharge,sediment trapping,flood storage,water quality improvement and fishery and wildlife habitat.Unfortunately,wetland loss has occurred at devastating rates throughout the world over the past two centuries due to climate change and human activities.In order to conduct a successful wetland restoration and sustainable management of wetlands,understanding and quantifying the hydrological processes are vital.The most common approach for determining wetland hydrology is to calculate water balance based on all sources and sinks to the system.Water balance for the Zhalong wetland was calculated for the period of 1956-2000.Firstly,the methods of accumulated difference is uesd to analyze the characteristics of water cycling elements including precipitation,evapotranspiration and inflow.Then,water balance was caculated in Zhalong wetland in light of its nanual condition for the period 1956-2000.The results show that the water storage of Zhalong wetland had a trend of slightly decrease by an annual average of 16.8×106m3.The annual average water inputs into Zhalong wetland were as follows:61.5% from precipitation,36.5% from upstream inflow,and 2.0% from upland runoff;the annual average water outputs from Zhalong wetland consisted of 74.4% from evaporation and evapotranspiration,14.5% from estimated seepage,and 11.1% from down-steram outflow.Finally,an effect analysis of the hydrological change to Zhalong wetland ecosystem was conducted.The results show that both quantity and qulity of the biology such as birds,fishes and reed marsh were degradated in the last decades.The paper also shows that additional water are required to restore the wetland ecosystem.Diverting water from Nenjiang River maybe a feasible measure to solve this problem,however,more work should be done for the reasonable wetland water resouces management.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    CHEN Tong-bin, SONG Bo, ZHENG Yuan-ming, HUANG Ze-chun, ZHENG Guo-di, LEI Mei, CHEN Huang
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    In order to assess healthy risk of nickel in vegetables and to select vegetable variety with high pollutant-resistance,a large scale survey on nickel concentrations in vegetable lands and vegetables planted or sold in Beijing,were carried out.A total of 54 soil samples were collected from vegetable lands and their nickel concentrations were determined using Graphite Furnace Atomic Absorption Spectrometry(GF-AAS).In addition,97 varieties with 412 fresh samples of vegetables were obtained from vegetable bases,supermarkets and wholesale markets,with sampling principle of taking both consumption and diversity of vegetables into account.The results showed that the nickel concentrations in vegetable lands ranged from2.8 to 46.5mg·kg-1,with median,arithmetical means(AM)and arithmetical standard deviation(SD)of 25.75,25.89 and 7.33mg·kg-1,respectively.Compared with the background concentrations of soil nickel in Beijing,nickel was found to be accumulated not significantly in the vegetable lands.Nickel concentrations in the vegetables ranged from 0.7 to 1689.0μg·kg-1 fresh weight,with arithmetical and geometrical and Box-Cox means of 91.3μg·kg-1,53.0μg·kg-1 and 55.4μg·kg-1 fresh weight,respectively.Nickel in most of the samples(97.38%)was below the limit,3.0mg·kg-1 and 0.3mg·kg-1 fresh weight pulse vegetables and other vegetables,respectively,set by Tolerance Limit of Nickel in Foods for the maximum permissible concentration of nickel in vegetables.The highest nickel concentration,1689.0μg·kg-1,was found in a green soybean(maodou)sample,followed by a cowpea(Vigna unguic-ulata)and soybean sprouts sample,992.7 and 965.8μg·kg-1,respectively,and then pea(Pisum sativum),celery(Apium graveolens)and horse bean(Vicia faba),745.3,704.3 and 697.4μg·kg-1,respectively.The nickel concentration of vegetables planted in the open field was significantly higher than those planted in greenhouse.Results of hierarchical cluster analysis on bioconcentration factor(BCF)of nickel in vegetables showed that beans round trellis(Vigna unguiculata)can be classified into one group with higher bioconcentration factors of nickel,and hence its nickel-resistant was lower;followed by cucumber(Cucumis sativus),pakchoi(Brassica chinensis),Chinese cabbage(Brassica pekinensis),radish(Raphanus),cabbage(Brassica oleracea),chili(Capsicum annuum)and wax gourd(Beninacasa hispida),which can be classified into one group;and the others were clustered to be a group with the lowest bioconcentration factor of nickel,including eggplant(Sola-num),welsh onion(Allium fistulosum),swiss chard(Beta vulgaris)and tomato(Lycopersicon esculentum).The average intake of nickel from vegetables was 99.5μg/individual/day for people of Beijing,and some vegetables with high nickel concentration may lead to a little of healthy risk for local people.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    HUANG Zu-hao, LIU Nai-fa, CONG Pei-hao, SHI Hong-quan
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    The An'xi Extra-arid Desert National Nature Reserve,situated in the west of the Hexi Corridor in Gansu Province,is a nature reserve for desert eco-system.Bird species and their abundances in the reserve were surveyed during 1988-1989.In order to gain an understanding of the changes of bird resource at the reserve since 1988,line-transect method was used to investi-gate bird species,amount and environmental condition during 2002-2004.A total of 103 species of birds were recorded in the reserve during this period.In comparison with the record of 1988-1989,31 were new(among which three species were new records for Gansu Province),but 36 disappeared.The state protected birds in China decreased from 18 species in 1988-1989 to 16 species in 2002-2004.Six additional protected species of birds were recorded,but eight species were not re-counted in the second survey.Fifteen birds listed in Convention on International Trade in Endangered Species of Wild Flora and Fauna(CITES)were recorded during 1988-1989 and 2002-2004,but the species changed.There were eight species that were listed in China Red Data Book of Endangered Animals:Aves in 1988-1989,however,six were in 2002-2004.Aegypius monachus and Phoenicurus alaschanicus were listed in Threatened Birds of Asia in 1988-1989,and Otis tetrax and Falco naumanni in 2002-2004.Comparing bird abundance between 2002-2004 and 1988-1989,the amount of birds in spring and summer decreased,but those in autumn increased.Specially,species and amount of dominant species significantly changed in each season between 1988-1989 and 2002-2004.The main factors that led to the change of bird resources in An'xi Extra-arid Desert National Nature Reserve were bird migration and human activities.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    WANG Ai-ling, ZHAO Geng-xing, WANG Rui-yan, YUAN Xiang-ming
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    Improving land quality is one of the important aims of farmland consolidation.It is the basis for regional farmland consolidation planning to evaluate consolidation grades of land quality and to determine regional spatio-temporal collocation,based on the impacts of land consolidation on land quality.Taking Qingzhou County of Shandong Province as an example,this paper established the quality evaluation index system and evaluation model for farmland consolidation,based on the systematical analysis of land consolidation characteristics and natural and social conditions in Qingzhou County.The integrated score of every evaluation unit was calculated by the method of integrated index evaluation and GIS techniques,and spatio-temporal collocation of regional farmland consolidation was proposed accordingly.The results indicated that the first class land consolidated area was 106.21km2,occupied 8.85% of the total consoli-dated area,distributing in the eastern plain of Qingzhou County;the second class area was 234.04km2,occupied 19.51% of the total area,distributing in the central plain and the western hilly region;the third class area was 559.36km2,occupied 46.63%,distributing in the western plain and central hilly region;and the fourth class,25.01% of the total area,distributing in the northern plain and the southern hilly region.The results will provide scientific basis for land consolidation planning and implementing in Qingzhou County.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    WU Yi, CHENG Wei-ming, REN Li-liang, ZHANG Yi-chi, ZHANG Xue-ren
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    The runoff of a catchment is affected comprehensively by human activities and natural conditions such as soil,vegetation,climate,etc.Therefore streamflow represents the characteristics of determinacy as well as stochasticism.Researches on runoff characteristics are beneficial for the sustainable utilization of water resources,water conservancy planning and agricultural develop-ment. The study area of this paper is Hotan catchment,which is located in the Tarim River Basin in southern Xinjiang,with an area of 48 870km2.The Hotan River is of great importance to ecosystem and society in Taklimakan Desert,because it is the only river that traverses the desert.The paper analyzed the intra-annual distribution and annual variation of runoff in the catchment according to observed data.Some indexes,including the coefficient of nonuniformity,the degree of concentration and the time of concentration,were used to analyze the intra-annual distribution of runoff;the methods of Kendall rank test and periodgram were used to analyze the trend and period of multi-annual runoff. The results show that due to the impacts of runoff-supplying sources,the intra-annual nonuniformity is very high,being more than 75% of the annual total runoff in summer.The coefficient of nonuniformity and the degree of concentration are much bigger than the normal,and the computed time of concentration is in accordance with the time of the observed maximum monthly runoff.The streamflow concentrated in some period of time could possibly arise the conflicts between water usage and supply,which will restrict the sustainable development of agricultural production and the socioeconomy.The Hotan River Basin is supplied by the glaciers and snow mountains,so the statistic of annual runoff Cv is small which indicates that the variation of annual runoff is weak.The annual precipitation,temperature and human activities exert impacts on the variation of runoff.The precipitation influences the runoff directly,in the past 40 years,the precipitation in the Hotan catchment presented an increasing trend.Under the background of global warming,the snow line on the mountains is hoisting and the glacier is shrinking.And with the development of agriculture,the irrigation water requirement is increasing constantly.Owning to the effect of these factors,the runoff in Hotan catchment presents a weak declining trend.The result of periodical analysis is that the annual runoff has no obvious periodicity.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    LIU Xiao-jie, SHEN Lei
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    Saving society(SS) is based on the premise of satisfying human's needs.Conse-quently,the saving idea could be linked to every field in our society in which fewer resources are used to produce more economical benefits and societal benefits,whilist realizing sustainable development.Apparently,there are some characters here about SS,for example,saving resources being the basic national policy;recycling economy becoming economically developmental model;a harmonious and steady society being built;science advancement and technology innovation being closely depened;and more friendly environment being realized. As a complex system,SS is composed of five sub-systems in resources,economy,society,technology and environment,which will be interacted and interdependent.Therefore the process for establishing a SS is to realize a highly harmonious system by which it can finally realize the reasonable use of resources,economic development,social advancement,technological progress and environmental conservation. Comprehensive appraisal for SS of China is carried out in this article based on the characters of SS and state situation of China.It can quantatively estimate the level of establishing SS and the developmental trend in each sub-system or compare them with each other.According to the design principles of indicator system,some principles,such as scientific,operable,entire,comparable,dynamic,are adopted and the comprehensive indicators and appraisal system of SS is given in the article,which is made up of four layers,five subsystems and 39 indicators.Then we set up two indicators here to evaluate the area,one is saving indiccator of developing:V=ωiXi,the other is saving indicator of coordinating:U=1-/.The method of entropy-value is used to help decide the weights of all indicators.According to the score of the appraisal indicators,the situation of SS can be divided into 25 situations,namely S1,S2,S3,...,S24,S25.On the basis of the indicators system,we put forward demonstration analysis on the data of 1990-2004 and concluded that during these years China was mainly in the stage of S16,S17 or S18,meanwhile in the future there will be a long way to go for China to realize its saving society.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    ZHOU Feng, PU Li-jie, PENG Bu-zhuo
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    Regional land use change is an important part of global change,especially in the areas where local economy is developing rapidly.The Su-Xi-Chang(Suzhou-Wuxi-Changzhou) area is one of the hot spots for socio-economic development in China,the land use change will be improved greatly.Based on the Landsat TM data in 1980,1995 and 2000,measurement of Su-Xi-Chang area's land use change was conducted with the support of RS and GIS.Based on the land use change matrix and the local social data,economic data and environmental data,the characters and the effectiveness of land use change was conducted.Conclusions of the study are drawn as follows: (1)Construction land expanded rapidly at the expanse of encroaching cultivated land.The quantity of construction land in 2000 was 1.77 times of that in 1980 and 42.48% of the increased part rooted in cultivated land,most of which was high quality paddy field. (2)Rural residential area spread at the same time in despite of the consolidation.From 1980 to 2000,rural residential area increased 480.55 km2 at the same rate of construction land increase.Despite of the rapid urbanization of the population,the urbanization of the land was laggard. (3)Cultivated land decreased rapidly with the trend of fragmentation and decentralization,the other land use types were centralized comparatively at the same time,especially construction land.The landscape diversity increased with the decrease of the landscape dominance. (4)Construction land expanded with the core of cities and traffic line.The land use transformation became more intensive with approach to the city and traffic line. (5)The land use change get good effect at the aspect of economic and society,focusing on the urban area.The GDP of industry and commerce,the local financial input,the gross output value of agriculture,the personal income and the number of employed got increased with the land use change. (6)The environmental effect of land use change was not good,focusing on the urban areas.The pollution became more serious with the expansion of construction land.Since 1995,the industrial pollution has been under control and reduced,but the urban pollution aggravated simultaneously.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    GUAN Wei-hua, GU Chao-lin, LIN Zhen-shan
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    The energy problem has been one of the important problems affecting the suitable development of socioeconomic in China.The change of the energy consumption structure not only accelerates the economic development,but also closely relates with the suitable development of national economy.In view of the simulation and prediction of total energy supply and demand in China,there is a great gap,thus it is necessary to reduce energy consumption and transit energy consumption structure.Based on the dynamics theory,this paper sets up a forecast model of energy supply and demand in China,and forecasts the energy consumption structure.The research shows that this model can preferably simulate and predict that,in China's energy consumption structure,the consumption rate of coal will decrease,while the rates of water and electricity,natural gas and petroleum will increase,especially the status of petroleum will ascend in the energy consumption structure.Thus,the problem about petroleum affecting the suitable development of socioeconomy in China will become more and more prominent.From the change of the energy consumption proportion in each department since the recent 10 years,the percentage of residential and primary industrial energy consumption descended a little,the percentage of tertiary industry energy consumption ascended,and the consumption proportion of energy for industrial production has been in the highest flight all along.Therefore,it is necessary to adjust the industry structure,reduce the percentage of industry with high energy consumption and depress the high-speed growth of energy consumption with the tertiary industry increasing quickly,so as to ensure energy consumption increase in a suitable speed.As for the balance of supply and demand of petroleum,on the one hand it is needed to improve the use efficiency and regulate the industrial structure;on the other hand it is necessary to take effective measure to reduce petroleum consumption in the tertiary industry.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    SHANG Hai-yang, MA Zhong, JIAO Wen-xian, MA Jing
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    Ecological Footprint is a new tool used to measure the sustainable development of environment.The Ecological Footprint,according to its concept,analyses the impacts of the people on environment and sustainable development by transferring the impacts caused by people through what they have consumed in a period(usually one year).Household consumption,behavior of the member of a household to sustain the daily life,influencing by the household income is more common to us.Here we can also use the Ecological Footprint to analyses the impact of the household consumption on the environment.This paper not only calculates the Household Ecological Footprint(HEF) of urban residents grouped by income in Gansu in 2002,but also analyses the relationship between dominated income and HEF.As we know,the income of a household,actually the dominated income,predominates the consumption level and style,and then causes the different quantities and compositions of HEF.Further,we get the Ecological Footprint Depredation(EFD) which we define as the difference between each colony and HEF of the average dominated income colony and the total EFD which sums up the EFD of each group.We calculate the Ecological Footprint unjust coefficient which imitated the calculation of the Gini factor.The results shows that the HEF for each group is 1.412×106gha(the highest income group),1.131×106gha(high),1.860×106gha(higher),1.793×106gha(moderate),1.536×106gha(lower),0.724×106gha(low),0.578×106gha(the lowest),and the provincial-average is 1.265×106gha.Because of the size variations in each group,the total HEF of each group,as we showed in the text,is not ordered exactly to the per capita HEF.The Ecological Footprint unjust coefficient is 0.24 which shows that the unjust HEF of each group is not obvious.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    ZHANG Qian, LI Wen-jun
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    Since the reformation in Parks Canada conducted after 1994,it seems like that there is a trend that national park administration in Canada has a superficial similarity with protected area management in China because both of them are supported jointly by the government appropriation from tax collection and the revenue from tourism businesses.However,there are tremendous differences in protected area management between Canada and China,including government support,management institutions and conditions for the reformation.Based on the interviews with different level officials of Parks Canada system and field survey in five national/provincial parks in Canada,this article reviewed the reformation in national parks management of Canada by using new public management(NPM) theory and polarity management tool.According to the Canadian experiences,it is proved that NPM could be applied in the public sectors responsible for natural resources management.It was implemented to eliminate the disadvantages of bureaucratic management after its full development,including X-inefficiency and expanding expenditure.The main content of the reformation had two aspects:one was to remove the disadvantages of bureaucratic management by decentralization and introducing market tools;and the other was to maintain the advantages of bureaucratic management by the application of User Fee Principle and Cost Recovery Principle,the improvement of legislations and regulations system and the strengthening of monitoring system.In this way,the advantages of both bureaucratic and market-oriented management were combined to achieve the protection of ecological integration.However,the protected areas in China began to introduce market tools before the establishment of perfect bureaucratic management.Because of the problems of fund shortage,defective legislations and regulation system and absence of a consolidated organization responsible for protected area management,the disadvantages of market tools could not be controlled effectively.Compared with the experiences of Parks Canada,it is very difficult to take full advantage of market tools in protected area management before the establishment of a perfect legislation and regulation system and a consolidated organization.Therefore,it is recommended for China that the market tools should be highly cautiously applied into the protected area management unless three conditions have been achieved:(a)the establishment of perfect legislations and regulations system and its implementation;(b)more financial support from government to protected areas;and(c)a consolidated bureaucratic administration responsible for protected areas.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    XIAO Jian-hong, SHI Guo-qing, MAO Chun-mei, XING Zhen-xiang
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    The accurate valuation of effects of hydraulic engineering on river ecosystem services is very important to Environmental Impact Assessment(EIA)of hydraulic engineering and the reserve river ecosystem services.On the basis of the effects features,an index system for the assessment of effects of the Three Gorges Project(TGP)on river ecosystem services has been established.The six positive effects and five negative effects were pre-evaluated when TGP was finished.The result indicated that flood control and hydropower generation were the main functions,with annual values being 106.84×108yuan(RMB)and 211.70×108yuan,respectively.Tourism,harmful gas emission reduction and navigation channel improvement were importance functions of TGP,too.Their annual values were 74.50×108yuan,79.44×108yuan,and 14.64×108yuan.The annual values of the six positive effects were 489.70×108yuan.The reservoir contamination,reservoir sedimentation and reservoir flowage by TGP were the main negative effects,and the annual losses were 24.06×108yuan,7.22×108yuan and 6.27×108yuan separately.At the same time,the effects of TGP on biological factors and occupation of river ecosystem were also negative effects,which couldn't be ignored and the annual losses were 0.27×108yuan and 0.01×108yuan respectively.The annual losses of the five negative effects totalled 37.83×108yuan.The researches show that EIA of the large hydraulic engineering was not only done on single factor evaluation,but more attention was also given to effects of engineering on river ecosystem health and river ecosystem services.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    LIN Gui-lan, ZUO Yu-hui
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    The cumulative ecological effects(CEE) of natural resource exploitation and utilization in bay,including accumulative action of the same characteristic effects and cooperative action of different characteristic effects,has brought about rapid changes in productivity and eco-service function of bay ecosystem.Base on fuzzy-correlation analysis,six indices,which are cumulative effects on topographical and geomorphological environment,water dynamical environment,water and sediment quality environment,ecological environment,landscape environment,and the potential incurrence effect on disaster,are selected as indices of CCE in bay.The grey model(GM) of CCE assessment is built and applied to monitor the cumulative effects arising from regular resource exploitation and utilization in bay,and Xiamen Bay is taken as a study case.The result indicated that the six indices of CCE in bay are pro-correlated with intensity of resource exploitation and utilization,while wetland area reduction,coastal topographical and geomor-phological change,water quality and sediment quality deterioration,bio-diversity decrease,landscape pattern break,etc.,are caused mostly by resource exploitation and utilization.And the score of GM assessment on Xiamen Bay in the 50 years is 0.56,which can be taken as a reference background of CCE in bay.This result of CCE has led to changes in the structure of resource and environment system in bay to a certain extent,consequently,the intensity and frequency of disaster and potential loss is increasing,the productivity and eco-service function of natural ecosystem is impaired,and the sustainability of development will be limited eventually.It is suggested that pattern of eco-city planning should be referred to and rational distribution of eco-source,eco-patch and eco-passage shoule be practised so as to prevent the occurrence of ecological desert in the sea sector due to constant increase in resources utilization.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    ZHAO Yun-ge, XU Ming-xiang, WANG Quan-jiu, SHAO Ming-an
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    Biological soil crust plays an important role in degraded ecosystem restoration.Large area of biological crust has formed after cropland shifting to revegetated grassland on the hilly Loess Plateau of China. Our objective was to determine the impact of biological crust on soil chemical and physical properties in the study area.In this paper,through field investigation and sampling analysis,some physical and chemical properties of different years rehabilitated grasslands on the northern slopes which had biological soil crust formed on the surface were studied.Eight research sites were selected and soil and crust samples were collected in April 2004,with the restriction that locations were confined to a single soil series that was representative of the local environmental condition,similar elevation and slope.At each sampling site,five samples taken randomly were mixed to form a composite soil sample.Samples were taken from the 0 to 20 cm deep profile in 6 layers(crust,0-2,2-5,5-10,10-15 and 15-20cm).Soil moisture,bulk density,cohesion of soil surface,infiltration rate,organic matter content,total nitrogen,total phosphorus and available N,P,K contents of the 0-20cm soil profile were measured for soil samples taken from the 8 sites.The results showed soil physical and chemical properties of the 0-20cm profile were affected significantly by the biological crust.1)After shifting from cropland to revegetated grassland,soil moisture in the 0-20cm profile increased firstly and then decreased with the increase of rehabilitation years.Because the formation of the biological crust,soil penetrability of the rehabilitated grasslands reduced significantly compared with cropland,this also resulted in lower soil moisture in this profile after 10 years' rehabilitation.2)Soil surface cohesion of the rehabili-tated grassland increased significantly with the formation of the biological crust after shifting from cropland.After 10 years revegetation,the crusted soil surface cohesion of the revegetated grassland was 6 times that of the fresh revegetated grassland.The reason for this was mainly due to the formation of the biological crust,rather than the increase of soil bulk density.3)Soil penetrability reduced significantly when shifting from cropland to revegetated grassland.The infiltration coefficient of crusted soil decreased gradually with the increase in years of revegetation.However,the infiltration coefficient increased gradually when getting rid of the crust.4)The formation of the biological crust brought to an enrichment of soil organic matter and total nitrogen in the upper soil.With the increased years of rehabilitation,the enrichment was even more obvious,and soil total phosphorus was also enriched to some extent.Soil available nutrient was improved as a result of the formation of the biological crust.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    MO Xing-guo, LIN Zhong-hui, LIU Su-xia
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    Huang-Huai-Hai region as the main grain-producing region,its production is closely r-elated with national food safety.Spatial-temporal evolution of crop production and its driving forces in this region should be clarified for regional scale productivity trend analysis.In this paper,a coupled model of Soil-Vegetation-Atmosphere Transfer(SVAT) and crop growth dynam-ics(VIP model) driven by AVHRR NDVI and climatic variables is applied to simulate the prod-uctivity of winter wheat in the Huang-Huai-Hai region from 1981 to 2000.In this period,air temperature became warmer and sunshine duration became shortened,whereas no obvious trend for precipitation was observed.The simulated grain yields are validated with statistic yield at county level gathered in Hebei Plain.It is found that the biomass increased before 1997 and then decreased.However,due to the improvement of harvest index,per unit area grain yield grew significantly during the whole period,with per unit area grain yield doubled in 2000 over 1981.The enhanced input of fertilizer and popularization of fine crop strains are the principal reasons for grain yield increase.The consumption of fertilizer was doubled from the 1980s to the 1990s,which contributed 40% of the grain yields.At the same time,the harvest index of winter wheat improved continu-ously from 0.31 to 0.44.However,the crop productivity was disturbed by climatic variability from year to year,which contributed 8.5% of the interannual variability of regional grain output.In the study area,the spatial-temporal evolution of grain production is clearly related with local conditions and manag-ement,e.g.irrigation facilities and soil conditions.The increment of grain yield is different in these 20 years.In the 1980s,there were 46% of the areas with an yield improvement by 30%,some areas even as high as 100%.However,the increment obviously stepped down in the 1990s,with the enhancement ranging between 15% and 30% in about 55% of the areas,and only 30% of the areas with an yield increment exceeding 30%.The grain yield of wheat in the Huang-Huai-Hai region has reached its plateau,which is supported by excess consumption of surface and ground water.To keep the agriculture sustainable in this area,water conservation and saving techniques and engineering projects should be widely improved.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    ZHANG Dong-qiu, SHI Pei-li, HE Yong-tao, XU Ling-ling, ZHANG Xian-zhou, ZHONG Zhi-ming
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    Qualification of soil heterotrophic respiration is an important component to estimate ecosystem carbon balance.However,it is difficult to directly measure and distinguish it from root respiration.The heterotrophic respiration of Steppe-Kobresia meadow ecosystem was measured in situ in Dangxiong county,central Tibet Autonomous Region by using Li 6400-09 soil chamber.Soil heterotrophic respiration had a strong correlation with soil temperature especially with that at 5cm deep.It indicated that soil temperature at a depth of 5cm was the key factor to determine soil heterotrophic respiration.We analyzed how the soil heterotrophic respiration by soil temperature was affected under different soil moisture regime during the growth period.The variation of soil heterotrophic respiration was differentiated into rainy seaspm(June through August) and dry season(May,September and October).The regression equations between soil heterotrophic respiration and 5cm soil temperature were Rh=0.106exp0.133T in rainy season and Rh=0.18exp0.0833T in dry season respectively.By estimating the soil heterotrophic respiration,the daily mean and total soil heterotrophic respiration were 2.4gCO2·m-2 and 219.6gCO2·m-2 in rainy season,and the value of Q10 was 3.8;While the daily mean and total soil heterotrophic respiration were 1.8gCO2·m-2 and 160.2gCO2·m-2 in dry season,and the value of Q10 was 2.3.The result suggested that soil heterotrophic respiration was more sensitive in rainy season than in dry season during the growth period.The soil moisture caused by rainfall patterns in different months played an important role in regulating the relationship between microbial heterotrophic respiration and soil temperature.Based on established models of soil heterotrophic respiration in relation to soil temperature,the amount of soil heterotrophic respiration was estimated as 379.8gCO2·m-2 in the growth period(May through October) of 2004.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    SHI Min-jun, CHENG Shu-lan, ZHAO Qiao-yun
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    Poverty alleviation and rangeland conservation are pressing issues facing sustainable development of Northwest China.A linear Bio-economic Model is introduced in this paper to an-alyze the farmer households'land use decision,their income change and driving forces under different land use regulation and other environmental policy scenarios in an agro-pastoral area of Inner Mongolia,China.The simulation results show that introducing sedentary beef cattle livesto-ck,improving credit provision and increasing off-farm employment opportunities might generate a significant increase of household income under alternative land use policy.Land use regulation is needed to conserve local rangeland ecosystem,and keeping grazing pressure at reasonable level and forbidding reclamation is a rational land use policy.To offset decrease of farmers'income with implementing land use regulation,it is absolutely necessary to introduce new technologies and to intensify farming activities.For poor households,they may increase 49%-52% of income by introducing sedentary beef cattle livestock under alternative land use policy scenario.Impro-vement of credit provision is an important subject factor for poor farmers to adopt sedentary beef cattle technologies.Poor households which introduced sedentary beef cattle livestock may increase 51%-416% of income if credit provision to poor farmers was improved.Furthermore,increase in off-farm employment opportunity has positive effect on urban-rural interaction,which may offset the decrease of households'income due to implementation of land use regulation.While regulation to keep grazing pressure at 1 sheep unit/ha was introduced,households' income will decrease 39%-65% compared to present land use policy.Households' income will reach 78%-93% of the present level under the land use regulation if there is an increase in off-farm employment opportunities.Based on the results,it may be concluded that intensification of agriculture and increasing urban-rural interaction is essential for restoration of deteriorated ecosystem and alleviation of poverty in ecological fragile area in northern China.That is to say,environmental policy should be combined with rural development policy,which includes prom-oting new technologies extension,improving credit service and increasing off-farm employment opportunities.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    SHI Zhi-hua, WANG Tian-wei, CAI Chong-fa, ZHAO Chun-hua, YANG Kai-wang
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    The Three Gorges Reservoir Area(TGRA) covers 21 counties and cities in central China's Hubei Province and Chongqing Municipality with a total area of 58 800km2.Though dominated by mountains,it is densely populated and has been intensively reclaimed and cultiv-ated.Due to long-term human activities including overuse and inappropriate development,soil erosion and forest degradation in TGRA have become serious ecological and environmental problems.To solve these problems,the Chinese government formulated a series of conservation policies including soil and conservation project in the middle and upper reaches of the Yangtze River,returning cultivated land to forest or pasture,and natural forest protection.In this study,the Letianxi Watershed,located at 1km downstream of the Three Gorges Dam lying between 30°51′~31°10′N and 110°8′~110°54′E,is taken as a case study to understand the impacts of ecological restoration measure on soil erosion,vegetation cover and land use change.Based on Landsat TM/ETM images in 1997 and 2002,the land use maps of the study area were compiled through methods of supervised classification and interactive modification,and land use type transition matrix and its three landscape indices(i.e.patch number,mean patch area and its standard deviation) were calculated by model and GIS.Relative land use suitability index(Lr),which is mainly used to reflect the suitability of land use structure,was calculated taking soil erosion into account. Vegetation coverage was estimated from soil-adjusted vegetation indices(SAVI) using a second-order polynomial equation.Dynamics of soil erosion were assessed with RUSLE using GIS,and data used for the RUSLE were either determined or taken from published literature pertai-ning to the Three Gorges Reservoir Area.As a result,this paper found that through 5 years ecological restoration measures,the vegetation coverage increased from 80.6% in 1997 to 83.23% in 2002.Furthermore,the quality of cover was improved,and the area of more densely covered type including forest and shrub increased 18.1% and 9.1%.The land use structure is more reasonable,and the rationality index of land use increased from 0.76 in 1997 to 0.81 in 2002.The intensive,moderate and slight eroded area reduced 4.61km2,26.43km2 and 11.49km2 respectively due to the improved land use structure.At the same time,the annual average soil loss rate was approximately 1 562.5t/km2 in 1997,whereas 870.7t/km2 was found in 2002.The ecolo-gical restoration measures taken from 1997-2002 in Letianxi Watershed have got good ecological and environmental effects.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    CAO Yu, CHEN Hui, OUYANG Hua, XIAO Du-ning
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    Study on landscape ecological classification is the basis for understanding landscape patterns and ecological functions in landscape ecology.And the application of remote sensing for classifying landscape ecological types was one of the most important methods in landscape ecology all along.For finding a way to enhance the ability of landscape ecological classification,this study will try using different vegetation indices and other band ratio indices to join the classification process.In this paper,with remote sensing and GIS techniques,Ejin natural oasis landscape ecological classification was carried out using Landsat7 Enhanced Thematic Mapper Plus data in 2001.Firstly,remote sensing image data preparation was done based on image masking,geometric correction and radiometric correction.Then,according to Ejin natural oasis landscape ecological classification system,unsupervised classification,vegetation indices and band ratio indices clustering,supervised classification and landscape types overlaying and integrating,orderly,were executed to interpret and classify the map of classification of Ejin natural oasis landscape in 2001.In order to use all the bands of original remote sensing image data,five vegetation indices such as NDVI,DVI,RVI,IPVI,SAVI and nine band ratio indices such as Index1,Index2,...,Index9 were selected to participate in the interpretation of landscape ecological types.Results show that,NDVI,DVI,IPVI,SAVI,RVI,Index5 and Index6,with similar characte-ristics,can obviously separate landscape types with vegetation ingredients.Index1 to Index4 have better spatial separability and can easily identify different landscape types.For Index7,Index8 and Index9,owing to their worse spatial separability,they can difficultly differentiate landscape types.In conclusion,during the processes of landscape ecological classification based on remote sensing image data,more vegetation indices assisting can not only find new information,but can also clearly enhance the ability of interpretation and classification of landscape ecological types,especially for those oasis landscapes in arid regions.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    ZHOU Hui-bin, ZUO Dan-ping
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    Travel cost method(TCM) determines the value of recreational function based on inferring indirectly demand curve of recreation of tourism destination itself via travel cost,namely,the curve of price of destination and the number of tourists.Since the 1990's,travel cost method has been introduced and applied in China and case studies increased rapidly in recent years.All the case studies adopted zonal travel cost method,and no individual travel cost method(ITCM) and random utility model(RUM) have been used so far.This paper analyses and valuates 11 typical case studies with zonal travel cost method.Most case studies of TCM in China can not make clear the relationship between travel cost and the price of destination itself,arguing that the travel cost is the same as the entrance price.Therefore their demand curve of recreation is the model of relationship between travel cost and the number of tourists,but not demand curve of recreation of the price and the number of tourists of destination itself.This paper gives a detailed explanation of the principle and operating approach of zonal travel cost method,and re-computes the recreational value of Dalinor National Nature Reserve to be 92.21 million yuan per year with the data from the article written by Qiao Guanhua et al.,nearly 10 times that of Qiao's result,which is 9.37 million yuan per year.At the same time,this paper discusses some questions such as the structure of travel cost.It argues that there are some problems in the research method when Qiao et al.inferred the demand curve of recreation.They calculated directly the travel cost and value of time as the value of recreational function.This approach is not accord with the basic principle of TCM and the economic theory of public goods without(lower) marketed price.The present study gives a result of 135.81 million yuan per year as the recreational value of the reserve after adjusting the data from Qiao's paper.It points out that most of the researchers in China who used TCM lacked the correlative economic theoretical basis and failed to grasp the core technology of TCM.Most of the case studies only copied the existing case studies.The reliability of conclusion of TCM in China is low,and further efforts must be made in order to improve future research level.