Table of Content

    20 May 2013, Volume 68 Issue 5 Previous Issue    Next Issue
    General characteristics of temperature change and centennial warm periods during the past 2000 years
    GE Quansheng, LIU Jian, FANG Xiuqi, YANG Bao, HAO Zhixin, SHAO Xuemei, ZHENG Jingyun
    2013, 68 (5):  579-592.  doi: 10.11821/xb201305001
    Abstract ( 1356 )   PDF (4478KB) ( 1306 )   Save
    The characteristics of warm/cold fluctuation for Northern Hemisphere (NH) and China during the past 2000 years were analyzed using the proxy-based temperature change series published recently. The duration of centennial warm periods before the 20th century and the difference between the warmth of the 20th century and the centennial warm periods that occurred prior to the 20th century were also investigated. The conclusions are summarized as follows: (1) Most of proxy-based NH temperature series show that the warm climate occurred in the periods of AD 1-270, 841-1290 and 1911-2000. In general, it was cool with multi-decadal temperature fluctuations from 271 to 840, and cold from 1291 to 1910. These centennial periods of warm/cold fluctuation over NH are corresponding to the Roman Warm Period (the 1st century BC to the mid-4th century AD), Dark Age Cold Period (the end of 4th century to the early of 10th century AD), Medieval Warm Period (the mid-10th century to the end of 13th century AD), Little Ice Age (the 15th to 19th century) and Warming Period in the 20th century illustrated by Lamb respectively. But they have different durations between the NH centennial warm/cold periods and those Warm/Cold Periods identified by Lamb. (2) The duration and amplitude of regional centennial phases of warm/cold fluctuation are different in China, but the timing of centennial periods of warm/cold over whole China, i.e. warm in AD 1-200, 551-760, 941-1300, 1901-2000 and cold in the others, which are consistent with that observed in NH approximately. (3) Most of proxy-based NH temperature change series show that the warmth in Medieval Warm Period is at least comparable to that during the Warming Period in the 20th century. The warmest 100-year and 30-year (i.e., warm peak duration) for whole China occurred in the periods of 941-1300 during the past 2000 years, which are slightly higher than in the 20th century respectively. Moreover, the temperature anomalies in the warmest 100-year and 30-year for whole China that occurred in the periods of 571-760 and 1-200 are comparable to and a little lower in the 20th century respectively.
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    Changes of spring frost risks during the flowering period of woody plants in temperate monsoon area of China over the past 50 years
    DAI Junhu, WANG Huanjiong, GE Quansheng
    2013, 68 (5):  593-601.  doi: 10.11821/xb201305002
    Abstract ( 916 )   PDF (3122KB) ( 874 )   Save
    The temperate monsoon area of China is an important agricultural region but late spring frosts have frequently caused great damage to plants there. Based on phenological data derived from the Chinese Phenological Observation Network (CPON), corresponding meteorological data from 12 study sites and phenological modeling, changes in flowering times of multiple woody plants and the frequency of frost occurrence were analyzed. Through these analyses, frost risk during the flowering period at each site was estimated. Results of these estimates suggested that first flowering dates (FFD) in the study area advanced significantly from 1963 to 2009 at average rates of-1.52 days decade-1 in Northeast China (P < 0.01) and-2.22 days decade-1 (P < 0.01) in North China. During this same period, the number of frost days in spring decreased and the last frost days (LFD) advanced across the study area. Considering both flowering phenology and occurrence of frost, the frost risk index, which measures the percentage of species exposed to frost during the flowering period in spring, showed a decreasing trend of-0.37% decade-1 (insignificant) in Northeast China and-1.80% decade-1 (P < 0.01) in North China. The results indicated the frost risk in the study region decreased over the past half century, and showed remarkable regional difference. These conclusions provide important information for agriculture and forestry managers in devising frost protection schemes.
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    Responses of vulnerability for natural ecosystem to climate change in China
    ZHAO Dongsheng, WU Shaohong
    2013, 68 (5):  602-610.  doi: 10.11821/xb201305003
    Abstract ( 1110 )   PDF (3862KB) ( 1078 )   Save
    Vulnerability of natural ecosystem to climate change is scientific basis for adapting and mitigating climate change, and is one of the important issues in the area of climate change and ecology. In this study, LPJ, a modified dynamical vegetation model according to features of China's natural ecosystems, was employed to simulate ecosystem dynamics under A2, B2 and A1B emission scenarios generated by PRECES (Providing Regional Climate for Impacts Studies) system. Using a vulnerability assessment model, vulnerability of natural ecosystem against climate change was evaluated in the future. Results suggest that vulnerability for China's natural ecosystems may strengthen in the east and weaken in the west, but the pattern of ecosystem vulnerability in China, decline from southeast to northeast, would not be altered under climate change. Ecosystem rising vulnerability may be mainly observed in temperate humid/sub-humid region and warm temperate humid/sub-humid region. Ecosystem decreasing vulnerability may be found in arid region of Northwest China and Tibetan Plateau region. In the near-term scale, natural ecosystem in China may be slightly affected by climate change. However, in mid-term and long-term scales, there may be severely adverse effect. Particularly, in the east with better water and thermal condition.
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    Extreme temperature events in Yangtze River Basin during 1962-2011
    WANG Qiong, ZHANG Mingjun, WANG Shengjie, LUO Shufei, WANG baolong, ZHU Xiaofan
    2013, 68 (5):  611-625.  doi: 10.11821/xb201305004
    Abstract ( 1226 )   PDF (6489KB) ( 1367 )   Save
    Based on daily maximum and minimum temperature observed by the China Meteorological Administration at 115 meteorological stations in the Yangtze River Basin from 1962 to 2011, the methods of linear regression, factor analysis and correlation analysis are employed to analyze the temporal variability and spatial distribution of climate extremes. Sixteen indices of extreme temperature are studied. The results are as follows: (1) The occurrence of cold days, cold nights, ice days, frost days and cold spell duration days has significantly decreased by-0.84,-2.78,-0.48,-3.29 and-0.67 days/decade, respectively, while the occurrence of warm days, warm nights, summer days, tropical nights, warm spell duration days and growing season length shows statistically significant increasing trends at rates of 2.24, 2.86, 2.93, 1.80, 0.83 and 2.30 days/decade, respectively. The tendency rate of monthly minimum value of daily maximum (minimum) temperature, monthly maximum value of daily maximum (minimum) and diurnal temperature range is 0.33, 0.47, 0.16, 0.19 and-0.07 ℃/decade, respectively. (2) The magnitudes of changes in cold indices (cold nights, monthly minimum value of daily maximum, monthly minimum value of daily minimum) are obviously greater than those of warm indices (warm nights, monthly maximum value of daily maximum and monthly maximum value of daily minimum). The change ranges of night indices (warm nights and cold nights) are larger than those of day indices (warm days and cold days), indicating that the changes of day and night temperature are asymmetrical. (3) Spatially, the regionally averaged values of cold indices in the upper reaches of the Yangtze River Basin are larger than in the middle and lower reaches. However, the regionally averaged values of warm indices and growing seasons except warm spell duration indicator are larger in the middle and lower reaches than in the upper reaches. (4) The extreme temperature indices are highly correlated with each other except diurnal temperature range.
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    OSL dating of the sediment stratigraphy of the Lajia Ruins in the Guanting Basin in the Upper Yellow River Basin
    ZHANG Yuzhu, HUANG Chunchang, PANG Jiangli, ZHOU Yali, ZHA Xiaochun, WANG Longsheng, ZHOU Liang
    2013, 68 (5):  626-639.  doi: 10.11821/xb201305005
    Abstract ( 1056 )   PDF (3329KB) ( 1135 )   Save
    The palaeo-ground of the Qijia Culture in the Lajia Ruins was found to be broken by several groups of earthquake fissures. One layer of conglomerated clayey mudflow deposit has blanketed the Lajia Runis and filled with the earthquake fissures. After detailed field observations, samples for OSL dating were taken from the sediment profile. OSL ages of the samples were obtained by using the single-aliquot regenerative-dose method. A chronological framework was established in the XLJ profile based on the OSL ages and in combination with the 14C ages and stratigraphic correlations, which indicates that the second terrace of the Yellow River was formed at 35.00 ka BP. Then, accumulation of the eolian loess-soil profile started. The red clayey mudflow deposit and the earthquake fissures were formed at 3.95 ka BP in the second terrace in the Guanting Basin. Sedimentary samples were taken from the profile and magnetic susceptibility and particle-size distribution were analyzed in the laboratory. The results show that the Malan loess (L1-1) was deposited during 35.00~11.50 ka BP. It was accumulated by dust storms and dust falls under a dry-cold environment during the late last glacial without being modified by pedogenesis. The transitional loess (Lt) was dated to be 11.50~8.50 ka BP. It was slightly affected by weathering and pedogenesis during the early Holocene because the climate was dry. The palaeosol (S0), i.e., Heilusol or Chernozem, was dated to be 8.50~3.10 ka BP. It was strongly affected by weathering and pedogenesis during the mid-Holocene Climatic Optimum. However, a layer of conglomerated red clayey mudflow, which blanketed the Lajia Ruins at 3.95 ka BP, made the palaeosol (S0) split into two sub-layers (S0-lower and S0-upper).
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    Dynamic sedimentary environment and the provenance characteristics in Yangtze River Estuary-Hangzhou Bay and its adjacent waters
    ZHANG Weiyan, ZHANG Xiaoyu, JIN Haiyan, FENG Xuwen, YAO Xuying, GAO Weili, ZHANG Fuyuan, GAO Aigen
    2013, 68 (5):  640-650.  doi: 10.11821/xb201305006
    Abstract ( 929 )   PDF (2886KB) ( 1216 )   Save
    There is a complicated dynamic sedimentary environment in Yangtze River Estuary-Hangzhou Bay and its adjacent waters, which is affected by the material transport and eco-environment of waters. In this paper, grain size distributions, rate earth elements and platinum group elements were analyzed for surface sediments from the Yangtze River Estuary-Hangzhou Bay and its adjacent waters. The investigated area has been partitioned into eight dynamic sediment environment divisions with a triangular diagram advanced by Pejrup M: two estuarine modern depositional regions with intense hydrodynamics; two nearshore modern depositional regions with the interaction on different water masses; one frontal region in the continental shelf; two relict sedimentary regions influenced by modern material supply from the warm current and the coastal current; and one modern depositional region with cyclonic eddy. By comparing grain size distributions and hydrodynamic patterns in different dynamic sedimentary environment regions, sedimentary features were revealed under different hydrodynamic conditions and the provenance characteristics were recognized in a variety of depositional environment.
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    Spatial-temporal analysis of coastline changes in northern China from 2000 to 2012
    XU Jinyong, ZHANG Zengxiang, ZHAO Xiaoli, WEN Qingke, ZUO Lijun, WANG Xiao, YI Ling
    2013, 68 (5):  651-660.  doi: 10.11821/xb201305007
    Abstract ( 1063 )   PDF (6543KB) ( 1736 )   Save
    This study examined the spatial distribution of the continent coastline in northern China using remote sensing and GIS techniques, and calculated the fractal dimension of the coastline by box-counting method, with a time span from 2000 to 2012. Moreover, we analyzed the characteristics of spatial-temporal changes in the coastline's length and fractal dimension, the relationship between the length change and fractal dimension change, and the driving forces of coastline changes in northern China. During the research period, the coastline of the study area increased by 637.95 km, at an annual rate of 53.16 km. On the regional level, the most significant change of coastline length was observed in Tianjin and Hebei. Temporally, the northern China coastline extended faster after 2008. The most dramatic growth was found between 2010 and 2011, with an annual rate of 2.49%. The fractal dimension of the coastline in northern China was increasing during the research period, and the most dramatic increase occurred in the Bohai Rim. There is a strong positive linear relationship between the historical coastline length and fractal dimension, with the correlation coefficient being 0.9962. Through statistical analysis of a large number of local coastline changes, it can be found that the increase (or decrease) of local coastline length will, in most cases, lead to the increase (or decrease) of the whole coastline fractal dimension. Civil-coastal engineering construction was the most important factor driving the coastline change in northern China.
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    Formation and evolution of sandy deserts in Xinjiang:The palaeo-environmental evidences
    ZHU Bingqi, YU Jingjie, QIN Xiaoguang, LIU Ziting, XIONG Heigang
    2013, 68 (5):  661-679.  doi: 10.11821/xb201305008
    Abstract ( 1673 )   PDF (9072KB) ( 1428 )   Save
    Based on the palaeoclimatic and palaeoenvironmental evidences of geological history and human history periods, this paper reviews the researches and progresses on the development of the sandy deserts in Xinjiang. It points out that under the tectonic conditions, the Tarim and Zhungarer basins are greatly influenced by the foehn effects originated from the planetary wind system of westerly, the East-Asia ocean-continental monsoon and the topographical mountain-valley winds. The regional patterns of climate and environment since the Quaternary have been characterized by the overall persistent drought accompanied by fluctuations in the secondary scale. Formations of aeolian sediments in the basins and at the margins are a potential response to global climate change, particularly to the aridification of the Asian hinterland deduced by the uplift of the Tibetan Plateau and its surrounding highlands. For the question about the formation time of the Taklimakan Desert, because the research methods, objects and information carriers used in previous studies are different, there are many disputes in the academic circles at present. Evidences from aeolian deposits/rocks at the edge and in the hinterland of these sandy deserts and their chronological data indicate that arid climate and land surface aeolian processes have been observed at the edge of the Tarim Basin and its hinterland areas since the Tertiary period.
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    Spatial-temporal changes of rice area and production in China during 1980-2010
    LIU Zhenhuan, LI Zhengguo, TANG Pengqin, LI Zhipeng, WU Wenbin, YANG Peng, YOU Liangzhi, TANG Huajun
    2013, 68 (5):  680-693.  doi: 10.11821/xb201305009
    Abstract ( 1121 )   PDF (18595KB) ( 2701 )   Save
    Rice is one of the most important staples in China. Rice's spatial-temporal distributions, which are vital to agricultural, environmental and food security research, are affected by natural conditions as well as social-economic developments. In recent years, most of agricultural land use change studies are focused on cultivated land change and its impact, while few are focused on arable crop area change because crop sown area estimates are based on statistics by administrative units, and such data lack accurate information on spatial and temporal variations. Other estimates are based on remote sensing, such data limited by spatial resolution which is difficult to capture the finer information of crops. Thus, multi-source data integration has become an effective way to determine spatial distributions of crops. Spatial Production Allocation Model (SPAM) is a multi-source data integration model that integrated arable land distribution, administrative unit statistics of crop data, agricultural irrigation data, and crop suitable data. It applied a cross-entropy method to allocate the statistics data of crop area and production down to such a fine spatial location, such as a pixel. This research uses the SPAM-China model to get a series of spatial distributions of rice area and production with a 10-km pixel at national scale, based on long-term county-and province-level agricultural statistics since the early 1980s, and then, analyzes the pattern of spatial and temporal changes. The results show that there are significant changes in rice in China during 1980-2010. Overall, more than 50% of rice area decreased, while nearly 70% of rice production increased in the change region during 1980-2010. Spatially, most of the increased area and production were in Northeast China, especially, in Jilin and Heilongjiang, most of the decreased area and production were located in southeastern China, especially, in rapidly urbanized provinces of Guangdong, Fujian and Zhejiang. Thus, the centroid of rice area was moved to northeast approximately 230 km since 1980, and rice production around 320 km, which means rice production moves northeastward faster than rice area because of the significant rice yield increase in Northeast China. The results also show that rice area change has a decisive impact on rice production change. Approximately 54.5% of the increase in rice production is due to the expansion of sown area, while around 83.2% of the decrease in rice production is due to shrinkage of rice area. This implies that rice production increased may be due to area expansion and other non-area factors, but reduced rice production could largely be attributed to rice area decrease.
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    Impact of the shrinking winter wheat sowing area on agricultural water consumption in the Hebei Plain
    WANG Xue, LI Xiubin, XIN Liangjie
    2013, 68 (5):  694-707.  doi: 10.11821/xb201305010
    Abstract ( 1064 )   PDF (2608KB) ( 984 )   Save
    This study firstly analyzed the shrinkage of winter wheat and the changes of cropping systems in the Hebei Plain from 1998 to 2010 based on the agricultural statistic data of 11 cities and meteorological data, including daily temperature, precipitation, water vapor, wind speed and minimum relative humidity data from 22 meteorological stations, and then calculated the water deficit and irrigation water resources required by different cropping systems, as well as the irrigation water resources conserved as a result of cropping system changes, using crop coefficient method and every ten-day effective precipitation estimation method. The results are shown as follows. 1) The sowing areas of winter wheat in all the 11 cities in the Hebei Plain shrunk during the study period. The shrinkage rate was 16.07% and the total shrinkage area amounted to 49.62×104 ha. The shrinkage was most serious in the Beijing-Tianjin-Tangshan Metropolitan Region, with a rate of 47.23%. 2) The precipitation fill rate of winter wheat was only 20%-30%, while that of both spring maize and summer maize exceeded 50%. The irrigation water resources demanded by the winter wheat-summer maize double cropping system ranged from 400 mm to 530 mm, while those demanded by the spring maize single cropping system ranged from 160 mm to 210 mm. 3) The water resources conserved as a result of the winter wheat sowing area shrinkage during the study period were about 15.96×108 m3/a, accounting for 27.85% of those provided for Beijing, Tianjin and Hebei by the first phase of the Middle Route of the South-to-North Water Diversion Project.
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    Responses of characteristic horticulture plant to climate change of Xinjiang
    LIU Jingqiang, Wahap HALIK, Hasm ABZ, DANG Jianhua, DENG Baoshan, ZHANG Yuping
    2013, 68 (5):  708-720.  doi: 10.11821/xb201305011
    Abstract ( 659 )   PDF (4101KB) ( 1148 )   Save
    Based on the meteorological material of the past 52 years obtained from 54 meteorological stations of Xinjiang, by using univariate regression linear inclination rate, Mann-Kendall abrupt change testing method and inverse distance weighted spatial difference method, we analyzed the temporal and spatial variations of the annual mean temperature, the precipitation above 10oC, and the temperature and precipitation from April to October in Xinjiang and four main horticulture bases. Besides, combined with exponential smoothing and linear trend rate, we analyzed the response of yield and planting area of apple, grape, pear and other kinds of horticulture products to climate change. The results show that there has been a linear growth trend in temperature and precipitation of Xinjiang and four main horticulture bases over the last 52 years. There was an obvious trend of warming and wetting from the mid-to late 1980s and the warm and humid climate trend was more significant in 2000 all over Xinjiang. However, there have been different climate change trends and the spatial and temporal distribution, as the four main horticulture bases are located in different locations. Compared to other horticulture bases, the linear growth rate of precipitation and temperature was the greatest and the precipitation was at its highest level in Yili Valley, the linear trend rate of precipitation was small and the temperature was high in Turpan-Hami Basin. The linear trend rate of temperature and precipitation on the northern slope of Tianshan Mountains and Tarim Basin was basically the same, and there was a warming and wetting significant trend in 2000. The warm and humid climate trend was conducive to the improvement of production of characteristic horticulture products, and the effect was more obvious when the climate tended to be warm and wet. Furthermore the temperature increase also promoted the acreage expansion of the thermophile horticulture products, and the horticulture products plant extended from high temperature region to low temperature region. As a result, spatial distribution trends of the horticulture products plant were consistent with those of the four main horticulture bases planned by the local government. However, high temperature and excessive rainfall, especially abrupt changes (increase or decrease) of temperature, precipitation and humidity have a great impact on the horticulture products. Therefore, some concrete measures should be taken to mitigate the impact of extreme climate change on characteristic horticulture products.
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