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    Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    JIANG Li-peng, QIN Zhi-hao, XIE Wen, WANG Rui-jie, XU Bin, LU Qi
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    Grassland ecosystem is a very important terrestrial ecosystem in China.It provides not only a large number of economic products but also many ecological services for mankind.Estimation of the grassland ecosystem services values is urgently required for administration of the precious natural resource.This paper intends to propose a practical method to estimate grassland ecosystem services value using remote sensing data.First of all,the relationship between the value of organic matter production,O2 released and CO2 fixed,nutrient recycle,and environmental pollution cleaning and the net primary productivity(NPP)was established using various methods such as market value,substitution,shadow price,opportunity cost.Consequently,the relationship between the value of soil erosion control and the quantity of soil conservation,which can be calculated from vegetation coverage fraction,was also constructed.The value of water conservation function was calculated by vegetation coverage fraction.Then,a net primary productivity(NPP)model of grassland based on photosynthesis efficiency model was proposed,in which all the parameters were retrieved from EOS/MODIS data.The method of determination of vegetation coverage fraction was also introduced.Finally,the value of grassland ecosystem services of China in 2003 was computed using the proposed method.Our results indicated that spatial variation of the ecosystem services value per unit area was consistent with the distribution of grassland types.The service value per unit area varied greatly with different grassland types.Shrub-meadow with sparse trees had the highest services value of 990259yuan/km2(RMB).The service value of upland meadow is also high up to 968586yuan/km2(RMB).Alpine desert steppe had the lowest services value of 56202yuan/km2(RMB).Alpine desert also had a low services value of 89952yuan/km2(RMB).Total service values of Chinese grassland ecosystem in 2003 was 1.70503×1012yuan(RMB).Different grassland types had different total services values depending on their areas.Alpine meadow had the largest amount of total value of 4.05998×1011yuan,accounting for 23.81% of the total services values of the entire Chinese grassland ecosystem.The services value was also varied with different ecosystem functions.The released O2 and the fixed CO2 contributed the highest percentage to the total service values being 54.06%.The contribution of organic matter production,soil erosion control,nutrient recycle,and water storage was 19.66%,14.28%,5.63% and 4.20%,respectively.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    DU Hong-liang, CHEN Bai-ming
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    China is a country with vast population and scarce land per capita and the arable land decreases substantially.To study the land of any types or in any region has been brought forward at the new round of land use restructuring planning,and it offers an important tract to plan synthetically and solve the arable land problem.This paper takes Hebei Province as a case to illustrate it.Firstly,to estimate quantificationally the sustainable throughput of all counties(towns or townships) and rank those by the value of throughput,sequentially to determine which places should be concerned highly in the course of the local government protecting the arable land;the process includes indicator system's design,ascertainment of the weighing,standardization of the data and division of the key regions;then 42 counties have been taken as national farmland protection regions,which are mainly located in the central and northern part of southern Hebei province and the peripheries of Beijing and Tianjin municipalities,and another 52 counties as provincial farmland protection regions,which are mainly located in the central Hebei province,the southwestern part of southern Hebei province,and the littoral of Hebei Province.Secondly,to differentiate the degree to which the construction activities endanger the quantity of arable land so as to lay the foundation for adopting different measures in different regions;the process includes analysis of the factors to endanger the quantity of the arable land,ascertainment of the indicators to classify the regions,ascertainment of the standards to classify the regions and the classification of the being-endangered arable land regions;then there are 10,11,29,25 and 19 counties taken as high,high-medium,medium,medium-low and low endangered regions respectively,among them the first two types are mainly located in the peripheries of the big cities and the neighboring regions along the main roads in Hebei Plain.Thirdly,to set up a series of rigid,flexible and expected indicators,then use them to regulate the local arable land at different scales and to different degrees.Lastly,to set down several countermeasures to guarantee these indicators to be implemented efficiently,which mainly includes(1)establishing digital management systems aiming at indicators brought forward above;(2)plotting out the regions of land us control;(3)reforming the revenues;and(4)designing and perfecting the new property right systems.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    LU Xiao-fang, WANG Yang-lin, ZHANG Yi-li, SHEN Yuan-cun
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    The ecological condition of agriculture in the west of China is extremely fragile and there exists the potential of a series of problems,such as severe desertification,environmental degradation.Meanwhile,its social and economic basis is relatively weak,especially in the typical agricultural regions.How can we not only realize agricultural industrialization and agricultural specialization in the fragile regions,but also combat the environmental problems in the process of their agricultural production,then develop sustainable economic system in local regions?芽It is necessary to make the functional regionalization of agricultural resources and environment ahead of schedule.Based on the sustainable idea and the eco-economical-system theory,this paper explores indexes of the agricultural-functional regionalization in Yanchi County,which is a typical agricultural county in central Ningxia Hui Autonomous Region.The paper combines mathematics-ecology models with clustering analysis models of statistics to make the agricultural-functional regionalization of the county.On the basis of physiographical regionalization,it adds the principal components analysis of social and economic indexes,which come from the analytic function models of SPSS and include four typical elements reflecting the standard of agricultural production profit,the population pressure,the population increasing rate and the standard of non-agriculture of each village respectively.The final result of agricultural-functional regionalization includes five agricultural-functional sub-regions: 1) the grain-economic-crop-wood-stockbreeding-medicine eco-economic region in the upland of northern part of the county,which consists of five villages,and its function should be focused on developing byproducts to meet the demand of good market condition while preventing desertification;2) the stockbreeding-wood-grassland-grain eco-economic region in sandy upland and bottom land,which consists of four villages,and its function should be focused on raising sheep while seeding degenerated pasture;3) the grain-oil-economic crop-stockbreeding-special local product region in the sandy bottomland which consists of two villages,and its function should be focused on developing special local farm products of food and oil plants while paying more attention to local salina;4) the grain-economic crop-fruit-vegetable-stockbreeding region in the upland and bottom land of Dashuikeng town,and its function should be focused on the economic product,such as fruit and vegetables while protecting drainage area in the south;and 5) the grain-oil-special local product-fruit-stockbreeding region in the upland and low mountain area which consists of four villages,and its function should be focused on planting oil plants and pasture of high quality while conserving soil and water in the loess upland.Through analyzing eco-economic characteristics of these regions,the paper proposes the sustainable development strategy for each region.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    YANG Wen-bin, WANG Guo-xiang, ZHANG Li-min, CAO Yun, PAN Guo-quan
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    Kuncheng Lake is one of the key freshwater lakes of Changshu City in Jiangsu Province.Temporal-spatial variability of water quality of the lake is analyzed by comprehensive index method,fuzzy mathematics and hierarchical clustering method,while eutrophication of the lake is assessed by TSIM indexes.The results show that quality of the lake water has degraded gradually in recent years,and has attained to or been worse than grade-Ⅴ;among all indexes,the total nitrogen pollution is most prominent;due to difference of terrestrial sources pollution and effects of encircling gear cultivation,pollution in northern and western parts are more serious than in southern part in this lake;and Kuncheng Lake has been subject to eutrophication.Non-point source,point source,domestic sewage pollution etc.of the lake are evaluated in this paper.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    QU Xiao-hui, ZHUANG Da-fang, PENG Wang-lu, QIAO Yu-liang
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    To protect basic cropland is the precondition of the agricultural sustainable development in China,dynamically detecting the change of cropland on a spatio-temporal scale can help to make out the agricultural development plan and managing the agricultural economic development.This article discussed the classification method of the remote sensing image using the BP artificial neural network,and on the condition of the precision of the classification,it explored a remote sensing dynamic detection model comprised of single component detection and multi-component detection,and described the algorithm about it in detail.Finally,an application of this model has been shown in an experimental area,and the result of the application has been analysed with the real data.It is shown that this model has excellently evaluated the amount and potential of the basic cropland in this experimental area,and opened out the change regular of the basic cropland in the experimental area on a spatio-temporal scale in a qualitative,quantitative and orientative way.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    LI Xiao-na, WU Ju-ying, TENG Wen-jun, LIU Hong-lu, WU Wen-yong
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    Alfalfa(Medicago sativa)is the dominant forage type in China and the shortage of water resources is the limiting element that influences its production.Reclaimed water is a valuable substitute water resource for forage irrigation.The influence of reclaimed water irrigation on the growth and nutrient up-take of alfalfa(Medicago sativa L.cv.'Algonquin')was studied by potted plants.Two water types(fresh vs.reclaimed) and three irrigation levels(high-,middle-,and low-)of water amount were used to irrigate alfalfa.The result showed that the growth height was positively related to the level of irrigation regardless of water types.Water type had significant effect on the number of side branches,highest increase was found under high-level irrigation of reclaimed water.Reclaimed water significantly increased the first-year hay production in comparison to fresh water.In the growth prophase of alfalfa,the root growth of alfalfa was negatively related to reclaimed water irrigation.The effect of irrigation water types on alfalfa absorbing N,P,Ca and Mg was mainly in the growth prophase of alfalfa while that of irrigation water types on alfalfa absorbing K was not significant.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    ZHANG Guo-kun, DENG Wei, LU Xian-guo, SONG Kai-shan, LI Heng-da, ZHANG Hong-yan
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    This article,using the model of land-use conversion matrix and landscape pattern index by the technical means of RS and GIS,quantitatively analyzes the dynamic changing process of landscape pattern in the Xinkai River Basin during the past 33 years(from 1969 to 2001).Results show that(1)the wetlands of Xinkai River Basin had changed to meadow,farmland,sandy land or salina to different degrees with the inerease of population,intensification of land-use practices and changes of hydrological conditions,leading to the converse growth of the vegetation.(2)With severe fragmentized situation in 2001,the average area of the parcels,the maximum area of the parcel and the perimeter of the maximum parcel decreased by 71.02%,71.08% and 64.76% respectively,compared with that of 1969.While the SL increased from 0.78 to 0.93.This research achievement can provide scientific basis for the protection and rational utilization of wetlands in the Basin.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    LI Li-juan, JIANG De-juan, LI Jiu-yi, LIANG Li-qiao, ZHANG Li
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    With rapid economic development and population growth,land use and land cover change(LUCC)have great effects on hydrological processes.The research in this field has been the focus of attention and the international frontier.In this paper,the study methods of hydrological response to land use and land cover change were analyzed,including experimental method,time series analysis method of hydrological characteristic parameters,hydrological model method and combination of multi-methods,and its progress was reviewed and discussed from points of view of driving forces of LUCC,such as afforestation and deforestation,urban and agricultural development as well as soil and water conservation.Some conclusions of this paper were drawn as follows:①Imperious area extension driven by rapid urban development could change the urban water balance,and then increase runoff coefficient,flood peak flow and its frequency,and contrarily decrease the ground recharge,but due to different levels of urbanization development,hydrological effects would make a certain difference.②Studies on hydrological response to soil and water conservation generally showed that,the underlying surface conditions alteration by soil and water conservation could decrease annual runoff and flood peak flow,and increase infiltration and runoff in the non-flood season,but due to different geographic locations,climatic conditions and so on,hydrological effect of soil and water conservation in different regions or watersheds also showed a certain difference.③In the respect of hydrological response to afforestation and deforestation as well as agricultural development,the results made a great difference due to the diversities of spatial scale,regional location,climatic conditions,and study objectives.Therefore,many affecting factors need to be considered comprehensively,and hydrological response to land use and land cover change should be assessed correctly so as to support scientific foundations for rational allocation and sustainable development of land and water resources.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    FU Hai-yue, LI Man-chun, MAO Liang, LIU Yong-xue
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    Evaluating human effects on the ecosystem is a critical issue in the process of general land use planning.In recent years,Ecological Footprint(EF)has been an widely accepted tool to quantify this kind of assessment in many fields.However,only few studies have addressed the problem of EF in the realm of land use general planning.Taking Langfang city as a case study,this paper develops an approach to quantitatively analyze the trends of EF and BC over the planning period in general land use planning and to evaluate the ecological effects of the land use general planning. In this paper,we introduced the concepts of change rates and scissors difference to indicate the tendencies of EF and BC time series.We calculated the change rates and scissors difference of per capita EF and BC over planning period of general land use planning(1997-2010),investigated the developing process during the past eight years(1997-2004),and predicted the future tendency in the following six years(2005-2010).Based on these,we assessed the possible effects of general land use planning(1997-2010) on the local ecosystem,and attempt to present suggestions for the following general land use planning(2005-2020). The results show that: 1)In Langfang city,trends of the per capita EF and BC are on the way round,and the ecological deficit enhanced from 1997 to 2010.The per capita EF increased from 1.583 ha in 1997 to 2.823 ha in 2010,while the per capita BC decreased over years from 0.563 ha in 1997 to 0.414 ha in 2010.Meanwhile,the ecological deficit in 2010 will be 2.619 times greater than that of in 1997.2)In Langfang city,the scissors difference between the trends of EF and BC time series had been decreasing until 2000,it began to rise after year 2000.This growth direction is not what we expected,with the aspect of ecological equilibrium.3)The general land use planning(1997-2010)of Langfang city had produced some positive effects on the local ecosystem.Thus,the ecological deficit at 2000 was lower than the expected,and the ecological difference had also been reduced during 1997-2004.But the expected biological capacity at 2010 can hardly be realized following this trend.The direction of reducing the ecological deficit by extensive land use is against the sustainable development.The general planning(2005-2020) of Langfang city should pay more emphasis on the land use spatial layout not rather than on the land use quantities layout and strengthen scientific,economical,intensive land use.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    HU Zhen-peng, WANG Qin-feng
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    The minerals are nonrenewable resources.For building a resources-saving and environment friendly society,recycling economy should be developed.The material is fully utilized in multiple hierarchies;energy is effectively converted through development of recycling economy in the technological process on mining,mineral separation and copper smelting in Jiangxi Smelting Copper Corporation.About 43500t of copper,12t of gold,300t of silver,1.1×106t of H2SO4,1×108kW·h of the electric energy and rhenium,molybdenum,selenium etc were produced by use of waste and 85% of waste water was repeatedly used every year.The profit from recycling economy amounts to 3×109 yuan and accounts for 24.6% of the total profit of the company in 2004.The dramatic economic,social and ecological benefits have been achieved simultaneously.The result of the case study shows that,the enterprises should enhance responsibility on building a resources-saving society,should promote and strengthen product chain or product network of recycling economy by advocating science & technology innovation and exploiting the key technology of reuse of the wastes and converting them into demanded products,in order to develop recycling economy for achieving most economic benefits with least resource expenditure and environmental pollution.The governments should set up the new mechanism,perfect the legal system and enhance the management in order to develop recycling economy.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    XU Zeng-rang, CHENG Sheng-kui, MIN Qing-wen, ZOU Xiu-ping
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    Developing bio-energy is a rational choice for solving problems of energy shortage and environmental pollution.As bio-energy is contained in biomass,and biomass has close relationship with characteristics of physiography,the suitability of developing bio-energy in a certain region must be evaluated according to its regional speciality.Based on the previous researches on solar energy,biomass,net primary productivity(NPP) of Tibet,accounting about the conversion process from solar energy to bio-energy and bio-energy sustainable utilization,the concept of usable productivity is presented.In order to keep biome community succession in sequence and restore endangered biome community,human being should not use up NPP.Under the condition of the stability and safety of biome community,part of NPP that human being can utilize is called Usable Productivity.Usable productivity can be used as biomaterial and bio-energy resource.With the help of these concepts,the quantity of bio-energy resource of Tibet is estimated.After analyzed the resource and environment of Tibet,the author finds out that the gross bio-energy resources is huge(24 million tce p.a.)for Tibet's expansion,while the average productivity of bio-energy resources is small(0.2tce per ha.in a year)in Tibet;that the environment is fragile,and the relationship between bio-energy utilization and environment is strain.Accordingly,the strategy of finite utilization according to different geographical characteristics is put forward.The core of the strategy is to balance the bio-energy exploiting and environmental protection,and the key of the strategy is to define the appropriate role of bio-energy in the whole energy consumption.Three measures are helpful to implement the strategy:1) to ascertain the useable productivity scientifically and control the quantity and intensity of biomass that is exploited and used;2)to prorate the quantity of biomaterial and bio-energy in the useable productivity;and 3) to suit measures in line with local conditions.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    GU Xiao-ping, HUANG Mei, JI Jin-jun, WU Zhan-ping
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    The climate change and its induced ecosystem change have gotten more and more attentions from scientists and societies.The past researches showed that the temperature and precipitation variations in southwestern mountainous area of China were different from those in the other parts of China.So the climate change and its impacts on ecosystem in southwestern China is still a question to be understood.In this study,the spatial distributions and interannual variations of net primary productivity(NPP)were simulated by the atmosphere-vegetation interaction model(AVIm2)in southwestern China.The responses of forests,shrub lands,grasslands and crop lands to temperature and precipitation change during 1980 to 2000 were discussed.The study indicates that the spatial distribution of vegetation NPP in southwestern China is positively correlated with the pattern of precipitation and negatively correlated with that of elevation.The total vegetation NPP of southwestern part increased in the 20 years period.More detailed analyses show that variation of plant function type's NPP are different due to precipitation in the areas where they are located varies.In forest area,where the mean temperature rise rate is 0.037℃ per year and the precipitation has no obvious trend,the simulated annual NPP does not show any increase or decrease trend.In shrub lands and grasslands area,where the temperature rise rate is 0.040℃ and 0.034℃ per year,individually,and the precipitations increased,both the simulated shrub and grass NPP show significant increase tendency.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    WANG Yi-rong
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    This paper mainly analyzes water-heat distribution and soil water variations in grassland area of southern Gansu by applying the EOF(empirical orthogonal function) and wavelet analysis.The results show there were jump-points in the evolvement of monthly rainfall and soil-water decreasing,and monthly temperature rise.The slopes of rainfall and temperature were different.The variation rate of monthly rainfall was-13.6mm/10a-4.3mm/10a and that of temperature,0.883℃/10a-0.108℃/10a.The obvious correlations of rainfall and temperature with soil water during growth periods were observed.Also the variation evolvement of rainfall and temperature corresponded with weak 4-year variation period.The change of soil water had good relations with annual rainfall and inter-decadal temperature variations.The oscillation of soil water responded obviously on short rainfall periods and long temperature periods.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    ZUO Qi-ting
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    At first,the concept "human-water system" is introduced in the paper.According to the difficulties and characteristics of human-water system modeling,and based on the theory of system dynamics,the embedded system dynamic model(ESD model),which is more useful in practice,has been put forward.The ESD model is built and coupled from system dynamic model and other professorial models,considering the characteristics and rules of socio-economic system and water cycle system(including social water cycle and natural water cycle),and taking full advantage of correlative methodology.The model either fully takes in the advantages of the system dynamics or draws on the research achievements of relevant subjects,greatly enhancing the application ability of system dynamics.On the other hand,the model can be used to simulate the complex and professorial systems,such as human-water system.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    CHEN Xiao-guang, XU Jin-tao, JI Yong-jie
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    This paper analyzes the factors which have potential effects on residential water demand in North China,including water price,income and water shortage.Empirical analysis shows that water price has an important effect on residential water demand;there is a U-shaped curve between residential water demand and income;and water shortage has a significant effect on residential water demand.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    YU Jin-guo, WANG Li-hua
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    Tourism industry plays an increasingly important role in the development of a city.As an urban tourism destination(UTD),tourism industry can have the leading role in developing the city.So it would be necessary to analyze UTD landscape features and changes in order to understand relationship between urban landscape and tourism,and to summarize evolution theory of UTD.A conceptual evolution model of UTD based on resort life cycle model and destination spatial structure according to urban landscape features.A UTD landscape classification method was provided based on tourism,with which UTD landscapes were divided into three main types,namely,tourism industry landscape type,non-tourism industry landscape type and intermediate landscape type,and three landscape types were further subdivided into 13 kinds of landscape types,the spatial distribution of UTD landscape types were based on the distribution of land use categories in 1980,1989 and 2003 in Dalian and the above classification method.The evolution rule of Dalian's landscape was summarized by virtue of software ArcGIS as a whole Dalian and according to different districts of Dalian through comparing spatial distribution of UTD landscape types in 1980,1989 and 2003.The main findings were as follows:1)Area of tourism industry landscape decreased by 4.81km2 from 1980 to 1989,and then increased by 34.7 km2 from 1989 to 2003,and CA(Class Area)and PLAND(Percentage of Landscape)of parks and squares increased,and its area increased by 14.05km2.2)PLAND of non-tourism industry landscape decreased by 8.5% after 1989.3)The process of tourismification was obvious in the inside circle and middle circle after 1989,PLAND of non-tourism industry landscape decreased by 5.8% and 5.86% in the inside circle and middle circle respectively,while PLAND of parks and squares in the inside circle and middle circle increased by 5.0% and 4.6% repectively.4)In the south of Dalian,PLAND of tourism industry landscape was larger in area than that of the north,and area of tourism industry landscape increased rapidly;while in the north of Dalian,the area of non-tourism industry landscape was larger,PLAND of it decreased obviously.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    ZHOU Feng, GUO Huai-cheng, LIU Yong, HE Bin
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    Socioeconomic development has led to lacustrine eutrophication,destroy of aquatic ecosystems and unbalance of water resource exploitation,consequently resulting in restriction on social and economic development.Based on systematic analysis of the wet lake basin(i.e.lake basin in humid region),this paper firstly presented four key points and four hierarchies of sustainable water resource development of wet lake basin(SWRDWLB).Also,deriving from the DPSIR Model,an indicator framework including three groups,two aspects and 25 indicators was founded.Secondly,the above framework including basic criteria,indicator system and Fuzzy Pattern Recognition model(FPR) was proposed in this study.The proposed assessment method was applied to a case study of the Lake Qionghai Basin and its three subregions in 2001,2005,2010 and 2015.In temporal scale,the result indicates that the trend of different regions' SWRDWLB was stepwise increasing and the relatively important indicators were in the order of eutrophication/ water quality index,forest coverage rate,groundwater exploitation rate,wastewater treatment percentage,and agricultural irrigation coefficient;in spatial scale,in which the region with the greatest degree of SWRDWLB was entire Lake Qionghai basin,then Xichang and Zhaojue,and the lowest was Xide,besides,the discrepancy of degree between each region was expanded in 2010 and 2015,and the relatively important indicators were in the order of eutrophication/water quality index,forest coverage rate,groundwater exploitation rate,water and soil erosion rate,population density and human health degree.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    ZOU Jun, YANG Yu-rong, TIAN Ya-ping, XIE Xiao-li
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    This paper aims at discussing the concept and connotation and evaluating index system of agricultural water resource vulnerability in hilly area of southern China.First,based on the analysis of the research result of vulnerability in the field of resource and environmental science,a concept of vulnerability of agricultural water resource which represents the characteristic of agricultural water resource system in hilly area of southern China is formed.Then the connotation about the vulnerability of agricultural water resource is probed.It is believed that the vulnerability of agricultural water resource includes two aspects of water quality and quantity,which consist of natural vulnerability,artificial vulnerability and burdening vulnerability.Finally,an assessment index system which concludes 12 indexes is built to express the vulnerability of agricultural water resource in the aspect of water quantity in Hengyang Basin which represents the typical hilly area in southern China.And the vulnerability degrees of 7 counties in Hengyang Basin are calculated by fuzzy matter element analysis method,the results show that vulnerability of five counties out of the total is serious.It is found by validation that the assessment results are consistent with the practical situation,indicating that the index system and the assessment method are credible.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    QIU Bing-wen, WANG Qin-min, CHEN Chong-cheng, CHI Tian-he
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    Land use drivers that best describe land use patterns quantitatively are often selected through regression analysis.A problem using conventional statistical methods in spatial land use analysis is that these methods assume the data to be statistically independent while spatial land use data have the tendency to be dependent,known as spatial autocorrelation.Although several techniques are available to deal with spatial autocorrelation,only a few studies of land use modeling were seen using them.As a result,spatial statistical method was applied in this study to derive the spatial distribution of land use.Fujian Province,in Southeast China,was selected as the study area.In this paper,Moran's I are used to describe spatial autocorrelation of dependent and independent variables and spatial autoregressive models which incorporate both regression and spatial autocorrelation were constructed.Six land use types and their 27 candidate driving force variables representing bio-geophysical and socio-economic conditions were selected.The smallest spatial units of investigation were 10000 by 10000 meter cells.Land use types and their candidate driving force data were collected and attributed to these cells.All attribute data for the cells of he base resolution were aggregated to higher artificial aggregation levels through averaging the data.The spatial autocorrelation land use types and spatial regression models that incorporate spatial autocorrelation were analyzed at multiple resolutions. Results show that five main land use types except unused land and all candidate land use drivers show positive spatial autocorrelation which decreases gradually with distance.Variables of slope and aspect factors and distance to town or city show weak spatial autocorrelation,while other candidate diving force variables show strong spatial autocorrelation which extend to over 60-220km.The spatial pattern of land use type is similar to its corresponding driving force variables which show that land use is the direct or indirect consequence of its driving forces.It is also shown that the occurrence of spatial autocorrelation is highly dependent on the aggregation level,higher aggregation level shows higher Moran's I. The residuals of the standard linear regression are less auto-correlated than the original data which show the driving factors used in the regression equation capture part of the pattern.While the residuals of the ordinary regression model also show positive autocorrelation,which indicates that the standard multiple linear regression model cannot capture all spatial dependency in the land use data.The visual presentation of the residuals of the models provides a clear insight in the difference between the two models.Clear spatial pattern was seen in the residuals of the standard linear regression while the residuals of the spatial model were randomly distributed and show no spatial autocorrelation. Spatial autoregressive models yield residuals without spatial autocorrelation and have a better goodness-of-fit.The spatial autoregressive model is statistically sound in the presence of spatially dependent data in contrast with the standard linear model.By using spatial models a part of the variance probably 25%-68% is explained by neighboring values.As a result,the estimated regression coefficients of the variables become smaller and the significance of the parameters also decreases in the spatial autoregressive model.But this is a way to incorporate spatial interactions that cannot be captured by the independent variables.