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  • Resource Ecology
    Analysis on Groundwater Supply Function of Wetlands in Jilin Province Based on Soil Permeability Coefficient
    CUI Li-juan, ZHAO Xin-sheng, LI Wei, KANG Xiao-ming, LEI Yin-ru, ZHANG Man-yin, SUN Bao-di, YU Jing-jing
    2017, 32(9): 1457-1468. https://doi.org/10.11849/zrzyxb.20160905
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    The amount of seepage and groundwater supply of wetlands in Jilin Province is about 9.971 billion m3 every year. The order of amount from different wetland types is marsh wetland (4.64 billion m3) > lake wetland (2.664 billion m3) > constructed wetland (2.148 billion m3) > river wetland (519 million m3). In different classes of wetlands, the annual amount of seepage and groundwater supply from inland salt-marsh is the maximum (1.86 billion m3), and the second is seasonal salt-marsh (1.493 billion m3), while the amount from aquaculture farm is the minimum (only about 5 million m3). The annual amount of seepage and groundwater is different from wetlands with different permeability coefficient in Jilin Province. The total value of groundwater supply of wetlands in Jinlin Province is 40.183 billion yuan RMB. The order of values of different wetland types is marsh wetland (18.699 billion yuan RMB) > lake wetland (10.736 billion yuan RMB) > constructed wetland (8.656 billion yuan RMB) > river wetland (2.092 billion yuan RMB). In different classes of wetlands, the value of inland salt-marsh is the maximum (7.496 billion yuan RMB) and the value of aquaculture farm is the minimum (20 million yuan RMB). The groundwater supply value of wetlands in Jilin Province wetlands mainly distribute in three areas: the “marsh wetland-lake wetland-river wetland” area centered on Baicheng and Songyuan, the constructed wetland area centered on Siping, Changchun and Liaoyuan, and the “marsh wetland-river wetland” centered on Jilin.
  • Resource Ecology
    Scenarios Simulation of the Spatial Stress on Wetlands by Urban Expansion: A Case Study of Huailai County
    ZHAO Xue, HUANG Qing-xu, HE Chun-yang
    2017, 32(9): 1469-1481. https://doi.org/10.11849/zrzyxb.20160835
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    Scenario simulation has shown prominent advantages in complex human-environment systems, for it considers the impacts of unexpected disturbance and focuses on long-term plans. The 2022 Beijing & Zhangjiakou Winter Olympics might accelerate economic development and urban expansion in Huailai, which would lead to a significant impact on the spatial stress of wetlands in this area. This paper adopted the scenario simulation method as well as LUSD-urban (Land Use Scenario Dynamics-urban) model and a spatial stress model to simulate the spatial stress on wetlands by urban expansion in Huailai in 2030. We designed three scenarios, i.e., the business-as-usual scenario, the urban planning scenario and the Winter Olympic scenario, and compared the results under the three scenarios. The results showed that the spatial stress on wetlands by urban expansion has increased by 10.03%, from 0.399 in 2000 to 0.439 in 2013. Meanwhile, the proportion of land with a spatial stress greater than 0.5 increased from 6.73% to 17.42%. The spatial stress on wetlands during 2013-2030 will increase by 0.002-0.005 under the three scenarios. The Winter Olympic scenario will witness the largest increase in spatial stress on wetlands. The hotspot area of spatial stress on wetlands will be 83.74 km2 under the Winter Olympic scenario, 1.44 times as large as the common hotspot area under the three scenarios. The non-urban land in the towns of Xinbao’an, Tumu and Shacheng will face high spatial stress. Thus, the future urban planning of Huailai County should take full account of the importance of wetland ecosystems, so as to protect the scarce wetland resources, improve the water quality in the Guanting Reservoir and promote economic development on the basis of an effective environmental protection.
  • Resource Ecology
    The Effects of Rural Roads on Forest Structure at the Community Level in Three Gorges Reservoir Area
    MA Xue-ying, SHAO Jing-an, XU Xin-liang
    2017, 32(9): 1482-1494. https://doi.org/10.11849/zrzyxb.20160840
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    Road as an artificial disturbance medium is considered as one of the main driving forces of the evolution of forest landscape and the conversion of forest usage at small spatial and temporal scales. It shows obvious “Channel-barrier” effect. Xituo town of Shizhu County in Chongqing city was selected as a research area. We used the buffer and overlay function in ArcGIS based on three phase remote sensing images and servey data to analyze the effects of road evolution on the changes of types, ages and origins of forest landscape. Results showed that: 1) The number of roads firstly increased and then decreased, and the road quality was most improved in substandard roads and village roads. 2) The disturbance of roads on forest landscape is obvious. The fragmentation of forest type, forest age and forest origin was higher in buffer zones of roads than in non-buffer zones of roads. Comparing the two periods of 1992-2002 and 2002-2014, the shrub forest, young forest and coppice forest reduced significantly in the first period, and the reduction were higher in buffer zones of roads than in non-buffer zones of roads. In the latter period, arbor forest, middle and old age forest increased, but shrubs and mature forests slightly reduced, among which the increase of arbor forest in buffer zones of roads was greater than in non-buffer zones of roads and the increase of middle age forest and coppice forest were lower in buffer zones than in non-buffer zones. 3) In the influence area of roads, if there is no intervention of policies, the increase of new roads and the improvement of road quality degraded the forest landscape, while the disappearance of low level roads was benefit to the restoration of forest landscape.
    • Resource Economics
  • Resource Economics
    Externality Measurement of Rural-urban Land Conversion Based on Probability Model: An Empirical Study on Jinghai District, Tianjin City
    CHEN Zhu, HU Wei, HUANG Lin-xiang
    2017, 32(9): 1495-1504. https://doi.org/10.11849/zrzyxb.20160857
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    Externalities are important elements in the process of rural-urban land conversion. The study analyses the effects of externalities, including various positive and negative effects such as cluster effect, land fragmentation, and pollution to agricultural land, et al. We propose a method by using land conversion probability instead of land price to identify externalities of rural-urban land conversion and present the measurements of externalities. In the empirical study, Probit model is used to estimate the externalities of rural-urban land conversion at the plot scale. Plot characteristics are considered in the model as control variables. Plot characteristic variables include distance from agricultural land to features, land price, land quality and prime farmland control, and externality variables contain externalities from commercial, residential and industrial land in different distances. Results show that: firstly, the distances from parcels to city, to town, to county, to highway entrance and to high level road could elevate the probability of land conversion, but the distances from parcels to county, to low level road and to runoff could decrease the probability. In addition, prime farmlands have lower probability of land conversion than lands in developable area, but land price and soil quality have no significant influence on the probability. Secondly, 1 hm2 agricultural land’s converting to industrial land raises the probability of agricultural land by 0.39%, 0.39% and 0.14% in the buffer area of 0-200, 200-400 and 800-1 600 m, respectively; 1 hm2 agricultural land’s converting to commercial and residential land increases the probability of land conversion by 0.08% in the 800-1 600 m extent. Therefore, the externalities of agricultural land conversion to industrial land are respectively 0.91×104, 0.91×104, 0.33×104 yuan/hm2 in 0-200, 200-400 and 800-1 600 m extend, externalities of agricultural land conversion to commercial and residential land is 0.18×104 yuan/hm2 in 800-1 600 m extent. Since the externality amount is relatively small, incentive of cluster effect is not enough in Jinghai District of Tianjin.
  • Resource Economics
    Impact Factors of Supervision and Maintenance Performance of Rural Land Consolidation: A Theoretical and Empirical Study Based on Transaction Cost Theory
    ZHAO Wei, YANG Gang-qiao, LI Jin-yu
    2017, 32(9): 1505-1516. https://doi.org/10.11849/zrzyxb.20160839
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    Rural land consolidation is typically conducted as a consecutive sequence: decision-making, planning and budgeting, constructing, and then followed by supervision and maintenance. The behavior of Supervision and Maintenance of Rural Land Consolidation (SMRLC) implies the transfer of rights and duties between different subjects of responsibility, while the aim of SMRLC is to sustain regular operation of infrastructure and equipment provided by rural land consolidation and coordinate interrelationship between human being and land resources. The performance study of SMRLC is vitally important to solve the current predicament of lower efficiency or even deficiency of supervision and maintenance. First, index system and assessment method for SMRLC performance are proposed. Performance indices are set from the stakeholders’ viewpoint and weights are gained from AHP method after consulting 12 scholars throughout China. Second, the kernel concept of transaction is introduced to describe the behavior of SMRLC. Therefore, based on transaction cost theory, Williams’ analysis framework is employed to explain the impact mechanism of the performance of SMRLC. The empirical study is carried out in Dengzhou, Henan and Longzhou, Guangxi, and instrumental variable method is applied to solve the endogenous explanatory variable. Both Ordinary Least Square (OLS) and Instrumental Variable (IV) regression results show that the most significant factors are specificity of material asset, specificity of labor asset, transaction uncertainty and transaction frequency. The resutls validate Williams’ analysis framework for transaction cost and thereby it is highly suggested that management agency should pay close attention to the production level of cultivated land, the involvement of village leaders, and the staffs for supervision and maintenance.
  • Resource Economics
    Research on Decoupling Relationship between Agricultural Chemical Inputs and Agricultural Economic Growth: Based on the Data of Six Provinces and One City in East China
    YNAG Jian-hui
    2017, 32(9): 1517-1527. https://doi.org/10.11849/zrzyxb.20160841
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    This paper selects agricultural chemicals and economic data of six provinces and one city in East China from 2001-2014 and analyzes Tapio decoupling relationship between agricultural chemistry and agricultural economic growth in the context of agricultural non-point source pollution control. The paper decomposes the factors of the agriculture chemical input with LMDI decomposition and then clusters agricultural chemical efficiency of provinces in East China by K-means. The results show that with the growth of agricultural output, the agrochemical inputs amount of six provinces and one city in East China showed a trend of “first increase and then decrease” during 2001-2014. Under the background of agricultural non-point source pollution control, the relationship between agricultural chemistry and agricultural economic growth presents absolute decoupling relationship. Agricultural economic growth and environmental resource protection can be developed coordinately, and the agricultural non-point source pollution control policy can be sustainably implemented based on the adjustment of agricultural chemical participation. The increase of agricultural chemical inputs is mainly caused by the land effect. The efficiency effect can slow down the growth of agricultural chemical inputs. The increase of agricultural output value of per unit, which depends on the agricultural chemicals production, is the driving force of the rapid increase of agricultural chemical inputs, and the progress of science and technology of agricultural chemicals production can reduce the amount of agricultural chemical inputs and ensure agricultural output value per unit area. There is great spatial difference in the dependence of the agricultural economy growth on agricultural chemicals. The dependence of agricultural economy growth on agricultural chemical is higher in Anhui Province. In short, agricultural economic can grow sustainably if agricultural non-point source pollution is controlled. To control agricultural chemicals, we need to improve the utilization rate of agricultural chemistry, use a variety of agricultural efficiency means and take the regional differences in consideration.
    • Resource Evaluation
  • Resource Evaluation
    Simulation of Industrial Carbon Emissions and Its Reduction in China Based on Input-output Model
    ZHAO Qiao-zhi, YAN Qing-you
    2017, 32(9): 1528-1541. https://doi.org/10.11849/zrzyxb.20160875
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    Scientifically measuring carbon emissions and evaluate mutually flow characteristics among industries will supply strong evidence for making different reduction measures for industrial sectors in China. This paper utilized adjusted input-output model to measure the direct intensity, indirect intensity and mutually flow properties of carbon emission among 30 industrial sectors. Possible reduction effects in 2017 were forecast. Results were as follows: 1) Carbon emission flows widely spread among sectors. The indirect carbon intensity of 24 industries was significantly higher than the direct intensity. Among 30 sectors, 12 sectors are whole-process high carbon industries, 1 sector is apparent-high carbon industries, 11 sectors are transmission-type high carbon industries and 6 sectors are low carbon industries. 2) The key sectors in carbon flow network are coal mining, chemical products manufacturing, petroleum and natural gas mining, smelting and pressing of metals, power production and supply industry, transportation, storage and post. They located in the center of the carbon flow network. 3) Change in relations among sectors reduced carbon emission by 12.43%. The growth of ultimate demands caused 70%-90% amount of increase of carbon emission. If the emission coefficient decreases by 10% in 2017, the carbon emission can be reduced by 8.76%, and if it decreases by 15%, the carbon emission can be reduced by 13.14%. Reduction measures controlled by industry emission reduction target did not have good effects. If the policy becomes stricter, the effect should be improved. When government makes industrial reduction plans, whole-process high carbon emission sectors and key sectors on the flow network should be paid more attention and should be strictly controlled to realize the 2020 and 2030 carbon reduction targets.
  • Resource Evaluation
    Spatio-temporal Variation of Soil Salinity in Wastelands inside and outside of Oasis in Manas River Watershed in the Context of Dripping Irrigation
    LÜ Na-na, LUO Ge-ping, DING Jian-li, LI Jian-jun, LIU Li-juan
    2017, 32(9): 1542-1553. https://doi.org/10.11849/zrzyxb.20160801
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    Studies on soil salinization of inland river watershed in arid area have focused on the cultivated land in oases, but the studies on the salinization of wastelands inside and outside of an oasis are poor. We employed GIS technology and mathematical statistics to investigate the general spatial and temporal variation of soil salinity at the depth of 0-30, 30-60, 60-100 cm of wastelands inside and outside of the south, middle and north parts of an oasis in the Manas River watershed under the background of dripping irrigation between 2006 and 2012. The contents of soil salinity, anions and cations except for Na+ and K+ at the soil depths of 100 cm in wastelands inside and outside of oasis in 2012 were all less than those in 2006. The dominant salt type transformed from Na2SO4 to NaCl during 2006-2012. The contents of soil salinity, anions and cations except Na+ and K+ did not show significant spatial differences in 2006. Whereas, the contents of soil salinity and ions except for Na+, K+ and CO32- in 2012 showed significant spatial difference, being higher in the middle part than in the south and north parts of the oasis. The utilization of groundwater and the pattern of irrigation system were the dominant factors resulting in spatial and temporal variation of soil salinity in the wastelands within and outside the oasis. The analysis of spatial and temporal variation of soil salinity in the wastelands inside and outside of oasis in the Manas River watershed would enrich the understanding of salinization and contribute to the reasonable development and utilization of land and water resources in oasis of arid watershed.
  • Resource Evaluation
    Spatial-temporal Pattern of Urban-rural Construction Land Transition in Shandong Province
    XU Feng-jiao, LÜ Xiao, CHEN Chang-ling
    2017, 32(9): 1554-1567. https://doi.org/10.11849/zrzyxb.20160842
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    Urban-rural construction land transition (URCLT) refers to the transformation process of urban-rural construction land use driven by the economic and social development in a region during a certain period of time, including urban-rural construction land structural transition, urban-rural construction land efficiency transition and urban-rural construction land function transition. This paper builds index system of URCLT and analyzes the spatio-temporal pattern of URCLT of 17 cities in Shandong Province during 2005-2014 using principal components analysis, Delphi method and spatial analysis method. Principal components analysis and Delphi method are used to obtain the weights of the indices and then the values of URCLT of 17 cities are calculated. Based on these values, spatial-temporal pattern of URCLT in Shandong Province is analyzed. Results show that: 1) The composite index of URCLT and each dimension of the transition have a certain degree of improvement in Shandong Province, in which the urban-rural construction land function transition has the great influence on URCLT. The city with the most URCLT is Heze, which has the change rate of 76.1%. However, the change rate of each dimension during 2005-2014 suggests that Binzhou has the biggest change in structural transition with the change rate of 79.5% and Zibo has the minimum change in structural transition with the change rate of -12.2%; Heze has the maximum change in efficiency transition with the change rate of 146.3%, and Binzhou has the minimum change in efficiency transition with the change rate of 36.3%. The city which has the biggest raise of function transition is Binzhou that the rate is 81.9%, and Dezhou has the minimum change of function transition with the rate of 39.0%. 2) Annual changes of the absolute difference and the relative difference of URCLT between 17cities are obvious; the spatial agglomeration of URCLT in Shandong Province is weak, and there is no obvious polarization of regional URCLT, except that the structural transition of urban-rural construction land has obvious spatial difference. The coefficient of structural transition, efficiency transition and function transition are 0.128, 0.081, and 0.044 in 2005, 0.134, 0.061 and 0.019 in 2009, 0.041, 0.053 and 0.044 in 2014, respectively. The spatial differences of structural transition, efficiency transition and function transition decrease in turn in 2005; the spatial difference of structural transition is the biggest and the spatial difference of function transition is the smallest in 2009; the degree of spatial difference of efficiency transition is the biggest and the spatial difference of structural transition is the smallest in 2014. 3) In the future, we should pay attention to URCLT’s role in protecting and treating environment and improving the life quality of residents as well as URCLT’s economic function. Also, regulation and intervention in the regional difference of URCLT are necessary.
  • Resource Evaluation
    Streamflow Reconstruction Based on Tree Ring in the Source Region of Yellow River Region over the Past 390 Years
    XIAO Ding-mu, HUANG Xiao-mei, QIN Ning-sheng
    2017, 32(9): 1568-1578. https://doi.org/10.11849/zrzyxb.20160884
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    The source region of the Yellow River in the hinterlands of the Tibetan Plateau is the principal headstream of the Yellow River. The ecological environment has deteriorated in recent decades and climate change influences have been observed in the area. Changes in the ecological environment mainly include substantial streamflow reduction, wetland destruction and severe droughts. Therefore, research regarding water resources including river formation and evolution in this area is needed for the preservation of the ecological environment and water supply. It is important to develop new tree-ring chronologies in the source region of the Yellow River in order to recognize streamflow variation in the past. A regional tree-ring width chronology (RC) was developed based on Sabina przewalskii Kom samples at two individual sites in the source region of the Yellow River. Tree-ring samples were prepared, cross-dated and measured following conventional procedures. Statistical analysis showed that the regional tree-ring chronology (RC) was highly correlated (r=0.73) with instrumental streamflow records from January to July at the hydrological stations. Based on the analyses, we reconstructed streamflow records from January to July during 1624-2013. The reconstruction captured 53.6% of the instrumental streamflow variance. In the past 390 years, we identified seven relatively high streamflow periods (1632-1643, 1657-1695, 1751-1764, 1798-1813, 1836-1856, 1886-1914 and 1934-1947) and ten relatively low streamflow periods (1644-1656, 1696-1706, 1708-1720, 1727-1750, 1787-1797, 1814-1835, 1857-1885, 1915-1933, 1952-1968 and 1993-2006). The longest high period is 1657-1695 (39 years), and the longest low period is 1857-1885 (29 years). The MTM analysis suggested the existence of significant change circles with intervals of 42, 18 and 2-4 years. The reconstruction was validated by comparison it with other reconstructions in the surrounding area. The streamflow reconstruction significantly correlates with the constructions in Tongtian River (r=0.51, P<0.001) and the upper Yellow River (r=0.60, P<0.001). Also, the streamflow reconstruction significantly correlates with the precipitation reconstructions in Delingha region (r=0.55, P<0.001) and the southern Tibetan Plateau (r=0.46, P<0.001). These three areas shared the same drought periods (1650s-1670s, 1780s-1800s, 1820s-1830s, and 1920s-1930s) and wet periods (1840s-1850s, and 1880s-1910s). The consistency and correlation of constructions in these regions proved the accuracy of the reconstruction sequence in this article.
  • Resource Evaluation
    Characteristics of Surface Humidity and Extreme Drought/Wet Events in Yangtze River Delta
    XU Yu, WU Yan-fei, XU Gang, LIU Min
    2017, 32(9): 1579-1590. https://doi.org/10.11849/zrzyxb.20160874
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    Based on the Penman-Monteith Model and the daily meteorological data of precipitation, temperature, wind speed, sunshine duration and relative air humidity at 43 stations in Yangtze River Delta from 1957 to 2014, reference crop evapotranspiration, surface humidity index and extreme drought/wet events were detected and counted. The spatial and temporal variation of humidity index and extreme drought/wet events were analyzed using linear regression, TFPW-MK trend test and Morlet wavelet. The results indicated: 1) Annual and seasonal mean humidity indexes showed similar distribution patterns in recent 58 year in Yangtze River Delta except in summer that higher values distributed in the south and lower values distributed in the north, which were mainly influenced by latitude, distance from the sea, topographic conditions, and general atmospheric circulation. In summer, the low values of relative humidity index emerged along the axis of “North-central of Anhui-South-central of Jiangsu-North of Zhejiang-Shanghai”. 2) The climate showed the tendency of turning arid that the annual humidity index decreased at the rate of -0.021/10 a. 1980s and 1990s are humid period. The sudden change of annual relative humidity occurred in 2003 according to TFPW-MK abrupt change test, and there were several oscillation periods of annual relative humidity according to wavelet analysis, such as 12-18-year period from 1957 to 1990, 8-10-year period since 1977. At seasonal scale, the climate in spring and autumn turned dry and the climate in winter and summer turned humid. The mutational years of spring, autumn and winter were 1999, 1988 and 1985 respectively. Moreover, there were also several oscillation periods at seasonal scale. The change characteristics were mainly influenced by the variation of precipitation, evapotranspiration, Southern Oscillation and subtropical high over the western Pacific. Spatially, the aridification mainly happened in southeast, east and part of the west regions, while the humidification mainly emerged in the north-central and southwest regions. The variation coefficient of annual relative humidity had the spatial pattern that high values occurred in the northwest and low values occurred in the southeast. 3) The frequency of annual extreme drought events showed upward trend with the rate of 0.121/10 a, and the frequency of annual extreme wet events showed downward trend with the rate of -0.052/10 a. Spatially, the frequency of annual extreme drought events increased in the west and southeast of Anhui, south central of Jiangsu and most parts of Zhejiang, while it decreased in north and east of Anhui, northwest of Jiangsu, and northeast of Zhejiang. The frequency of annual extreme wet events presented the opposite spatial patterns with the frequency of annual extreme drought events, i.e. the frequency of annual extreme wet events increased in northwest region and decreased in southeast region.
  • Resource Evaluation
    Effects of Urbanization on Precipitation Characteristics
    CHEN Xiu-hong, LIU Bing-jun, CHEN Gang
    2017, 32(9): 1591-1601. https://doi.org/10.11849/zrzyxb.20160868
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    With the process of urbanization, the changes of surface types and atmospheric layer have affected precipitation in urban areas. Based on the remote sensing data of the year 1980, 1990, 2000 and 2010, the urbanization process of Guangzhou was analyzed. The possible effects of urbanization on precipitation were further investigated using the hourly precipitation data in flood seasons of 1984-2015. Results show that: 1) The urban land has expanded at the rate of 20.3 km2/a since 2000, which suggests Guangzhou is in the period of rapid urbanization. 2) Compare with that in slow urban expanding period, the diurnal variation of short term precipitation in rapidly urban expanding period changed greatly, that the frequency of short-term rainfall events with 1-3 h duration in the afternoon increased by 4.1% and the frequency of rainfall events with 4-6 h duration in night increase by 5.2%. 3) In rapidly urban expanding period, the precipitation intensity in the city strengthened that the average precipitation intensities of rainfall events with 1-3 h and 4-6 h duration improved 7.4% and 10.9% respectively and the percentages of extreme hourly precipitation improved 2.4% and 4.4% respectively. 4) The rainfall pattern of precipitation events with 4-6 h duration evidently changed in rapidly expanding period that the annual mean frequencies of rainfalls with unimodal peak and rainfalls with early or middle peaks increase by 29.1% and 41.9%, respectively.
  • Resource Evaluation
    A Survey on the Spatial Distribution and Community Types of Mangroves in Guangxi Based on High-resolution Satellite Imageries
    TAO Yan-cheng, GE Wen-biao, LIU Wen-ai, PAN Liang-hao, QIU Guang-long, WANG Xin, FAN Hang-qing
    2017, 32(9): 1602-1614. https://doi.org/10.11849/zrzyxb.20160803
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    Based on the data of multi-source high-resolution satellite imageries, the spatial distribution and the community types of mangroves along the coast in Guangxi were studied using the methods image processing, geographic information systems (GIS), global positioning system (GPS) technology and field investigations. The results showed that there were 7 243.15 hm2 of mangroves in Guangxi in 2013. Totally, 2 793 mangrove patches were found, with the average patch-area of 2.59 hm2. The area of the largest mangrove patch in Guangxi was 173.67 hm2. The total area and the number of patches of mangrove in Beihai city were 3 263.66 hm2 and 905 respectively, accounting for 45.06% of mangroves in Guangxi. There were 2 097.41 hm2 in Qinzhou city, which had 1 259 patches and accounted for 28.96% of mangroves in Guangxi. Fangchenggang city had the smallest area of mangroves among the three coastal cities in Guangxi, with 1 882.08 hm2 in area, 629 patches which accounting for 25.98% of mangroves in Guangxi. Twenty-one types of mangrove communities in Guangxi were identified, including Community Avicennia marina, Community Avicennia marina+Aegiceras corniculatum, Community Aegiceras corniculatum, Community Aegiceras corniculatum+Avicennia marina, and Community Bruguiera gymnoihiza -Avicennia marina, etc. Among them, Community Avicenniat marina (3 022.96 hm2, 41.74%), Community Aegiceras corniculatum (2 383.81 hm2, 32.91%), Community Avicennia marina+Aegiceras corniculatum (405.42 hm2, 5.60%), Community Bruguiera gymnoihiza -Avicennia marina (303.93 hm2, 4.20%), Community Rhizophora stylosa -Avicennia marina (214.43 hm2, 2.96%), Sonneratia apetala -Aegiceras corniculatum (138.46 hm2, 1.91%), Community Bruguiera gymnoihiza -Aegiceras corniculatum (128.40 hm2, 1.77%) were the most dominant mangrove communities. The mangrove area in this study did not consist with the results of other studies, which can be attributed to different research methods and different image data sources.
    • Resource Research Method
  • Resource Research Method
    Comparison and Selection of Land Consolidation Planning Schemes Based on AHP-DEA Model
    CHENG Wen-shi, QIAO Hong-qiang, LIU Xue-lu, HUANG Xin
    2017, 32(9): 1615-1626. https://doi.org/10.11849/zrzyxb.20160838
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    To promote the comprehensive land consolidation results of specific land consolidation project, the key is to design different schemes and select the best one. In this paper, the project of land consolidation for Shuangtong Village in Qingyang city of Gansu Province, China, was chosen as an example. Four schemas were designed for the land consolidation project for different perspectives: schema equally emphasizing on ecology and economy, schema dominated by economic benefits, schema matched with infrastructure and schema guaranteeing people’s livelihood. Two indicators, total investment and labor input, were chosen according to the items, the investment level and efficiency measurement of the project. Another five indicators were chosen according to yield to set up indicator system, which are the yield added value per unit area, the static return on investment return, the rate of increased farmland, the increment of annual net income per capita and the increment of vegetation coverage. With the two groups of indicators, a DEA model with AHP constraint cone was created and then the four schemes were compared. The values of the four schemes from No. 1 to No. 4 were as follows: 1.000 0, 0.864 5, 0.652 7, 0.963 8, suggesting the first scheme (the schema equally emphasizing on ecology and economy) was the best one, followed by the fourth scheme (the schema guaranteeing people’s livelihood), then the second scheme（dominated by economic benefits）and finally the third scheme (schema matched with infrastructure). The study showed that the DEA model could combine the traditional objective analysis of input and output data with the subjective preference of decision-maker and adopt the advantages of AHP and DEA could produce more objective and accurate evaluation results than that only by AHP or DEA. The study also demonstrated that both ecological and economic benefits should be considered to promote the result of land consolidation. People’s wish to improve livelihood should also be considered when designing land project scheme. The study provided scientific methods for comparing and selecting the design scheme of land consolidation project, put forward suggestion for the main perspective of designing land consolidation plans, and provided preference for reasonable evaluation and conduction of land consolidation.
  • Resource Research Method
    Forecasting the Promotion Potential of Grain Yield per Unit in Mid-long Term with a Decay Model:A Case Study in Henan Province
    ZHU Jia-wei, ZHOU Lin-lin, XIE Xiao-tong
    2017, 32(9): 1627-1638. https://doi.org/10.11849/zrzyxb.20160824
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    The increase of grain output mainly depends on the improvement of grain per unit yield. To scientifically determine grain production capacity in the future and make food production strategy, it has great significance to accurately forecast the grain yield per unit. At present, the prediction models based on grain yield per unit could not reflect the limited growth and the slowing down of growth rate well. Therefore, a new prediction method of grain yield per unit based on the decaying of the promotion potential is proposed and its application in Henan Province is carried out in this paper. With this method, the promotion potential of grain yield per unit can be calculated with the average potential yield and the actual yield in past years. Due to the year-by-year decrease of the promotion potential of yield per unit, a model of promotion potential for grain yield can be established and the grain yield can be predicted with an exponential decay function. The results are as follows: 1) There is a linear decrease of the logarithm of the promotion potential of grain yield per unit during 1978-2015, and an exponential regression model can be established. 2) The regression model, Vq-Vt=e-0.009 5t+9.464 7, is significant at the confidence level of 0.01. 3) The model has a clear theoretical meaning which shows the finite and the attenuation of the yield potential, that is, the limitation to the yield per unit caused by the promotion potential. 4) To test the model’s accuracy, the grain yields per unit in Henan during 1978-2000 are taken as samples to forecast the grain yields during 2001-2015, and the actual grain yields during 2001-2015 are used to test the predicated results. The result shows the average absolute error of predication is 129.15 kg/hm2, which is 0.17-0.82 times of the errors of other methods. So it is more precise. Furthermore, the error of this method is more stable than errors of other models, so this new method is more suitable to forecast grain yield per unit in mid-long term. 5) The forecasted grain yields per unit in 2015, 2020, 2030 in Henan are 6 375, 6 765 and 7 155 kg/hm2, respectively, and the annual increase is 85.20-74.55 kg/hm2 during 2016-2030 with decreasing increment rate.