Table of Content

    28 May 2008, Volume 23 Issue 3 Previous Issue    Next Issue
    Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    Correlation Analysis between Regional Cultivated Land Change and Grain Production Capacity—A Case Study in Northeast China
    SHI Shu-qin, CHEN You-qi, YAO Yan-min, LI Zhi-bin, HE Ying-bin
    2008, 23 (3):  361-368.  doi: 10.11849/zrzyxb.2008.03.001
    Abstract ( )   PDF (401KB) ( )   Save
    To research the changing patterns of current regional cultivated land and explore its impact on grain productivity is of great significance.Taking Northeast China as a study area,this paper analyzed the impact of the cultivated land change on grain sown area,per unit grain yield and total grain yield,and also the impact of the change of main crop planting structure on grain yield.The result shows: ⑴The cultivated land increased 188.8×104ha with a general trend of increase in the northern part and decrease in the southern part in view of the spatial distribution.⑵The grain sown area has increased 162.67×104ha.Per unit grain yield in most high-yield cultivated land presented an increase trend;per unit grain yield in mid-yield cultivated land presented a steady-going trend and furthermore with little increase in a few places;the changing trend of per unit grain yield in most low-yield cultivated land presented an increase trend.⑶The area of high-yield cultivated land,mid-yield cultivated land and low-yield cultivated land increased by 34.44×104ha,12.57×104ha and 141.83×104ha respectively,but their increase amount of grain yield was 305.04×104t,14.25×104t and 122.88×104t respectively.This shows the increase of both per unit grain yield in high-yield cultivated land and area of low-yield cultivated land promoted the increase of total grain yield in Northeast China.⑷The grain yield of four major crops in Northeast China presented different changing trends: the corn presented an "increase-decrease-increase" trend,the rice and wheat presented an "increase-decrease" trend and the bean yield increased continuously.The grain sown area of the four major crops presented a fluctuated changing trend: the corn presented an "increase-decrease-increase" trend,the bean sown area increased continuously,the rice sown area presented little increase and wheat presented an "increase-decrease" trend.In view of the regional difference,the corn production in Northeast China was further concentrated in Jilin province while that of bean,rice and wheat production further concentrated in Heilongjiang province.In a word,the grain production in Northeast China presented an obvious specialization and regionalization trend.
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    An Empirical Study on Factors Affecting the Households' Behavior in Cultivated Land Transfer
    CHEN Mei-qiu, XIAO He-liang, HE Wei-jia, DEN Ai-zhen, ZHOU Bin-juan
    2008, 23 (3):  369-374.  doi: 10.11849/zrzyxb.2008.03.002
    Abstract ( )   PDF (256KB) ( )   Save
    Cultivated land transfer is an essential means for resolving the harmonies between the flaw of household contract responsibility system and the demands of agricultural modernization.In this paper,basing on the survey of 1396 households in 74 villages of 38 counties in Jiangxi province,the Logistic regressive model was set up to analyze factors affecting the households' behavior in cultivated land transfer out and in.And the affecting factors were divided into 3 groups: family characteristic factors,household economic factors and cultivated land resource gift.The family characteristic factors include total population,total labor forces,proportion of employees at non-agriculture to total labor forces;the household economic factors include income per person,the proportion of income from farmland to total income;and resource gift factors include physiognomy,cultivated land area per person,and spatial distribution of cultivated land.The results showed that non-agriculture employment opportunity plays a most important role in the cultivated land transfer out;the household income level and cultivated land transfer are mutually affected,the household income of transfer out is generally higher than that of transfer in;physiognomy is another important factor affecting the households' behavior in cultivated land transfer,the more flat physiognomy is,the more easy the cultivated land transfer out.So,in order to promote cultivated land transfer,some actions should be taken such as accelerating rural labor forces transfer into non-agriculture,increasing support for agriculture,and improving the spatial distribution of cultivated land.
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    Study on Comprehensive Control Measures of Soil Erosion about Shixia Small Watersheds in the Upper Miyun Reservoir
    HE Ji-jun, CAI Qiang-guo, LU Bing-jun, WANG Xue-qiang,
    2008, 23 (3):  375-382.  doi: 10.11849/zrzyxb.2008.03.003
    Abstract ( )   PDF (553KB) ( )   Save
    The control measures of the slope land and types of land use are the most important factors for controlling water and soil loss,and the appropriate control measures of the slope land and types of land use could control soil erosion,protect land resource,and improve the environment effectively.In this study,based on the survey data of runoff plots,the effect of integrated water and soil conservation measures on slope surface on water and soil loss was researched.The results showed that compared with the slope land,the sediment reduction rate of terrace and narrow terrace reaches 64.83%-91.81%,this shows terrace could control soil erosion effectively,and the water and soil reduction benefits from terrace on the shady slope are better than the terrace on the sunny slope and the wide narrow terrace with ridge is better than the one without ridge.The water and sediment benefits from comprehensive water and soil conservation measure are very high,which can get to 96.21%-99.38%.At the same time,the soil erosion modulus of runoff plots with comprehensive control measure is less than the soil loss tolerance of 200t/km2·a in earthy-rocky mountain area of northern China,which is promulgated by the Ministry of Water Resources of the People's Republic of China.The natural prohibition can also control water and soil loss effectively,but as a result of comprehensive control measure induced changes of the slope surface shape,slope grade has less impact on water and soil loss.
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    Dry Soil Layer Forming and Soil Nitrogen Consumption Characteristic of Alfalfa Grassland in the Semi-humid Region of the Loess Plateau
    WAN Su-mei, JIA Zhi-kuan, WANG Yong, HAN Qing-fang
    2008, 23 (3):  383-390.  doi: 10.11849/zrzyxb.2008.03.004
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    In order to study dry soil layer forming and soil nitrogen consumption characteristic,promote fertilizing and grass-crop rotation in alfalfa grassland,the paper investigated the dry soil layer and soil nitrogen consumption in the grasslands with alfalfa growing for three years,four years,six years,12 years,14 years,18 years and 26 years.The results showed that dry soil layer was divided into three types: slightly dry soil layer(9%-11%),moderately dry soil layer(7%-9%)and highly dry soil layer(<7%).Slightly dry soil layer occurred in 80-100cm soil of wild land and dry soil layer appeared in 140-600cm soil in alfalfa land.With the prolonged period of alfalfa growth,dry soil layer extended its lower boundary downward and became intensified,moderately dry soil layer appeared in the grasslands with alfalfa growing for 12 years and expanded beyond 500 cm deep below ground.There are regular changes in the available N contents in the alfalfa grassland with different number of growth years.The soil available N contents decreased with the deepening of soil depth,and tended to keep a stable state in soil deeper than 300cm below soil surface;after 26 years of alfalfa growth,the soil N content began to rebound to a certain degree in the upper soil of 0-200cm,but it was difficult to rebound at depths of 200-1000cm.The study showed that reasonable fertilization and grass-crop rotation should be practiced to maintain N balance and continue to increase land productivity after alfalfa growing for more than six years in semi-arid areas of the Loess Plateau.
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    Study on the Energy Balance Closure of Alpine Meadow on Tibetan Plateau
    LI Quan, ZHANG Xian-zhou, SHI Pei-li, HE Yong-tao, XU Ling-ling, SUN Wei
    2008, 23 (3):  391-399.  doi: 10.11849/zrzyxb.2008.03.005
    Abstract ( )   PDF (538KB) ( )   Save
    Through adopting the means of OLS Linearity return and calculating EBR energy balance,and based on the three-year flux amount data of Damxung rangeland station,we conducted a research on the energy balance closure aiming at the Tibet Plateau alpine meadow.The results show that,there exists a phenomenon of in-complete closure of energy and the slope of OLS curve is relatively low.The closure condition of energy balance in growing season is better than that in non-growing season;day-time is better than night;fine day is better than windy,rainy or snowy days.Later on,we have an analysis on the reason in energy in-closure.When the time of latent heat fluxes,sensible heat fluxes and soil heat fluxes is advanced,the closure condition of energy balance is improved.We draw a conclusion that the difference in the rate of heat transference has a great impact on the energy balance closure.Other reasons as the deviations in samples and instrument,the loss of high frequency and low frequency,the ignorance of some energy item and loss of advection have also contributed to the in-closure of energy balance.
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    Instream Ecological Flow of Dammed River—A Case Study of Huaihe River
    ZHAO Chang-sen, LIU Chang-ming, XIA Jun, WANG Gang-sheng, LIU Yu, SUN Chang-lei, WANG Rui, JI Xiao-yan
    2008, 23 (3):  400-411.  doi: 10.11849/zrzyxb.2008.03.006
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    We present a method for dammed river Instream Ecological Flow(IEF)—Adapted Hydraulic Radius Approach(AEHRA).This approach can compute Instream Ecological Water-level(IEW) as well as IEF.We applied this method to the Huaihe River to compute the ecological flow of four typical river-sections respectively in the upper,middle and lower reaches of the Huaihe River taking fishes as target species.Results show:(1) in the spawning season IEF is greater than that in the non-spawning season and IEF downstream is greater than that upstream,IEF in the middle reach is between them—IEF is mainly affected by the form of the river course cross-section;in the non-spawning season,IEF in the middle reach is greater than that downstream and upstream—IEF is mainly influenced by fish types;(2) dam operation is necessary to keep IEW corresponding to IEF;(3) the Huaihe River is greatly affected by human beings and the continuum is destroyed,which results in the appearance of no order in IEF change from upstream to downstream.Only when IEF has been satisfied through dam operation,will riverine aquatic ecologic restoration be possible to realize.
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    Natural Ecological Carrying Capacity in Hainan Province
    FU Guo-ji, XU Heng-li, CHEN Wen-ting
    2008, 23 (3):  412-421.  doi: 10.11849/zrzyxb.2008.03.007
    Abstract ( )   PDF (244KB) ( )   Save
    Natural ecological carrying capacity is one of the leading fields of international quantitative study of sustainable development.The model calculated regional natural ecological carrying capacity with actual productivity and effective service function of natural ecological system and coupled self-purification ability with water resource supplying function.Therefore the model was named as "actual supply law".The research indicated that "actual supply law" reflects a regional natural ecological carrying capacity objectively and accurately.This paper applied "actual supply law" to the calculation and analysis of the characteristics of dynamic changes of natural ecological carrying capacity of Hainan province from 1952 to 2004 based on the existing data of Hainan Province Statistical Yearbooks and ecological survey data: ①The natural ecological carrying capacity of Hainan Province has been increasing for a long time,per capita natural ecological carrying capacity increased from 7.0804 ha in 1952 to 8.5984 ha in 2004,an increase of 1.5180 ha and an annual average increasing rate of 0.4%.②The carrying capacity of renewable resource occupied considerable proportion of total ecological carrying capacity,accounting for respectively 98.6% and 92.3%;however,the ecological carrying capacity of un-renewable resource occupied only 1.4% and 7.7% in 1952 and 2004.③The carrying capacity of water resource decreased from per capita 6.8165 ha in 1952 to 0.4473 ha in 2004;but the carrying capacity of arable land,sea sector and freshwater body showed a rising tendency,which increased from 0.1277 ha,0.0057 ha and 0.0001 ha in 1952 to 2.6066 ha,3.1192 ha and 1.1468 ha in 2004,and other types of land ecological carrying capacity kept basically unchanged.④In the composition of the ecological carrying capacity,the proportion of water resources changed significantly from 96.3% in 1952 to 5.2% in 2004 dramatically;but the arable land,sea sector and freshwater body had a reversed remarkable change,respectively from 0.1277 ha,0.0057 ha and 0.0001 ha in 1952 increased to 2.6066 ha,3.1192 ha and 1.1468 ha in 2004,and other types of land showed ascending change but the proportion is relatively small.The arable land,sea sector and water resources are the main factors of the ecological carrying capacity of Hainan,the summation of these three factors occupies 71.8%-98.2%.The paper analyzed the causes of dynamic changes of ecological carrying capacity in Hainan Province.Firstly,the advancement of science and technology and improvement of management level are the fundamental reasons for the continuous increase of ecological carrying capacity in Hainan Province.Secondly,dynamic changes of ecological carrying capacity of all types of land are induced by synthetically factors of nature and society reflected the change of their actual ecological service function.Thirdly,the module amelioration is a key factor reflecting mainly the regional natural ecological carrying capacity.Finally,a pronounced drop of ecological carrying capacity of water resources in Hainan Province has both natural and man-made causes.
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    Analysis on Comprehensive Response Degrees to Urbanization Level and Ecological Quality in Jiangxi Province
    LIU Yao-bin
    2008, 23 (3):  422-429.  doi: 10.11849/zrzyxb.2008.03.008
    Abstract ( )   PDF (333KB) ( )   Save
    This paper analyzes the temporal response characteristics and total response intensity for ecological quality to urbanization level in Jiangxi province.Firstly,the paper designs the index system and appraisal model of comprehensive indexes of urbanization level and ecological quality with hierarchical synthetic method,and respectively calculates the indexes and their components.Next,the paper puts forward a comprehensive response degree model by means of elastic formula in the field of economy,which is expressed as cj=∑nt=11Tθj(t)(j=1,2,k;t=1,2,…n),and analyzes the comprehensive response degrees with the calculated comprehensive indexes of urbanization level and ecological quality.The calculated comprehensive indexes of urbanization level and ecological quality show:(1) The comprehensive urbanization level in Jiangxi province has increased gradually since the reform and opening to the outsides world.Two periods can be identified in the process,of which the former is a slower development stage during 1978-1990 and the latter a relatively rapid stage during 1991-2005.The present urbanization process in Jiangxi province has entered a rapid stage.(2) The comprehensive index of ecological quality and their components take on different curves.Among them,the index of ecological level and the index of ecological resistance ability are the same to the comprehensive indexes of ecological quality,which takes on an"U-shaped" curve,but the index of ecological pressure presents a periodic variation.The calculated comprehensive response degrees reveal:(1) The comprehensive response degrees and their components for ecological quality to urbanization level in Jiangxi province are generally higher than the entire inspection period and in 1991-2005,indicating that there is a much stronger sensitive intensity during 1978-1990 for ecological quality to urbanization process.Obviously,there doesn't exist a corresponding relationship between the urbanization process and the changing ecological quality,which concerns with not only the advancement pattern of urbanization itself,but also the way of eco-environment construction and protection;(2) The established comprehensive response degree model is easy to operate,and to the degree can promulgate the comprehensive response condition,but there are some limits to the application because its foundation is elastic formula in the field of economy,and the reflected response relations are only fitting tendencies for two variables in a certain period of time.Therefore,there exist not only the least samples but also the fitting accuracy for the model to be applied.
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    An Evaluation of Stability of Farmland Ecosystem Based on Processes in Hebei Plain
    LI Xin-wang, MEN Ming-xin, WANG Shu-tao, QI Yue-pu, DU Bo-yang, XU Hao
    2008, 23 (3):  430-439.  doi: 10.11849/zrzyxb.2008.03.009
    Abstract ( )   PDF (602KB) ( )   Save
    This paper aims at discussing the concept and connotation and evaluating index system of the stability of farmland ecosystem in Hebei Plain of China.First,based on the analysis of the research result of vulnerability in the field of ecosystem science,a concept of stability of farmland ecosystem which represents the characteristic of farmland ecosystem in Hebei Plain of China is formed.Then,the connotation about the stability of farmland ecosystem is probed.It is believed that the assessment index system of the farmland ecosystem stability includes four aspects of input-output process,yield formation process,soil ecological process and eco-environmental effect of farmland ecosystem and 22 concrete indices.Finally,the evaluating model of the stability of farmland ecosystem is built,and is applied to evaluate synthetically the status of stability of farmland ecosystem by taking Xiongxian county of Hebei as an example.It is found by validation that the stability of farmland ecosystem varies greatly,which presents a linear decreasing trend in 1995-1999 and wavy development in 2000-2005 with the greatest impact of input-output process.
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    Impact of Land Use Change on Ecosystem Service Values in Shenzhen
    LI Wen-kai, LI Tian-hong, QIAN Zheng-han
    2008, 23 (3):  440-446.  doi: 10.11849/zrzyxb.2008.03.010
    Abstract ( )   PDF (291KB) ( )   Save
    The evaluation of ecosystem services is conducive to clarify the ecological and environmental changes with urbanization and to provide useful references for city development planning.With Shenzhen,a city experienced rapid economic development and urbanization in the past decades,as study area,the impacts of land use change on ecosystem service values were discussed.The ecosystem service value in Shenzhen was 2775.97 million RMB in 1996,2 911.41 million yuan in 2000 and 2 544.66 million yuan in 2004 respectively,with a decrease of 231.31 million yuan from 1996 to 2004 mainly due to the decrease of woodland and wetland area.Woodland,water-body,wetland and orchard nursery contributed over 90% of the total service value among the land use types.Water supply and waste treatment were the top two service functions with high service value,contributing about 40% of the total service value.Areas with high service values are mainly located in the southeast and southwest while those with low service values around the center.The results suggest that a reasonable land use plan should be made with highlight of protecting wetland,water-body and woodland so as to balance economic and ecological goals in the future.
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    Modification of Ecological Footprint Assessment Based on Emergy:A Case Study in the Upper Reach of Minjiang River
    LIU Miao, HU Yuan-man, CHANG Yu, ZHANG Wen-guang, ZHANG Wei
    2008, 23 (3):  447-457.  doi: 10.11849/zrzyxb.2008.03.011
    Abstract ( )   PDF (764KB) ( )   Save
    Ecological footprint(EF) analysis has gained much attention since developed,but some deficiencies were also criticized.Now,EF has been used in regional ecological carrying capacity and sustainability estimation widely.Zhao Sheng modified EF approach with Emergy theory in 2005,called emergy EF approach,which made up the deficiencies of EF limited with biosphere.However,this article improved the modified method for the deficiencies of the modified approach,which does not consider the local situation and technological advances.Finally,the EF of the upper reach of Minjiang River was estimated based on the three methods from 1982 to 2002.The results demonstrated that the EF of the study area increased slowly.The results of regional EF were greater than that of emergy EF,and that of conventional EF were the least.The ecological carrying capacity with conventional EF and regional emergy EF decreased smoothly,however,that of emergy EF changed irregularly.Although the regional emergy approach overcomes some shortcomings of EF,it can not replace the conventional EF.If the two approaches used together,more information would be discovered.
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    Quantitative Assessment of the Effect on the Eco-environment from LUCC in a Region Scale—A Case in the City Proper and the Suburbs of Tongchuan
    XIE Hong-xia, LI Rui, REN Zhi-yuan, YANG Qin-ke
    2008, 23 (3):  458-466.  doi: 10.11849/zrzyxb.2008.03.012
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    The effect on the eco-environment from LUCC in a region scale is a very important content of the research in the global change.Ecological service value is a hotspot problem of Ecology and Ecological Economy at present.This research tries to combine these two things together to assess the effect on the eco-environment from LUCC in the city proper and the suburbs of Tongchuan by using the ecological service value with the data of terrain,soil,vegetation,climate,land use,etc.The authors calculated the ecological service value over the years from 1994 to 2003 in the research area and simulated the ecological service value by assuming the scene without land use change using the model of calculating the ecological service with data of the soil,vegetation,terrain,land use,climate,etc.Based on the results of the calculation,the authors tentatively put forward the concept of Ieoefluc,index of the effect on the environment from the land use change,and assessed the effect on the eco-environment from LUCC quantitatively using the index.The calculating results are as follows.Firstly the ecological service value varied between 477,000,000 and 1,560,000,000 yuan from 1994 to 2003 for the climate change,human action especially LUCC.Then we didn't take LUCC into account,the simulated value was figured out and it was less than the value we calculated considering LUCC.Finally the index of the effect on the environment from the land use change was calculated with the ecological service value under the condition with and without land use change.We can find that all the indexes are greater than one and increase generally in fluctuations.All of these indicated that LUCC in the study area during this period of time was beneficial to the development of the eco-environment.
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    Study on Biomass of Pinus elliottii Forest in Subtropical China Assisted with Remote Sensing
    MA Ze-qing, LIU Qi-jing, XU Wen-jia, LI Xuan-ran, LIU Ying-chun
    2008, 23 (3):  467-478.  doi: 10.11849/zrzyxb.2008.03.013
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    Based on field survey data,TM imagery acquired in 2005 was applied for organ-specific biomass estimation of Pinus elliottii plantation as well as other forest types in Qianyanzhou of Jiangxi Province,China.A total of 28 plots was investigated and the relationship of biomass with vegetation indices was clarified using image analysis including PCA(Principal Component Analysis) and TASSEL(Tasseled cap transformation).A series of regression models comparing biomass and spectra or vegetation index were established.The sequence of correlation coefficients from high to low was foliage biomass>branch biomass>above-ground biomass>stem biomass.The average above-ground biomass of Pinus elliottii forest as estimated with multiple regression analysis was 6628 g·m-2,with leaf biomass of 573 g·m-2,less than the mean result by field survey.Correlation of biomass with a single vegetation index was quite low,indicating that NDVI alone is not sufficient for estimating biomass of densely closed forest.Results of regression analyses were slightly better using PCA and slightly worse with TASSEL.
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    Change Characteristics and Driving Forces of Base Flow of Yellow River Basin
    WANG Yan-lin, WANG Wen-ke, QIAN Yun-ping, DUAN Lei, YANG Ze-yuan
    2008, 23 (3):  479-486.  doi: 10.11849/zrzyxb.2008.03.014
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    Base flow is one of the primary parts of the river runoff.In this paper,through the analysis of base flow of 10 control stations on the mainstream and 15 tributaries from the 1950's to 2000,the authors firstly analyzed the characteristics and driving forces of base flow of the mainstream and tributaries of the Yellow River basin.The result showed that first,the base flow of the Yellow River is 44% of runoff of the Yellow River,and so it is important to maintain sustainable development of the river.Second,influenced by the natural change and human activity,base flow of the mainstream and tributaries of the Yellow River basin is down generally in the past 50 years,base flow of tributaries of the Yellow River basin is divided into three types as double-humped curve,single-humped curve and linear decrease curve,base flow between two stations of the mainstream of the Yellow River is mainly reduced in the middle reaches of the Yellow River.Third,base flow of the Yellow River has such eco-environmental functions as maintaining runoff,keeping river eco-environment and improving surface vegetation.Reduction of base flow of the Yellow River leads to negative eco-environmental effect such as lake shrinkage,vegetation degeneration,aggravating Yellow River cut-off.Forth,formation,development and evaluation of base flow of the Yellow River are the integrative effect of natural factor and human factor.The result showed natural factor,mainly including precipitation,decides the structure in time and space of base flow of the Yellow River basin.Human factor,including riverside pumping,metal mining,building reservoir,soil and water conversation,exerts influence on increasing or decreasing base flow of the Yellow River.Exploitation and utilization of groundwater is the most important factor in all kinds of human factors.The human activity is intense and frequent in the middle reaches and Datonghe river,Huangshui river basin of the upper reaches of the Yellow River,where the base flow of the Yellow River is reduced significantly.So,maintaining normal Yellow River condition needs scientifically protecting and rationally exploiting and utilizing base flow of the Yellow River.
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    Analysis of the Spatio-temporal Characteristics of UV-B Strength Change over the Yunnan Plateau
    ZHOU ping, CHEN Zong-yu
    2008, 23 (3):  487-493.  doi: 10.11849/zrzyxb.2008.03.015
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    In this article,the UV-B data from different altitude,longitude and latitude stations on Yunnan low latitude plateau were analysed and the spatio-temporal characteristics of UV-B strength of Yunnan Province were discussed.The results indicate that:(1)The chronometer factors have an effect on the basic change of UV-B strength,the changing characteristics are directly related to the total radiation and have obvious daily and yearly variations.(2)The UV-B strength is affected by the latitude of the survey points.With the increase of latitude,the UV-B strength decreases.When the latitude rises 1o,the UV-B strength decreases 0.679 W/m2 and 0.157 W/m2 respectively in the dry and rainy season in the same longitude and decreases 0.340 W/m2 and 0.306 W/m2 in different longitude.The changing ratio of UV-B strength in dry season is larger than in the rainy season,having obvious dry-rainy season characteristics.(3)UV-B strength is affected by the altitude,with the increase of altitude of survey points,the UV-B strength increases.When the altitude increases 100m,the UV-B strength increases 0.202 W/m2 and 0.090 W/m2respectively in the dry and rainy season,having also obvious dry-rainy season characteristics.
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    Calculation and Analysis of the Economic Value of Water Resource
    LI Liang-xian, GAN Hong, WANG Lin, NI Hong-zhen, MU Shu-min
    2008, 23 (3):  494-499.  doi: 10.11849/zrzyxb.2008.03.016
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    Based on the theory of utility value,the paper discusses how to calculate the economic value of water resources(EVW) applying benefit sharing coefficient method from each sub-sector.The method is used in six case study districts of Haihe River basin,where we get the EVW of irrigation farm production,industry(mining,manufacturing,electricity,gas and water production and supply),construction industry and tertiary industries,the integrated EVW of the six districts is from 5.9yuan/m3to 25.2yuan/m3,Beijing is the highest,Anyang with the lowest,and all the results can provide reference basis for charging water fees and formulating scientific policies of water resource.
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    The Allowable Exploitation Rate of Rivers Water Resources of the Seven Major Rivers in China
    WANG Xi-qin, ZHANG Yuan
    2008, 23 (3):  500-506.  doi: 10.11849/zrzyxb.2008.03.017
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    This essay analyzes the factors effecting the exploitation rate of surface water resources from the point of view of binary water circulation.The result indicates that there is close relationship between the exploitation rate of surface water resources and watercourse ecological demands of water,also between regression water and its pollutants' concentration.Besides,in this essay,taking the watercourse ecological demands of water and the ratio between the quantities of polluted water and runoff for condition,the connection between the exploitation of water resources and consumption coefficients is discussed,which presents the increasing trends in logistic curve.With the augment of consumption coefficients,the exploitation rate of water resources is allowed to experience a trend from increasing to maximum to decreasing,while the range is from 20% to 50% to 40%.Taking the seven major rivers in China as an example,this essay estimates the allowable thresholds of exploitation rate of surface water resources under the condition of current water resources consumption.The result shows that the thresholds of Songhuajiang River,Liaohe River,Haihe River,Yellow River,Huaihe River,Yangtze River and Zhujiang River prove to be respectively 34%,38%,45%,36%,38%,31% and 32%.Compared with the seven rivers current exploitation rate of water resources,the results show that the rates of Songhuajiang,Yangtze River and Zhujiang River are within their thresholds' range,while the rates of Liaohe River and Haihe River,Yellow River and Huaihe River all exceed the maximal allowable exploitation rate.
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    Reconstruction of Sparse Forest Canopy Height Using Small Footprint LiDAR Data
    QIN Yu-chu, WU Yun-chao, NIU Zheng, ZHAN Yu-lin, XIONG Zai-ping
    2008, 23 (3):  507-513.  doi: 10.11849/zrzyxb.2008.03.018
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    This study estimates canopy height using multi-returns data acquired by the small footprint lidar of sparse forest and explores the precision of different methods such as IDW(Inverse distance weight),Spline method,OK(Ordinary Kriging) to reconstruct the canopy elevation and the ground elevation.It is found out that the performance of the different methods is different between the condition of the forest canopy and the ground.Thereinto the Spline method has the best precision on the reconstruction of forest canopy,the mean of absolute value error is 0.95m,and the variance is 3.42.But in the case of ground,the OK method's mean of absolute value error is the lowest,being 0.35m,but the variance of Spline method is the lowest,being 0.48.But integrating the precision of ground elevation with canopy elevation,and choosing the canopy elevation reconstructed by Spline and the ground elevation reconstructed by OK,it is possible to achieve the abstraction of the canopy height of the study area.
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    Evaluation of CLIGEN Precipitation Parameters in the Semiarid and Arid Regions of the Yellow River Basin
    LIN Zhong-hui, MO Xing-guo
    2008, 23 (3):  514-527.  doi: 10.11849/zrzyxb.2008.03.019
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    Precipitation records from 15 weather stations in the arid and semiarid regions in the Yellow River Basin of China were used to validate the CLIGEN weather generator.Daily records of 41 years from 15 stations were used to evaluate the generator.Generally,the performance of the CLIGEN generator is better in semiarid regions than in the arid regions.Results show that the generator was successful in modeling the means of the total of the annual,monthly and daily precipitation,the monthly probabilities of wet and dry days,and the variability of daily,monthly and annual precipitation.Mean absolute relative errors for simulating daily,monthly and annual precipitation across 15 stations were 2.1%,2.4% and 2.4% for the means and 3.6%,4.1% and 15.9% for the standard deviations,respectively.The relative error for the standard deviation of annual precipitation was relative high.Thus,the improvements of precipitation occurrence are expected.Mean absolute relative errors for the all-time maxima of daily,monthly and yearly precipitation were 5.2%,17.3% and 11.1%,respectively.Most of the maxima values across these stations were overestimated.It may lead to overestimation of runoff and sediment yield by the soil erosion models such as WEPP using the precipitation patterns generated by the CLIGEN model.The validation of the parameters of storm events such as storm duration and peak rain density are needed to conduct by using the pluviograph data.
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    Application of Multi-level Recursive Method in Forecasting Inconsistent Annual Runoff Series under Changing Environment
    FANG Yan-na, CHEN Xing-wei, YANG Qing-chun
    2008, 23 (3):  528-533.  doi: 10.11849/zrzyxb.2008.03.020
    Abstract ( )   PDF (347KB) ( )   Save
    Owing to the effects of changing environment,such as human activities and climate,the natural annual runoff series for water resources evaluation calculation lost their consistency.In order to adapt to a changing environment demand for inconsistent annual runoff forecast,multi-level recursive method is applied.Different from previous mathematical statistic method with fixed-parameters,the multi-level recursive method is the one just dealing with the time-space variation system.The dependability of forecasted results will be enhanced because the regime of runoff is forecasted based the time-varying parameters forecasted in the model.The paper will illustrate the method by taking Zhuqi station of Minjiang River as an example,and the results will provide scientific basis for planning water use in the future.
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    A Methodology for Multiple Cropping Index Extraction Based on NDVI Time-Series
    ZHU Xiao-lin, LI Qiang, SHEN Miao-gen, CHEN Jin, WU Jin
    2008, 23 (3):  534-544.  doi: 10.11849/zrzyxb.2008.03.021
    Abstract ( )   PDF (509KB) ( )   Save
    Multiple cropping system characterized by cropping index is crucial to Chinese food security.Multiple cropping index(MCI)refers to the times of sequential crop planting in the same arable land in one year,reflecting utility degree of arable land to be used at a certain period.It is desired to extract the MCI and its spatial distribution information by remotely sensed data for sustainable agricultural development.Traditionally,the MCI is calculated by statistical data at local administration unit,which is time-lagged,labor-consuming and poor in creditability as well as lack of spatial distribution.Meanwhile,remote sensing technology has been widely applied to agriculture and crop monitoring.The advancement in remote sensing technology provides potenial to obtain the actual MCI information efficiently and reliably.Many researches indicate that crop growth dynamic can be monitored by the time series of Normal Difference Vegetation Index(NDVI) data.It is found that the peak of the time series of the NDVI curve indicates that the ground biomass of crops reaches the maximum,and fluctuates with the crops growing processes such as sowing,seeding,heading,ripeness,and harvesting within one year.Thus,the MCI is defined as the number of peaks of the time series of the NDVI curve.However,since NDVI data are affected by cloud and poor atmospheric conditions,the curve of time series of NDVI turns out to be noisy with a lot of small peaks and valleys in one cycle,which makes it more difficult to extract the actual MCI.This study develops a new method for extracting cropping index based on NDVI time-series by which cloud and other contaminations can be corrected effectively.The details about the method include:(1) smoothing the NDVI time-series by Savitzky-Golay filter to get the long-term growing trend;(2) correcting the growing trend curve by iteration process to get rid of the false peaks;and(3) obtaining the MCI by counting the number of true peaks.Using 1km 10-day Maximum Value Composite SPOT/VGT NDVI time-series,the MCI of 17 provinces of northern China from 1999 to 2004 was extracted by this new method.The results revealed that: the cropping index of Huang-Huai-Hai region was higher than that of the other regions in northern China.The spatial distribution of the extracted MCI was consistent with the actual Chinese cropping system.The total precision of sample validation based on visual identification was 95.24%,the coefficient of Kappa 0.9057,and the slope of linear regression of the MCI between remotely sensed data and statistical data was 0.9288(R2=0.9159,P<0.001),suggesting that this method could provide an effective way to extracting spatial information of the MCI for agriculture and land management.
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    The Regional Relationship under Cross-regional Resources Deployment Project:Taking the South Passage of the West-East Electricity Transmission Project as an Example
    LIU Yu, FENG Jian
    2008, 23 (3):  545-552.  doi: 10.11849/zrzyxb.2008.03.022
    Abstract ( )   PDF (342KB) ( )   Save
    In recent years,great progresses have been made in several cross-regional resources deployment projects both in general and regional values.But however,there are also many contradictions between export provinces and import provinces.And with the increase of quantity of electric charge,it is possible that the conflicts between them would be greatly deepened.In the south passage of the West-East Electricity Transmission Project(WEETP),greater difference exists in the level and increasing trend of price,the time distribution of feeding electricity,and the ecological compensation of resources and environment etc.At present,there are lots of irrational factors and actions at aspects of electricity trade and interest distribution.The main content of WEETP is selling and buying electricity,but it happens between developed area and undeveloped area.At the same time,WEETP is also an important stratagem of China.So the pattern of WEETP must be different from ordinary electricity trade.It needs the joint efforts of market and governments.Market economy is the direction of WEETP,but it is absolutely necessary that governments elaborate the comprehensive benefits,potential benefits and recessive benefits of WEETP.
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