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    20 September 2012, Volume 27 Issue 9 Previous Issue    Next Issue
    Gully Erosion Soil Quality Assessment on the Cultivated Slope Land in the Loess Plateau Region, China
    LI Qiang, XU Ming-xiang, ZHAO Yun-ge, GAO Li-qian, ZHANG Jin, ZHANG Xiao-wei
    2012, 27 (9):  1001-1012.  doi: 10.11849/zrzyxb.2012.09.001
    Abstract ( )   PDF (2000KB) ( )   Save
    Characterized by dry climate, concentrated rainfall and fragile soil, the Loess Plateau has experienced serious soil erosion for long time. Gully erosion of cultivated slope land is wide and serious,which has led to tremendous soil and nutrient losses as well as production reduction. However, the effect of gully erosion on soil degradation hasn’t been paid enough attention from the managers and agricultural scientists because soil degradation is a gradual process and might not ostensibly lead to a serious loss of agricultural production. It’s still not quite clear about the effect of gully erosion on soil attributes and soil quality on the Loess Plateau. In the present study, the soil in the inter-gully was chosen to be the control soil. Sixty-four profiles, with various erosion depths were selected and 16 soil physiochemical indicators were determined in gully and inter-gully soil. Subsequently, a comprehensive assessment model was established through analyzing the effect of gully erosion on soil quality factors. Using principal component analysis (PCA) and stepwise discriminant analysis, the soil quality evolution under different gully erosion depths was evaluated quantitatively with weighted integrated method of PCA. The result showed that the effect of gully erosion on soil quality indicators was different in the cultivated slope land. In detail, gully erosion would harden the surface soil and increase pH value, while the changes of soil water-stable aggregate and nutrient content showed an obvious hierarchy with increment of gully erosion depth. The change law presents a "W shaped" pattern. The relationship between gully erosion and soil quality index (SQI) could be preferably fitted by the power function curve of y=0.8668 x-0.142(R2=0.877). Therefore, the SQI under the condition of low erosion intensity (<5 cm), moderate erosion intensity (5-30 cm) and high erosion intensity (30-50 cm) reduced 10.6%, 27.9% and 36.5%, respectively as compared with the control soil. It was noted that the SQI under moderate erosion intensity was 17.3% lower than that of low erosion intensity while about 8.6% higher than that of high erosion intensity. Thus, the erosion depths of 5 cm and 30 cm were the two critical points where the SQI reduced significantly. Besides, the soil quality indicators that could well responded to the gully erosion in the cultivated slope land could be classified into soil fertilizer indicator, texture indicator and structure indicator. Moreover, four soil quality indicators including soil organic matter, soil specific surface area, soil aggregate content and soil bulk density were identified as the most sensitive and simplified indicators for evaluating soil quality influenced by gully erosion in the cultivated slope land on the Loess Plateau.
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    Spatial and Temporal Characteristics of Spatial Expansion of Urban Land in Wuhan Urban Agglomeration
    GUAN Xing-liang, FANG Chuang-lin, ZHOU Min, WU Hong
    2012, 27 (9):  1447-1459.  doi: 10.11849/zrzyxb.2012.09.002
    Abstract ( )   PDF (4167KB) ( )   Save
    As industrialization and urbanization accelerates, urban land expansions of many urban built-up areas in middle-western region are obvious. It is significant to obtain accurate information and analyze urban expansion process and its driving force. Based on Landsat TM, ETM+, MSS imagery data, this paper obtained the urban land use information of the three stages (1980-1990, 1990-2000 and 2000-2010) in Wuhan Urban Agglomeration with the application of remote sensing and GIS technology. Furthermore, the paper analyzed the temporal and spatial patterns of urban expansion, the expansion process and its driving force of Wuhan Urban Agglomeration using the urban expansion index and urban expansion model. The main conclusions are as follows: Firstly, the urban land of Wuhan Urban Agglomeration areas have experiencing a rapid expansion process; urban expansion intensity index in the mentioned three periods were 0.0732, 0.0289 and 0.0993 respectively, showing a significant fluctuation characteristics. Secondly, the spatial pattern of urban land use in Wuhan Urban Agglomeration was emerging conspicuous concentration during the study period; Wuhan was the center of the ring-layered expansion patterns. Moreover, the urban land-use expansion relatively centralized along the directions represented by the Third-Ring Road in Wuhan, Beijing-Guangzhou Railway and other transportation corridors. The urban expansion pattern was different in different stages. Thirdly, the expansion process of Wuhan Urban Agglomeration had formed one pole and four belts, one pole and one belt, three poles and six belts during 1980-1990, 1990-2000, 2000-2010 respectively. Fourthly, it was worth noting the fact that economic reform, national non-balanced development strategy, resource-saving and environment-friendly society building, and the Yangtze River, Beijing-Guangzhou Railway and other major transport arteries were the main driving factors for urban land use change. However, the dominant driving mechanism was different in different stages.
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    Changes of Temperature and Precipitation in Growing Season and Cropping Strategy under Global Climate Change in Jilin Province
    JIN Ying-hua, ZHOU Dao-wei
    2012, 27 (9):  1460-1470.  doi: 10.11849/zrzyxb.2012.09.003
    Abstract ( )   PDF (2936KB) ( )   Save
    This study aims to reveal the temperature and precipitation changes during the growing season in plain and forest regions of Jilin Province under global climate change and put forward the regional crops adjustment for these regions. The results showed that the greatest change of the first growing season advanced, the last growing season delayed, the growing season lengthening and active accumulated temperature increasing occurred in plain region, so it has the largest adjusted space for cropping strategy. In forest regions, changes of the length and active accumulated temperature of high and mid-altitude regions were bigger than those of low altitude region in the growing season, and the changes of growing season lengthening for three forest regions mainly occurred based on the last delayed growing season.For example, in plain region, advancing the sowing date, delaying the harvest date and sowing the late maturing variety instead of mid-late maturing variety is a better mode for corn. In order to avoid spring drought, the middle-late maturing variety is still planted in the western plain region. In low altitude forest region, middle maturing variety should be replaced by middle-late maturing variety. In mid-altitude forest region, early maturing variety and middle-early maturing variety should be replaced by middle-early maturing variety and middle maturing variety. In high altitude forest region, exceedingly early maturing variety and early maturing variety should be replaced by middle-early maturing variety. In these three regions, the heat resources need to make crop mature should be attained by delaying the harvesting date.
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    Quantitative Analysis on the Impact of Water Resource on Crop Production in Horqin Sandy Land—A Case Study in Naiman Banner
    GE Xiao-dong, HU Su-jun, YE Qing
    2012, 27 (9):  1471-1479.  doi: 10.11849/zrzyxb.2012.09.004
    Abstract ( )   PDF (1392KB) ( )   Save
    A model was built up based on the Cobb-Douglas Function. The impact of three kinds of variables, included climate factors, economic factors and technological factors, on the crop production during the period from 1987 to 2008 was quantitatively analyzed. The results showed that: 1) The labor (t=9.44, P=0.00), the irrigation water (t=6.89, P=0.00) and the precipitation (t=8.33, P=0.00) were the most important factors to the crop production, when being compared to other 7 factors. The irrigation water and the precipitation were related to the water resource, reflecting that water resource accelerated the crop production. 2) Actually, the labor kept declining since 2003, leading to the serious waste of water resource. According to the regressed model, the irrigation water increased by 3.31% when the labor declined by 1%. And also, the irrigation water increased by 0.94% when the annual precipitation declined by 1%. 3) The fluctuation of the annual precipitation affected the yield per unit area greatly. The change of the annual precipitation was negatively related to the change of the area of the arable land, since local residents frequently enlarged their arable land when the weather got drier. The irrigation water also impacted the yield per unit area greatly. In a word, the water resource played much more important role in the crop production, and the water consumption brought heavier burden on local ecosystem.
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    The Inflection Point Theory of Mineral Resources Demand and Peak Forecast
    REN Zhong-bao, WANG Shi-hu, TANG Yu, ZHOU Hai-dong
    2012, 27 (9):  1480-1489.  doi: 10.11849/zrzyxb.2012.09.005
    Abstract ( )   PDF (2674KB) ( )   Save
    The contradiction between mineral resources finiteness and rapid growth of demand became increasingly prominent. These questions such as in the future, rapid economic development requires how many mineral resources and when reaching demand peak in China, are the basis of formulating mineral resource strategy. The study proposed double inflection points theory of mineral resource consumption: on the one hand, the peak that mineral resource consumption intensity reaches corresponds with the inflection point, as mineral resources utilization transforms from the extensive to intensive; on the other hand, the peak that mineral resources consumption level reaches corresponds with the inflection point, as mineral resources consumption converts increase to reduce. After logic derivation, it support this theory by the evolution track of mineral resource consumption and the economic development in the United States. Through comparative study, it suggests that mineral resources demand in China has great potential in the next few years. Choosing the BP neural network and ridge regression forecast methods, comprehensive consideration of the economic development, population change and technology progress, based on the Matlab software, it forecasted mineral requirements and peak inflection point in China. The prediction results show that energy demand inflection point in the 14th Five-Year Plan period will peak for 4.5-5 billion tons of standard coal; steel demand inflection point in the 13th Five-Year Plan period will peak for 800 million tons; copper demand inflection point in the 13th Five-Year Plan period will peak for 9 million tons; and the peak of aluminum demand inflection point in the 12th Five-Year Plan period is 16-17 million tons.
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    Empirical Analysis on Impacts of the New International Pricing Mechanism on Iron Ore Imports of China
    TIAN Yu-jun, ZHU Ji-shuang, MA Guo-xia, LI Lu-ning
    2012, 27 (9):  1490-1496.  doi: 10.11849/zrzyxb.2012.09.006
    Abstract ( )   PDF (1527KB) ( )   Save
    With the development of China’s foreign trade and large domestic demand for iron ore, iron ore imports have risen sharply in recent years. According to statistics, by the end of 2011 the iron ore imports is 6.18×108 t, an increase of 6.7 times compared with 2001. Nowadays, China has become the largest iron ore consumer. Meanwhile, international iron ore giants abandon long agreement price mechanism, and unilateral implementation of new pricing mechanism. In order to understand the impact of new pricing mechanism on iron ore imports, using statistic and Granger cause, this paper explored the linkages between new international pricing mechanism and China’s iron ore imports. The results show that iron ore imports of China frequently fluctuated in recent years, and iron ore prices shock that caused by international iron ore pricing mechanism change, is the main drive force for China’s iron ore imports fluctuations. Furthermore, in future short-term fluctuations of China’s iron ore imports will continue.
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    Flooding Risk Assessment of Agriculture in Fujian Province Based on Information Diffusion Theory
    WANG Jia-yi, CHEN Jia-jin, LIN Jing, YANG Kai, MA Zhi-guo, HUANG Rong-cheng, XU Zong-huan
    2012, 27 (9):  1497-1506.  doi: 10.11849/zrzyxb.2012.09.007
    Abstract ( )   PDF (1150KB) ( )   Save
    According to the statistical data of flooding stricken area and disaster area during the period of 1978-2008 in Fujian Province, the disaster index reflect the influence area of flood, the disaster and affected index ratio (DSR) reflect the influence intensity of flood, the flooding risk assessment of agriculture was obtained based on the theory of normal information diffusion, and the result of assessment was validated by occurrence frequency method. The results showed that: the probability of flooding risk on agriculture declined with the increase of risk level; as the same risk index, the risk probability of DSR was higher than the probability of stricken risk, and the probability of stricken risk is higher than the probability of risk disaster; the average probability of stricken risk, disaster risk and DSR was 0.4487, 0.48 and 0.6516 respectively; the influence of flood was comparatively frequent, and the influence area was comparatively serious. Data analysis and risk assessment results are basically consistent with the actual situation.
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    The Analysis of Spatial Conflict Measurement in Fast Urbanization Region Based on Ecological Security—A Case Study of Changsha-Zhuzhou-Xiangtan Urban Agglomeration
    PENG Jia-jie, ZHOU Guo-hua, TANG Cheng-li, HE Yan-hua
    2012, 27 (9):  1507-1519.  doi: 10.11849/zrzyxb.2012.09.008
    Abstract ( )   PDF (6208KB) ( )   Save
    Spatial conflict, a direct cause for the formation and intensification of contradictions in the process of urbanization, is the key factor for regional sustainable development. It is essential to measure the level of spatial conflict for optimizing regional development model and avoiding the ecological risk. Based on analyzing the changes of Changsha-Zhuzhou-Xiangtan Urban Agglomeration’s spatial pattern from 1993 to 2008 by using remote sensing image processing software (ENVI) and GIS analysis software (ArcGIS), and quantifying the external pressure, ecological risk exposure and the value of ecological risk of space resources affecting ecological security of the region, this article builds a comprehensive conflict measure model based on ecological safety, and assesses the level of spatial conflict of Changsha-Zhuzhou-Xiangtan Urban Agglomeration which has experienced rapid urbanization. Research results can be obtained as following. Spatial conflict is an objective geographical phenomenon arising with the competition for spatial resources, which stems from the scarcity of space resources and the spillover of space functions. The level of spatial conflict can be characterized by three factors, which are external pressure, ecological risk exposure and the value of ecological risk of space resources affecting ecological security of the region. From the measurement results of Changsha-Zhuzhou-Xiangtan Urban Agglomeration’s spatial conflict, we can draw out that, with the increasingly frequent changes in spatial patterns of Changsha-Zhuzhou-Xiangtan region in recent years, the spatial conflict of Changsha-Zhuzhou-Xiangtan Urban Agglomeration presents a rising trend overall. From 1993 to 2008, the average value of spatial conflict index increased from 0.264 to 0.323. And the seriously uncontrollable spatial conflict increases the biggest in area ratio, up to 1.07 times. Different spatial landscape types have different ecological benefits. Therefore, there are some differences in intensity of the spatial conflict between the landscape types. The level of woodland and farmland landscape spatial conflict is lower, and the construction landscape conflict’s level is higher. Urban and rural transitional zone has the most frequent, intense spatial conflict of the region, followed by the inner cities, and the intensity of rural areas’ spatial conflict is far lower than in urban space.
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    Study on Dynamic Security of Land Ecology in Water Source Area of South-to-North Water Diversion Project:A Case Study of Shangluo City, Shaanxi Province
    SUN Pi-ling, YANG Hai-juan, LIU Qing-guo
    2012, 27 (9):  1520-1530.  doi: 10.11849/zrzyxb.2012.09.009
    Abstract ( )   PDF (1657KB) ( )   Save
    As a research proposition in the field of land science, land ecological security has an important influence on the regional sustainable development. The research of land ecological security plays a significant role in protecting water source area. The paper takes Shangluo City located in Shaanxi Province as a study area, which is an important water source area of South-to-Noorth Water Diversion Project. The data used in this paper is mainly from the statistics of socio-economy and land-use structure in this city from 2000 to 2009. An evaluation index system consisting of 23 indices from the natural, social, economic and environmental factors influencing land ecological security has been established based on comprehensive consideration of land-use structure change. Related mathematical methods and econometric models have been used to make a quantitative and comprehensive appraisal of land ecological security in Shangluo City. The results are as following: 1) The land ecological security of Shangluo City was improved gradually since 2000, although the land ecological security was still in a sensitivity state in 2009. In the past decade, the comprehensive value of land ecological security rose from 0.2516 to 0.6951. But the pressure of land ecological security remained. The land ecological security needs to be further improved in the future. 2) There has a stable decline of the information entropy of land-use structure in Shangluo City. From 2000 to 2009, the entropy-value of land-use structure dropped from 1.0314 to 0.9805. At the same time, the land-use structure of original state has been broken. The balance degree of the land-use structure in Shangluo City was dropping gradually, while the order of land-use structure system developed to non-equilibrium. 3) The threat to the land ecological security came from the subsystem of land natural ecology and the declining negative influence of the subsystem of land economic ecology on land ecological security. The subsystem of land social ecology and the subsystem of land environmental ecology had less influence on land ecological security. 4) The indices of cultivated land per capita, flood insurance yield, natural population growth rate, fertilizer using intensity per unit area and plastic film much using intensity per unit area became major limited factors to the land ecological security. Finally, some measures are proposed to cope with the pressure of land ecological security.
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    Analysis of the Influence of Water Use on the Eco-environmental Change in Dunhuang City
    MA Li-bang, NIU Shu-wen, YANG Li-na
    2012, 27 (9):  1531-1542.  doi: 10.11849/zrzyxb.2012.09.010
    Abstract ( )   PDF (2719KB) ( )   Save
    Based on the interpretation analysis of remote sensing data, it was found that the area of natural vegetation decreased 543.69 km2 and natural ecosystems area reduced 17.62% from 1987 to 2007 in Dunhuang City, which shows the obvious trend of land desertification. According to actual quadrate biomass measured and area of each land use type, we fit curves and estimate total biomass of the natural vegetation. The results demonstrate that the total biomass decreased from 102.42?104 t in 1987 to 72.33?104 t in 2007(nearly 30%). Water consumption of natural vegetation decreases from 3.0727?108 m3 to 2.17?108 m3 in this period. Water consumption of human activity increases from 3.3157?108 m3 to 4.093?108 m3 accordingly. However, the total volume of water consumption is about 6.3?108 m3. In the main stream of Shule River and its tributary Danghe River, the water used for natural vegetation was crowded out because water consumption of human activity increased greatly. Especially, agricultural irrigation occupies most of water resource. This became the main reason for eco-environmental degradation in Dunhuang. To recover and protect the eco-environment from degradation, not only human activity should be regulated in Danghe River Basin, but also in Shule River Basin.
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    Characteristics of Soil Seed Bank of Soil Pile Made by Zokor in Alpine Meadow Area in Eastern Qilian Mountains
    LI Chun-ming, CHEN Shu-yan, XU Chang-lin, YANG Lei, CHEN Jian-gang, ZHANG De-gang
    2012, 27 (9):  1543-1549.  doi: 10.11849/zrzyxb.2012.09.011
    Abstract ( )   PDF (683KB) ( )   Save
    The seed density and species of seed bank in soil pile made by zokor in alpine meadow in the eastern Qilian Mountains were studied and compared with that of the natural alpine meadow through field investigation and germination test. The result indicated that the seed density in new pile, old pile and natural meadow was 176.93?135.51 seeds/m2, 1486.15?900.78 seeds/m2 and 2937.01?2471.60 seeds/m2 respectively. Elsholpzia bensa var. calycocarpa, Chenopodium glaucum and Poa poophagorum were main species in new pile seed bank. Chenopodium glaucum, Hypecoum leptocarpum and Poa poophagorum were main species in old pile seed bank.Lepidium apetalum, Delphinium caeruleum, Stipa aliena, Potentilla bifurca, Ranunculus tanguticus and Oxytropis ochrocephala were main species in natural meadow seed bank. The difference of seed density was greater but not for the species composition between old and new piles. The difference of both seed density and composition was great between soil piles and natural meadow. Most seeds in soil seed bank of soil piles were annual species and this suggested that the succession of vegetation was in early phase.
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    Variation Characteristics of Water Vapor Resources over the Three Gorges Reservoir Area during 1980-2009
    LIU Xiao-ran, YANG Qian, WANG Ruo-yu, CHENG Bing-yan
    2012, 27 (9):  1550-1560.  doi: 10.11849/zrzyxb.2012.09.012
    Abstract ( )   PDF (4911KB) ( )   Save
    On the basis of meteorological sounding data at 15 stations in the Three Gorges Reservoir Area (TGRA) and its surroundings from 1980 to 2009, the variation characteristics of water resources in air over the TGRA are analyzed. The results show that the water vapor content increases gradually from northeast to southwest over the TGRA. The water vapor over the TGRA mainly comes from the transportation of southwest water vapor, which has the greatest intensity in summer. There is convergence of water vapor over most of the TGRA, apparently in northwest and southeast of the TGRA. The water vapor over the TGRA mainly inflows from south boundary and outflows from east boundary. The net water vapor flux is positive in each month, showing a single peak changes at maximum in July. The integrated net water vapor transport flux has experienced a parabolic decadal change with first increasing and then decreasing, and had an decreasing trend in spring and winter and an increasing trend in summer, autumn and annual mean in the past 30 years.
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    Temporal and Spatial Change of the Potential Evaporation and Its Impact Factors in Gansu Province
    LIU Pu-xing, ZHUOMA Lan-cao
    2012, 27 (9):  1561-1571.  doi: 10.11849/zrzyxb.2012.09.013
    Abstract ( )   PDF (2826KB) ( )   Save
    Based on the daily temperature, precipitation, wind speed, sunshine hours, total solar radiation and related humidity data of the 27 weather stations of Gansu Province from 1960 to 2008, evapotranspiration (ET0) was estimated with the methods of Penman-Monteith model and the temporal-spatial variation of ET0was analyzed by using Kriging interpolation in different climate regions of Gansu Province. The results indicated that ET0 was different in different climate regions of Gansu and changing trends of ET0 were increasing except for Hexi Corridor. The changing trend of ET0 was increasing most obviously in high-cold humid area of Gannan, the change rate was 10.36 mm/10 a (α=0.001). In four seasons, summer ET0 was maximum, autumn and spring ones occupied the second place, and winter ET0 was minimum. ET0 had the characteristic of remarkable spatial variation,with the decreasing from northwest to southeast, with the smallest in Gannan plateau, while the biggest in the warm temperate zone of Hexi Corridor. But the changing trend was different in different climate regions of Gansu Province. There was remarkable positive correlation between the mean annual ET0 and the annual mean wind speed,the annual total solar radiation,the annual mean highest temperature, respectively in the warm-temperate zone, cold-temperate zone, arid region of Hexi Corridor and Longnan humid region, semi-arid region of Longzhong,Gannan and Qilian mountainous regions of Gansu. Climatic influencing factors of the typical weather stations of each climate region were similar as those of the seven climate regions and the ETrad was mainly impacted by the total solar radiation, while the ETaero was affected by the wind speed.
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    Chinese Scarcity Factors of Resources/Energy and their Application in Life Cycle Assessment
    HOU Ping, WANG Hong-tao, ZHU Yong-guang, WENG Duan
    2012, 27 (9):  1572-1579.  doi: 10.11849/zrzyxb.2012.09.014
    Abstract ( )   PDF (1033KB) ( )   Save
    With the scarcity factors of resources and energy, the overall resource consumption along a product life cycle can be evaluated in LCA(Life Cycle Assessment) studies. In this paper, CADP (Chinese Abiotic Depletion Potential) factors of various resources and fossil energy in the Chinese context were obtained by adopting the broadly used Abiotic Depletion Potential (ADP) factors in CML methods and modifying them with self-sufficiency rate of individual resources in China. The factors will support the assessment of resource and energy consumption for LCA studies and relevant policy studies in China. It also provides an adaptable method for other national or regional analysis. The case study shows that the CADP of 1 kWh grid power is 1.02 kg coal-R eq. The 60.46% of contribution comes from the coal consumption, then from oil consumption (11.63%), and the consumption of other resources like copper, nickel etc. in infrastructure construction also contributes.
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    Agricultural Technical Efficiency Measurement under the Environmental Constraints
    LIANG Liu-tao, QU Fu-tian, FENG Shu-yi
    2012, 27 (9):  1580-1589.  doi: 10.11849/zrzyxb.2012.09.015
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    This paper applied the directional distance function model and measured agricultural technical efficiency under the environmental constraints using inter-provincial panel data from 1997 to 2009, then analyzed temporal and spatial characteristics of agricultural environmental technical efficiency, and lastly explored the factors affecting the evolution of agricultural environmental technical efficiency. The main findings are: 1) The average value of agricultural environmental technical efficiency from 1997 to 2009 was 0.692. From the temporal perspective, in general agricultural environmental technical efficiency appeared an increase-decrease-increase trend. 2) Agricultural environmental technical efficiency was related with regional economic development and agricultural production condition. Provinces with a higher level of economic development in Eastern China have higher environmental technical efficiency; while provinces with a lower level of economic development in Central and Western China have lower environmental technical efficiency. 3) Factors affecting agricultural environmental technical efficiency are multifaceted. With good economic development, people have higher environmental requirements, have greater capacity and willingness to prevent and control agricultural environmental pollution, and therefore promoting agricultural environmental technical efficiency. Changes of agricultural structure, including crop structure and agricultural production value structure, affect agricultural environmental technical efficiency as well. Agricultural infrastructure investment is helpful for agricultural environmental technical efficiency. However, the role of agricultural resource endowments and agricultural environmental management policies on agricultural environmental technical efficiency is not obvious.
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    Estimating Urban Impervious Surface Based on Thermal Infrared Remote Sensing Data and a Spectral Mixture Analysis Model
    LI Bo, HUANG Jing-feng, WU Ci-fang
    2012, 27 (9):  1590-1600.  doi: 10.11849/zrzyxb.2012.09.016
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    The rapid growth of impervious surface is one of the remarkable characteristics of urbanization. Rapid extraction of urban impervious surface using remote sensing has been a hotspot research at home and abroad for large-scale urban monitoring. This paper explored extraction of impervious surface information of Hangzhou from a Landsat 7 ETM+ image based on the integration of a spectral mixture analysis model and land surface temperature generated by thermal infrared images. The linear combination of high albedo, low albedo, vegetation and soil fraction was used to characterize the different types of urban land. The land surface temperature was considered as a mask to remove the "noise" from low albedo fraction, and soil fraction was used to remove the "noise" from high albedo fraction. The modified high albedo fraction and low albedo fraction were adopted to estimate impervious surface distribution of Hangzhou. The result showed that the average RMSE was 0.0036 in the study area. Impervious surface distribution estimated using the above method and the interpretation from high resolution images in Google earth and SPOT 4 image was comparatively analyzed, and the majority of differences between estimating values and interpreting values of samples were ranged from -0.15 to +0.15. There was a promising accuracy. The result indicated that the method was feasible and reliable to precisely estimate impervious surface based on thermal infrared remote sensing images and a spectral mixture analysis model.
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    Research and Application of Regional Irrigation Amount Forecast for Cropland Based on RS and GIS
    LIU Yong-hong, YE Cai-hua, LI Wen-hua
    2012, 27 (9):  1601-1609.  doi: 10.11849/zrzyxb.2012.09.017
    Abstract ( )   PDF (1695KB) ( )   Save
    The spatial difference of soil, crop and atmosphere should be taken into account for cropland irrigation amount forecast in regional scale. To resolve the present agricultural production problems, water requirement irrigation forecast model and soil wetting layer irrigation forecast model were developed. Also, RS and GIS were introduced in the forecast models for the spatial variability of forecast parameters. Cropland irrigation forecast with a spatial resolution of 250 m over regional scale was initially implemented and it was applied in irrigation water forecast of winter wheat over Beijing area. The applied results showed that the forecast irrigation volume of grain-filling stage in June and frozen-water stage in late November in 2010 were 375 m3/hm2 and 600 m3/hm2, respectively. The irrigation amount of forecast was less than that recommended of current agricultural production, and there is the potential of water-saving economic benefits. These results indicated that RS and GIS had good application potential in cropland irrigation forecast over regional scale and the consistency between forecast and application effects.
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    Estimation Model of Natural Rubber Yield Based on Net Primary Production and Remote Sensing
    LI Hai-liang, LUO Wei, LI Shi-chi, DAI Sheng-pei, LIU Hai-qing
    2012, 27 (9):  1610-1621.  doi: 10.11849/zrzyxb.2012.09.018
    Abstract ( )   PDF (5033KB) ( )   Save
    A net primary productivity (NPP) model for natural rubber was established with 250 m?250 m MODIS remote images and meteorological data on the Yangjiang Farm at growing season from April to December 2009. And the potential productivity of natural rubber was estimated based on the NPP and the natural rubber allocation rate of dry matter. The natural rubber yield estimation model was established with actual rubber yield in each task and the potential productivity of natural rubber based on regression analysis. The accuracy of yield estimation model was validated by the actual rubber production data in July 2010 on the Yangjiang Farm. The root mean square error(RMSE) is 1.78 g穖-2, and the relative root mean square error(RMSEr)is 18.25%. The results show that the natural rubber yield estimation model based on remote sensing information and net primary productivity has a good effect.
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