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在全球变暖背景下,干旱灾害对中国农业生产的影响日益严重,然而由于旱灾损失的复杂性及其显著的区域差异,至今对中国农业旱灾损失规律及其影响机制的认识十分有限。文中利用1961年以来中国农业干旱灾害的灾情资料和常规气象资料,系统分析了近50年来中国农业干旱灾害不同受灾强度分布比率和综合损失率等指标的变化趋势及其在北方和南方的区域差异,研究了20世纪90年代的气温突变对农业旱灾损失率的影响特征,探讨了农业旱灾综合损失率对气温和降水等气候要素变化的依赖关系及其在气候空间的分布特征。结果发现,在气候变化背景下,近50年来中国农业旱灾综合损失率平均每10 a约增加0.5%,风险明显增大。而且,北方综合损失率每10 a约增加0.6%,高出南方1倍,风险增大的速度明显比南方快;北方农业旱灾几乎在很宽松的气温条件下就可以发生,而南方更多发生在气温较高的年份。并且,在气温突变后,变化趋势明显加剧,全中国综合损失率约增加了0.9%,风险明显增高;而且北方综合损失率的增值高达1.8%,是南方的4倍还多,气候突变对北方农业旱灾风险的影响明显比南方更凸出。综合损失率在北方对降水变化的响应要更敏感,而在南方对气温变化的响应更敏感。同时,关键影响期降水对综合损失率的影响比全年降水影响更显著;北方的关键影响期作用比南方更凸出。这些新的科学认识对中国农业旱灾防御具有重要意义。  相似文献   

3.
Streamflows have a direct dependence on precipitation and these are directly linked to the climate. Then, in this paper the temporal climatic variability in the Río de la Plata Basin is analysed through the changes in the river's discharges. These are the reflection of the climatic inputs areally integrated, and in consequence, contain more information on climate variability than that provided by the scarce punctual records of precipitation and temperature. The time series of streamflows correspond to monthly and annual means in stations selected in the basin for the period 1931–1992. However, in the present paper, the period 1901–1992 was considered in all cases whenever possible. The following changes and tendencies in the flow series were detected: 1. An important change of tendency between 1970 and 1972, and another not so significant before that date were detected in 1917–1918 and 1943–1944. 2. The jumps in the means in several sub-periods were detected using different methods. They showed jumps mainly in the period 1970–1972 in the annual streamflows series. The jumps in the annual streamflow series consist of an abrupt change in climatic variables affecting temporarily the averages of such variables during a certain period of time (years). The results are consistent with the conclusions obtained by other authors for the same region, both in precipitation and in the general circulation of the atmosphere. Keeping in mind this analysis of the series of streamflows, indicators of normal variability of tendencies relative to natural regional causes were detected, although the local causes were not anthropogenically analysed, and so no other manifestations of randomless in the zone of the Basin under study because of the lacking of data.  相似文献   

4.
Evidence for the existence of the medieval warm period in China   总被引:4,自引:0,他引:4  
De'Er Zhang 《Climatic change》1994,26(2-3):289-297
The collected documentary records of the cultivation of citrus trees andBoehmeria nivea (a perennial herb) have been used to produce distribution maps of these plants for the eighth, twelfth and thirteenth centuries A.D. The northern boundary of citrus andBoehmeria nivea cultivation in the thirteenth century lay to the north of the modern distribution. During the last 1000 years, the thirteenth-century boundary was the northernmost. This indicates that this was the warmest time in that period. On the basis of knowledge of the climatic conditions required for planting these species, it can be estimated that the annual mean temperature in south Henan Province in the thirteenth century was 0.9–1.0°C higher than at present. A new set of data for the latest snowfall date in Hangzhou from A.D. 1131 to 1264 indicates that this cannot be considered a cold period, as previously believed.  相似文献   

5.
Tree-ring estimates of Pacific decadal climate variability   总被引:10,自引:0,他引:10  
 Decadal-scale oscillatory modes of atmosphere-ocean variability have recently been identified in instrumental studies of the Pacific sector. The regime shift around 1976 is one example of such a fluctuation, which has been shown to have significantly impacted climate and the environment along the coastline of the western N and S Americas. The length of meteorological data for the Pacific and western Americas critically limits analyses of such decadal-scale climate variability. Here we present reconstructions of the annual Pacific Decadal Oscillation (PDO) index based on western North American tree-ring records which account for up to 53% of the instrumental variance and extend as far back as AD 1700. The PDO reconstructions indicate that decadal-scale climatic shifts have occurred prior to the period of instrumental record. Evaluation of temperature and precipitation-sensitive tree-ring series from the northeast Pacific as well as these reconstructions reveals evidence for a shift towards less pronounced interdecadal variability after about the middle 1800s. Our analyses also suggest that sites from both the northeast Pacific coast as well as the subtropical Americas need to be included in proxy data sets used to reconstruct the PDO. Received: 15 September 2000 / Accepted: 30 March 2001  相似文献   

6.
The climatic habitat of the hazardous agricultural vermin, Colorado beetle, on the territory of Russia and neighboring countries is computed using the model agroclimatic methods. The meteorological dataset of daily resolution available on the website of All-Russian Research Institute of Hydrometeorological Information-World Data Center is used and the requirements of the species to the habitat climate accepted in agroclimatology are taken into account. The computations are carried out for three time periods: 1951–1970, 1991–2010, and 2031–2050. Climatic characteristics (average annual temperature and accumulated effective temperatures) of the third period were estimated by means of linear interpolation proceeding from the first two periods. It is demonstrated that the changes in climatic habitat boundaries of the second period as compared with the first and third periods and of the third period as compared with the second period have a common trend: the broadening of the habitat takes place in the northern and especially eastern directions. The computed data are corroborated by the observational data on the actual distribution of Colorado beetle on the territory of Russia and neighboring countries.  相似文献   

7.
利用景区水库的降水和水文观测历史记录,采用对邻近气象测站测值进行同比气候差订正的方法来弥补少量资料的断缺,以形成完整的历史资料链条。运用与周边气象站对比分析的统计方法,对景区降水、泉瀑汇流水量的年度分布、多年变化趋势进行分析,结果表明:云台山景区降水资源较周边地区显著偏多,降水主要集中在汛雨阶段,多局地性的暴雨、大暴雨日;景区库区来水量分为丰、平、枯年,与汛期降水关系密切,其降水有明显的年代际变化特征,近期正在向少雨年代过渡。  相似文献   

8.
Based on two field surveys of permafrost distribution, conducted 26 years apart, along the Mackenzie Highway south of Great Slave Lake, Canada, the southern limit of the sporadic discontinuous permafrost zone in the region has migrated northward by about 120 km. To substantiate that the disappearance of perennial frozen ground is largely caused by climatic warming, a detailed trend analysis of monthly air temperature records from nine weather stations was performed using the non-parametric Kendall's test. The results show that the region experienced a general warming trend for the period 1949–1989 and warming is more prominent in the minimum than the maximum temperature series. From estimates of the magnitude of warming trends on a monthly basis, the resultant increase in mean annual air temperature could readily lead to the observed northward migration of permafrost.  相似文献   

9.
Changes in climatic parameters are often given in terms of global averages even though large regional variability is generally observed. The study of regional tendencies provides not only supplementary conclusions to more large-scale oriented results but is also of particular interest to local policy-makers and resource managers to have detailed information regarding sensible and influential climatic parameters. In this study, changes in precipitation for the Balearic Islands (Spain) have been analyzed using data from 18 rain gauges with complete daily time series during the period 1951–2006 and two additional sites where only monthly totals were available. Tendencies for maximum and minimum 2-m temperatures have also been derived using data from three thermometric stations with daily time series for the period 1976–2006. The thermometric stations are located at the head of the runways in the airports of the three major islands of the archipelago, where urbanization has arguably not had a relevant impact on the registered values. The annual mean temperature in the mid-troposphere and lower stratosphere has also been analyzed using the Balearics radiosonde data for the period 1981–2006. Results show there is a negative tendency for annual precipitation (163 mm per century) with 85% significance on the sign of the trend. An abrupt decrease in mean yearly precipitation of 65 mm is objectively detected in the time series around 1980. Additionally, the analysis shows that light and heavy daily precipitation (up to 4 mm and above 64 mm, respectively) increase their contribution to the total annual, while the share from moderate-heavy precipitations (16–32 mm) is decreasing. Regarding the thermometric records, minimum temperatures increased at a rate of 5.8°C per century during the 31 years and maximum temperatures also increased at a rate of 5.0°C per century, both having a level of statistical significance for the sign of the linear trend above 99%. Temperatures in the mid-troposphere decreased at a rate of ??5.4°C per century while a tendency of ??7.8°C per century is found in the lower stratosphere. The level of statistical significance for the sign of both the tropospheric and stratospheric linear trends is above 98% despite the great inter-annual variability of both series.  相似文献   

10.
1980-2008年黑龙江省气候变暖及其对大豆种植的影响   总被引:2,自引:0,他引:2  
基于黑龙江省10个农业气象观测站1980-2008年地面观测田平行观测资料和逐日气象资料,运用气候倾向率、M-K检测和统计回归等方法,分析研究区表征气候变暖的主要气候要素的时空变化规律以及气候变暖对大豆的影响。结果表明:1980-2008年,研究区气候出现明显变暖趋势,年平均气温升高,热量增加,无霜期延长,且区域间存在差异,南部地区热量资源增加显著。大豆百粒重随9月平均气温的升高而增加,却随年平均气温的升高而下降,表明秋季增温对大豆产量有正效应,而年平均气温的升高对大豆产量存在负作用。气候变暖对大豆生产的影响是利弊兼存,在调整种植布局时应给予重点关注。  相似文献   

11.
Summary Rescaled range analysis of the annual mean surface air temperatures at 7 meteorological stations in Hungary for the period of 1901–1991 indicates that the considered temperatures are fractals with a mean fractal dimension of 1.23 ± 0.01. This value compares favourably with the fractal dimensions of other climatic records, both on small time scale of 10–100 years and for time spans 103–106 years. Possibly such fractal dimensions are characteristic of climate change over the whole spectral range of 10 to 106 years. If this assumption becomes confirmed through analysis of a wider set of climatic records, long-range climatic prediction (in statistical sense) on different time scales will appear feasible.With 4 Figures  相似文献   

12.
This article describes a historical archive of proxy and actual precipitation data that extends the African climate record back to the early nineteenth century. The `proxy' archive includes verbal, documentary references which contain information related to rainfall conditions, such as references to famine, drought, agriculture or the nature of the rainy season. The precipitation archive includes all observations made in Africa during the nineteenth century. It consists of records for 60 stations in Algeria, 87 stations in South Africa and 304 stations scattered over the rest of Africa. Information is particularly plentiful for the 1880s and 1890s. The two parts have been be combined into a semi-quantitative regional data set indicating annual rainfall conditions in terms of anomaly classes (e.g., normal, dry, wet). This data set extends from the early nineteenth century to 1900 and distinguishes seven anomaly classes, using numbers ranging from –3 to +3 to represent very wet, wet, good rains, normal, dry, drought, and severe drought. The regionalization is based on 90 geographical regions shown via studies of the modern precipitation record to be climatically homogeneous with respect to the interannual variability of rainfall. The regional aggregation allows the voluminous fragmentary information available in historical sources to be used systematically to produce multi-year time series that can be directly integrated into the modern record for each region. The resultant time series can also be subjected to statistical analysis, in order to investigate nineteenth century climate over Africa. Spatial detail is added to the data set by utilizing a unique methodology based on climatic teleconnections established from studies of rainfall variability over Africa. The historical information and station records have been combined into a file containing a regional anomaly value for up to 90 geographic regions and the years 1801–1900. Gaps necessarily remain in the matrix, but as early as the 1820s over 40 regions are represented. By the 1880s generally around 70 regions or more are represented.  相似文献   

13.
An investigation is made of the possible impacts of a climatic change (induced by a doubling of atmospheric carbon dioxide concentration) on the European agricultural sector. Two general circulation models have been used to develop climatic change scenarios for the European study area. From the scenarios, information was obtained concerning the possible behavior of temperature, precipitation, solar radiation, and relative humidity in the altered climatic state. This meteorological information was then employed in two separate crop-weather models - an empirical/statistical model (for winter wheat) and a simple simulation model (for biomass potential). This type of approach represents a considerable departure from that employed by previous large-scale climate impact studies. Both the seasonal and regional components of a possible climatic change are incorporated directly in the two crop-weather models. The results of this investigation demonstrate that a simple crop-weather simulation model may be more suitable for the purposes of agricultural impact analysis than the linear regression models frequently used in such studies. In order for such an impact analysis to be accepted as a valid scientific experiment, a full presentation of the underlying assumptions and uncertainties is essential.  相似文献   

14.
Climatic changes at the Earth's surface propagate slowly downward into theground and modify the ambient ground thermal regime. However, causes of soiltemperature changes in the upper few meters are not well documented. One majorobstacle to understanding the linkage between the soil thermal regime andclimatic change is the lack of long-term observations of soil temperatures andrelated climatic variables. Such measurements were made throughout the formerSoviet Union with some records beginning at the end of the 19th century. Inthis paper, we use records from Irkutsk, Russia, to demonstrate how the soiltemperature responded to climatic changes over the last century. Both airtemperature and precipitation at Irkutsk increased from the late 1890s to the1990s. Changes in air temperature mainly occurred in winter, while changes inprecipitation happened mainly during summer. There was an anti-correlationbetween mean annual air temperature and annual total precipitation, i.e., more(less) precipitation during cold (warm) years. There were no significanttrends of changes in the first day of snow on the ground in autumn, but snowsteadily disappeared earlier in spring, resulting in a reduction of the snowcover duration. A grass-covered soil experiences seasonal freezing for morethan nine months each year and the long-term average maximum depth ofseasonally frozen soils was about 177 cm with a range from 91 cm to 260 cm.The relatively lower soil temperature at shallow depths appears to representthe so-called `thermal offset' in seasonally frozen soils. Changes in meanannual air temperature and soil temperature at 40 cm depth were about the samemagnitude (2.0 °C to 2.5 °C) over the common period of record, but thepatterns of change were substantially different. Mean annual air temperatureincreased slightly until the 1960s, while mean annual soil temperatureincreased steadily throughout the entire period. This leads to the conclusionthat changes in air temperature alone cannot explain the changes in soiltemperatures at this station. Soil temperature actually decreased duringsummer months by up to 4 °C, while air temperature increased slightly.This cooling in the soil may be explained by changes in rainfall and hencesoil moisture during summer due to the effect of a soil moisture feedbackmechanism. While air temperature increased about 4 °C to 6 °C duringwinter, soil temperature increased by up to 9 °C. An increase in snowfallduring early winter (October and November) and early snowmelt in spring mayplay a major role in the increase of soil temperatures through the effects ofinsulation and albedo changes. Due to its relatively higher thermalconductivity compared to unfrozen soils, seasonally frozen ground may enhancethe soil cooling, especially in autumn and winter when thermal gradient isnegative.  相似文献   

15.
基于GIS的雪灾风险区划   总被引:2,自引:0,他引:2  
依据巴彦淖尔地区冬春季节降水少、年变率大的气候特点和易形成雪灾的量级指标进行雪灾风险区划。选取1971—2010年11月到次年3月,日降雪量大于等于3mm,并出现积雪和结冰现象为研究对象,分析了降雪量大于等于3mm的降雪日数和积雪深度大于等于5cm的积雪日数年代际变化,结合民政部门历史灾情记载、实地调查、农牧业现状以及各种基础资料数据与GIS技术,从致灾因子、脆弱性评估分析方面,在NOAA卫星遥感雪覆盖监测图像上,利用加权综合与层次分析法,构建雪灾判别模型,得出巴彦淖尔地区雪灾风险区划:雪灾最严重的地区为五原县大部、乌前旗南部和东北部部分区域、乌中旗东南和西南两区域、乌后旗的海力素附近大片区域。  相似文献   

16.
海南岛近42年气候变化特征   总被引:9,自引:1,他引:9  
陈小丽  吴慧 《气象》2004,30(8):27-31
利用 1 96 1~ 2 0 0 2年海南岛 1 1个气象站各季和年的平均气温、平均最高气温、平均最低气温、降雨量等资料 ,对海南岛近 4 2年的气候变化作了较全面的分析。线性倾向估计表明 :季和年的平均气温、平均最高气温、平均最低气温具有显著增温趋势 ,特别是平均最低气温尤其显著。从全岛平均情况看 ,降雨量除了冬季有明显增加趋势外 ,其余各季和年的降雨量仅有弱的增加趋势 ;从各地区看 ,仅南部地区降雨量有显著增多趋势 ,其余地区各季呈弱的增加或减少趋势。Mann Kendall检验表明 :从2 0世纪 70年代末到 80年代末 ,各季和年的气温要素几乎先后发生了突变 ,80年代至今海南省进入明显的暖期。周期分析显示 ,各研究要素基本具有准 2~ 5年和准 7~ 1 1年的周期。  相似文献   

17.
Evidence is presented that suggests that annual and seasonal temperatures are in phase throughout the New Zealand region for climatic variation. Annual and seasonal temperature curves dating back to 1853 based on the longest instrumental records show a warming of over 1 °C between the early 1860's and the present day, with a 0.5 °C discontinuity since the mid 1940's. Although the warming is regional, the magnitude and timing of the fluctuations vary because of the country's high relief, and wide latitude range. These factors give differing exposure to the atmosphere and oceanic circulations, the resultant interaction of which allows the country to be divided into six temperature response areas which are homogeneous for fluctuations. The information of the last fifty years in these areas is compared. The story from the longer record is supported by phenomena documented from historical sources such as glacial variations, iceberg sightings, and severe snowstorm occurrences. The length and intensity of the growing season is examined in two climatically different areas of New Zealand to ascertain the agricultural significance of the described climate record.  相似文献   

18.
全球年平均人为热释放气候强迫的估算   总被引:6,自引:0,他引:6       下载免费PDF全文
利用能源经济领域具有权威性的英国石油公司(BP)世界能源统计资料和联合国人口统计资料,通过一些简单的数值计算,初步估算了人为热释放的全球气候强迫。结果表明:当前(2008年)全球年平均人为热释放的气候强迫还不是很大,约为0.031W/m2;但随着人口及能源消费总量的增加,未来人为热释放产生的全球年平均气候强迫将有可能达0.30W/m2。  相似文献   

19.
In our paper we analyze the influence of climatic changes on annual price fluctuations (harvest year) of agricultural products in Germany during the 16th century price revolution. The price series under analysis are from Nuremberg, Cologne, Augsburg, and Munich. The prices are compared with quarterly climatic indices for Germany, which cover the observation period 1500-1599. The main finding is that the length of the vegetation period is an important factor in determining grain price fluctuations. During the climatic deterioration in the 16th century, there is some evidence that the impact of climate (and therefore of supply fluctuations) on grain price fluctuations increases.  相似文献   

20.
Fire is a dominant ecological factor in Mediterranean ecosystems, and changes in the fire regime can have important consequences for the stability of our landscapes. In this framework I asked firstly, what is the trend in fire number and area burned in the eastern Iberian Peninsula, and then, to what extent is the inter-annual variability of fires determined by climatic factors. To answer these questions I analysed the meteorological data (temperature and precipitation) from 350 stations covering the eastern Iberian Peninsula (1950–2000), and the fire records for the same area (historical data, 1874–1968, and data from recent decades, 1968–2000). The results suggested a slight tendency towards decreasing summer rainfall and a clear pattern of increasing annual and summer temperatures (on average, annual temperatures increased 0.35 °C per decade from 1950 to 2000). The analysis of fire records suggested a clear increase in the annual number of fires and area burned during the last century; however, in the last three decades the number of fires also increased but the area burned did not show a clear trend. For this period the inter-annual variability in area burned was significantly related to the summer rainfall, that is, in wet summers the area burned was lower that in dry summers. Furthermore, summer rainfall was significantly cross-correlated with summer area burned for a time-lag of 2 years, suggesting that high rainfall may increase fuel loads that burn 2 years later.  相似文献   

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