共查询到20条相似文献，搜索用时 39 毫秒
1.
The starting dates of the pre-summer rainy season during historical times （1736- 1911） in Fuzhou and Guangzhou of South China, were determined and reconstructed on the basis of historical documents in the Yu-Xue-Fen-Cun archive, together with observed features of precipitation during the pre-summer rainy season. In addition, starting dates of the pre-summer rainy season from 1953 in Fuzhou and from 1952 in Guangzhou were reconstructed for the instrumental period. These data allowed for analyses of inter-annual and inter-decadal changes in the starting dates of the pre-summer rainy season in South China over the past 300 years. Results show that the mean starting date of the pre-summer rainy season in South China was the first pentad of May; in addition, periodicities in the starting dates of 2-3 years, 10 years, and 40 years were detected during the period 1736-1911, and of 2-3 years, 10 years, and 22 years during the instrumental period. From 1736 to 1911, the earliest starting dates at Fuzhou and Guangzhou both occurred at the fourth pentad of April, while the latest starting dates were at the sixth pentad of May in Fuzhou and the first pentad of June in Guangzhou. During the instrumental period, the earliest and latest starting dates were at the fourth pentad of April and the first pentad of June, respectively, in both Fuzhou during 1953-2010 and Guangzhou during 1952-2010. The maximum difference between neighboring decades during 1736-1911 was 2.2 and 1.6 pentads in Fuzhou and Guangzhou, respectively, and during the instrumental period it was 2.5 and 2.4 pentads in Fuzhou and Guangzhou, respectively. 相似文献
2.
1736-2010年华南前汛期始日变化 总被引：1，自引：1，他引：0
根据清代华南雨雪分寸记载的内容、特点,参照华南地区前汛期降水特征,提出了利用雨雪分寸记载重建华南前汛期开始时间的方法,重建了1736-1911 年福州与广州前汛期开始日期变化序列;并利用福州与广州（分别始于1953 和1952 年）逐日降水观测记录辨识了器测时期两地前汛期的逐年开始时间;据此分析了过去300 年华南前汛期开始日期的年-年代际变化特征。结果表明：1736-2010 年间,福州、广州两地前汛期开始时间平均为5 月第1 候;但存在显著的年际和年代际波动,其中重建时段（1736-1911 年）的主周期为2~3 年、准10 年和准40年,器测时段的主周期为2~3 年、准10 年和准22 年。在年际尺度,重建时段福州和广州前汛期开始时间最早的年份均为4 月第4 候,最晚的年份则分别为5 月第6 候和6 月第1 候;而器测时段两地前汛期开始时间的最早年、最晚年均为4 月第4 候和6 月第1 候。在年代际尺度,重建时段福州和广州相邻年代最大变幅分别为2.2 候和1.6 候;器测时段福州和广州相邻年代最大变幅则分别为2.5 候和2.4 候。 相似文献
3.
1960-2014年中国绿洲严寒期的时空变化特征与成因分析 总被引：2，自引：1，他引：1
基于中国绿洲74个地面气象站的逐日平均气温观测资料,计算候平均温度≤ 0 ℃的严寒期起止候及候数,运用线性趋势法、M-K突变检验、Morlet小波分析法、相关分析等方法,分析中国绿洲严寒期的起止候及候数的时空变化特征与成因。结果表明：近55年来,中国绿洲严寒期起始候推后、终止候提前、候数缩短,变化倾向率分别为0.3 p/10a、-0.27 p/10a和-0.58 p/10a;且空间差异显著,其中,柴达木盆地绿洲严寒期来的最早、结束的最晚,严寒期变化趋势最显著。严寒期起止候及候数分别在1990年、1998年、1994年发生突变。严寒期起始候与候数表现出与大气环流和厄尔尼诺有关的显著周期,终止候表现出与太阳活动有关的显著周期,可以证实严寒期起始候和候数的变化与大气环流和厄尔尼诺密切相关,而终止候的变化则与太阳活动有关。青藏高原指数、亚洲区极涡面积指数和二氧化碳排放量是影响研究区严寒期的主要因子,而南亚夏季风指数则对柴达木盆地绿洲影响最显著。研究区严寒期随着经纬度和海拔高度的增加,起始候提前、终止候推后、候数延长,并以纬度的变化最显著。严寒期起止候及候数对区域增暖具有极好的响应,但区域增暖对起止候及候数的影响各不相同。 相似文献
4.
Based on daily average temperatures and observation data from 74 meteorological stations in Chinese oases, we calculate five-day (pentad) average temperature ≤0°C for the start and end pentad as well as pentads of cold period using linear regression analysis, nonparametric Mann-Kendall tests, the Morlet wavelet power spectrum, and correlation analysis. We also analyze spatial and temporal variations and their effects on the start and end pentad as well as pentads of cold period in Chinese oases. Results show that over the last 55 years, the start pentad of cold period has been postponed while the end pentad has been advanced. Overall, the pentads have gradually shortened over time at trend rates that are 0.3 p/10a,–0.27 p/10a, and–0.58 p/10a, respectively. Spatial differences are significant, especially for the Qaidam Basin oasis where the start pentad is the earliest, the end pentad is the latest, and the trend of change is most obvious. Mutation points for the start and end pentad as well as pentads of cold period were observed in 1990, 1998, and 1994, respectively. Of these, the start pentad and pentads of cold period show a periodic cycle, related to atmospheric circulation and El Nino events, while the end pentad exhibits a periodic cycle, related to solar activity. The Tibetan Plateau index (TPI), the Asian polar vortex area index (APVAI), and carbon dioxide emissions (CDE) are the main factors affecting cold period in the study area, whereas the South Asian summer monsoon (SASM) index exerts the greatest effect on the Qaidam Basin oasis. The start and end pentad as well as pentads of cold period increase in concert with latitude, longitude, and altitude; in response to these changes, the start pentad is advanced, the end pentad is postponed, and pentads of cold period are gradually extended. Results show that change in latitude is most significant. Overall, the start and end pentad as well as pentads of cold period show clear responses to regional warming, but there are different effects on each. 相似文献
5.
1766～1911年黄河中游汛期水情变化特征研究 总被引：2，自引：1，他引：1
根据1766～1911年万锦滩汛期涨水情况的历史文献记录,重建研究时段内黄河三门峡断面逐年汛期流量R(109m3/a)和汛期开始时间T(侯尺度),其平均水平分别为径流量R=51.06×109m3/a,汛期开始时间T平均情况为7月上旬(7月第2个侯),对应于梅雨结束平均日期。研究时段内,1840 s前流量平,汛期开始时间总体较稳定;1840～1850 s流量普遍偏丰,汛期到来偏晚;1860 s开始流量减少,汛期提前,此阶段持续约40 a左右,是近300 a中黄河中游产流微弱持续最长的1个时期。 相似文献
6.
1736年以来西安气候变化与农业收成的相关分析 总被引：7，自引：1，他引：6
基于清代雨雪与农业收成等档案记载及现代气象观测记录,根据西安冬季降雪与平均气温之间的统计关系、降水入渗与水量平衡模型,分别重建了西安1736~2000年冬季平均气温与4季降水序列,并分析了该地区气候变化特征及其对1736~2000年农业收成的影响。主要结论如下：(1) 西安的冷暖变化存在明显的百年际波动：其中18世纪相对温暖,19世纪寒冷,20世纪又转为温暖,且增暖趋势极为明显。(2) 西安的降水变化存在明显的年代际波动。自1736年以来,共经历了6个多雨期与7个少雨期,其中多雨期的平均雨量比少雨期多16%。(3) 气候变化对农业收成的影响极为明显。其中夏季降水量与秋收关系显著,而夏收又与前一年秋~当年春季的降水明显相关,且大多数严重歉收年均由降水明显偏少而致。虽然温度的年际变化与收成没有显著的联系,但温度年代际变化,即气候的冷暖阶段变化却与收成的阶段性变化关系密切。 相似文献
7.
根据国家气候中心最新颁布的华南前汛期业务监测标准,采用小波分析、合成分析、相关分析等统计方法研究了1961~2014年华南前汛期入汛日期、出汛日期、持续时间及前汛期累计降水量异常的变异特征。结果表明：华南前汛期入汛日期的年际变化特征主要表现为7~8 a及准2 a周期,年代际变化特征主要表现为20世纪60至70年代入汛偏晚,80年代入汛偏早;华南前汛期出汛日期的年际变化特征主要表现为6~7 a周期,年代际变化特征表现为20世纪60年代中期前出汛偏早,70年代中期以来出汛偏早。华南前汛期入汛早晚对其持续时间及累计降水量有很好的指示意义,表现为入汛越早,华南前汛期持续时间偏长的可能性越大,对应前汛期累计降水量偏多。 相似文献
8.
17111911年昆明雨季降水的分级重建与初步研究 总被引：3，自引：0，他引：3
利用清代档案和其他文献资料,重建了17111911年间昆明雨季降水的分级序列。在重建中采取了纠偏措施,有效地解决了资料存在的系统偏差问题。对重建序列的分析表明,昆明降水存在较大的波动,可以分为4个大的时段。总的来说,18世纪的雨季降水略少于19世纪。和喜马拉雅山区达索普冰芯恢复的印度季风降水序列的比较表明,19世纪70年代是两个序列中降水量最多的10年,且19世纪后半期同是两个序列波动较大的时期。但也有不一致的地方,说明两地降水机制有所差别。同时太阳活动的世纪周期对昆明的雨季降水有影响。对中间分辨率资料的开拓利用,有助于拓展高分辨率历史气候序列重建的范围。 相似文献
9.
应用EOF、Morlet小波分析方法对云南雨季开始期的时空特征及多尺度周期变化特征进行分析,使用相关分析初步分析印度季风和南海季风开始期与其关系.结果表明：（1）云南雨季开始期的EOF第一模态表明全省雨季开始期一致偏早（晚）,EOF第二模态表明滇中及以东、滇东北、滇东南、滇西南部分地区与滇西、滇西北、滇南大部分地区雨季开始期反相变化的空间分布特征.（2）云南雨季开始期存在着明显的周期性波动,连续小波变换分析表明云南雨季开始期存在2～4年和5～7年的振荡周期.（3）南海季风开始期与云南雨季开始期相关不好,印度季风开始期与云南雨季开始期存在很好的相关性. 相似文献
10.
清代云南雨季早晚序列的重建与夏季风变迁 总被引：6，自引：0，他引：6
根据以档案为主的历史文献资料逐年进行考订,复原了云南1711~1911年间的雨季早晚序列,并利用多种资料进行了检验。分析表明,云南雨季开始期年际和年代际的波动都较剧烈,还存在年代际尺度以上的长时间尺度波动。雨季开始期从18世纪初逐步转向偏早,19世纪又转向偏迟,到20世纪又偏早,这在一定程度上反映了夏季风的长期变迁。云南雨季开始期存在明显的准3年和11.3年周期,准3年周期可能和El Nino事件的准3年周期有关,11.3年周期明显和太阳活动的11年周期有关。同时发现,El Nino事件对云南雨季的开始期有重要的影响,在El Nino年云南雨季开始期主要为偏迟或正常,但这种影响存在明显减弱的时期,可能意味着ENSO事件对亚洲夏季风的影响存在某种震荡。 相似文献
11.
利用清代雨雪分寸记录和现代器测资料,重建了成都1796—2015年分辨率为年的雨季降水量序列。结果表明,过去220 a间成都的平均雨季降水量为838 mm,19世纪20~40年代、80年代到20世纪10年代、20世纪30~40年代降水偏多,19世纪初到20年代、50~70年代、20世纪20年代、50年代到21世纪初降水偏少,并在1879—1880年发生了由少到多的明显突变;降水最多的10 a为1832年、1896年、1898年、1899年、1903年、1907年、1915年、1921年、1937年和1947年,最少的10 a为1814年、1838年、1865年、1868年、1869年、1872年、1930年、1939年、1970年和2002年。成都雨季降水量存在显著的50~75 a周期,和太平洋年代际振荡（Pacific Decadal Oscillation, PDO)指数在50~70 a信号上存在较强的负相关,且与上一年冬季至当年秋季北印度洋的全球海表温度（SST）及当年夏秋季赤道太平洋的SST也存在较强的负相关,SST偏暖（冷）时,雨季降水量往往偏少（多）。 相似文献
12.
According to the textual research into the historical documents dominated by ar-chives yearly, as well as the verification with several other kinds of data, the later or earlier starting time of the rainy seasons in Yunnan during 1711–1982 has been reconstructed. The analysis indicates that there are obvious fluctuations in the starting date of the rainy seasons in Yunnan in a year or years, and long fluctuation on the decadal scale. The rainy season comes earlier in the early 18th century, later in the 19th century and earlier again in the 20th century. This reflects to a certain degree the gradual change of the summer monsoon in Yunnan. There exists an obvious quasi-3 years cycle, which is related to El-Nino’s quasi-3 years cycle, and a 11.3-year cycle which is notably related to the 11-year cycle of the solar activity of starting date of the rainy seasons in Yunnan. Meanwhile, the dissertation finds that the El-Nino is very important to the starting date of the rainy seasons in Yunnan. The starting date of the rainy seasons in Yunnan often comes later or normally in the year of El-Nino. However, there is an obvious imperfect period in such influence, which in turn may mean that there is a certain fluctuation in the effect of ENSO on Asian summer monsoon. 相似文献
13.
14.
15.
1736-1911年中国水灾多发区分布及空间迁移特征 总被引：1，自引：1，他引：0
重建历史时期极端气候灾害的时空格局,对于认识当前和未来的灾害演变趋势,辨识灾害高风险区,更好地应对气候变化的挑战具有重要意义。本文基于《清史·灾赈志》中的历史水灾记录,以县级政区为单元,逐年提取了1736-1911年间中国境内的8582个水灾发生地点;利用核密度估计法对这一时期及3个特征时段(1736-1795、1796-1850和1851-1911年)的水灾空间分布特征进行分析,并结合风险理论框架讨论水灾多发区的分布及迁移的影响因素。主要结论如下：①1736-1911年水灾多发区主要集中在华北平原北部的海河、黄河下游,淮河下游,长江中下游三大平原及沿江地带,与现代分布格局存在一定差异;②华北平原北部是清代水灾最为集中的区域,这与当时华北平原降水偏多有关,而进入19世纪后,当地社会经济系统的高脆弱度也大大加重了灾情;特别是1855年黄河改道后,因政府应对不力,使得1851-1911年间鲁西北地区沿黄河下游河道出现一个条带状水灾多发区;③19世纪长江中下游地区水灾频次激增,其原因除梅雨变化导致的极端降水事件增多外,人类不合理的农业开发活动大量挤占湿地和水体,也在相当程度上增大了当地面对水灾时的物理暴露度。 相似文献
16.
Timothy M. Shanahan Jonathan T. Overpeck J. Warren Beck C. Winston Wheeler John A. Peck John W. King Christopher A. Scholz 《Journal of Paleolimnology》2008,40(1):339-355
The sediments from Lake Bosumtwi, Ghana contain a unique record of fine-scale (mm to sub-mm) laminations, which will provide
a valuable annual chronometer for reconstructing paleoenvironmental changes in West Africa covering much of the last 1 Ma.
Comparisons of laminae counts to independent 210Pb dates and the rise in anthropogenic “bomb” radiocarbon support the interpretation of the laminations in the uppermost sediments
as registering annual events. Radiocarbon dates on in-situ fish-bone collagen are in agreement with varve counts, further
supporting the annual nature of our varve chronology. Over the instrumental period (1925–1999), dark-varve thickness measurements
are correlated with local rainfall (r = 0.54) and appear able to resolve decadal-scale changes in precipitation. The relationship between varve thickness and rainfall
provides support for our interpretation that dark-colored varve thickness records catchment runoff during the rainy season
rather than dust flux during the dry season. Dark laminae alternate with organic and carbonate-rich light laminae formed during
the fall period of enhanced productivity. Downcore, varves undergo significant microstratigraphic and geochemical variations,
but retain the same pattern of alternating clastic and organic-rich laminae, providing support that the laminae may represent
annual time markers for reconstructions of the deeper part of the record. 相似文献
17.
Most farmers in the Ethiopian highlands depend on rain‐fed agriculture. Some areas have the favourable situation of having two rainy seasons, Belg (February‐May) and the long rainy season Kiremt (June‐October), which is the case in some parts of South Wollo. Tef (Eragrostis tef) is the staple crop that farmers prefer to grow and the 90‐day variety is suitable for growing during the short rainy season. One out of eight Ethiopians lives in tef potential areas which have Belg rainfall. The aim in this study is to analyse rainfall variation in South Wollo, in particular the area east of the small town of Hayk, and to study its effect on the ability to grow tef during the Belg season. Results from interviews showed that a more difficult farming situation had emerged during the past 40 years, largely due to deterioration of physical resources such as rainfall. Rainfall is analysed by comparing daily rainfall data from four stations in two periods, 1963 to 1982 and 1984 to 2003, for changes in totals, seasonal distribution and variability. Coefficient of variance, rainy days, rainfall intensity and dry spells were analysed. Results from this study show that there have been minor rainfall changes but greater rainfall variability. During fieldwork key informants were asked if they were able to harvest tef during the past nine years, a period that has been used in a model of rainfall influence on tef cultivation during the Belg season. In both 20–year periods, farmers were able to grow tef every second year. In spite of a greater variability in rainfall the farmers proved their knowledge and flexibility and were able to harvest tef in the same number of years during both periods. 相似文献
18.
1711-1982年云南雨季早晚序列的重建与夏季风变迁 总被引：1，自引：1，他引：0
According to the textual research into the historical documents dominated by archives yearly, as well as the verification with several other kinds of data, the later or earlier starting time of the rainy seasons in Yunnan during 1711-1982 has been reconstructed. The analysis indicates that there are obvious fluctuations in the starting date of the rainy seasons in Yunnan in a year or years, and long fluctuation on the decadal scale. The rainy season comes earlier in the early 18th century, later in the 19th century and earlier again in the 20th century. This reflects to a certain degree the gradual change of the summer monsoon in Yunnan. There exists an obvious quasi-3 years cycle, which is related to EI-Nino＇s quasi-3 years cycle, and a 11.3-year cycle which is notably related to the 11-year cycle of the solar activity of starting date of the rainy seasons in Yunnan. Meanwhile, the dissertation finds that the EI-Nino is very important to the starting date of the rainy seasons in Yunnan. The starting date of the rainy seasons in Yunnan often comes later or normally in the year of EI-Nino. However, there is an obvious imperfect period in such influence, which in turn may mean that there is a certain fluctuation in the effect of ENSO on Asian summer monsoon. 相似文献
19.
利用汕尾站、广州站和阳江站1953-2008年56a的逐月降水量、逐月的日最大降水量作为基本资料,探讨广东省降水量的时空分布特征、长期变化趋势及突变分析。Morlet小波变换表明各城市降水量存在着7.8a和11a等周期变化,与厄尔尼诺和太阳黑子的运动周期相关。其次运用皮尔逊Ⅲ型分析3城市的最大日降雨量的极值分布情况,其中阳江站5年一遇的年最大日降水量300mm,达到特大暴雨的标准。M-K检验表明阳江站和广州站降水量分别于1971、1981年发生突变,年降水量由少雨期进入多雨期,且R/S分析表明其增长趋势持续至今,但不同站点有各自的变化特点。 相似文献
20.
基于清代雨雪档案和现代气象观测资料,利用自然降水入渗试验结果及雨雪分寸与降水量统计关系,重建南京1736~2006年逐季和年降水量。分析显示:(1) 18世纪春、冬季为多雨期,秋季为少雨期;19世纪秋、冬季和全年为多雨期,春季为少雨期;20世纪上半叶,4季和全年均为少雨期;自20世纪末期始夏季和全年进入多雨期。(2) 年降水变化存在2~5 a周期,经历1851~1860年和1893~1894年两次突变。研究结果与区域内其他旱涝等级或降水量序列有较好可比性。绝大多数粮食欠收年对应于降水异常年,生长期为干旱异常的欠收年数量多于为洪涝异常的欠收年。 相似文献