近50年中国光合有效辐射的时空变化(英文)

Based on long-term measurement data of weather/ecological stations over China,this paper calculated and produced annually-and seasonally-averaged Photosynthetically Active Radiation(PAR) spatial data from 1961 to 2007,using climatological calculations and spatialization techniques.The spatio-temporal variation characteristics of annually-and seasonally-averaged PAR spatial data over China in recent 50 years were analyzed with Mann-Kendall trend analysis method and GIS spatial analysis techniques.The results show that:(1) As a whole,the spatial distribution of PAR is complex and inhomogeneous across China,with lower PAR in the eastern and southern parts of China and higher PAR in the western part.Mean annual PAR over China ranges from 17.7 mol m-2 d-1 to 39.5 mol m-2 d-1.(2) Annually-and seasonally-averaged PAR of each pixel over China are averaged as a whole and the mean values decline visibly with fluctuant processes,and the changing rate of annually-averaged PAR is-0.138 mol m-2 d-1/10a.The changing amplitudes among four seasons are different,with maximum dropping in summer,and the descending speed of PAR is faster before the 1990s,after which the speed slows down.(3) The analysis by each pixel shows that PAR declines significantly(α=0.05) in most parts of China.Summer and winter play more important roles in the interannual variability of PAR.North China is always a decreasing zone in four seasons,while the northwest of Qinghai-Tibet Plateau turns to be an increasing zone in four seasons.(4) The spatial distributions of the interannual variability of PAR vary among different periods.The interannual variabilities of PAR in a certain region are different not only among four seasons,but also among different periods.     

近50 年中国光合有效辐射的时空变化特征

基于中国陆地区域1961-2007 年逐年/季节平均光合有效辐射(PAR) 的空间化数据(10km×10km),结合GIS 空间分析技术与Mann-Kendall 趋势分析方法对近50 年年/季节平均PAR进行时空变化特征分析。结果表明：① 全国PAR的空间分布差异明显,总体上呈现东南低、西部高的特点,年均PAR在17.7~39.5 mol m^-2 d^-1之间。② 全国像元平均的年/季节平均PAR表现出一个较明显的波动下降过程,年均PAR降幅为0.138 mol m^-2 d^-1/10a,不同季节下降幅度存在差异,夏季降幅最大。③ 逐像元分析显示全国大部分地区PAR呈现显著下降趋势(α = 0.05),东部趋势变化较西部明显,夏冬两季在PAR年际变化中的贡献最大。华北地区在不同季节都是下降区域,而青藏高原西北地区在不同季节都表现为上升趋势。④ PAR年际变化率空间分布在不同时段差异明显,同一地区PAR年际变化率不仅在不同季节存在差异,而且在不同时段也不相同,总体上1990年代之前PAR下降较快,之后下降趋势变缓。     

Estimation of diffuse photosynthetically active radiation and the spatiotemporal variation analysis in China from 1981 to 2010

Photosynthetically active radiation (PAR) is the energy source of plant photosynthesis, and the diffuse component can enhance canopy light use efficiency, thereby increasing the carbon uptake. Therefore, diffuse PAR is an important driving factor of ecosystem productivity models. In this study, we estimated the diffuse PAR of over 700 meteorological sites in China from 1981 to 2010 using an empirical model based on observational data from Chinese Ecosystem Research Network (CERN) and China Meteorology Administration. Then we derived the spatial data set of 10 km monthly diffuse PAR using ANUSPLIN software, and analyzed the spatiotemporal variation characteristics of diffuse PAR through GIS and trend analysis techniques. The results showed that: (1) The spatial patterns of annual average diffuse PAR during 1981-2010 are heterogeneous across China, lower in the northeast and higher in the west and south. The nationwide average value for 30 years ranges from 6.66 mol m^-2 d^-1 to 15.27 mol m^-2 d^-1, and the value in summer is the biggest while the value in winter is the smallest. (2) There is an evident increasing trend of annual diffuse PAR during recent 30 years, with the increasing amplitude at 0.03 mol m^-2 d^-1/10a. But a significant declining trend is shown in the first 10 years, and obvious anomalies can be seen in 1982, 1983, 1991 and 1992. And there is a downtrend in spring and an uptrend in all the other seasons. (3) The spatial distribution of temporal variation rates of diffuse PAR is inhomogeneous across the country, generally decreasing in the north and increasing in the south.     

秦岭南北地区光合有效辐射时空变化及突变特征

基于秦岭南北地区47个气象站1960-2011年的逐日气象数据,通过Angstrom方程和Penman-Monteith公式计算了各站点的光合有效辐射(PAR),并借助Spline空间插值、Pettitt突变点检验和相关分析等手段对PAR的空间分布、时空演变、突变特征及其可能成因进行了分析。结果表明:① 秦岭南北地区PAR的时间和空间分布特征明显,在空间上呈北高南低的分布格局;在季节分布上,夏季、春季、秋季、冬季依次减小。② 52年间,该地区年PAR整体呈显著下降趋势,下降速率由南向北,由东向西递减;时间变化方面,春季PAR呈现不显著的上升趋势,其余季节均呈下降趋势,夏季减小最快,其次为冬季,秋季最小。③ 该地区89%的站点年PAR存在突变,突变站点中的85%发生于1979-1983年间;夏季89%的站点发生突变,突变站点中的90%发生于1979-1983年间;冬季68%的站点发生突变,但突变时间同步性和一致性较差;春季和秋季突变现象不甚明显。④ 气候变化(风速下降)、城市化进程加快以及工业生产导致的气溶胶增多是导致PAR显著下降的主要原因,而火山爆发引发的气溶胶增加则是PAR波动的主要原因。     

1951-2008年中国西北干旱区降水时空变化及其趋势

在全球气候变化背景下,地处生态脆弱区的中国西北干旱区降水响应特征及其未来变化趋势的量化研究极为重要,依据中国西北干旱区95个站点1951-2008年月降水资料,运用自然正交分解法(EOF)、Morlet小波分析、轮次分析、游程理论、极差分析、季节性指数分析、Mann-Kendall检验及气候趋势系数分析等方法分析了西北干旱区降水时空变化特征及其未来趋势。结果表明:西北干旱区降水场前4个特征向量累计方差贡献率达81.61%,第一特征向量最高为48.53%,属"相间复杂"型,依据其荷载空间分布特征将研究区划分为北疆子区、南疆子区、河西子区、青海子区及内蒙古子区;西北干旱区及各子区降水存在9年及12年主周期;各地的极大丰水历时均小于极限枯水历时,单独丰水年的概率高于单独枯水年,连枯年的概率高于连丰年,干旱主要发生在新疆和河西地区;降水序列具有长期相关性,Hurst系数在0.629～0.845间波动;西北干旱区40.0%的地区降水具有明显的季节性分布;61%地区重现性指数大于0.7,降水年内分配的年际差异较小;86.3%地区降水量呈增加趋势,其中20.0%通过信度0.01的显著性检验,48.4%通过了0.05显著性检验,增幅16.6～0.1 mm/10a;11.6%地区呈减少趋势,减幅为5.2～0.3 mm/10a。     

中国近30年气候要素时空变化特征

利用1971~2000年中国603个气象站点逐日平均温度和降水量数据,借助ArcGIS空间分析工具,采用自组织特征映射模型(SOFM),对中国气候变化的时空特征进行分析。研究结果表明:近30年中国气候变化的总体特征以增温为主,增温增湿的地区面积最为广大;季节变化构型也以增温增湿为主,秋季略有异常;从年代际变化来看,1971~1980年间,中国的气候以降温为主,而从1981年开始的20年间,全国的气候变化转为增温占主导。SOFM网络分类结果可以描述为缓增温少降水、剧增温平降水、缓增温缓降水和剧增温剧降水等四种类型。     

Trend in pan evaporation and its attribution over the past 50 years in China

Trends in pan evaporation are widely relevant to the hydrological community as indicators of hydrological and climate change. Pan evaporation has been decreasing in the past few decades over many large areas with differing climates globally. This study analyzes pan evaporation data from 671 stations in China over the past 50 years in order to reveal the trends of it and the corresponding trend attribution. Mann-Kendall test shows a significant declining trend in pan evaporation for most stations, with an average decrease of 17.2 mm/10a in China as a whole, the rate of decline was the steepest in the humid region (29.7 mm/10a), and was 17.6 mm/10a and 5.5 mm/10a in the semi-humid/semi-arid region and arid region, respectively. Complete correlation coefficients of pan evaporation with 7 climate factors were computed, and decreases in diurnal temperature range (DTR), SD (sunshine duration) and wind speed were found to be the main attributing factors in the pan evaporation declines. Decrease in DTR and SD may relate to the increase of clouds and aerosol as well as the other pollutants, and decrease in wind speed to weakening of the Asian winter and summer monsoons under global climate warming.     

近50年中国蒸发皿蒸发量变化

Trends in pan evaporation are widely relevant to the hydrological community as indicators of hydrological and climate change. Pan evaporation has been decreasing in the past few decades over many large areas with differing climates globally. This study analyzes pan evaporation data from 671 stations in China over the past 50 years in order to reveal the trends of it and the corresponding trend attribution. Mann-Kendall test shows a significant declining trend in pan evaporation for most stations, with an average decrease of 17.2 mm/10a in China as a whole, the rate of decline was the steepest in the humid region (29.7 mm/10a), and was 17.6 mm/10a and 5.5 mm/10a in the semi-humid/semi-arid region and arid region, respectively. Complete correlation coefficients of pan evaporation with 7 climate factors were computed, and decreases in diurnal temperature range (DTR), SD (sunshine duration) and wind speed were found to be the main attributing factors in the pan evaporation declines. Decrease in DTR and SD may relate to the increase of clouds and aerosol as well as the other pollutants, and decrease in wind speed to weakening of the Asian winter and summer monsoons under global climate warming.     

近50 a来乌鲁木齐河源区径流变化及其机理研究

 乌鲁木齐河源区径流是供给中下游地区和乌鲁木齐市的重要水源。通过对河源区3个水文断面（1号冰川、空冰斗和总控）有观测记录以来的径流变化研究,一方面提供径流观测的最新资料,使人们对乌鲁木齐河源区径流近期变化有新的认识;另一方面通过对气候、冰川变化的综合分析,揭示乌鲁木齐河源区径流近50 a变化事实和可能的原因。结果表明：河源区3个水文断面径流自有观测记录以来整体上呈增加趋势,其中总控水文断面径流虽有增加,但不显著。影响3个水文断面径流变化的因素不同,1号冰川水文断面径流变化受控于冰川区热量条件,当消融期气温大于2 ℃时,径流呈加速增长。1号冰川径流不仅包含了冰川对气候变化的瞬时响应,也包含了冰川对气候变化的滞后响应,由冰川物质平衡和面积计算的冰川体积损失量变化较好地验证了径流变化。对于空冰斗融雪径流,降水量多寡是导致径流变化的主导因素,但冰斗区固态降水多,气温亦起着不可忽视的作用。总控水文断面径流大小与气温和降水关系比较复杂,表现为近年来气温和降水增加,径流却有下降趋势,这可能与河源区实际蒸散增强、冰川快速退缩导致径流峰值已经出现、大范围冻土消融导致的地下渗漏量增多等原因有关。     

黄河流域近50年降水变化趋势分析

本文简要分析了黄河流域降水空间分布规律,用非参数检验方法（Mann-Kendall法）对流域内77个气象站近50年的降水资料进行了年月降水序列趋势检验,并用线性回归方法与其进行了比较。结果表明,对于年降水序列,有65个气象台站呈现下降趋势,典型月（包括1月、4月、7月、10月）中4月、7月和10月对年降水下降趋势贡献较大,但其趋势空间分布情况存在差异。对于所有月降水序列,全年4⁵月以及7¹2月降水呈现下降趋势。而其趋势空间分布,黄河上游北纬35°以南地区除7⁹月外其余月份降水呈现增长趋势。渭河上游及呼和浩特地区降水趋势随月份时有变化,流域内其他地区降水则呈减少趋势。对比两种方法,Mann-Kendall方法在冬季（12月至次年2月）的检验结果中无变化趋势气象站数明显多于线性回归方法,且后者估计出的趋势变化幅度略大于Mann-Kendall方法所估计出的结果。     

近50 a中国大陆无雨日的时空变化特征分析

利用中国大陆678个台站1958-2007年的50 a逐日降水资料,分析了年、季无雨日和不同干旱程度持续性无雨日的时空特征和气候变化.结果表明:我国无雨日的空间差异很大,局地无雨日变化受大地形影响明显,无雨日高值区在南疆盆地.低值区在四川盆地,年均最大持续无雨日在南疆高于130 d,四川盆地则少于15 d.近50 a无...     

增暖背景下中国东北地区极端降水事件的演变特征

利用中国东北地区93站1959~2002年逐日降水资料,研究该区极端降水事件时空演变特征,结果表明:东北地区极端降水事件阈值由东南沿海向西北内陆逐渐减小,6~9月是极端降水事件集中出现月份;1985~2002年是极端降水事件偏多,且为一突变现象;东北地区短时间内连续发生极端降水事件概率较大,其中1~5天时间间隔极端降水事件占23.7%;80年代中期后东北地区增暖背景下,极端降水事件和有1~5天时间间隔的极端降水事件明显增加,特别是松花江下游和牡丹江流域及西辽河上游地区,频次和强度存在增加或增强趋势。     

近60 a新疆大气水分亏缺的时空变化特征

在全球陆地大气水分亏缺(VPD)已经增加、并将持续增强的背景下,新疆大气环境是否趋于干旱化值得探讨。利用1961—2020年地面气象观测资料,采用线性趋势分析、Mann-Kendall检验等方法,研究了新疆VPD的分布及时空演变特征。结果表明：(1)近60 a来新疆VPD整体呈现显著增加趋势,增幅为0.015 kPa·(10a)^-1。VPD在2005年发生突变,突变前为弱波动变化,突变后呈增加趋势。(2)各季节VPD均以增势为主,其中春、夏季增幅较大,冬季增幅最小。春、秋季VPD突变特征与年变化较为一致,夏季略晚(2006年出现突变)。(3)空间分布上,VPD呈现“山区低、盆地高”的鲜明格局。时空演变分析表明,全疆大范围地区(近83.65%的气象站点)VPD呈增势变化,而VPD呈下降趋势的站点多分布在天山山脉东段的北麓以及南疆盆地的北、西北缘。季节尺度上,春季VPD呈增势变化的站点数占比最高(96.15%),是新疆大气水分胁迫范围最广的时段,而冬季大气水汽含量相较稳定。     

Spatio-temporal variation and the driving forces of tea production in China over the last 30 years

As a daily necessity and an important cash crop in China and many other countries, tea has received increasing attention. Using production concentration index model and industry’ s barycenter theory, we analyzed the spatio-temporal distribution of tea production and barycenter movement trajectory of tea plantations and production in China between 1986 and 2015. Driving forces of the movement were also analyzed. From 1986 to 2000, tea production in China’s Mainland of grew slowly (by 210×10³ t). The continuous increase in tea yield per unit area was the primary contributor (more than 60%) to the growth in tea production during this period. Since China joined the World Trade Organization (WTO) in 2001, tea production has grown rapidly, by 1.59×10⁶ t between 2001 and 2015. The increase in the tea plantations area is the main contributor. Over the last 30 years, the barycenters of tea production in China have moved westward from the Dongting Lake Plain to the eastern fringe of the Yunnan-Guizhou Plateau. Guizhou, Guangxi, and Sichuan in southwestern China have gradually become regions of new concentrated tea plantations and main tea production provinces. Lower cost of land and labor in southwestern China are the main drivers of the westward movement of China’s tea industry. In addition, supportive policies and the favorable natural geographical environment contribute to the westward movement of tea industry. Our research highlights the spatio-temporal variation of China’s tea production in the last three decades. The result indicates importance to make appropriate policies to promote the development of tea industry in China.     

近15a陕西省植被时空变化与影响因素分析

利用2000—2014年MODIS/NDVI时间序列数据,采用栅格像元趋势分析、稳定性评价的方法,研究了陕西省近15 a植被的时空变化特征和规律;利用Hurst指数对陕西省植被未来变化趋势进行了预测;并利用相关性分析法分析了NDVI与年均温度和降雨量的关系。结果表明,2000年、2015年陕西省NDVI均值分别为0.4273、0.4942, 15 a来增加了0.067,增长了16.0%,其中陕北地区NDVI增加明显,关中部分地区出现负增长,陕南地区NDVI总体依旧维持在较高水平。陕西省植被变化趋势具有明显的空间差异性,全省植被未变化的占52.0 %,改善部分占44.27 %,退化部分占3.73%,说明15 a间陕西省植被覆盖改善面积大于退化面积,植被状况有所改善;其中陕北地区植被呈明显改善区域面积较大,关中地区植被覆盖面积有所减少,陕南地区植被变化幅度较小。陕西省植被稳定区域占50%以上（0 0.2),说明15a间陕西省植被较为稳定,变化程度不大;其中陕西省植被最稳定地区主要集中在陕南、延安南部,榆林部分、西安、渭南少部地区变化幅度较大。Hurst指数分析表明陕西省44.54%面积的植被未来有可能面临退化,主要分布在陕北和关中地区的北部,植被未来有可能退化也有可能改善的面积占49.78%,主要分布在延安和陕南地区。陕西省近15 a气温和降水量总体呈增加趋势,增加速率分别为0.48 ℃·(10 a)-1和69.5 mm ( a)-1;相关性分析结果表明,年均降雨量是影响NDVI的主要气象因子,同时陕西省植被变化也受到了退耕还林还草、防沙治沙、生态政治等人为因素的影响。     

中国近50年降水变化趋势及突变的Hurst指数试验

利用1953-2002年中国722个台站的降水资料,应用分形理论中的R/S分析法基本原理,设计了两种降水Hurst指数试验,研究预测了中国五大区年降水的气候变化趋势及其突变。通过两种试验对比得出:年降水20年试验能有效确定降水状态的转折点,进而判断降水变化的突变。研究表明:中国五大区年雨日有着完全一致的减少趋势,期间不存在年雨日由减少转为增加的突变点。今后年雨日仍将继续减少,依照五大区气候倾向率,未来10年,东部北方区、西北区、东部南方区、西南区、青藏高原区平均每10年减少雨日分别为6.8天、4.1天、5.9天、11.4天和3.7天。中国1953-2002年,有三次降水量突变。第一次年降水量由减少突变为增加,它包括了东部北方区的H11980、西北区的H11981和青藏高原的H11982;第二次年降水量由增加突变为减少,它依次包括上述三区的H21988,H21985和H21987;第三次年降水量由减少突变为增加,它仅包括青藏高原的H31991。中国五大区中,东部北方区和西北区的年降水量未来10年仍将继续减少,依气候倾向率,它们平均每10年分别减少15.3 mm和6.2 mm。东部南方区、西南区、青藏高原未来10...     

石羊河流域近50 a来日照时数的时空变化特征分析

 基于石羊河流域5个气象站点1959—2008年的日照时数资料,采用气候倾向率分析、Kriging空间插值、Mann-Kendall检验、小波分析等方法对石羊河流域日照时数的变化特征进行了分析。结果表明,近50 a来,石羊河流域年日照时数呈显著增加趋势,其变化倾向率为33.9 h/10a;四季日照时数均呈增加趋势,春季增加最显著,对年日照时数的贡献率最大,冬季次之。石羊河流域日照时数空间差异显著,表现为年日照时数自南向北递增。突变分析表明,1987年为日照时数的突变年。Morlet小波分析表明,石羊河流域年日照时数存在8 a的显著周期。     

Forest change of China in recent 300 years

Based on historical documents, modern survey and statistics, as well as the result of predecessor studies, the trend and main process of forest dynamics are recognized. The forest area and forest coverage rates for each province of China from 1700 to 1949 are es-timated backward by every 50 years. Linking the result with modern National Forest Inventory data, the spatial-temporal dynamics of Chinese forest in recent 300 years (AD 1700–1998) is quantitatively analyzed. The study shows that in recent 300 years, the forest area in current territory of China has declined by 0.95×108 hm2 (or 9.2% of the coverage rate) in total, with a trend of decrease and recovery. Before the 1960s, there was a trend of accelerated de-scending. The forest area was reduced by 1.66×108 hm2 (or 17% of the coverage rate) in 260 years. While after the 1960s, there has been a rapid increase. The forest area increased by 0.7×108 hm2 (or 8% of the coverage rate) in 40 years. The study also shows that there is a significant spatial difference in the dynamics of forest. The amplitudes of increasing and de-creasing in western China are both smaller than the ones in eastern China. During the rapid declining period from 1700 to 1949, the most serious decrease appeared in the Northeast, the Southwest and the Southeast, where the coverage rate in most provinces dropped over 20%. In Heilongjiang Province, the coverage rate dropped by 50%. In Jilin Province, it dropped by 36%. In Sichuan Province and Chongqing Municipality, it dropped by 42%. In Yunnan Prov-ince, it dropped by 35%. During the recovery period 1949–1998, the western provinces, mu-nicipality and autonomous regions, including Ningxia, Gansu, Inner Mongolia, Si-chuan–Chongqing, Yunnan, Tibet, Xinjiang and Qinghai, etc, the increase rates are all below 5%, while the eastern provinces, municipality and autonomous regions (except Heilongjiang, Hubei, Jiangsu–Shanghai) have achieved an increase over 5%, among which the Guang-dong–Hainan, Guangxi, Anhui, Beijing–Tianjin–Hebei, Shandong, Henan, Zhejiang, and Fu-jian have an increase over 10%.     

300年来中国森林的变化

Based on historical documents, modern survey and statistics, as well as the result of predecessor studies, the trend and main process of forest dynamics are recognized. The forest area and forest coverage rates for each province of China from 1700 to 1949 are estimated backward by every 50 years. Linking the result with modern National Forest Inventory data, the spatial-temporal dynamics of Chinese forest in recent 300 years （AD 1700-1998） is quantitatively analyzed. The study shows that in recent 300 years, the forest area in current territory of China has declined by 0.95×10^8 hm^2 （or 9.2% of the coverage rate） in total, with a trend of decrease and recovery. Before the 1960s, there was a trend of accelerated descending. The forest area was reduced by 1.66×10^8 hm^2 （or 17% of the coverage rate） in 260 years. While after the 1960s, there has been a rapid increase. The forest area increased by 0.7×10^8 hm^2 （or 8% of the coverage rate） in 40 years. The study also shows that there is a significant spatial difference in the dynamics of forest. The amplitudes of increasing and decreasing in western China are both smaller than the ones in eastern China. During the rapid declining period from 1700 to 1949, the most serious decrease appeared in the Northeast, the Southwest and the Southeast, where the coverage rate in most provinces dropped over 20%. In Heilongjiang Province, the coverage rate dropped by 50%. In Jilin Province, it dropped by 36%. In Sichuan Province and Chongqing Municipality, it dropped by 42%. In Yunnan Province, it dropped by 35%. During the recovery period 1949-1998, the western provinces, municipality and autonomous regions, including Ningxia, Gansu, Inner Mongolia, Sichuan-Chongqing, Yunnan, Tibet, Xinjiang and Qinghai, etc, the increase rates are all below 5%, while the eastern provinces, municipality and autonomous regions （except Heilongjiang, Hubei, Jiangsu-Shanghai） have achieved an increase over 5%, among which the Guangdong-Hainan, Guangxi, Anhui, Beijing-Tianjin-H     

西北地区东部可利用降水的时空变化特征

 利用西北地区东部91站1961-2009年间的实测气温降水资料,分别计算了该区水分资源各分量降水、蒸发及可利用降水,使用REOF等统计方法,整体分析了该区可利用降水的时空变化特征。结果表明：西北地区东部水分资源匮乏且年际变化大,水分资源各分量时空分布极不均匀;总体上各分量从该区东南部向西北部递减,呈南多北少特征,其中该区东南侧的陕南、陇南、六盘山区及青藏高原东部部分地区年降水量、蒸发量和可利用降水量分别在500、200和200 mm以上,年降水可利用率在30%~50%,可利用降水标准差达80~110 mm,而该区西部的河西走廊和青海西部的年降水量不足50 mm、年可利用降水量不到10 mm,年降水可利用率不足10%,可利用降水标准差在20 mm以下;各分量夏季最大,冬季最小,5~9月是该区主要降水和可利用降水的集中期;降水在水资源各分量中起决定性作用,因此降水的小幅变化导致可利用降水的大幅变化是降水稀少的西北地区东部可利用降水资源匮乏的主要原因,但气温变化造成的影响也不可忽视;西北地区东部5~9月可利用降水异常分布的局域特征明显,常出现陇南、河东、高原、河西走廊等4种异常分布特征。近50 a来,区内可利用降水总体呈东部减少(六盘山区及陇南区尤甚),西部增加的变化格局。