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1.
辽宁省近44年夏季降水变化及区域特征分析 总被引：9，自引：3，他引：6
利用辽宁省39个气象观测站1961-2004年夏季(6~8月)的降水资料,通过趋势系数、REOF、滑动均方差等方法,对辽宁省近44年夏季降水的时空变化特征进行了分析。结果表明,辽宁夏季降水长期变化呈微弱的减少趋势,以14 mm/10 a的速率减少。20世纪60年代到70年代中期降水以偏多为主,70年代中期到80年代初降水偏少,80年代中期降水偏多,80年代末到90年代初降水偏少,90年代中期降水偏多,90年代后期至今降水一直持续偏少。辽宁夏季降水分为中北部地区及盘锦、抚顺、营口地区、辽河以西部地区、东南部地区3个不同的区域,3个区夏季降水的长期变化趋势都为减少趋势,其中东南部地区降水减少趋势明显大于其他两个区。 相似文献
2.
陕甘宁及内蒙古西部地区夏季降水的异常气候特征 总被引：8，自引：3，他引：5
利用陕西、甘肃、宁夏和内蒙古西部地区64个气象站1961-2000年夏季(6～8月)降水资料,通过Mann-Kendall法和Morlet小波法分析其空间分布和时间变化特征,并选取5个典型多雨年和5个典型少雨年,用NCEP/NCAR资料进行降水异常的对比分析.结果表明:陕甘宁及内蒙古西部地区夏季降水具有明显的空间差异,东南部降水多、西北部降水少,降水整体呈缓慢增多的趋势,线性趋势为2.3 mm/10 a;1976年前后区域内降水发生突变,存在14～16 a的长周期和2 a、2～4 a和准5 a的短周期.多雨年北半球欧亚500 hPa高度距平场中贝加尔湖至我国西北地区为负距平区,东亚沿海为正距平区;温度距平场中贝加尔湖地区为负距平区,距平零线位于西北地区东部.少雨年北半球欧亚500 hPa高度距平场中冷空气主体偏北,贝加尔湖至我国西北地区为正距平区,东亚沿海为负距平区;温度距平场中冷空气活动的区域偏北,贝加尔湖至我国西北地区为正距平区. 相似文献
3.
利用黑河流域13个气象站建站至2012年3—5月降水量资料和黑河莺落峡水文站流量资料,分析了黑河流域春季降水的基本气候特征;通过EOF、REOF、Morlet小波变换等方法,对黑河流域春季降水的时空特性进行了研究;用Mann-Kendall检验法检验黑河流域春季降水序列是否存在突变现象.结果表明:黑河流域春季降水空间分布极不均匀,其空间分布特征是南部为多雨区、北部为少雨区.黑河流域春季降水在第一空间尺度上为全区一致,在第二空间尺度上可分为2个自然气候区,在第三空间尺度上可分为3个自然气候区.从年代际变化来看,21世纪最初10年是近半个世纪来降水最多的10年,20世纪70年代是降水最少的10年;黑河流域春季降水的年际变率十分显著,降水最多的年份是最少年份的6倍多.1961—2012年间河西走廊春季降水发生了明显的突变:2001年出现了一次趋于增多的突变.最显著的周期是4年的短周期、14年和22年的长周期.黑河流域春季各月降水与黑河流量均呈正相关,尤其是春季各月降水滞后1个月的相关和5月份降水的同期相关性显著;春季气温与黑河流量也均呈正相关,特别是春季各月气温的同期相关和3月气温滞后1个月的相关性显著,说明黑河流量的增加取决于前期降水量的增加和同期气候的明显变暖. 相似文献
4.
Monthly mean temperatures and monthly precipitation totals at six stations from theCappadocian sub‐region in the continental Central Anatolia region of Turkey were analysed in order to detect the response of the variability in the Cappadocian climate to the variability of the North Sea ‐ Caspian Pattern Index (NCPI). Most of this region is classified as semi‐arid according to various climate classifications. Time series of the NCPI for the period 1958–1998, enabled each month from October toApril to be classified as belonging to the negative phase NCP(?), positive phase NCP(+) or neutral conditions. Monthly temperature and precipitation series for each station were analysed separately for both phases. Temperatures during NCP(?) were found to be considerably higher than during NCP(+). These results confirm previous results regarding the role of the NCP in controlling the temperature regime in that region. No significant differences were found in precipitation totals between the two phases, but major differences were identified in their spatial structure. 相似文献
5.
中国天气发生器的降水模拟 总被引：27，自引：0，他引：27
天气发生器是气候影响评价研究的重要工具,在气候变化、地球生态系统及极端气候事件发生的风险分析等方面有着广泛的应用。为了建立一个适用于中国广大地区的天气发生器,需要对各种模拟模型及其参数的估计进行深入的研究。其中降水的模拟及其参数的估计是关键,因为气温、辐射等其他气候要素的模拟依赖于降水的发生。本文重点介绍了常用的随机降水模拟模型：两状态一阶马尔科夫链和两参数GAMMA分布。根据中国672个气象站点1961~2000年的逐日降水资料,计算了降水转移概率P (WD)、P (WW) 及GAMMA分布参数ALPHA和BETA,并分析了4个参数在中国各地的空间分布特征与不同地区各参数的季节分布特征。最后根据各地不同月份计算的四个降水模拟参数对中国各地的逐日降水进行模拟,并利用1971~2000年的实测数据对30年模拟结果在统计意义上进行了检验,模拟结果较好。 相似文献
6.
Stochastic modeling of daily precipitation in China 总被引：6，自引：1，他引：6
1IntroductionWeather Generator (WG) is a stochastic model that can be used to simulate daily weather based on parameters determined by historic records. Precipitation, maximum temperature, minimum temperature, radiation and more can all be simulated by WG. Recently WG has gained renewed attention and has been extensively applied in studying impacts of climate change on a variety of systems including ecosystem and risk assessment. Specifically, it has been used in the following ways. 1) WG … 相似文献
7.
A stochastic model for daily precipitation simulation in China was developed based on the framework of a 'Richardson-type' weather generator that is an important tool in studying impacts of weather/climate on a variety of systems including ecosystem and risk assessment. The purpose of this work is to develop a weather generator for applications in China. The focus is on precipitation simulation since determination of other weather variables such as temperature is dependent on precipitation simulation. A framework of first order Markov Chain with Gamma Distribution for daily precipitation is adopted in this work. Based on this framework, four parameters of precipitation simulation for each month at 672 stations all over China were determined using daily precipitation data from 1961 to 2000. Compared with previous works, our estimation for the parameters was made for more stations and longer observations, which makes the weather generator more applicable and reliable. Spatial distributions of the four parameters are analyzed in a regional climate context. The seasonal variations of these parameters at five stations representing regional differences are discussed. Based on the estimated monthly parameters at 672 stations, daily precipitations for any period can be simulated. A 30-year simulation was made and compared with observations during 1971-2000 in terms of annual and monthly statistics. The results are satisfactory, which demonstrates the usefulness of the weather generator. 相似文献
8.
中国天气发生器的降水模拟 总被引：1，自引：0，他引：1
A stochastic model for daily precipitation simulation in China was developed based on the framework of a ‘Richardson-type‘ weather generator that is an important tool in studying impacts of weather/climate on a variety of systems including ecosystem and risk assessment. The purpose of this work is to develop a weather generator for applications in China. The focus is on precipitation simulation since determination of other weather variables such as temperature is dependent on precipitation simulation. A framework of first order Markov Chain with Gamma Distribution for daily precipitation is adopted in this work. Based on this framework, four parameters of precipitation simulation for each month at 672 stations all over China were determined using daily precipitation data from 1961 to 2000. Compared with previous works, our estimation for the parameters was made for more stations and longer observations, which makes the weather generator more applicable and reliable. Spatial distributions of the four parameters are analyzed in a regional climate context. The seasonal variations of these parameters at five stations representing regional differences are discussed.Based on the estimated monthly parameters at 672 stations, daily precipitations for any period can be simulated. A 30-year simulation was made and compared with observations during 1971-2000 in terms of annual and monthly statistics. The results are satisfactory, which demonstrates the usefulness of the weather generator. 相似文献
9.
纵向岭谷区北回归线一带年降水区域分异特征 总被引：6，自引：3，他引：3
利用纵向岭谷区北回归线沿线及南北两侧的24 个站点1961-2007 时段月降水资料,基于全部站点的年降水主要特征统计,以及北回归线沿线的9 个站点的年降水变化的趋势性和阶段性检验、9 个站点间的年降水和5-10 月各月降水序列的相关性检验,分析研究区的年降水及变化分异特征。结果表明：研究区年降水主要特征及其年际变化,呈现出西部、中部、东部的空间分异,即三个区域各自内部自相似度高,而三个区域之间分异明显。北回归线沿线9 个站点的年降水序列都未表现出明显的“突变趋势性-阶段性”变化。研究区中部“岭-谷”相间的地形格局,对中部区域降水空间分异产生一定的影响,但相邻站点间多年际降水序列呈高度相关,意味着控制中部区域降水的决定性因素并不存在明显分异,间隔分布的“岭-谷”地形会带来局地性降水量的分异。 相似文献
10.
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
11.
基于PRISM和泰森多边形的地形要素日降水量空间插值研究 总被引：25，自引：5，他引：20
以黑河流域河西走廊中段地区为例,利用该研究区年、月降水与地形间较强的相关性特点,在PRISM方法的基础上对该地区日降水量进行了空间插值计算。文章提出了以月降水量的PRISM空间插值结果为该月逐日降水空间分布的参考本底,利用泰森多边形方法确定空间日降水的概率,从而实现黑河流域河西走廊中段地区日降水的空间制图方法,并对该方法得到的日降水时空数据集进行了误差分析和评估。分析结果表明,这一方法简单可靠,满足分布式水文模型或相关陆表过程分布式模拟对分布式日降水数据时空精度的要求。 相似文献
12.
1960～1997年新疆北部降水序列的趋势探测 总被引：25，自引：13，他引：25
利用非参数统计检验法（Mann-Kendall法）分析了新疆北部地区13个气象台站1961-1997近40年降水序列的趋势。因季节性差异，对1月、4月、7月、10月的降水序列也进行了分析。结果表明，1961-1997年新疆北部地区年降水序列大致存在增加的趋势，但不是很普遍；多数测站的年降水序列无趋势。以4月、10月为代表的春秋季降水量没有趋势存在；在少数测站以1月为代表的冬季降水序列出现了上升趋势，说明1961-1997年间新疆北部冬降水量有一定量的增加；3个测站在以7月以代表的13个夏季降水序列中出现了上升趋势，还有一个测站出现了下降趋势，说明新疆北部地区夏季降水在1961-1997年间有少量的增加，并且降水变化趋势存在一定的地区差异。 相似文献
13.
新疆北部的降水量线性变化趋势特征分析 总被引：4，自引：6，他引：4
应用新疆北疆地区以及天山山区26个气象站1961-2005年的月降水量资料,分析了新疆北部地区、天山山区、北疆沿天山经济带、北疆平原、北疆北部流域、北疆西部流域6个区域的年、暖季(5-10月)、冷季(11-4月)以及各月的降水量线性趋势特征。结果显示:6个区域及26个气象站的年降水量45a年来均呈线性增加趋势;暖季降水量6个区域均呈线性增加趋势,北疆区、天山山区最显著;冷季降水量6个区域全部呈明显的线性增加趋势;月降水线性趋势变化较显著的月份为1、2、7、11、12月,其它各月没有通过0.10显著性水平检验,12个月中增湿趋势站数明显占优势的月份可占80%左右,3、9月呈下降趋势的站数较多。增湿结果已给新疆带来风吹雪、雪崩、畜牧业雪灾、洪水、融雪性洪水、泥石流、滑坡等灾害。 相似文献
14.
A two component mixed log-normal distribution effectively models annual precipitation totals at two stations in Peru characterized by widely differing interannual patterns of precipitation. Physical evidence supports the division of station records into two subsamples. Years with ENSO events and years without ENSO events identify the components of a mixed probability model. The mixed model produces a superior fit to the two parameter log-normal distribution. Model application provides a reliable means of precipitation prediction and also quantitatively describes the highly variable temporal and spatial pattern of annual precipitation in western Peru. 相似文献
15.
三江源地区1961-2010年降水时空变化(英文) 总被引：2，自引：0，他引：2
Based on a monthly dataset of precipitation time series (1961-2010) from 12 meteorological stations across the Three-River Headwater Region (THRHR) of Qinghai Province, China, the spatio-temporal variation and abrupt change analysis of precipitation were examined by using moving average, linear regression, spline interpolation, the Mann-Kendall test and so on. Major conclusions were as follows. (1) The long-term annual and seasonal precipitation in the study area indicated an increasing trend with some oscillations during 1961-2010; however, the summer precipitation in the Lantsang (Lancang) River Headwater Region (LARHR), and the autumn precipitation in the Yangtze River Headwater Region (YERHR) of the THRHR decreased in the same period. (2) The amount of annual precipitation in the THRHR and its three sub-headwater regions was greater in the 1980s and 2000s. The springs were fairly wet after the 1970s, while the summers were relatively wet in the 1960s, 1980s and 2000s. In addition, the amount of precipitation in the autumn was greater in the 1970s and 1980s, but it was relatively less for the winter precipitation, except in the 1990s. (3) The normal values of spring, summer, winter and annual precipitation in the THRHR and its three sub-headwater regions all increased, but the normal value of summer precipitation in the LARHR had a negative trend and the normal value of winter precipitation declined in general. (4) The spring and winter precipitation increased in most of the THRHR. The summer, autumn and annual precipitation increased mainly in the marginal area of the west and north and decreased in the regions of Yushu, Zaduo, Jiuzhi and Banma. (5) The spring and winter precipitation in the THRHR and its three sub-headwater regions showed an abrupt change, except for the spring precipitation in the YARHR. The abrupt changes of spring precipitation were mainly in the late 1980s and early 1990s, while the abrupt changes of winter precipitation were primary in the mid-to late 1970s. This research would be helpful for further understanding the trends and periodicity of precipitation and for watershed-based water resource management in the THRHR. 相似文献
16.
中国高分辨率温度和降水模拟数据的验证 总被引：17，自引：3，他引：17
PRISM模型是一种基于地理特征和回归统计方法生成气候图的模型。基于中国及其周边国家地区2450多个气象台站观测数据,以PRISM模型模拟生成了中国2.5′×2.5′(≈4～5km)逐月温度和降水数据。利用独立于模拟数据的中国生态系统研究网络18个野外观测站的长年气候观测数据,检验了PRISM模型的模拟结果,表明PRISM模型较好地模拟了我国温度和降水的空间分布及季节变化,除了在高山和亚热带地区由于地表覆盖和局部地形的差异影响模拟结果,其模拟值与实测值之间的趋势线同1∶1线基本一致,具有显著相关关系,其中降水效果略差 相似文献
17.
Based on the daily precipitation from a 0.5°×0.5° gridded dataset and meteorological stations during 1961-2011 released by National Meteorological Information Center, the reliability of this gridded precipitation dataset in South China was evaluated. Five precipitation indices recommended by the World Meteorological Organization (WMO) were selected to investigate the changes in precipitation extremes of South China. The results indicated that the bias between gridded data interpolated to given stations and the corresponding observed data is limited, and the proportion of the number of stations with bias between -10% and 0 is 50.64%. The correlation coefficients between gridded data and observed data are generally above 0.80 in most parts. The average of precipitation indices shows a significant spatial difference with drier northwest section and wetter southeast section. The trend magnitudes of the maximum 5-day precipitation (RX5day), very wet day precipitation (R95), very heavy precipitation days (R20mm) and simple daily intensity index (SDII) are 0.17 mm·a-1, 1.14 mm·a-1, 0.02 d·a-1 and 0.01 mm·d-1·a-1, respectively, while consecutive wet days (CWD) decrease by -0.05 d·a-1 during 1961-2011. There is spatial disparity in trend magnitudes of precipitation indices, and approximate 60.85%, 75.32% and 75.74% of the grid boxes show increasing trends for RX5day, SDII and R95, respectively. There are high correlations between precipitation indices and total precipitation, which is statistically significant at the 0.01 level. 相似文献
18.
1961-2005年水利水保措施对潮河流域年径流量的影响(英文) 总被引：1，自引：0，他引：1
Taking the Chaohe River Basin above the Miyun Reservoir in North China as a study area,the characteristics and variation trends of annual runoff and annual precipitation during 1961-2005 were analyzed applying Mann-Kendall test method on the basis of the hydrologic data of the major hydrological station(Xiahui Station) located at the outlet of the drainage basin and the meteorological data of 17 rainfall stations.Human activities including water conservancy projects construction and water diversion as well as implementation of soil and water conservation from 1961 to 2005 were carefully studied using time series contrasting method.The referenced period(1961-1980) that influenced slightly by human activities and the compared period(1981-2005) that influenced significantly by water conservancy and soil conservation measures were identified according to the runoff variation process analysis and abrupt change points detection during 1961-2005 applying double accumulative curve method,mean shift t-test method and Mann-Kendall mutation test technique.Based on the establishment of a rainfall-runoff empirical statistical model,impacts and the runoff-reducing effects of water conservancy and soil conservation measures on runoff reduction were evaluated quantitatively.The major results could be summarized as follows:(1) The annual precipitation in the drainage basin tends to decrease while the runoff has declined markedly since the 1960s,the average annual runoff from 1991 to 2000 was only 90.9% in proportion to that from 1961 to 1970.(2) The annual runoff variations in the drainage basin are significantly related to human activities.(3) During 1981-1990,1991-2000,2001-2005 and 1981-2005,the average annual runoff reduction amounts were 1.15×108,0.28×108,1.10×108 and 0.79×108 m3 respectively and the average annual runoff-reducing effects were 31.99%,7.13%,40.71% and 23.79% accordingly.Runoff-reducing effects by water conservancy and soil conservation measures are more prominent in the low water period. 相似文献
19.
云南月季气温时空变化特征 总被引：2，自引：0，他引：2
用主分量分析研究云南气温变化特点,结果表明,气温变化在空间上区域分布特点明显,时间变化呈升温趋势,且秋、冬升温明显。月、季气温空间分布呈现全省一致型、东西型、东北西南型等3种主要分布类型。通过对主分量的分析,冬季用较少的主分量就能描述气温的空间分布,而夏季需要较多的主分量才能描述气温的空间分布。不同季节的气温变化趋势不尽相同,夏季主分量有下降趋势,其它季节有上升趋势。20世纪70年代中期开始夏季气温逐渐上升,90年代中期开始秋、冬气温明显上升,且月间变化振幅较大。 相似文献
20.
Yevgeniy I. Aleksandrov Nikolay N. Bryazgin Eirik J. Førland Vladimir F. Radionov Pavel N. Svyashchennikov 《Polar research》2005,24(1-2):69-85
Observation data of temperature, precipitation and snow depth have been compiled and generalized climatologically for a network of 38 stations in and around the Barents and Kara seas, for the period 1951–1992. The monthly precipitation totals were corrected for measuring errors, and the correction method is described in detail. The corrected precipitation values show that the annual precipitation in the region ranges from more than 500 mm along the coast of the Kola Peninsula to less than 200 mm in parts of the north-eastern Kara Sea. The solid fraction of the annual precipitation ranges from 70% in northern parts to 35% in southern parts. For the period 1951–1992 the analysis indicates decreasing trends in annual values of temperature, precipitation and snow depths in the north-eastern parts of the region. 相似文献