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Table of Content

    25 August 2005, Volume 20 Issue 4 Previous Issue    Next Issue
    Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    The Spatial and Temporal Variability Characteristics of Precipitation in the Yellow River Basin of Recent 30 Years
    ZHU Qing-lin, Zhang Liu-zhu, YU Gui-rui, DAI Dong, CAI Fu, LIU Xin-an
    2005, 20 (4):  477-482.  doi: 10.11849/zrzyxb.2005.04.001
    Abstract ( )   PDF (951KB) ( )   Save
    Surfaces of monthly mean precipitation were fitted with data from 269 observation sta-tions of recent 30 years,including stations of China Meteorological Administration and Yellow River Conservancy Commission,using the Plate Smoothing Spline interpolation method.We performed the interpolation of precipitation of 1km×1km grid by using the ArcMap/ArcInfo to generate output maps on which we further analyzed the spatial distribution of monthly and yearly precipitation.The Mann-Kendall trend test was applied to examine the trend of monthly precipi-tation in recent 27 years.The results show that there is a weak negative trend for yearly precipitation,and the decline area focuses on the south of the basin.For months of autumn and winter,the rainfall presents an apparent decline trend;but during spring and summer except April,there is an increasing trend in the recent 27 years.There are more negative trend months,but they all include autumn and winter,therefore,the yearly precipitation only has a slight decline trend.Due to different changing trends in the distributions of precipitation in each month it becomes more imbalance,with less rainfall in autumn and winter while more rainfall in May,June and July.
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    Spatial Pattern of Soil Water and its Influencing Factors in a Gully Catchment of the Loess Plateau
    HUANG Yi-long, CHEN Li-ding, FU Bo-jie, WANG Yang-lin
    2005, 20 (4):  483-492.  doi: 10.11849/zrzyxb.2005.04.002
    Abstract ( )   PDF (317KB) ( )   Save
    Analysis of the soil moisture dynamic and relative importance of land use and environ-mental factors on the spatial variability of soil moisture were the base to guide ecological resto-ration and agricultural development.We analysed spatial variability of soil moisture upon 44 sample plots(176 sample points)at 5 depths (0~20,20~40,40~60,60~80 and 80~100cm)in the Anjiagou catchment of Loess Plateau in China from April to September 2002. Time-averaged soil moisture of cropland was the highest among the five land use types;fallowland was in the middle; woodland,shrubland and wasteland were the lowest in wet moisture status (from 24-Apr to 23-Jun). The layer-averaged soil moisture of all the five land use types decreased with depth in wet moisture status and increased with depth in dry moisture status (from 12-Jul to 9-Aug).The layer-averaged soil moisture of fallowland,cropland and shrubland decreased with depth,but wasteland and woodland both decreased and then increased with depth in medium moisture status(from 23-Aug to 18-Sep).Land use was the key factors that influence the spatial variability of the layer-averaged moisture of the four soil layers(20~40,40~60,60~80 and 80~100cm)in wet and medium moisture status.Land use has slight influence on spatial variability of layer-averaged moisture of all the five soil layers in dry moisture status.Slope aspect has significant influence on the layer-averaged soil moisture of some soil layers in wet and medium moisture status for wasteland,shrubland,woodland and fallowland.The other four environmental factors(slope profile curvature,slope position,relative elevation and slope gradient)had slight influence on the layer-averaged soil moisture of all the five land use types under the three water status.The spatial variability of layer-averaged soil moisture was controlled by local factors in dry moisture status.Finally,it was found that the deficit of soil moisture in June and July had severe influence on plant growth.The results of this study suggest that(1)constructing a mosaic pattern of different land uses should be useful to control soil erosion;and (2)intercropping,irrigation and mulching should be implemented to advance the vegetation restoration and agricultural development.
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    Hydrological Regime Changing Process and Analysis of Its lnfluencing Factors in a Typical Wetland Watershed of the Sanjing Plain
    LIU Hong-yu, LI Zhao-fu
    2005, 20 (4):  493-501.  doi: 10.11849/zrzyxb.2005.04.003
    Abstract ( )   PDF (219KB) ( )   Save
    Wetlands Rave peculiar hydrological regulating functions due to their peculiar soil hy-dro-physical properties and special geographical sites in a watershed. However,the water and land resources exploitation and utilization in a watershed often resulted in wetlands loss and degradation,thus destroying,wetland hydrological regulating functions. A case study on the changing processes of river flows and their influencing factors since wetland reclamation in a typical wetland watershed of the Sanjinag Plain in the 1960s has been conducted.The results indicated that annual mean flows showed a decreasing trend in 1965~1999.But,the changing processes were different in monthly mean,maximum and minimum flows,and the maximum flows increased and the minimum flows decreased in the study watershed.The main influencing factors leading to the above hydrological changes were estimated quantitatively.Further analysis indicated that land use/cover changes and water conservancy projects(WCP) were the main influencing factors,their effects accounted for 76% and 16% respectively;the effects of rainfall and WCP construction caused spring runoff decrease accounted for 47% and 56% respectively;also the land use/cover changes and WCP autumn runoff and river flow increase accounted for 52% and 37% respectively;and the effects of other factors such as evaporation and rainfall on watershed hydrological regime were very small.So human activities were the main factors affected hydrological regime in a wetland watershed.
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    Quantitative Analysis of the Impact of Irrigation Water from Kaidu River on the Area Change of Bosten Lake
    GAO Hua-zhong, ZHU Cheng, LI Zong-yao
    2005, 20 (4):  502-507.  doi: 10.11849/zrzyxb.2005.04.004
    Abstract ( )   PDF (291KB) ( )   Save
    Bosten Lake is the largest lake in Xinjiang and also the largest inland freshwater lake in China,which lies in the southeast of Yanqi Basin (41°56′~42°14′N,86°40′~87°56′E) and be-longs to the arid desert climate.It is of great value in environment,ecology and economy.The tre-mendous changes in the area of Bosten Lake have been seen in recent 45 years,and its area decreased from 1 159.9km2 in 1958 to 886.5km2 in 1987,and then increased to 1251.1km2 in 2002. Kaidu River is the longest river which flows into Bosten Lake,and its average runoff rea-ched 23.62×108m3/a during 1958 to 2002,accounting for over 80% of the recharge of Bosten Lake.Therefore the water area of Bosten Lake is chiefly controlled by the runoff volume of Kaidu River,and also affected by the amount of water diverted from Kaidu River Irrigation Area (KRIA).The quantity of the water diversion from KRIA ranging from about 8.17×108m3 to 13.18×108m3 has been witnessed in recent 45 years.The average amount of irrigation water reached 10.14×108m3/a in the 1960s,making up 31.6% of the runoff of Kaidu River,and went up to 12.15×108m3/a in the 1970s,or 36.5% of Kaidu River's runoff.The average amount decreased to 11.29×108m3/a in the 1980s and further declined to 9.85×108m3/a in the 1990s,only accounting for 27.1% of the runoff of Kaidu River. Based on the analysis of water balance and the calculation of correlation and regression,the data on the area change of Bosten Lake influenced by the amount of the irrigation water of KRIA are obtained.The average amount reached 62.4km2 in the 1960s,80.8km2 in the 1970s,90.4km2 in the 1980s,and 76.7km2 in the 1990s,but only 41.3km2 since 2000.Those data show that the impact of irrigation water from KRIA on the area change of the Bosten Lake has undergone a weak to strong and then weak process in the past 45 years.
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    The Current Distribution and Conservation Status of Black Muntjac in Gutian Mountain Nature Reserve
    ZHENG Xiang, BAO Yi-xin, GE Bao-ming, ZHENG Rong-quan
    2005, 20 (4):  508-513.  doi: 10.11849/zrzyxb.2005.04.005
    Abstract ( )   PDF (163KB) ( )   Save
    From March 2003 to December 2003,the distribution,population density and conser-vation status of black muntjac were surveyed in Gutian Mountain Nature Reserve,Zhejiang Province.The results showed that the optimal habitat elevation of black muntjac was 800~1000m.With dejecta and footmark as indirect indication,the authors used the sampling line method to obtain the field censusing data.The population density was estimated to be 3.30±0.45(ind./km2)in the nature reserve,then in core area,cushion area and experiment area the densities were signifi-cantly different by one way variance analysis(P<0.01).In different seasons,the population densities in nature reserve were insignificantly differencet(P>0.05).The changes of black muntjac in elevations in different seasons were mainly attributed to the seasonal modification of food resource.Losses of forest,hunting and human disturbance were the main threat against black muntjac's survival.According to the result of survey and local conditions,the idea for conservation of black muntjac and suggestion for future management were described in this paper.
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    Study on Grassland Grazing Capacity in the Heihe River Basin
    ZHANG Hui, SHEN Wei-shou, WANG Yan-song, ZOU Chang-xin
    2005, 20 (4):  514-521.  doi: 10.11849/zrzyxb.2005.04.006
    Abstract ( )   PDF (173KB) ( )   Save
    Using RS & GIS techniques,the areas suitable for livestock grazing in the Heihe River Basin were identified based on natural conditions such as vegetation types,soil erosion,slope,distance to water,as well as the need of conservation for biological diversity and ecosystem.In those areas suitable for livestock grazing,the forage production was estimated for each individual grassland type based on the past surveys.The allotments of forage for ecological needs were taken into account from following two aspects.The first aspect includes the allotments of forage for soil resistance to erosion,ensuring plant community resilience and regeneration under drought season.The second aspect includes those for insects,nematodes,wildlife habitat needs.Reductions in grazing capacity are adjusted by distance to water and slope. On the above bases,the grassland grazing capacity that meets the ecological needs in the Heihe River Basin is calculated.The study indicates that the area of capability and suitability for livestock grazing is 17.693% of the total land area and natural grassland grazing capacity is at the ranges from 0.009 to 2.055 sheep/hm2.
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    Strategy Research for Urban Land Reserve System under Rapid Urbanization-A Case Study on Longgang,Shenzhen
    JIN Xiao-bin, ZHOU Yin-kang, ZHANG Hong-hui, YIN Shao-mei, XU Yan-xi
    2005, 20 (4):  522-528.  doi: 10.11849/zrzyxb.2005.04.007
    Abstract ( )   PDF (1387KB) ( )   Save
    With rapid urbanization,land reserve system has become an important means for ratio-nal land use and land optimized configuration.It has been put into practice in many cities. However,there are two basic problems in the process of putting the system into effect.One of which is capital oriented,i.e.the area and location of land reserve is usually determined and/or disturbed by capital requirement of the municipal government.The other is investment required,i.e.the area and location of land reserve is usually determined and/or distributed by the invest-ment required from the investors.Obviously,the two kinds of problems are prone to bring the gap between long-term urban planning and short-time capital shortage in urban construction.In view of the successful experiences of advanced countries and regions in urban land reserve system,a rational urban land reserve and supply plan is the key to the urban land reserve system.It is propitious for urban land reserve system to the transformation of capital oriented into function oriented and investment required into planning introductory.Using Longgang district,Shenzhen city as a case,urban land reserve plan is studied from three connected steps in the present paper.First of all,the amount of the construction land requirement in the near future is predicted using econometric and urban expansion model.Subsequently,the potential reservable land is evaluated by GIS techniques based on the establishment of the evaluating indices of potential urban land reserve.Finally,the executive short-term land reserving plan and mid-term developing land reserving plan are set down.
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    Effect of Vegetation on Soil Organic Carbon of Slope Land in Gully Region of Loess Plateau
    LIU Shou-zan, GUO Sheng-li, WANG Xiao-li, XUE Bao-min
    2005, 20 (4):  529-536.  doi: 10.11849/zrzyxb.2005.04.008
    Abstract ( )   PDF (258KB) ( )   Save
    Vegetation recovery is an important measure to mitigate soil erosion and improve soil quality in the Loess Plateau.To understand the impact of vegetation recovery on soil quality,soil organic carbon (SOC) and total soil nitrogen(TSN)level and distribution characteristics along a slope under vegetation conditions were investigated on slope of Wangdonggou Watershed in Gully Region of Loess Plateau.Five experiment sites were set up along Fanjialiang.Site I to site Ⅳ along the eastern slope of Fanjialiang was Xingniugua,Dujiaping,Baiyanggua east and Bai-yanggua west,being adjacent to each other with similar slope and aspect.The vegetations were Prunus armeniaca L,orchard(Malus pumila),Robinia pseudoanacia and grass(Bothriochloaischaem- um(L.)Keng),respectively.Soil samples(0~20cm)at each site were taken from the upper slope,middle slope,lower slope and the foot slope,respectively.Site V at the western slope of Fanjialiang was Shaozhongwan with six vegetation types including Robinia pseudoanacia,arborvitae(Platycl- adus orientalis Endl.)、Chinese pine(P. tabulaeformis Carr),Hippophae rhamnoides L. subsp,Malus pumila and grass.Soil samples(0~60cm)were taken under vegetations.Types,population,and height of plants of each site were surveyed. The results demonstrated that compared with grassland,SOC content increased by 9.3%(P>0.05)for Chinese pine and decreased by 40.1%(P<0.05)for orchard.SOC content under Hippophae rhamnoides L.subsp.,arborvitae,and Robinia pseudoanacia was lower than that of grassland,but the difference was not significant(P>0.05).The level of SOC decreased with depth.For the site under grass,the content of SOC at lower slope and foot slope was respectively 47.6% and 62.9% higher than that at the upper slope with 7.8g·kg-1.For the site of orchard,SOC content was 6.17g·kg-1~6.69g·kg-1 at the middle and foot slope,higher than that at the upper (5.54g·kg-1).For the site of Robinia pseudoanacia,content of SOC varied from 8.55 to 10.50g·kg-1,similar SOC along slope changes under orchard and Robinia pseudoanacia.For the site of Prunus armeniaca L.the content of SOC varied from 9.79g·kg-1 to 14.41g·kg-1,higher in the middle along the slope.In addition,there was a significant(R2=0.925)correlation between TSN and SOC. Intensive human disturbance resulted in lower SOC content in the region.Planting orchard on the slope significantly improved the productivity of soil,but it is not profitable to SOC accu-mulation.Some suggestions on vegetation construction in the region were put forward:1)vegetation types should be considered fully when vegetation regeneration and rehabilitation were carried out on the slopes in the region. 2)To adjust the growth conditions and increase input of SOC is essential to enhance SOC accumulation in the region.
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    Spatial Variability of the Density of Organic Carbon and Carbon Storage in the Sediment Profiles of Wetlands in Sanjiang Plain,Northeast China
    ZHANG Wen-ju, WU Jin-shui, TONG Cheng-li, YANG Gai-ren, HU Rong-gui, TANG Guo-yong
    2005, 20 (4):  537-544.  doi: 10.11849/zrzyxb.2005.04.009
    Abstract ( )   PDF (333KB) ( )   Save
    Wetland is recognized as a large reservoir of organic carbon(C)in terrestrial ecosystems.In this study,the density and variations of organic C in the sediment profiles(totally 16) of the 3 types of wetlands in Sanjiang Plain,Northeast China was investigated.Results demonstrated that the depth of the organic horizon varied in the range of 11~29,18~58 and 70~130 cm;the content of organic C in the horizon in the range of 29~75,124~348 and 187~389g/kg (dry matter);and the density of organic C in the range of 31~48,35~59 and 49~94kg/m3 for marshy meadow,humus marsh,and peat fen,respectively.However,the content and density of organic C in the mineral-illuvial horizon of all the 3 types of wetlands were relatively low and stable.Due to the variations in the content of organic C,a big variation in the density of organic C also occurred not only in the sediment profiles of different types of wetlands but also the same type of the wetland.This variability,together with that in the depth of the organic horizon,resulted mainly in uncer-tainties in the estimates of organic C storage in wetlands.Based on data obtained,it was estimated that the amount of organic C storage per unit area was 8×103,18×103 and 72×103t/km2(with variation coefficients of 40%,49% and 34%) in the organic horizon,and 17×103,27×103 and 83×103t/km2(with variation coefficients of 16%,49% and 30%)in the organic horizon plus 1 m mineral-illuvial horizon of the marshy meadow,humus marsh,and peat fen,respectively.It also suggested that the organic C storage would be greatly underestimated if we only take 1 m as the standard depth in the estimating method for organic C storage.
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    Countermeasure and Regionalization of Hippophae Plantation in the "Three Norths" Region of China
    HU Jian-zhong, TAI Yuan-lin, LU Shun-guang
    2005, 20 (4):  545-554.  doi: 10.11849/zrzyxb.2005.04.010
    Abstract ( )   PDF (451KB) ( )   Save
    Different climatic zones need different seabuckthorn species with adaptabilities and eco-economic functions in the "Three Norths" region (northern,northeastern and northwestern parts)of China.Only the principles of matching trees with suitable sites are followed and the measures suitable to local conditions are taken,can the expected eco-economic result be got in practice.Seabuckthorn plantation areas in the"Three Norths"region include five plantation zones of sub-humid prairie climate zone for eco-economic type of seabuckthorn plantation in southern part of the Loess Plateau,semi-arid steppe climate zone for eco-economic type of sea-buckthorn plantation in central part of the Loess Plateau,arid desert steppe climate zone for ecological type of seabuckthorn plantation in northern part of the Loess Plateau,semi-arid and sub-humid steppe climate zone for eco-economic type of seabuckthorn plantation in northern Hebei and western Liaoning,and cold humid steppe climate zone for economic type of sea-buckthorn plantation in the northern part of Northeast China.In every zone of so called Five Zones,there are suitable seabuckthorn seed sources,plus trees breeding and cultivation centers,bases,stations and spots.From the strategic viewpoints of solving eco-economic problems from seabuckthorn development in the"Three Norths"region,every seabuckthorn center(including base,station and spot)must have its own genes conserving garden,standard plantation for popularizing,excellent seed and seedling nursery,and sufficient afforestation areas for demonstration and spreading.The essential of the division of the Five Zones is to avoid planless introduction,but realizing scientific layout and intensive plantation.Under the prereguision of the plantations zonation for introducing seabuckthorn,the other three measures,that is,the introduction,selection and cross-breeding of good species,controlling of plant diseases and insect pests through mixed measures,and occupyin-g international market of seabuckthorn products to promote seabuckthorn plantation in China,must be paid more attention to in the seabuckthorn development in the "Three Norths"region of China.
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    Revelation of Ecological Evaluation of the Farming-pastoral Transitional Zone to Land Arrangement—A Case Study on Zhenlai County
    ZHANG Yan, YANG Zhi-feng, LI Wei
    2005, 20 (4):  555-563.  doi: 10.11849/zrzyxb.2005.04.011
    Abstract ( )   PDF (813KB) ( )   Save
    The objective of this study is to provide a scientific enlightment for future ecological land use arrangement that can not only ensure the food supply,but also protect the eco-environ-mental quality,in the transition region of the farming-pastoral zone,through prohibiting from exploiting blindly wetlands and reclaiming farmlands from lakes.Although the concept of land arrangement is firstly provided in Land Management Law of the People's Republic of China enacted in 1998,the works of land arrangement (such as land development and renovation,land reclamation) have already been unfolded for a long time.Through the analysis of land use changes from 1986 to 2000,the traces of land arrangement are derived.At the same time,the ecological evaluation of land use changes will provide a scientific basis for future land arrangement work.Zhenlai County,the typical transitional belt of the farming-pastoral zone in the west of Jilin Province,is chosen as a case study area in this paper.Based on the interpretation of Landsat data,which are distilled from digital images taken in 1986,1996 and 2000 respectively,the land use and land cover changes are studied,the analysis of shape readjustment and the evaluation of the ecosystem services function of readjustment in Zhenlai County are unfolded applying the transitional matrix,landscape pattern method and ecosystem services function method.The preliminary results are as follows:1)Farmlands and pastoral land are the main land use categories in Zhenlai County;2)from 1986 to 1996,the work emphasis on land arrangement is the transformation between cultivated land and unused land,such as consolidating farm plots and developing unused land;3)and from 1996 to 2000,the work emphasis is the transformation of farmlands to grasslands.The land use arrangement will be bound to lead to the value changes of ecosystem services function,but with the degradation of eco-environment,the tiny changes of uncontrolled unit,such as wetland and water area,will induce the prodigious transformation.So the future focus and difficulty are to realize the ecological land arrangement from the point of view of cultivating ecosystem.
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    Studies on Service Value Evaluation of Agricultural Ecosystem in Beijing Region
    YANG Zhi-xin, ZHENG Da-wei, WEN Hua
    2005, 20 (4):  564-571.  doi: 10.11849/zrzyxb.2005.04.012
    Abstract ( )   PDF (352KB) ( )   Save
    The agricultural ecosystem in Beijing rural areas plays a special role in maintaining the environmental function of the city.At present,because area of farmland in the area is decrea-sing,a series of ecological problems are becoming more and more serious.The accurate valuation of farmland ecosystem services is very important to reserve rational development of agricultural resources.In this paper,the agricultural ecosystem (farmland and orchard) service values are evaluated by various methods such as market value,substitution engineering,shadow price,pportunity cost for various crop types.Some index systems are selected for assessment of agricultural ecosystem services,which consist of 11 service indexes such as agricultural products,CO2 fixation and O2 release,environment purifying such as air quality purifying,sewage treatment,dung decomposition,OM accumulation in soil,nutrients cycle,soil conservation,water storage,and agriculture tourism.The results showed that the total service value of agricultural ecosystem decreased from 45133.84 million yuan in 1996 to 34 269.90 million yuan in 2002 a decrease of 10 863.93 million yuan,of which various values of food crops decreased and others increased to some extent.The total average value of agriculture services during six years was eight times of the production value.The total average value of agricultural ecosystem services during this period of time added up to 91 567.61 million yuan with indirect values being 34 616.05 million yuan,i.e.,six times of the direct values.In terms of composition,under present cultivation system,the value of farm products is 12.41%;the total value,including carbon fixation,oxygen production and environment purification,are very great,making up 77%(carbon fixation and oxygen production 39.48% and environment purification 37.51%);the value of soil OM accumulation 4.4%;nutrients cycle maintenance 1.27%;water-holding and agricultural tourism 2.21% and 3.8% respectively; and soil conservation 0.01%.Therefore,agricultural ecosystem has provided huge indirect values to human beings besides direct values.
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    Study on Landscape Effects from Cultivated Land Consolidation
    YANG Xiao-yan, YAN Dong-hao, CHENG Feng
    2005, 20 (4):  572-581.  doi: 10.11849/zrzyxb.2005.04.013
    Abstract ( )   PDF (459KB) ( )   Save
    This article analyzes the landscape effect resulting from cultivated land consolidation in Yanqing county by contrasting landscape characteristics of different types of cultivated land between those obtained from the survey in the representative areas and those under detailed designing and planning for landscapes at different consolidation levels.The indices are introdu-ced to measure the changes of patch characteristics before and after consolidation,such as mean area of a patch,mean perimeter of a patch,patch density,perimeter density and the ratio of mean perimeter of a patch to its area.The differences of corridor characteristics before and after consolidation are illustrated by the indices of types of corridor landscapes,the proportion of area of all the corridors to the area of cultivated land,density of different corridors,networks connectivity,networks ring,etc.The results indicate that the mean area and mean perimeter of a patch obviously increase and the patch density,perimeter density and the ratio of the mean patch perimeter area decrease after consolidation.This implicates that cultivated land consolidation increases landscape granularity and decreases the degree of fragmentation and boundary division of landscapes.The proportion of the area of all the corridors to the area of cultivated land falls after consolidation,which reduces the coefficient of non-effective cultivated land.The proportions of the length of every corridor to that of all the corridors are rationalized.Farmland shelterbelt enriches corridor types in cultivated land which can be taken as additional corridor types.The connectivity of corridors networks and ring roads or ring ditches is enhanced,which benefits the flow of energy and material.
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    The Analysis of Products Trade Impact on Regional Water Resource
    NI Hong-zhen, WANG Hao, WANG Dang-xian, ZHANG Qing-hua
    2005, 20 (4):  582-589.  doi: 10.11849/zrzyxb.2005.04.014
    Abstract ( )   PDF (132KB) ( )   Save
    Using the input-output analysis method,this paper sets up the input-output analysis mo-del of water resources,which reflects economic operation,water use and sewage discharge of national economic departments fully.Using the index of water input coefficient and total water input coefficient of industrial departments,this paper analyzes the characteristics of regional industry water utilization and taking the index of sewage discharge coefficient and total sewage discharge coefficient of industrial departments,the paper studies the effect of sewage discharge of regional industrial departments.Comprehensively analyzing the effect of water use and sewage discharge,the paper probes into the impact of industrial department products trade on regional water resources. Taking the city of Beijing as an example,the thesis has calculated the coefficients of water input and sewage discharge of every industrial department of Beijing in 1997.According to the result,we find,on the one hand,that some industrial departments such as agricultural and chemical,in which the coefficients of water use and sewage discharge were higher,the water use was inefficient,and the import volume of products trade in Beijing was relatively larger;on the other hand,the coefficients of water input and sewage discharge of other industries such as goods posting,electronics,service,etc,are much lower,their water use was more efficient,and their export volume of products trade was larger. Studies reveal that Beijing exported 1 499 420 000m3 of water with products trade,imported 3 040 010 000m3 of water,which resulted a net import of 1 540 590 000m3 of water;with products trade,Beijing exported 793 000 000m3 of sewage,imported 415 060 000m3 of sewage,which resulted in a sewage shift of 377 940 000m3.This indicated that Beijing's products trade in 1997 served as an effective means to alleviate the urgent water shortage situation. Finally,directed at more severe water resource situation in the future of Beijing,the thesis proposes that Beijing should consolidate and develop undertakings such as goods posting,elect-ronics,service industries,etc.,which belong to high efficient water use,trade and try to compress the industries in which water use is less efficient such as agriculture,food,electricity,textile,chem-istry,catering trade,papermaking,etc.,so as to mitigate water pressure by importing commodities promote water saving awareness,improve water use efficiency,establish water-saving industrial structure matching the characteristics of water resource of Beijing.
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    Eco-economic Effect of Actualizing De-farming and Reafforestation Policy in Desertification Areas: Taking Minqin County as a Case
    MA Yong-huan, FAN Sheng-yue
    2005, 20 (4):  590-596.  doi: 10.11849/zrzyxb.2005.04.015
    Abstract ( )   PDF (278KB) ( )   Save
    Chinese government has adopted many measures to protect fragile eco-environment. De-farming and reafforestation are the primary contents of eco-environmental protection.Accor-ding to the environmental sociology research method,representative and sample investigations have been taken about the households' willingness to return farmland to forest.Then the responses of households to policy of returning farmland to forest were applied in this paper by taking Minqin county of Gansu province as a case where serious desertification has taken place.Simultaneously,the investigation data were gathered.Because farmland returning to forests involved the change of the utilization mode of households' farmland,the households' willingness of de-farming lies in the gain and loss of their income after de-farming.Though households have endured the burden of income loss due to de-farming in recent years,they will benefit from the effect of retaining fertilizer and the eco-economic effect of mitigating the loss resulting from dust storm disasters in future.De-farming and reafforestation characterizing typical external economies,the costs of farmland returning to forests should be born by our government.In the course of regulating the farmland structure and optimizing the model of returning farmland to forest,efforts should be made to harmonize the relations between the farmland returning to forest and increase the income of households.
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    Study on Evaluation Indexes of Regional Water Resources Carrying Capacity
    WANG You-zhen, SHI Guo-qing, WANG De-sheng
    2005, 20 (4):  597-604.  doi: 10.11849/zrzyxb.2005.04.016
    Abstract ( )   PDF (317KB) ( )   Save
    Based on the analysis of the water resources-society-economic system,this paper stu-died the evaluation index system of the water resources carrying capacity.Macroscopical indexes and integration indexes are put forward to evaluate the water resources carrying capacity. Macrosc-opical indexes are made up of the population and economy scale which the water resources are capable of supporting.They describe whether the water resources carrying capacity is big or small according to the water supply and demand.Integration indexes are made up of carrying capacity exponent and harmony exponent.The carrying capacity exponent reflects the status of water carrying capacity and the harmony exponent reflects the status of the water resources-society-economy system harmony.Based on the evaluation index systems,the mathematical models and algorithm of the water resources carrying capacity were established.Macroscopical indexes were calculated by the water supply and demand.Integration indexes were calculated by the analytic hierarchy process.As a case study,the water resources carrying capacity in North Huaihe River Region of Anhui Province was studied.Both of the systematic indexes and the models developed in this dissertation were calibrated and testified with the data of current year.It is found that the results of the different level year were satisfactory.
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    An Economic Analysis of the Effect of Subsidies on Forestry and Forest Ecological Benefit: A Quantitative Model
    TAN Rong, QU Fu-tian
    2005, 20 (4):  605-612.  doi: 10.11849/zrzyxb.2005.04.017
    Abstract ( )   PDF (548KB) ( )   Save
    To encourage afforestation and improve the social welfare,governments provide subs-i-dies to support the forestry.Different types of subsidies give different results.Some can improve the social welfare,but the others cannot.The reason is that the subsidy changes the benefit and cost cash flow during the farmers'planting process and influences the time that maximizes the net present value of the farmers,which causes the optimal harvest time delayed or ahead to the social one.In order to distinguish the different effects,this paper sets up a quantitative model for forestry management,which includes the social benefit due to carbon sequestration of forest.Then the model is employed to analyze a subsidy provided by a city government in East China to support a local forest farm.The result shows the optimal harvesting age excluding social benefits is 19 years.When including social benefits,the optimal harvesting age increases from 19 year to 31 years as the carbon price rises from 0 yuan/t to 1 000 yuan/t.The inclusion of subsidies to encourage afforestation shortens the optimal harvesting age to 11 years from the forest owner's point of view.Compared with no subsidy,the subsidy causes much more social loss,which increases from 7 750 yuan/t to 17 704 yuan/t.The reason is that the subsidy brings forward the optimal harvest time,and the farm owner will not concern the externalities of the forest.The result indicates that not only to consider the social benefit but also to maximize the net social present value is important to a reasonable forestry subsidy.
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    Research on Dynamic Change and Effect Factors of Xianghai Wetland
    ZHANG Hong-yan, LONG En, CHENG Wei-ming
    2005, 20 (4):  613-620.  doi: 10.11849/zrzyxb.2005.04.018
    Abstract ( )   PDF (979KB) ( )   Save
    The Xianghai Natural Reserve is one of the most important natural reserves in China,located in the northwest of Jining province,Northeast China.It is of great biological,economic,social and cultural significance.With climate change and human over-activities,the water area of the wetland is descending quickly,hence the reserve is faced with threat of saline-alkalization and drying up.In this paper,based on the technologies of Remote Sensing and Geographical Information System,landsat imageries of different periods,rainfall data of five metrological stations,population,farmland and livestock data of Tongyu County from statistical yearbooks are used to quantitatively analyze dynamic change and evolution of the wetland over the last 15 years. The results show:(1)that the total area of the wetland decreased from 500km2 to 422km2,and salty swamp enhanced from 127km2 to 204km2 between 1988 and 2002,the obvious change is shrinkage and disappearance of small ponds around Xianghai reservoir,and original swamp vegetation types are being replaced by salty meadow or grass types.(2)There are complementary relations among pure water,swamp and salt marsh according to annual rainfall amount,when area of pure water increases,the other two types will decrease and vice versa.But the salt marsh possesses an increasing tendency,whose area has expanded from 119km2 to 204km2 since 1998,indicating that the environment of the wetland is degenerating.(3)Since 1981,the rainfall amount has decreased continually(except 1998),and there is obvious synchronous relationship between rainfall and area of the wetland.The growth of population,increase of farmland and livestock need lots of water,which lead to over-grazing and desertification. So,the main reasons for the degeneration for the wetland are the degenerating regional en-vironment,rising temperature,too much population and human over-using water resources.In the future,lots of materials,such as surface runoff data,and regional NDVI data etc.,must be collected to farther analyze and research dynamic change,the effect of regional climate change on the wetland,the function of the wetland to the surrounding environment,thus better method or suggestions can be put forward to continually protect Xianghai Wetland.
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    Preliminary Study on Optimization Technology of Fisheries Environment in Taihu Lake
    FEI Zhi-liang, ZHOU Gang, CHENG Jian-xin
    2005, 20 (4):  621-627.  doi: 10.11849/zrzyxb.2005.04.019
    Abstract ( )   PDF (139KB) ( )   Save
    This paper systematically analyses and studies the changing tendency of the main nutrients such as N,P in East Taihu Lake culture area on the basis of the result of following the tracks to the major hydrochemistry index.The results show that the annual average total phosphorus of in-net-enclosure and out-net-enclosure is 0.034mg/L and 0.042mg/L respective-ly,and the annual average total nitrogen is 0.72mg/L and 0.73mg/L respectively.The paper also estimates the contribution portions of Taihu Lake culture fisheries to the water body nutrition according to the parallel experimental results.The aquatic product can bring out 19.51t N and 6.62t P of the laket hrough this culture modes.By culture model optimization and regulation,we energetically spread and applied net enclosure culture of rotation grazing type,hence greatly reducing the number of juvenile crabs,arranging in pairs or groups with some silver carps or bighead carps,disseminating and planting the predominant hydrophytes,and transplanting the bottom-dwell animals of the Taihu Lake.The function of this culture mode is to use hydrophytes and bottom-dwell animals to depurate the culture environment,to feed the culture animals as the suitable feedstuff,to use the lower price fish as the feedstuff of the crabs,and finally to change the water vascular bundle grass snail and lower price fish into aquatic high price products.By means of the aquatic products,the nutrimental material can be brought out of the lake body,and the goal of optimizing the fishery environment can be realized.
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    Types of Agricultural Structure and Technical Countermeasure of Agriculture Sustainable Development in Liuyang County
    MOU Zi-ping, WU Wen-liang, LEI Hong-mei
    2005, 20 (4):  628-635.  doi: 10.11849/zrzyxb.2005.04.020
    Abstract ( )   PDF (159KB) ( )   Save
    A classification method of regional agricultural structure types was established accordcoring to the characteristics of agricultural natural resources,the developmental level of agricultural economy and the conditions of agricultural eco-environment.The regional agricultural structure was classified into 8 types.Classification methods are used to study the agricultural resources,economy and ecological structure types of Liuyang County.The results indicate that Liu-yang agricultural structure belongs to the type of relatively short of natural resources,relatively developed in agricultural economy and relatively worse in environmental conditions.Locational analysis methods are used to study the characteristics of locatio of agriculture,location of resources,location of economics and location of eco-environment in Liuyang County.Comparative analyses are made of the benefit situation of 15 agroecosystem models.In light of the situation of agricultural development,and the existing problems in resources utilization,industrial development and eco-environment,the technical countermeasures are put forward for the realization of agricultural sustainable development:labor-intemsive technology,the improvement of breed resources and introduction of good quality agro-biological resources,processing and deepprocessing technologies of agricultural products,development and utilization of harmless,green,organic food and tourism resources,as well as resourceful utilization of wastes.
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