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    Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    WANG Fang, LIANG Rui-ju, YANG Xiao-liu, CHEN Min-jian
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    Ecological water requirement is a new research direction of water resources manage-ment.There are many different understandings about this concept.The paper analyses the essence of ecological water requirements basing on sustainable development.It also analyses the principle of vegetation with water that answers the following questions:Which part of vegetation is sus-tained only by precipitation rather than by transforming runoff?Which part of vegetation is sus-tained mostly by runoff?And what relation is between vegetation and groundwater table in dry land?
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    WU Xian-feng, LIU Chang-ming, YANG Zhi-feng, WANG Xi-qin
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    The area of the West Route Project of South-to-North Water Transfer,located in the upper reaches of the Yangtze River and the marginal areas of the Qingh ai-Tibet Plateau,has sufficient water resources but fragile eco-environment ,eco-environment water demand is the key element which determines the available quantity of water transferred because of the lower water demand for local social and economic development.Considering the effect on the eco-environ-ment ,this paper gives the available quantity of transferable water in the West Route Project of South-to-North Water Transfer for the purpose of protecting the local eco-environment and de-creasing the crisis of water resources in the western areas,by taking water demand for river channel eco-environment at downstreams of the dams as the main constraints.In order to calcu-late the eco-environment water demand,low runoff and Tennant methods are used.According to the results of risk analysis,the proposed schemes of the available quantity of water transferred have high reliability and low risk.The risk will be further reduced if multi-reservoir joint opera-tion are put to effect.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    LI Dao-feng, NING Da-tong, LIU Chang-ming, YANG Zhi-feng
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    Based on the analysis of climate,engineering and terrain characteristics within the exported region along the Tongtian,Yalong and Dadu rivers,using the method of inte-grating quantitative calculation and qualitative approach,the impacts on local climate in the adjacent lower reaches of the dam sites,reservoir regions and dry valley regions are em-phatically analyzed.The results show that the West Route Project of South-to-North Water Transfer would not have obvious effect on the local climate over reservoirs,and on the tem-perature,humidity and precipitation of lower reaches of the dam sites.In addition,the dry valley regions would also be triflingly influenced.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    HU Ru-ji, MA Hong, FAN Zi-li, YANG Qing, WU Su-fen, HUANG Yu-ying
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    Consisted of the oases,deserts,basins,plains and surrounding mountains,the vast terri-torial system of Xinjiang is an important component in arid areas of Northwest China.Because the geomorphological features having high mountains are in alternation with basins,the unique water cycle systems and the interior drainage basins,big or small,without hydraulic connections are thus formed.In the water circulating process,the mountains,basins,plains,oases and deserts are connected due to the formation and conversion of the water resources through the streams.The streams from the mountains to the deserts,basins and plains are the main sources of the wa -ter resources in Xinjiang because the runoff formation does not occur in the desert,basin and plain systems.Water resources serve not only as the control factors of the ecology and environ-ment,but also as the material base for socio-economic development.Since the late1980s,precip-itation in Xinjiang has increased by20%~30%,stream runoff has universally increased,water level of the lakes has obviously raised,surface area of the lakes has continuously enlarged,and the groundwater level has raised step by step.The synthetic analyses on the main changes of wa -ter resources,slight increase in temperature,obvious increase in precipitation,etc.,show that the regional climate and hydrology are changing towards the favorable aspect to the socio-economic development in Xinjiang in the context of global climate change.It is predicted that this trend will continue untill the first20years of the21st century.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    ZHANG Jia-bao, YUAN Yu-jiang
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    With the aid of math statistical method,the latest findings derived from integrated ac-curate data of meteorology and hydrology covering1958~1997are used to reveal the climatic features,the basic facts and statistical regularities of climate change as well as the impact of cli-mate change on water resources,in Xingjiang.T he trend of future climate change and its impact on the region's water resources are tentatively discussed.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    GE Xiang-dong, PENG Bu-zhuo, PU Li-jie, HUANG Xian-jin, ZHANG Yong-qin
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    The strategic ultimate aim of the dynamic balance maintenance of total farmland is to ensure the safety of food supplies and to make the output capacity of reserved farmland and the per capita output level increase.Because of the difference in occupied and supplement ed farmland quality,while the system quantity of farmland is monitored,we should warn the spatial-temporal range and dangerous degree of the quality degradation critical value.Therefore we can reflect the state of farmland system on the whole.The monitoring of farmland quality should be inte grated with the dynamic change of farmland area of all grades.The researches on the grading and ranks of farmland,the dynamic change of farmland quality and the monitoring system of dy-namic balance maintenance of total farmland should have unified index system and technological project,so we can solve the operational problem of"occupying one but supplying some "in ba-lancing occupation and supplementation of farmland quality.On the basis of the fixed-site moni-toring of occupied and supplemented farmland and farmland productivity grade based on the in-dex of farmland productivity,we have carried out the critical alertness and early warning of dy-namic balance maintenance of the total farmland,regarded that actualizing the strategy of dy-namic balance maintenance of the total farmland should be combined with the construction of farmland quality,the protection of basic farmland,technical advancement and population control-ling.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    SUN Shi-jun, DING Yue-yuan, CAO bo, TIAN yuan
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    Since the1980s,because of scarcy precipitation in northern China,the level of farm-land groundwater has been decreasing and the storage capacity of soil risen accordingly.Ac cord-ing to the information observed from the experimental site of water resources to the south-east plain of Beijing,the0~3m layer soil was determined as the defined depth of soil reservoir and its pondage capacity was analyzed.Through computation it was found out that,before the rainy season during1991~1995,the normal annual available pondage capacity of soil reservoir was137.4mm(0~2m depth)and188.8mm(0~3m depth)respectively.The results showed that soil reservoir had very good regulation capacity and85%of the normal annual precipitation was stored in the3m deep soil(the defined depth of soil reservoir).So if some available measures are taken before an extraordinary rainstorm happens,then there will be no or less surface runoff ap-pearing and most of the precipitation will be stored in soils.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    WANG Wei-wei, HU Zheng-hai, GUAN Gui-lan, KONG Ai-qin
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    The nodulation and nitrogen fixation of major cultivated and wild legumes separated from98species under36genera in central western Gansu province and southern Ningxia Re-gion have been studied.Some 360strains of root nodular bacteria have been isolated from about 400samples,among them44strains were obtained from30unreported species in Allen's"The Leguminoaes"and other literatures.Most of which were tested infecting in22model species that belong to20genera as host,81.2%strains of tested rhizobia can nodulate with host plants.Above85%of those nodule samples were effective for nitrogen fixation.The result showed that the activities of nitrogen fixation in nodules of various species varied greatly and all of them were relatively low,i.e.,46.6%of them are under1μmol C 2 H 4 ?gFWh and6.8%,more than10μmolC 2 H 4 ?gFWh .The nitrognase activity was closely related to the growth period of plants.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    LIU Guang-quan, WANG Hao, QIN Da-yong, NI Wen-jin
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    By means of standard site-water balance fields and gathering baskets,the main func-tion s of litter layers for3forest-types of the Pine-oak forest belt in Qinling Mts.were examined,the result s are as follows:the average standing crop for sharptooth oak stand at age26,Ar mand pine stand at age24and Chinese pine stand at age24was17.475t/ha in the order of Armand pine>Chinese pine>sharptooth oak stand.The average annual falling litters for the3stands was4.179t/ha,of which the sharptooth oak stand was1.4times as high as the Armand pine or Chi-nese pine stand,but the accumulated litters for the former was less than half of the latter two.During the growth season the average retaining water for the3stands was44.81mm,being4.47% of the corresponding atmospheric precipitation.Among which the amount in broad-leaved stand was higher than in needle-leaved stand and changed with accumulated litters and tree species composition and so on.The orders of woodland evaporation and it's rate are put as naked land>broad-leaved woodland>needle-leaved woodland and naked woodland>litter-covered woodland,the seasonal variation for the woodland evaporation in needle-leaved stand was much more stable than in broad-leaved stand.The average percentage contents of N,P,K,Ca and Mg in the litters for the3stands was1.08,0.07,0.37,1.37and0.21respectively.In general,the average fig ure in sharp tooth oak stand was much higher than in Armand pine and Chinese pine stands,but there was no evident difference between that in Armand pine and Chinese pine stands.The average nutrient accumulated contents of the litters for the3stands was502.5kg/ha in the order of Chinese pine>Armand pine>sharptooth oak stand.The annual nutrient uptake and return of the sharptooth oak,Chinese pine and Armand pine stand were334.4and147.2,195.5and66.9,138.8and80.4kg /ha respectively with difference in the determined elements.The sharptooth oak stand not only required much more nutrient contents,but also had quicker bio-cycling rate than Chinese pine and Armand pine stand.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    YU Yun-jiang, LIN Qin-gong, GAO Yong-gui, QIU Ming-xin, LIU Jia-qiong
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    Based on community succession and analysis of sand flow,the stability of com munity was studied.In Shapoptou area,the artificial communities in which Artemisia ordosica communi ty is dominant are adaptable to the habitat environment in long-term natural succession and they are stable.The results of observation and comparative study of vegetation succession in Shapotou and the vicinity showed that existing vegetation communities are evolving towards disclimax and in the future long periods of time Artemisia ordosica community will be stable.These succes-sions can facilitate the evolution of the local artificial vegetation towards more stable artificial natural compound ecosystem and even natural ecosystem.Furthermore,the research result of im-pact of wind flow on plant and earth-surface wind-tunnel experiment result showed that main vegetation and earth-surface of Shapotou at present can resist greater stress from wind flow and the ecosystem that can stand sand-dust storms has been formed.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    ZHONG Lin-sheng, XIAO Du-ning, ZHAO Shi-dong
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    The conception and principles of ecotourism suitability evaluation are raised according to the definition of ecotourism in this paper.And Wusuli river national forest park is taken as a case for explaining the method of evaluation.Firstly,the impact factors of ecotourism suitability evaluation are determined.Then their relative weights are assigned with Analytic Hierarchy Pro-cess.Statistical analysis with Geographical Information System reveals only1814.76ha(7.9%)of the total area are most suitable for ecotourism exploitation,623.44ha(2.7%)are moderately suit-able,12209.00ha(53.1%)are suitable,and2614.76ha(11.36%)are marginally suitable.Final-ly,the thesis puts forward some suggestions by taking into considerations of different values of e-cotourism suitability.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    WANG Gen-xu, CHENG Guo-dong, SHEN Yong-ping
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    A series of changes have taken place in the last50years in regional hydrology and e-co-environment in Hexi Corridor region due to dual driving force of intense human activities and regional climate changes.(a)Regional runoff processes flowing out from mountains showed that mean annual outflow of the Shiyang River from mountains at the east section of the corridor tended to decrease significantly;annual outflow of the Heihe River and the Shule River at the middle and west sections of the corridor tended to increase,but the downstream discharge sharply decreased and displayed obvious anthropogenic hydrological features.Water salinization and pollution tended to be exacerbated,of which theⅣ~Ⅴgrades of polluted river course reached208km.(b)Forest area in the south Qilian Mountain region decreased by16.5%but it has gradually increased since the1990s.However,natural desert forest in the northern part of the corridor continuously degraded and rapidly disappeared,only in Minqin and Ejin counties about 34.31×10 4 hm 2 of woodland have disappeared.Grassland ecology showed a continuous degradation tendency,grassland area decreased,desertification exacerbated,carrying capacity re-duced and total area of degraded grassland in Hexi corridor region occupied46.86%.(c)Land de-sertification in Hexi corridor region developed rapidly in the last50years and reached a highest an nual rate of2.15%in the early1980s,but from the late1980s to the1990s its develop ment rate significantly reduced.The essential ways to improve regional sustainable development capa-bility are identified as to take river basin as an unit,make overall plans of water use and man-agement by taking water demand for economic development and eco-environmental construction of different regions in to consideration;to take healthy development of ecosystem as the principle,follow ecological laws to exploit and utilize land resources;and to take river basin as an unit,conduct systematic work to protect the ecological function.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    YANG Jie, GAO Qing-zhu, LI Guo-qiang, HE Li-huan, JIN Zheng-ping, WANG Zheng-wen
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    According to the field monitoring data in the growing season of a water abundant year(1998)and a water deficient year(1999),this paper deals with water regime of three dominant shrubs-- - Hippophae rhamnoides,Salix psammophyla and Caragana intermediai in Huang-fuchuan watershed.The results show daily changes of the transpiration intensity of the three dominant shrubs have different characters in sunny days and cloudy days.In sunny days,the dai-ly changes of the transpiration intensity of S.psammophyla and C.intermedia have double peaks and noon depression,while H.rhamnoides has single peak without noon depression.In cloudy days,the daily changes of transpiration intensity of these three dominant shrubs have single peak without noon depression.In both the abundant year and the deficient year,the transpiration inten-sity of the three dominant shrubs shows similar seasonal variations.It fluctuates with the in crease and decrease of soil water content and precipitation.The correlation between transpiration of the dominant shrubs and soil water content is different from each other.The transpiration of H.rham-noides correlates closely with soil water content,but the relationships between the transpiration of the other two shrubs and soil water content are insignificant The above-ground biomass and water consumption of the three dominant shrubs showed synchronized increase in both abundant and deficient year.In deficient year,the above-ground biomass and water consumption of the three dominant shrubs reach the highest values in July,but reaching the highest values in August in abundant water year.And in growing season,transpiration coefficients of all the domi nant shrubs are very high.It is thus concluded that the shrubs grow at the expense of vast amount of water content which is one of the main limiting factors.The transpiration coefficient of C.intermedia is the smallest,this indicates that C.intermedia consumes water and accumulates dry matter more ef-ficiently than others,so it is more suitable to Huangfuchuan watershed.Under condition of water balance in Huangfuchuan watershed,suitable coverage of H.rhamnoides is61~79%,C.intermedia is43~55%and S.Psammophyla is46~59%.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    WANG Chuan-sheng, SUN Xiao-wu, LI Jian-hai
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    Water-front resources are the important parts of land resources in China.But there are few practical studies,whether in China or in other countries of the world.In China,the studies have begun from the end of1980s' and have mostly been on the down and middle of Changjiang main stream.In the methods,quantitative analysis and GIS tools have been exercised.Based on the old researches,this paper summarized three kinds of and three steps of evaluating water-front resources.Three kinds are the evaluation for classifying water-front quality,the evaluation for water-front applicability and the integrated evaluation of water-front.The steps are to cut cells,to evaluate each factor,and to grade water-front.And more,as a background of the meth-ods of resource research,by a case:the water-front evaluation to nature setting for ports on the Changjiang mainstream in Wuhan metropolis,the author discussed systemically general steps of applying GIS to evaluate water-front resources.The evaluation is finished by four principal steps:data prepared,database set up,evaluation implementation and results output.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    SHAN Sheng-dao, WU Ci-fang
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    Great importance should be attached to the understanding of"Shadow Massif"-it is not an actual massif but an"invented"one.It is the abstraction of the characteristics of a piece of land.Taking Wenzhou Chashan Forest Park as an example,we solved technical problem on woodland evaluation which is caused by the obvious differences of site condition.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    ZHOU Xiao-dong, ZHU Qi-jiang, WANG Jin-di, SUN Rui, CHEN Xue, WU Men-xin
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    On the basis of an observation to summer maize canopy PAR during growing period at Luancheng,Hebei,the incident PAR,the reflective PAR of the canopy,the PAR reached the land surface through canopy,the reflective PAR of the land surface,the reflectance of land surface,the Absorbed Photosynthetically Active Radiation(APAR)and the reflectance diurnal change of the canopy and land surface under clear and cloudy conditions respectively were stud-ied in this paper.Also,the FPAR at an interval of five minutes and the average value of a day were calculated according to each PAR components in canopy.Then the relationship between daily variation of FPAR and crop growth periods as well as the variation of LAI were examined and a linear relationship between FPAR and LAI was presented.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    RAN Sheng-hong, JIN Jian-jun, XUE Ji-yu
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    The interior structure of vulnerable ecological regions is instable and these regions are hypersensitive to the exterior disturbances.Actually,their development trends and stability are the inherent forms of vulnerable ecological regions' basic properties.Therefore,the assessment of vulnerable ecological regions should include three parts:assessment of status quo,assessment of development trend and assessment of stability.Base d on new concept of vulnerable ecological re-gions,this paper assesses the status quo by fuzzy theory and predicts its develop ment trend by grey theory.Non-linear theories are applied to assess stabilities of vulnerable eco logical regions for the first time and the effect is very well.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    XU Yue-qing, LI Xiu-bin
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    This paper analyses the dramatic change of cultivated land during the last50years in Hebei Province.Based upon which,the situation and composition of cultivated land loss during1988~1995are examined.The causes of cultivated land loss are discussed and the countermea-sures are advanced.It is found out that the adjustment of agricultural structure is the main cause of cultivated land loss,which accounts for47%of the total amount of cultivated land loss;land devoting to non-agricultural constructions and damaged by natural hazards are the secondary causes,which respectively account for22%and30%of the newly added types of cultivated land,reclamation and reuse of abandoned land are the main sources of cultivated land increase,which respectively account for49%and44%of the total increased cultivated land.