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  • 2012 Volume 31 Issue 1
    Published: 25 January 2012
      
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  • Recent Progresses on the Application and Improvement of the CLUE-S Model
    WU Jiansheng, FENG Zhe, GAO Yang, HUANG Xiulan, LIU Hongmeng, HUANG Li
    2012, (1): 3-10. https://doi.org/10.11820/dlkxjz.2012.01.001
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    Land use change is one of the main research subjects of global environmental change and sustainable development. Land use models are useful for disentangling the complex suite of socio-economic and biophysical forces that influence the rate and spatial pattern of land use change and for estimating the impacts of changes on land use. Furthermore, models can support the exploration of future land use change under different scenarios and conditions. The CLUE-S (Conversion of Land Use and its Effects at Small Region Extent) model, which is based on comprehensive consideration on the basis of natural and human factors, can simulate small-scaled land use change scenarios with characteristics of integrity, openness, spatiality and competitive efficiency. This paper introduce the CLUE-S model improvements in the fields of the selection of driving factors, land requirements calculation, accuracy of the model calculation and model application development. Setting up the relationship between driving forces and spatial distribution is the core of CLUE-S model. Some suggestions for improving CLUE-S have also been put forward. Finally, we an draw three conclusions. First, CLUE-S is a mature integrated model for simulating the land use change. Using the spatial and non-spatial analysis, this model has been well developed and widely used in several areas in different land use fields all over the world. Second, coupled with other economic, statistic and mathematic models, the CLUE-S model has significant advantages in evaluating the land use change effects. Third, in the future, the improved prediction accuracy and the expansion of model application will probably better serve the objective of the understanding of land use change processes.
  • Overview of Researches Based on DMSP/OLS Nighttime Light Data
    WANG Herao, ZHENG Xinqi, YUAN Tao
    2012, (1): 11-18. https://doi.org/10.11820/dlkxjz.2012.01.002
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    The stable lighttime data, the radiance-calibrated nighttime light intensity data and the non radiance- calibrated nighttime light intensity data are the three major products that have emerged in the field of the DMSP/OLS nighttime light data. It has several advantages, namely, easy acquisition of data, detection of low-intensity lights, unaffected by shadows, convenient provision of conditions for urbanization strength and its spatial- temporal difference analysis, and so on. At present, there are many research results on DMSP/OLS data, which mainly focus on city development, human activity and effect, eco-environment impact, but there are few studies on systematic results. This paper analyzed the existing researches on DMSP/OLS data, summarized and drew some conclusions based on the existing research results, the technical methods and the advantages and disadvantages of the methods, as well as explored the application prospect of DMSP/OLS nighttime light average intensity data. It predicted the future research trends of the data: (1) an in-depth study on processing methods of the data; (2) further expansion of data application; (3) the integrated study on DMSP/OLS data and other data models need to be deepened; (4) combine the existing research results, make further research on mechanism issues of geography phenomenon.
  • Land Use in Green Belts in the United Kingdom and Its Implications for China: A Case Study of Spelthorne Borough in the Suburbs of London
    TAN Minghong, LI Xiubin, XIN Liangjie, CHEN Yuqi, ZHANG Leina
    2012, (1): 20-25. https://doi.org/10.11820/dlkxjz.2012.01.003
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    The policy of Green Belts is regarded as a core element of England plans, which holds an important position in the system of town and country planning in the United Kingdom. The policy plays a key role in controlling urban expansion and protecting the countryside landscape. Land use is one of key contents of the policy of Green Belts. This article firstly introduces the functions and the extent of Green Belts. Then, the planning system of the United Kingdom is explained, among which local plan plays a very important role in land use and the protection of Green Belts. So, taking Spelthorne borough as an example that neighbours the Greater London, this paper examines the land use of Green Belts from four aspects: the selection of housing sites, the coordination of construction activities, the countryside environment and the land use in rural areas. Lastly, the implications derived from the Green Belts land use in the United Kingdom are discussed, which may be helpful for land use of metropolitan areas in China.
  • Characteristics of Interconnected Rivers System and Its Ecological Effects on Water Environment
    XIA Jun, GAO Yang, ZUO Qiting, LIU Xiaojie, CHEN Qingmei, DOU Ming
    2012, (1): 26-31. https://doi.org/10.11820/dlkxjz.2012.01.004
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    As there is a trend of deterioration of the water resource and environmental quality in China, the interconnected rivers system, which is an important target for river health and enhancing water resource utilization, was emphasized by National 12th Five-year Plan (2011-2015). Currently, we are lack of knowledge in characteristics on drainage connectivity and river health. Thus, the aim of this paper is to clarify the definition of interconnected rivers system, classification, evaluation indicators, impact factors and the effects on water environment health. The interconnected rivers system can improve wetland ecological environment, maintain biodiversity, and safeguard flood control security and sustainable utilization of water resources. However, interconnected rivers system has eclogical and environmental adventure, including: (1) because of interconnected rivers, the water quality, wherein original river is good, will be worse due to mixing with poor water quality; (2) interconnected rivers will increase the competition of fish and other species in the rivers; (3) through interconnected rivers system, the rivers and lakes which have plenty of rainwater supplement those lack of rainwater, which will greatly reduce the effective water resource; (4) reducing runoff from the rivers and lakes which are plenty of rainwater will result in reducing evaporation in the area of the land surface and the water cycle, and then, lead to climate change in the region; (5) the connectivity of upstream and downstream will result in dramatic increase in sand and sediment in downstream rivers.
  • Wavelet Analysis of Rainfall Variations in Maigang Reservoir Catchment, Guizhou Province
    LI Chunmei, LI Shuangcheng, WANG Hongya
    2012, (1): 32-39. https://doi.org/10.11820/dlkxjz.2012.01.005
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    Maigang Reservoir catchment is located in Ziyun County of Guizhou Province, Southwest China. It has sub-tropical monsoon humid climate and is a carbonate-rock-dominated catchment of 7.5 km2. The environment here is very fragile, accompanied with serious problems, such as soil erosion, and rockification. Precipitation influences the environment to a great extent. So it is important to analyze the precipitation changes. Wavelet analysis is evolved from Fourier analysis, and it is usually used in multiple-scale analysis of the earth surface process, such as precipitation, runoff and temperature time series. It is an alternative and effective approach to analyze climate change at multi-time scales and forecast short-time climate variations. Based on the principle of wavelet analysis, the Mexican hat wavelet was chosen as the mother wavelet for continuous wavelet analysis in this paper: the multi-time scales characteristics of seasonal and annual precipitation in the past 48 years (1960-2007) of Maigang reservoir catchment were analyzed based on the monthly and annual precipitation from 1960 to 2007 by using Mexican Hat wavelet analysis. The periodic oscillation of precipitation variations and the points of abrupt changes of different time scales in the precipitation series of different seasons and years were discovered. The conclusions can be shown as follows. (1) The periodic oscillations of the spring precipitation were 8 years and 2 years. (2) There were periodic oscillations of 8 years and 1 year for both summer and annual precipitation. (3) The periodic oscillations of the autumn precipitation were 16 years and 1 year. (4) There were periodic oscillations of 3 years and 8 years for the winter precipitation. (5) Both the summer and annual precipitation had the periodic oscillations of 1 year and 8 years, and had the same trends of precipitation changes. The summer precipitation obviously influenced the annual precipitation.
  • A Study on Variations and Comprehensive Zoning of Climate Comfort Degree in Anhui Province in the Past 50 Years
    WANG Sheng, TIAN Hong, XIEWusan, TANGWeian, DING Xia
    2012, (1): 40-45. https://doi.org/10.11820/dlkxjz.2012.01.006
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    Based on data of daily average temperature, average wind velocity and average relative humidity in 70 observatories in Anhui Province from 1961 to 2010, the spatial-temporal distribution of climate comfort degree was calculated by the model of climate comfort degree index. The comprehensive zoning and evaluation was done by using of spatial interpolation techniques of Geographic Information System. The results show that the temporal and spatial distribution of climate comfort degree is significantly different in Anhui. The climatic condition is relatively comfortable from April to October in general, yet uncomfortable in wintertime mainly from November to next March; the climate comfort degree in the southern part of the region is better than in the northern part. Since the 1960s, the annual climate comfortable days have obviously increased in general under global warming, and the linear increasing trend once mutated around 1986 at 95% level; however, the annual climate uncomfortable days have obviously decreased, and the linear decreasing trend mutated around 1997 at 95% level. Comprehensive zoning shows that the best comfortable climate regions are mainly located in the southern part of Jiangnan and areas along the Yangtze River; while the northeast of Huaibei Region, Dabie Mountains and mountainous areas of South Anhui are the most uncomfortable areas in terms climate.
  • Changes of Intensity and Frequency of Typhoon Heavy Rainfall Events in Eastern Taiwan during 1960-2009
    CHANG Poyu
    2012, (1): 46-55. https://doi.org/10.11820/dlkxjz.2012.01.007
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    In this study, the typhoon rainfall data of Ilan, Hualian, Chengkung, Taitung, Dawu and Lanyu weather stations located in eastern Taiwan during 1960-2009 are concerned. With the criteria of the issuing of typhoon warnings and 24-hours maximum rainfall above 50 mm, typhoon-induced heavy rainfall events were identified. Trend change and periodic change in the series of 24-hours maximum rainfall are taken as the intensity indicator and the annual number of heavy rainfall events was examined by using some nonparametric statistical methods. The results of data collation show that the number of target events ranges from 117 to 151 stations within the target period of study. Station-based analysis demonstrated that no significant change was found in the intensity series of typhoon heavy rainfall events in the study area. In contrast, there is a periodic increase in frequency of typhoon- induced heavy rainfall events. This change also implies that potential of hydrological and geological hazards will become higher. It is required that all these hazards be taken notice of in the future for disasters prevention.
  • Comparative Analysis of Three Covariates Methods in Thin-Plate Smoothing Splines for Interpolating Precipitation
    LIU Zhengjia, YU Xingxiu, WANG Sisi, SHANG Guiduo
    2012, (1): 56-62. https://doi.org/10.11820/dlkxjz.2012.01.008
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    In the thin-plate smoothing splines interpolation, the accuracy of interpolation results is mainly determined by choosing the independent covariate. Annual precipitation data were extracted by using daily precipitation data of 728 meteorological stations from 2001 to 2009 in China. We evaluated spatial correlation relationships between annual precipitation and two covariates such as DEM and distance from the coastline to each point (DCL) and compared the accuracy difference of precipitation interpolation results from different covariates in the national scale and regional scale. All interpolation work has been conducted with the aid of the software of ANUSPLIN. We used three interpolation methods, which respectively considered DEM, DCL and DEM-DCL as the covariates to obtain spatial distribution of precipitation. Our analyses show that, (1) in the national scale, the mean absolute error (MAE) of interpolation method of DEM is 47.79, which is slightly lower than that of the method of DEM-DCL (48.90), while obviously lower than that of the method of DCL (55.54), and MRE and RMSE of the method of DEM were also lower than other two methods significantly. (2) In regional scale, the errors of three methods of interpolation are the same as that in national scale except Tibet. The accuracy of precipitation interpolation results was the highest using DCL method, and the poorest using DEM method. Results suggest that precipitation interpolation method of DEM could be widely used in some relevant national scale researches, and precipitation interpolation method of DCL was strongly recommended in Tibet.
  • Comparative Studies on Degree of Adaption of Wheat under Climate Change between Areas South and North of Huaihe River in Henan Province
    SU Kunhui, YAN Junping, BAI Jing, ZHANG Liwei, WANG Xiaozhe, LI Jianshan, TIAN Qingxia
    2012, (1): 63-71. https://doi.org/10.11820/dlkxjz.2012.01.009
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    Degree of adaption is one of the key components of adaptability processes under climate change. In this paper, we established the concepts and methods of degree of adaption (DA) in order to comparably analyze the DA of wheat in area south and north of the Huaihe River in Henan Province. Results demonstrate that the climate dividing line is not the mainstream areas of Huaihe River, but the largest tributary of the area is located in were the further north, about 300 km away from the original zone. And the spatial variation of DA of winter wheat is approximately distributed around this area. The DA of the area, which is to the south of the dividing line of the Huaihe River, is 62.57%, which is higher than 56.81% in the northern area. Therefore there is still a large space which requires the human regulation and control to adapt the wheat to the climate change. And the pressure on human control in the northern area is greater than in the southern. As regards to the annual change, accompanied by the abrupt climate change in the 1980s, the temperature DA surged but the moisture DA plunged. In the following periods when the climate became stable, DA kept an increasing tendency. However the increasing speed of DA declined in the early 21st century when a plunge trend appeared, indicating that the negative impact on wheat from global warming has become increasingly prominent.
  • Climate Significance of Tree Ring Width of Huangshan Pine and Chinese Pine in the Dabie Mountains
    ZHENG Yonghong, ZHANG Yong, SHAO Xuemei, YIN Zhiyong, ZHANG Jin
    2012, (1): 72-77. https://doi.org/10.11820/dlkxjz.2012.01.010
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    Two well-replicated tree-ring width chronologies more than 100 years were developed by using the tree ring cores of Huangshan Pine (Pinus Taiwanese’s Hayata) and Chinese Pine (Pinus tabulaeformis Carr.) sampled in 2010 for the Dabie Mountains. The Huangshan Pine chronology covers the period 1869-2009 and the Chinese Pine chronology from 1883 to 2009. To explore the climate significance of tree ring width of Huangshan Pine and Chinese Pine in the study of dendroclimate, correlation analyses were conducted between the two chronologies and four climate variables at Macheng meteorological station. These climate variables include monthly mean maximum temperature, monthly mean temperature, monthly mean minimum temperature and monthly precipitation, all of which cover the period from 1959 to 2009. The results showed that the Huangshan Pine chronology was characterized by a higher mean sensitivity, standard deviation and signal to noise ratio than the Chinese Pine chronology, which might means that Huangshan Pine has more climate signals and higher value than Chinese Pine in the study of dendroclimate. The results of correlation analysis showed that the radial growth of Huangshan Pine was closely related to the February-July mean temperature, while there was no significant correlation with precipitation in any month or season. In contrast, the radial growth of Chinese Pine was mainly influenced by the total precipitation in the period from May to June, while there was no significant correlation with temperature in any month or season. The radial growth of Huangshan Pine and Chinese Pine shows different responses to climate variables. One reason may be that they are different species, and the other reason may be that they were sampled at different altitudes. Different from the earlier concept, this study showed that the inter-annual changes of climate variables also have a strong restrictive effect on the radial growth of some tree species in warm and humid areas in subtropical China, which showed that the change of tree ring width can be a well indicator for climate change in these areas. The results not only can further supplement the study of tree-ring width chronologies, but also can provide reference for the study of dendroclimate reconstruction in warm and humid areas in subtropical China.
  • Demands and Key Scientific Issues in the Synthesis Research on Regional Terrestrial Ecosystem Carbon Budget in China
    WANG Qiufeng, LIU Yinghui, HE Nianpeng, FANG Huajun, FU Yuling, YU Guirui
    2012, (1): 78-87. https://doi.org/10.11820/dlkxjz.2012.01.011
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    Process mechanisms of carbon budget and carbon cycle in terrestrial ecosystems are the research hotspots in analyzing the causes of global climate change, forecasting the climate change trend, and making mitigation and adaptation countermeasures, which have attracted broad attention from the scientific community and international community. In this paper, we review the history of the research on the carbon budget and carbon cycle process in Chinese terrestrial ecosystems; summarize the main characteristics of each development stage. Based on the review, we discuss the demands for carrying out the systhesis research on regional terrestrial ecosystem carbon budget in China from the aspects of science and technology and society, bring forward the main existing problems, and explore the key scientific issues in related fields. The paper analyzes the importance for carrying out the synthesis research on regional terrestrial ecosystem carbon budget in China from various aspects such as socio-economic development, ecosystem management, and eco-security as well. Simultaneously, the paper points out that, in China, we are still lack of practical investigation data of carbon budget for various ecosystem types, lack of data integration at national scale, lack of modelling tools that can be used in carbon accounting and assessment, and no information system platform has been developed for national carbon source/ sink accounting, assessment, authorization and decision making. Through the above analysis, we think that, in order to enhance the innovation capacity in the area of ecosystem and global change in China, to provide fundamental theory and advanced technology for national ecosystem and greenhouse gases management, more emphasis should be placed on the following frontier fields, such as the coupling relationships among carbon-nitrogen- water cycles in terrestrial ecosystems and their response and adaptation to global climate change, ecological stoichiometry characteristics of carbon-nitrogen-phosphor and their environmental impact, and the biological regulation mechanisms of the processes of carbon-nitrogen-water coupling cycles as well.
  • Effects of Land Use and Cover Change on Terrestrial Carbon Balance of China
    FU Chao, YU Guirui, FANG Huajun, WANG Qiufeng
    2012, (1): 88-96. https://doi.org/10.11820/dlkxjz.2012.01.012
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    Accurate estimation on the effects of land use and cover change (LUCC) on terrestrial carbon balance has become one of the focuses in the research on the global carbon cycle. This paper attempts to review the studies on LUCC in recent years and its effects on terrestrial carbon balance in China, to provide references for the assessment of China’s terrestrial carbon balance and the choice of future research topics. The extensive information has been obtained from researches on China’s LUCC in recent years, and the corresponding carbon source and sink effects have been assessed by using the inventory method presented by IPCC and the satellite-based method respectively. Results indicate that land use activities, especially those related to agriculture and forest management, are affecting terrestrial carbon balance positively. However, the satellite- and inventory-based estimates indicated significant uncertainty in the estimates. Future researches should focus on the development and application of estimation methods based on the information of land-use conversion areas, to improve the assessment on effects of LUCC on China’s terrestrial carbon balance.
  • Carbon Emission and Spatial Pattern of Soil Respiration of Terrestrial Ecosystems in China: Based on Geostatistic Estimation of Flux Measurement
    ZHAN Xiaoyun, YU Guirui, ZHENG Zemei, WANG Qiufeng
    2012, (1): 97-108. https://doi.org/10.11820/dlkxjz.2012.01.013
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    Soil respiration is a major process of carbon dioxide emission from terrestrial ecosystems to atmosphere. Researches on spatiotemporal patterns of soil respiration could be helpful to the construction of a quantitative evaluation model of soil respiration at regional scale, and also, could improve our predictive ability of carbon balance status under future climate change of typical ecosystems at regional or global scale. This paper integrated the main research results about the soil respiration at regional scale in China, analyzed the statistical characteristics and regional difference of temperature sensitivity and soil respiration, and in addition, the quantitative evaluation on the spatiotemporal distribution and its effects on the carbon balance at China’s even global scale was also given in this paper. The results showed that Q10 of forest ecosystem was the highest, followed by that of farmland ecosystem, and Q10 of grassland ecosystem was lowest, indicating that Q10 was higher while air temperature was lower. Also, Q10 of terrestrial ecosystem in China was lower than that of other countries. Rs displayed a significant seasonal variation. Rs of different ecosystems presented a similar changing trend with Q10. There was seasonal dynamics of monthly Rs along latitude and longitude gradients. Additionally, the seasonal amplitude of Rs increased with increasing longitude. Between 1995 and 2004, the Rs in China, with an average value of 3.84 Pg C·a-1, contributed 4.87% to the global soil CO2 emission.
  • The Changes of Net Primary Productivity in Chinese Terrestrial Ecosystem: Based on Process and Parameter Models
    GAO Yanni, YU Guirui, ZHANG Li, LIU Min, HUANG Mei, WANG Qiufeng
    2012, (1): 109-117. https://doi.org/10.11820/dlkxjz.2012.01.014
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    Net primary productivity (NPP) is a basis of material and energy flows in terrestrial ecosystems, and it is also an important component in the research on carbon cycle and carbon budget. At present, studies on NPP on regional and global scales mainly depend on model simulation, among which process and remote sensing models are widely used. In this paper, we analyzed the published NPP for Chinese terrestrial ecosystem and its response to future climate change which were computed by process and remote sensing models. The results revealed that the averaged NPP in Chinese terrestrial ecosystem was (2.828?0.827) PgC穉-1. Between 1982 and 1998, NPP tended to fluctuate but increased by 0.027 PgC穉-1 with an annual rate of 1.07%. Among different vegetation types, NPP per unit area was the maximum in evergreen broadleaf forests, which varied in a wide range among different researches; the values had a small discrepancy among deciduous needleleaf forests, evergreen needleleaf forests and deciduous broadleaf forests, and the value of croplands was lower than that of broadleaf forests, but higher than that of needleleaf forests; both grasslands and deserts had relatively low values, with the former having a significantly higher value than the latter. Furthermore, the total amount of NPP was the maximum in croplands followed by grasslands. The sum of both accounted for 58.34% of the gross. Except shrublands and evergreen needleleaf forests, all the other vegetation types had less than 10% of the gross. In the future climate scenarios, the NPP of Chinese terrestrial ecosystem might increase firstly, and then decrease.
  • Fluxes of Particulate Carbon from Rivers to the Ocean and Their Changing Tendency in China
    ZHU Xianjin, YU Guirui, GAO Yanni, WANG Qiufeng
    2012, (1): 118-122. https://doi.org/10.11820/dlkxjz.2012.01.015
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    The river is the linkage of terrestrial and ocean carbon pools, the flux of which is a critical component of global carbon cycle. In this paper, The authors analyze the characteristics of the fluxes of particulate carbon from rivers to the ocean (FPC) in China and predicted their tendency based on the data obtained from Bulletin of Chinese River Sediment. The results indicate that, from 1965 to 2005, the annual mean FPC is 29.57TgC yr-1, 36.02% of which is organic carbon, and the rest is inorganic carbon. FPC accounts for 42% of the river carbon fluxes. The quantity of particulate carbon flux from the Yangtze River, the Yellow River and the Pearl River accounts for 96.25% of the total amount in China. There is a decreasing tendency of FPC since 2003, while the ratio of organic part to the total shows an increasing tendency. The FPC of 2009 is only 6.59TgC穣r-1, which is only 22.3% of the annual mean FPC from 1965 to 2005. Therefore, it is necessary to lay emphasis on the fluxes of particulate carbon in terms of its significant role in river carbon fluxes and terrestrial carbon budget.
  • Review on Carbon Budget of the Grassland Ecosystems on the Qinghai-Tibet Plateau
    WANG Junbang, HUANG Mei, LIN Xiaohui
    2012, (1): 123-128. https://doi.org/10.11820/dlkxjz.2012.01.016
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    Terrestrial ecosystem carbon budget is a hot topic in the research on global climate change. The grassland of Qinghai-Tibet Plateau, which is sensitive to climate change, plays an important role in the regional carbon balance. However, there is great uncertainty in the estimation on the spatial-temporal pattern of carbon budget due to different methods and some other reasons. To some extent, climate warming results in the increase of vegetation primary productivity and biomass in the alpine meadow ecosystem, which may compensate the decomposition release of soil organic carbon. Hence, the Qinghai-Tibet Plateau grassland still functions as a carbon sink. The effects of human activities, such as overgrazing, on grassland ecosystems are very complex. Therefore, under the impacts of future climate change and human activities, how to distinguish the influence of climate change from that of human activities on ecosystems, and how to quantitatively assess carbon source / sink pattern, are a very interesting research field, but also a great challenge, especially on the plateau.