Archive

  • 2011 Volume 31 Issue 4
    Published: 20 April 2011
      

  • Select all
    |
  • FANG Xiu-qi, HOU Guang-liang
    Download PDF ( )   Knowledge map   Save
    About 1397 temperature records during the Holocene are collected to establish a temperature data set of the Holocene in China. 1140 of the 1397 records are available after eliminated the abnormal values statistically. There are more than 10 available records in most centuries during the Holocene in China. A synthesis reconstruction method, named the converted single sample from local to regional and averaged by the multiple samples, are designed to quantitatively reconstruct temperature change during the Holocene in China. The synthetically reconstructed Holocene temperature series in China ensures both the quantification and the higher temporal resolution continuously. According to the reconstructed temperature series, the Holocene temperature change in China could be obviously divided into three stages. The early Holocene (11.5-8.9 ka B.P.) was warming period when the temperature rose to near the present with fluctuation. The mid Holocene (8.9-4.0 ka B.P.) was a warmer period named the Holocene Megathermal, when the temperature was 1 ℃ higher than the present in average, with 1.5℃ higher than the present in maximum during 8.0–6.4 ka BP. The late Holocene (after 4.0 ka BP) was a cooling period.
  • ZHAO Jing-bo, HOU Yu-le, CAO Jun-ji, ZHANG Chong
    Download PDF ( )   Knowledge map   Save
    According to the analysis on soil moisture and particle size of the grass land at Jiermeng in Gangcha, the soil moisture content and its impacts on vegetation development were studied. The grain size composition of the middle and upper part of soil in the study area is mainly coarse silt, and at the lower part of soil is mainly fine sand. Soil moisture content in grassland appeared more gravity water in 2009 in this region, and the depth of gravity water in the grass land was up to about 60 cm. Soil moisture is rich in the upper layers and seriously short in the lower. Moderate dried layers with the soil moisture lower than 9% and some serious dried layers with the soil moisture lower than 6% occurred under the soil profiles with the depth of about 80 cm. The development of dried soil layer at this region is due to less precipitation, which held up precipitation infiltrating into the deeper area under ground, so precipitation is generally not the supply source of groundwater. Surface water circulation is mainly through evaporation and transpiration, and belongs to the type of abnormal water cycle. Soil water balance is the negative one in this region, which shows that the local rainfall does not fully meet the needs of growth and development of grass vegetation and is not suitable to forest planting. Soil thickness at Jiermeng Village is thicker than other areas around Qinghai Lake. Because soil water storage is less and soil reservoir can not provide enough water for the growth of herbaceous plants in dry year, the area is prone to environmental degradation. In order to maintain the water level stable and ecological balance of Qinghai Lake, we should develop natural grass vegetation which is suitable to the local climate and consumes less water, and limit the development of artificial vegetation such as the rape consuming more water and simultaneously restrict grazing.
  • LIU Jing-hua, ZHANG Ping-zhong, MENG Cai-hong, ZHANG De-zhong, YANG Xun-lin
    Download PDF ( )   Knowledge map   Save
    Based on high-precision 230Th dates and high-resolution oxygen isotope records of a stalagmite collected from Wanxiang Cave,Wudu,together with the references of Chinese historical documents from Wudu and the neighboring areas,the variation of monsoonal precipitation in the modern Asian monsoon marginal zone over the past 500 years was reconstructed.This study indicated that the speleothem δ18O is a good proxy for the Asian monsoon strength and associated precipitation on inter-annual to centennial timescale.Variation of the monsoonal precipitation during the past 500 years can be divided into three stages,decreasing from 1470 A.D.to 1700 A.D.,stable between 1701 A.D.and 1875 A.D.,and increasing thereafter.This variation is quite similar to that of the Drought/Flooding index archived from Chinese historical documents.Monsoonal precipitation shows stepwise pattern in the monsoonal marginal region of China during the transition from the Little Ice Age to the Current Warm Period.The variation of stepwise precipitation suggested that the monsoonal precipitation over the monsoon marginal zone in large-spatial-scale is consistent,and this variation and the Northern Hemisphere temperature,Chinese temperature varied synchronously on interdecadal to centennial timescale.
  • SHI Shu-qin, CHEN You-qi, LI Zheng-guo, YANG Peng, WU Wen-Bin, Tang Fang
    Download PDF ( )   Knowledge map   Save
    In order to adapt maize planting according to current climatic, soil conditions and modern agricultural technique, planting structure of maize and its variety should be optimized at the regional level. In this paper, an indicator system was developed for evaluating the suitability of maize planting in Jilin Province, which is a main maize production area in Northeast China. Thereafter, both spatial interpolation technique and auxiliary information were used for spatial modeling of precipitation, soil conditions and the maize yield. In details, observed precipitation records from climate observing stations in study area were firstly interpolated by using an integrated means of multiple regression and residual error interpolation. Second, with a consideration of soil type information, the relevant factors were utilized as co-factors for interpolating soil properties (i.e. pH, soil organic matter, available K, available N and available P of soil) by using the means of Cokriging technique. Third, the map of statistics-based maize yield was validated by the spatial map of cultivated land quality. Fourth, with the aids of terminal condition law, comprehensive analytic approach and experience index law, the suitability evaluation for maize planting was implemented as the basis of regionalization research. From the regionalization results, 13 zones of planting maize can be indentified in Jilin Province, which are further reclassified into four major suitability levels as high, moderate, low and nun-suitability.
  • HU Ke, MO Duo-wen, MAO Long-jiang, LI Shui-cheng, WANG Hui, CAO Wei, ZHANG Yi-fei
    Download PDF ( )   Knowledge map   Save
    In this paper, we discuss the relationship between mankind settlement sites and 6 topography factors in Wuding River Basin of Shaanxi in China during the Longshan period. This study aims to eatablish the digital elevation model of Wuding River Basin by GIS software. The main method of this study is to overlay the distribution of 293 Longshan sites with spatial analysis results of the digital elevation model, and to execute cluster analysis by SPSS software. The result shows that settlement behavior has a strong relationship with the hydrological condition, landform and ground slope, but no obvious relationship with the slope direction. The priority order of topography factors which affected the mankind settlement is that landform types, the distance to the river, the ground slope, the river grade and the slope direction.
  • CAO Wei, ZHOU Sheng-lu, WU Shao-hua, ZHENG Qun-ying
    Download PDF ( )   Knowledge map   Save
    Based on the currently land use database in Yixing of Jiangsu Province, landscape pattern indices were firstly calculated. According to these computed landscape pattern indices, Yixing was divided into four landscape zones of land use by the use of rough set theory and catastrophe progression method. The zoning result reflects that land use under the influence of regional geomorphology characteristic is the main factor of the landscape pattern’s variation of land use. With the increase of the area of water and forest proportion, the human disturbance to land system will gradually weaken, patch fragmentation will reduce, patch shape complexity will enhance, and landscape diversity will decrease. The hidden rule under the raw data is simply obtained by knowledge reduction of data in rough set theory. Without the determination of the weight, it just needs to arrange indicators according to the computed importance of attribute. The landscape zoning of land use, finally, is made by multi-indicator integrated catastrophe progression method. The catastrophe progression method, in a large extent, avoids the subjectivity in the process of determining the factor’s weight.
  • Song Zhi-jun, LIU Li-ming
    Download PDF ( )   Knowledge map   Save
    Because of the different natural conditions, urbanization and industrialization, the circles of suburban agricultural areas in Beijing has different productive / non-productive functions. In this paper, agricultural multifunctionality theory and industrial economy theory have been employed to analyze the spatial characteristics of surburban agriculture area in Beijing. The reslute shows that the agriculture can be divided into two transition pathways from the plain outskirts to the outer mountainous suburbs. Firstly, agricultural transition pathway has emerged from modern urban agriculture to the traditional agriculture; secondly, it is a fan-shaped agricultural transition pathway expanding from the plains to the mountainous area. But there is a non-agricultural industry dominated buffer zone 30–40 km away from the central city, which has become the boundary belt due to urban functions transfering to the village functions. The modern agriculture and recreational agriculture have become the dominant rural economy outside the buffer zone. Its non-productive functions are being strengthened, which are also spreading to the outer mountainous suburb, and the ecological function can be the leading one among the multifunctions in Beijing’s midst and outer spheres.
  • CHEN Feng, YUAN Yu-jiang, WEI Wen-shou, YU Shu-long, ZHANG Rui-bo, FAN Zi-ang, ZHANG Tong-wen, SHANG hua-ming, LI Yang
    Download PDF ( )   Knowledge map   Save
    We presented a drought reconstruction for the northern central China based on the earlywood width chronology developed from one site of Pinus tabulaeformis at South Margin of Tengger Desert, China. The drought reconstruction in 1691-2005 was developed by calibrating tree-ring data with the Palmer Drought Severity Index (PDSI), which is used to describe the regional moisture condition properly. The reconstruction was verified with the independent data, and accounted for 42.0% of the actual PDSI variance during their common period (1960-2005). The mean PDSI over the 1691-2005 period was estimated at-0.32. The full reconstruction indicated that the regional drought variability was variable and persistent. The comparison between the reconstructed PDSI and historical archives and other reconstructions was conducted based on tree-ring in Northwest China. The results revealed common climatic extremes and change over much of Northwest China. Many of these events have had profound impacts on human being over the past several centuries. The drought epoch in the late 1920s was the most severe one in our reconstruction. The wet epochs in the 1730s and the 1750s were the wettest in our reconstruction. Spatial correlations between the PDSI 5-6 reconstruction and the girded PDSI dataset showed that the reconstruction varied indifferent areas; which were affected by the Asian monsoon. The multitaper method (MTM) spectral analysis indicated that there are 6 periodic change of 25 a (95%), 12 a (95%), 3.4 a (99%), 2.8 a (99%), 2.6 a (99%), 2.3 a (95%), which is similar with the PDSI reconstructions at East Margin of Tengger Desert and South Margin of Badain Jaran Desert.
  • Mansur SABIT, Lutpulla IMIN
    Download PDF ( )   Knowledge map   Save
    Based on the GIS, and the statistical data of cities and counties of Xinjiang, this paper analyzed the characters of land use change and its eco-effects in southern Xinjiang. The results showed that: 1) In 1996-2008, arable land, garden, forest, water area and construction land have increased, however, the grass land and unused land area decreased. The dynamical degree of land use was 0.88%, garden, construction land and arable land showed bigger annual change rates; forest, grass land, water area and unused area showed smaller annual change rates. There was an obvious regional difference in land use change. Except the unused land area, the other types of land use changes in Bazhou were bigger than the same types land use changes in whole Southern Xinjiang, while the all types of land use changes in Hotan were smaller than the same types land use changes. 2) With the increase of population, human activities changed land use structures, enlarged oasis arable land area, which brought destructions to the desert vegetation. The bad ecological effects were as follows: desertification, land solemnization, land barrenization, arable land pollution, reducing of grassland, ecological deterioration of plain reservoir and ecological degradation of ecotone between oasis and desert, as a result, the sustainable development of oasis was affected seriously by these effects.
  • LIANG Fa-chao, LIU Li-ming, XU Jin-lu
    Download PDF ( )   Knowledge map   Save
    The Shipu Basin in the northern Fujian was selected as the study area, and its landscape pattern were analyzed using landscape indices. Based on that, from the two aspects of the economic factor and the land factor, we constructed coordination evaluation index system of land use system in the Shipu Basin, and assessed its coordination making use of the multi-level fuzzy comprehensive evaluation model. The results showed that fragmentation of landscape types is greater, and the complexity of patch shape is the middle in the Shipu Basin. The basic trend of coordination of the economic factor and overall coordination land use system is upward, however, coordination of the land factor is in the decline, indicating that rapid economic development has been at the cost of some extent irrational utilization of land. The model evaluation result not only provides the basis for land use planning in the Shipu Basin, but also provides references for the research on land use system in other domestic small basin.
  • WU Bo-ren, QIAN Jia-zhong
    Download PDF ( )   Knowledge map   Save
    Indexes of fluoride ions and total dissolved solids from 73 samples in shallow groundwater in Huaibei Plain, Anhui Province, ware measured. And the characteristics of spatial variation is analyzed by mathematical methods of statistics and geostatistics. Results show that: 1) Fluoride ions (F-) and total dissolved solids (TDS) obey the logarithmic normal distribution. The coefficients of variation were 0.77 and 0.36, respectively. 2) The fluoride ions and total dissolved solids from groundwater satisfy the Gaussian semi-variogram model and exponential model respectively. Fluoride ions have an autocorrelation in the 49.00 km. Total dissolved solids have an autocorrelation in the 7.21 km. 3) The zone with concentration of fluoride ions >1 mg/L is located in the northeast and central region of Huaibei Plain. The zone with concentration of total dissolved solids >1 g/L lies mainly in Suzhou and Huaibei cities in the Huaibei Plain. The spatial distribution characteristics of total dissolved solids are similar with those of fluoride ion.
  • ZHENG Zuo-fang
    Download PDF ( )   Knowledge map   Save
    High quality data series are not only the base of our study on climate change, but also the base of the diagnosing, forecasting and valuating climate. Because of sites moving and observation method changing, the climate data have been inhomogeneity for a long time. The original data applied in this paper sourced from Beijing meteorological information center, and were homogenized by the method of MASH (Multiple Analysis of Series for Homogenization). The MASH package consists of an interative procedure designed to detect possible break points through mutual comparisons of a number of climate data series, in which each series is not necessarily homogeneous. Possible break points and shifts were detected and adjusted through mutual comparisons among all available series. It can be seen from historical records that, since 1960, the site of Beijing meteorological observatory has been moved for five times, and the moving was taken place in 1965, 1969, 1970, 1981 and 1997 respectively. This paper describes annual mean yearly temperature time series before and after homogenized correction. It can be found that the difference between them is obvious. The discontinuity points in the series are in 1964, 1980 and 1996 respectively. As can be seen that they are all near the year when the site was moved. It illuminates that it is necessary to homogenize the original data. Based on the homogenized daily maximum and minimum temperature in meteorological stations of Beijing during 1960-2009, the temporal characteristics of extreme temperature variation and the response of extreme temperature to urbanization during 1960-2009 were studied. The results show that, in Beijing, the warming rate of annual average temperature was 0.39℃ per 10 a in recent 50 a, and 0.22℃ per 10a higher than the national average level. But the warming rate was unsymmetrical. The warming rate of annual average minimum temperature was much higher than that of annual average maximum temperature over the same period. That means that, in recent 50 years, climate warming in Beijing is mainly manifested as the rising of lowest temperature. As a whole, the extreme high temperature and extreme low temperature varied significantly with the rate of linear increasing tendency of 0.23℃ per 10a and 1.02℃ per 10 years, and the abrupt change of climate warming happened about 1988. In 1997-2009, Beijing had the most high temperature days and the least frost days in the past 50 a. From 1980 to 2009, the extreme high temperature and the high temperature days increased more in urban areas, and less in suburbs and exurbs of Beijing. The extreme low temperature and the low temperature days decreased more in urban areas and suburbs, and less in exurbs. Results show that the variations of extreme temperature have been obvious affected by the process of urbanization in Beijing. This result will reference on studying fundamentals about urbanization effect on urban climate.
  • XIE Wen-xia, ZHAO Quan-sheng, ZHAG Fang, MA Xiao-fei
    Download PDF ( )   Knowledge map   Save
    Characteristics of N2O flux in Phragrmites australis wetland affected by tides and weeds wetland without flooding perennial in the Dagu river estuary of Jiaozhou Bay in autumn and winter were observed using a static chamber and gas chromatograph technique from September 2009 to February 2010. N2O emission and absorption of the two types of wetlands have a significant diurnal variation. Day maximums occurred at 12 o'clock and 21 o'clock, and the minimum value were usually at about 6 o'clock in the morning. The maximum values in Phragrmites australis wetland and weeds wetland were 151.1μg/(m2·h), 29.3μg/(m2·h) and the minimum values were-128.9μg/(m2·h) and-21.5μg/(m2·h), respectively. N2O flux in Phragrmites australis wetland in autumn and winter during the day time was 1.54 and 2.09 times as much as that in the night, respectively. And there were more N2O fluxes from weeds wetland in the day than during the night in autumn, just the opposite for winter. The highest monthly emissions of N2O in Phragrmites australis wetland and weeds wetland were 42.42 mg/m2, 6.89 mg/m2 and they were observed in November. Monthly N2O fluxes in Phragrmites australis wetland were more than weeds wetland. Seasonal N2O emissions in autumn and winter were 56.32 mg/m2and 63.38 mg/m2 in Phragrmites australis wetland, and 10.45 mg/m2 and 3.08 mg/m2 in weeds wetland, respectively. N2O flux from weeds wetland in autumn and winter was 5.39 and 20.58 times as much as that from Phragrmites australis wetland which caused by different hydrologic characteristics of wetlands and the different types of vegetation. Further analysis indicated that N2O fluxes in weeds wetland in autumn and winter were significantly positively correlated with 5cm, 10cm ground temperature(P<0.05). The relation between N2O fluxes in Phragrmites australis wetland and 5cm,10cm ground temperature was not significantly, N2O emission and absorption in Phragrmites australis wetland was influenced largely by the tides. In addition to affected by temperature at monitoring sites, the process of alternating wet and dry, water level, salinity and tidal effected the emissions and absorption of N2O greatly. In autumn and winter, Phragrmites australis wetland and weeds wetland in the Dagu river estuary of Jiaozhou Bay were the "source"of atmospheric N2O.
  • WANG Chuan-hui, ZHOU Shun-wu, TANG Xiao-ping, WU Ping
    Download PDF ( )   Knowledge map   Save
    Based on the daily precipitation data of 48 stations over the Tibetan Plateau from 1961 to 2008, the characteristics of spatial and temporal distribution during the summer and winter half years over the Plateau are analyzed. It is shown that the spatial distribution of strong precipitation is very similar to that of the total precipitation over the Plateau, which decreases from southeast to northwest during the summer half year, while declines from the hinterland of the Plateau located in the east of Tanggula Mountains to the surrounding during the winter half year. The heavy precipitation during the summer half year has inter-annual oscillation cycle with quasi-three years, quasi 6 years and decadal oscillation cycle with quasi 10-11 years, while has the cycle with 6-7 years and decadal cycle with quasi 15 years during the winter half year. The trend of heavy rainfall is quite different in spatial distribution. During the summer half year, it increases (decreases) in most regions over the northern (southern) Plateau. The overall heavy precipitation of the Tibetan Plateau shows a weak decreasing trend during the summer half year and an increasing trend in the Yarlung Zangbo River during the winter half year. There was an abrupt change of precipitation in 1976.
  • BAI Ying-ying, ZHANG Yan, GAO Yang-hua, HE Ze-neng, LI Yong-hua
    Download PDF ( )   Knowledge map   Save
    Daily meteorological data of Sichuan basin, NCEP/ NCAR reanalysis data and global temperature anomalies data of NCDC were employed to diagnose the spatial differences of precipitation in Sichuan basin. The results show that the main spatial distribution of precipitation in Sichuan Basin appears to be east-west oscillation, from 1961 to 2006. The precipitation of western basin decreases significantly, but that in the eastern basin was not obvious decreased. There is a reverse distribution between plateau summer monsoon index, north boundary index and ridge index of west Pacific subtropical high and summer precipitation of Sichuan basin, which indicates that plateau summer monsoon and west Pacific ocean subtropical high may be the important reasons of the east-west oscillation of precipitation in Sichuan Basin. Using the regressive analysis and composition analysis, we found that the anomalies of precipitation over Sichuan basin have a relationship with the global mean temperature. With air temperature increasing, the precipitation over the western basin decreases significantly, while the trend in the eastern basin was not obvious, which indicates that the spatial differences of precipitation trends, especially for warming and drying of climate in western basin, are the response to global warming.
  • WU Yan, HAO Qing-ju, JIANG Chang-sheng
    Download PDF ( )   Knowledge map   Save
    The effects of tillage system on total soil organic carbon, soil active organic carbon and soil stable organic carbon were studied in a long-term field experimental station in Chongqing, China. The content of total soil organic carbon in the 0-60 cm soil layers under different tillage systems was LM: no-till and ridge culture with rotation of rice and rape system (22.74 g/kg)>DP: conventional tillage with rice only system (14.57 g/kg)>XM: no-till and plain culture with rotation of rice and rape system (13.73 g/kg)>LF: tillage and ridge culture with rotation of rice and rape system (13.10 g/kg)>SH: conventional tillage with rotation of rice and rape system (11.92 g/kg). The order of soil active organic carbon was LM(22.74 g/kg)>DP(14.57 g/kg)>XM(13.73 g/kg)>LF(13.10 g/kg)>SH(11.92 g/kg). The proportion of soil stable organic carbon to total soil organic carbon was LM(85%)>SH(78%)>XM(77%)>LF(75%)>DP(74%). Overall, long-term LM treatment performed good effects on the soil carbon sequestration and fixation.
  • WANG Rui-jing, ZHAO Min, GAO Jun
    Download PDF ( )   Knowledge map   Save
    In the context of global change, research on the terrestrial ecosystem carbon cycle has become a big trend. Due to human activities and the impact of urbanization, such native terrestrial ecosystem as Amazon is becoming less and less. On the contrary, such region as Chongming Island which has been seriously affected by human activities is getting more and more. In this study, the carbon storage of vegetation types in Chongming Island was studied based on an method combining field sampling survey and laboratory simulation. Firstly, stratified sampling method was used and randomly picked 234 sample plots with vegetation in Chongming Island; Secondly, biotic parameters (e.g. diameter at breast height DBH, tree height, etc.) were investigated; Thirdly, the improved volume-derived biomass method was used to calculate the carbon storage of main vegetation types. The results showed that: 1) In Chongming island, the carbon storage among different forest type was different, coniferous forests (e.g., M. glyptostroboides, C. fortunei, and P. thunbergii) had the higher carbon storage compared with the broadleaved forests (e.g., C. camphora).2) The disparity of carbon storage in spatial distribution existed in Chongming Island, and vegetation carbon storage is mainly distributed in the river banks, both sides of roads, and residential areas. 3) The carbon storage of the main vegetation in Chongming Island is 491 212.16 mg, and mean vegetation carbon density is 18.70 mg/ha. And 4) the future work in this study area was explored based on this study results. Not only does this study provide a scientific method in studing peri-urban forest vegetation carbon issues, but also scientific data for building Chongming eco-island and managing "zero carbon emission" city.
  • LUO Xiao, LI Zhong-wu, YE Fang-yi, HUANG Jin-quan
    Download PDF ( )   Knowledge map   Save
    About 44 paddy soil samples from the typical red soil hilly areas of the southern China were analyzed by field sampling and laboratory analysis. Using pH, organic matter, total N, available N, available P, rapidly available K as the indicators, the fertility of paddy soil samples was evaluated and the relationship between the soil fertility and rice yield was analyzed with PI index model method. The results revealed that: 1) the paddy soils in the studied area were weakly acidic or neutral, with abundant organic matter, high N-supplying capacity and relatively low P and K levels, which is suitable for rice growing. 2) The correlation coefficient between the soil fertility and actual yield was 0.736 (significantly), which indicated that there was a positive correlation between rice yield and soil fertility.
  • YU Fen, QIAN Huai-sui, DUAN Hai-lai
    Download PDF ( )   Knowledge map   Save
    A climate risk assessment model, based on the suitability model, is established combining with the mean suitability level and the influence of the climate change. Using the glide modeling technology, the article analyzed and assessed the climate risk to rice of Huaihe River Basin. Considering the temperature, precipitation, hours of sunlight and climate risk degree for rice, the article divided Huaihe River Basin into three types of regions: the low risk region, the medium risk region and the high risk region. In recent years, the climate risk to rice has an increasing trend in the Huaihe River Basin. The low risk region of the eastern has the decreasing trend, on the contrary, high risk region of the western Huaihe River Basin has the increasing trend, even will be possibility extending to eastern coastal regions in the future.
  • LIU Ce, SONG Shao-hua, KONG Xiang-hui, LIU Zhao, XIAN Feng, WU Zhen-kun
    Download PDF ( )   Knowledge map   Save
    A 200-cm long successive loess core was firstly obtainded by diging a well at Caijiazui section in the Xifeng located in central loess Plateau in China. According to 14C-AMS dating results and the grain size model, the reliable chronologic framework of Xifeng section over the past 20 ka was derived in turn. Multi-proxy analysis on the magnetic susceptibility, grey scale and grain size clearly reveal the typical climatic episodes such as Heinrich 1 (H1), Bølling-Allerød (B-A), Younger Dryas (YD), and 8.2 ka event. It suggests the potential ability of Xifeng loess section for recording the abrupt climatic variations on the small scale.