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Risk analysis for clustered check dams due to heavy rainfall 认领
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作者 Zuyu Chen Xieping Huang +3 位作者 Shu Yu Wei Cao Weiqin Dang Yangqiang Wang 《国际泥沙研究:英文版》 SCIE 2021年第2期291-305,共15页
Check dams are commonly constructed around the world for alleviating soil erosion and preventing sedimentation of downstream rivers and reservoirs.Check dams are more vulnerable to failure due to their less stringent ... Check dams are commonly constructed around the world for alleviating soil erosion and preventing sedimentation of downstream rivers and reservoirs.Check dams are more vulnerable to failure due to their less stringent flood control standards compared to other dams.Determining the critical precipitation that will result in overtopping of a dam is a useful approach to assessing the risk of failure on a probabilistic basis and for providing early warning in case of an emergency.However,many check dams are built in groups,spreading in several tributaries in cascade forms,comprising a complex network.Determining the critical precipitation for dam overtopping requires a knowledge of its upstream dams on whether they survived or were overtopped during the same storm,while these upstream dams in turn need the information for their upstream dams.The current paper presents an approach of decomposing the dam cluster into(1)the heading dam,(2)border dams,and(3)intermediate dams.The algorithm begins with the border dams that have no upstream dams and proceeds with upgraded maps without the previous border dams until all the dams have been checked.It is believed that this approach is applicable for small-scale check dam systems where the time lag of flood routing can be neglected.As a pilot study,the current paper presents the analytical results for the Wangmaogou Check Dam System that has 22 dams connected in series and parallel.The algorithm clearly identified 7 surviving dams,with the remaining ones being overtopped for a storm of 179.6 mm in 12 h,which is associated with a return period of one in 200 years. 展开更多
关键词 Risk analysis Check dam Critical precipitation Cascade dams
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From China’s Heavy Precipitation in 2020 to a “Glocal” Hydrometeorological Solution for Flood Risk Prediction 认领
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作者 Huan WU Xiaomeng LI +10 位作者 Guy J.-P.SCHUMANN Lorenzo ALFIERI Yun CHEN Hui XU Zhifang WU Hong LU Yamin HU Qiang ZHU Zhijun HUANG Weitian CHEN Ying HU 《大气科学进展:英文版》 SCIE CAS 2021年第1期1-7,共7页
The prolonged mei-yu/baiu system with anomalous precipitation in the year 2020 has swollen many rivers and lakes,caused flash flooding,urban flooding and landslides,and consistently wreaked havoc across large swathes ... The prolonged mei-yu/baiu system with anomalous precipitation in the year 2020 has swollen many rivers and lakes,caused flash flooding,urban flooding and landslides,and consistently wreaked havoc across large swathes of China,particularly in the Yangtze River basin.Significant precipitation and flooding anomalies have already been seen in magnitude and extension so far this year,which have been exerting much higher pressure on emergency responses in flood control and mitigation than in other years,even though a rainy season with multiple ongoing serious flood events in different provinces is not that uncommon in China.Instead of delving into the causes of the uniqueness of this year’s extreme precipitation-flooding situation,which certainly warrants in-depth exploration,in this article we provide a short view toward a more general hydrometeorological solution to this annual nationwide problem.A“glocal”(global to local)hydrometeorological solution for floods(GHS-F)is considered to be critical for better preparedness,mitigation,and management of different types of significant precipitation-caused flooding,which happen extensively almost every year in many countries such as China,India and the United States.Such a GHS-F model is necessary from both scientific and operational perspectives,with the strength in providing spatially consistent flood definitions and spatially distributed flood risk classification considering the heterogeneity in vulnerability and resilience across the entire domain.Priorities in the development of such a GHS-F are suggested,emphasizing the user’s requirements and needs according to practical experiences with various flood response agencies. 展开更多
关键词 FLOODING flood risk global to local hydrological model extreme precipitation
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Precipitation Microphysical Processes in the Inner Rainband of Tropical Cyclone Kajiki (2019) over the South China Sea Revealed by Polarimetric Radar 认领
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作者 Hepeng ZHENG Yun ZHANG +2 位作者 Lifeng ZHANG Hengchi LEI Zuhang WU 《大气科学进展:英文版》 SCIE CAS 2021年第1期65-80,共16页
Polarimetric radar and 2D video disdrometer observations provide new insights into the precipitation microphysical processes and characteristics in the inner rainband of tropical cyclone(TC)Kajiki(2019)in the South Ch... Polarimetric radar and 2D video disdrometer observations provide new insights into the precipitation microphysical processes and characteristics in the inner rainband of tropical cyclone(TC)Kajiki(2019)in the South China Sea for the first time.The precipitation of Kajiki is dominated by high concentrations and small(<3 mm)raindrops,which contribute more than 98%to the total precipitation.The average mass-weighted mean diameter and logarithmic normalized intercept are 1.49 mm and 4.47,respectively,indicating a larger mean diameter and a lower concentration compared to the TCs making landfall in eastern China.The ice processes of the inner rainband are dramatically different among different stages.The riming process is dominant during the mature stage,while during the decay stage the aggregation process is dominant.The vertical profiles of the polarimetric radar variables together with ice and liquid water contents in the convective region indicate that the formation of precipitation is dominated by warm-rain processes.Large raindrops collect cloud droplets and other raindrops,causing reflectivity,differential reflectivity,and specific differential phase to increase with decreasing height.That is,accretion and coalescence play a critical role in the formation of heavy rainfall.The melting of different particles generated by the ice process has a great influence on the initial raindrop size distribution(DSD)to further affect the warm-rain processes.The DSD above heavy rain with the effect of graupel has a wider spectral width than the region without the effect of graupel. 展开更多
关键词 South China Sea cloud precipitation microphysics polarimetric radar tropical cyclone rainband
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文章速递不同光合途径植物红砂和珍珠猪毛菜幼苗对氮沉降及降水变化的光合响应 认领
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作者 田艳丽 种培芳 +1 位作者 陆文涛 贾向阳 《草地学报》 CAS CSCD 北大核心 2021年第1期121-130,共10页
氮素和水分是影响植物光合特性的重要因素,而不同光合途径植物对水、氮的响应能反映出植物与环境的关系。为探究氮沉降和降水变化对C 3植物和C 4植物生长方式的影响,以C 3植物红砂(Reaumuria soongorica)和C 4植物珍珠猪毛菜(Salaola pa... 氮素和水分是影响植物光合特性的重要因素,而不同光合途径植物对水、氮的响应能反映出植物与环境的关系。为探究氮沉降和降水变化对C 3植物和C 4植物生长方式的影响,以C 3植物红砂(Reaumuria soongorica)和C 4植物珍珠猪毛菜(Salaola passerina)为研究对象,利用盆栽试验,设置不同氮沉降水平(0 g·(m^2·a)^-1,4 g·(m^2·a)^-1,8 g·(m^2·a)-1)和不同降水处理(W-30%,W,W+30%),比较两种植物单生和混生下的光合色素、光合气体交换参数和叶绿素荧光参数等的差异。结果表明:水氮耦合使红砂和珍珠猪毛菜光合能力均增强,且在降水增加30%和施氮量8 g·(m^2·a)^-1时达最大;红砂的叶绿素、净光合速率分别最大可增加3.63倍、1.19倍,珍珠猪毛菜最大分别增加0.95倍和1.13倍。二者混生显著提高红砂的光合能力,而珍珠猪毛菜的竞争加强,氮水耦合可显著减弱竞争强度,说明在未来氮沉降和降水增加环境下,有利于红砂-珍珠猪毛菜混生群落的发展。 展开更多
关键词 氮沉降 降水 生长方式 光合特性 红砂 珍珠猪毛菜
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文章速递Tree mortality and biomass loss in drought-aff ected forests of East Texas,USA 认领
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作者 Mukti Ram Subedi Weimin Xi +2 位作者 Christopher B.Edgar Sandra Rideout-Hanzak Ming Yan 《林业研究:英文版》 SCIE CAS CSCD 2021年第1期67-80,共14页
Changes in tree mortality due to severe drought can alter forest structure,composition,dynamics,ecosystem services,carbon fl uxes,and energy interactions between the atmosphere and land surfaces.We utilized long-term(... Changes in tree mortality due to severe drought can alter forest structure,composition,dynamics,ecosystem services,carbon fl uxes,and energy interactions between the atmosphere and land surfaces.We utilized long-term(2000‒2017,3 full inventory cycles)Forest Inventory and Analysis(FIA)data to examine tree mortality and biomass loss in drought-aff ected forests for East Texas,USA.Plots that experienced six or more years of droughts during those censuses were selected based on 12-month moderate drought severity[Standardized Precipitation Evaporation Index(SPEI)-1.0].Plots that experienced other disturbances and inconsistent records were excluded from the analysis.In total,222 plots were retained from nearly 4000 plots.Generalized nonlinear mixed models(GNMMs)were used to examine the changes in tree mortality and recruitment rates for selected plots.The results showed that tree mortality rates and biomass loss to mortality increased overall,and across tree sizes,dominant genera,height classes,and ecoregions.An average mortality rate of 5.89%year−1 during the study period could be incited by water stress created by the regional prolonged and episodic drought events.The overall plot and species-group level recruitment rates decreased during the study period.Forest mortality showed mixed results regarding basal area and forest density using all plots together and when analyzed the plots by stand origin and ecoregion.Higher mortality rates of smaller trees were detected and were likely compounded by densitydependent factors.Comparative analysis of drought-induced tree mortality using hydro-meteorological data along with drought severity and length gradient is suggested to better understand the eff ects of drought on tree mortality and biomass loss around and beyond East Texas in the southeastern United States. 展开更多
关键词 Generalized nonlinear mixed model Endogenous factors Drought index Standardized precipitation evaporation index(SPEI) Above-ground biomass Competition index Biomass lost to mortality East Texas
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文章速递黄土高原刺槐人工林林下植物多样性对模拟降水变化的响应 认领
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作者 邓强 刘迪 +1 位作者 时新荣 袁志友 《水土保持研究》 CSCD 北大核心 2021年第1期1-10,共10页
气候变化对物种多样性具有重要影响,探究物种多样性对未来气候变化的响应规律是生态学研究的重点之一,但目前关于森林生态系统林下植物多样性对降水变化的响应研究仍然较少。利用野外控制穿透雨试验,观测了9个降水梯度处理(减雨80%,60%,... 气候变化对物种多样性具有重要影响,探究物种多样性对未来气候变化的响应规律是生态学研究的重点之一,但目前关于森林生态系统林下植物多样性对降水变化的响应研究仍然较少。利用野外控制穿透雨试验,观测了9个降水梯度处理(减雨80%,60%,40%,20%和增雨20%,40%,60%,80%及对照)对黄土高原刺槐人工林林下植物物种组成、群落结构和物种多样性的影响。结果表明:随着降水量的增加,土壤含水量呈增加趋势,减雨80%处理0—20 cm和20—40 cm土层土壤含水量分别比对照处理低23.6%和16.1%,增雨80%处理0—20 cm和20—40 cm土层土壤含水量分别比对照处理高26.2%和13.0%。不论降水减少或增加,都提高了蔷薇科和杂类草物种的重要值,但降低了豆科和禾本科物种的重要值,降水量的增加也提高了菊科物种的重要值。降水减少处理降低了物种多样性指数和均匀度指数,减雨80%和60%的物种多样性指数和均匀度指数显著低于对照组,而增雨20%和40%增加了物种多样性指数和均匀度指数,但增雨60%和80%降低了物种多样性指数和均匀度指数,增雨80%的物种多样性指数和均匀度指数显著低于对照组。群落物种丰富度、多样性和均匀度指数与0—20 cm土层土壤含水量呈显著正相关关系,Simpson指数与20—40 cm土层土壤含水量呈显著正相关关系(R 2=0.630)。上述结果说明,黄土高原刺槐人工林林下多为一年生植物,主要受浅层土壤含水量的影响,不同生活型和水分生态类型植物对降水变化的响应存在差异,降水变化不利于水分胁迫耐受性低的物种生存,进而影响群落物种多样性。研究结果有助于深入了解降水对物种多样性的影响以及对气候变化背景下的黄土高原植被建设和生态恢复具有重要意义。 展开更多
关键词 降水变化 土壤含水量 物种多样性 黄土高原 刺槐人工林 控制试验
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文章速递岩溶断陷盆地不同地貌部位土壤水时空分布 规律及其影响因素 认领
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作者 曾锐 张陶 +3 位作者 蒲俊兵 李建鸿 王赛男 陈金珂 《水土保持研究》 CSCD 北大核心 2021年第1期50-57,共8页
云南蒙自岩溶断陷盆地作为典型的石漠化地区,对其土壤水文过程及其影响因素的揭示是土壤保护和植被恢复的必要条件。通过在盆地、坡面、高原面设置高分辨率长期监测站,探讨云南蒙自岩溶断陷盆地不同地貌部位不同深度土壤水分的时空动态... 云南蒙自岩溶断陷盆地作为典型的石漠化地区,对其土壤水文过程及其影响因素的揭示是土壤保护和植被恢复的必要条件。通过在盆地、坡面、高原面设置高分辨率长期监测站,探讨云南蒙自岩溶断陷盆地不同地貌部位不同深度土壤水分的时空动态及其影响因素。结果显示:(1)研究区土壤水分含量的空间分布有两大趋势,一是随着海拔升高而增加,二是随着土层深度增加而降低;(2)土壤含水量雨季高于旱季,但土壤水变异程度的年内季节差异较小,属于弱变异及中等程度变异,表明研究区土壤水分的年内波动较为和缓,对植被的生长恢复有利。(3)盆地土壤水受前期土壤水分条件影响,在全年的变异程度强于坡面及高原面。同时受土壤质地及孔隙度等影响,盆地及高原面的下层土壤水分变异低于上层土壤。(4)各监测点土壤水分含量变化与降水变化的一致性较高,说明降水是影响该区土壤水分含量变化的重要因素,但由于土壤质地、植被、裸岩等因素的差异,盆地与降水之间的一致性要优于坡面及高原面。总之,云南蒙自岩溶断陷盆地不同地貌部位的土壤水分在土壤质地、植被及降水环境的综合影响下具有显著且规律的时空变化,这将有助于指导盆地的植被复建以及水资源调配工作,为岩溶断陷盆地的石漠化治理提供依据。 展开更多
关键词 土壤水 时空异质性 土壤质地 降水 植被 裸岩
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文章速递云贵高原气温与降水空间分布特征及其影响因素 认领
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作者 郭晓芳 李旭东 程东亚 《水土保持研究》 CSCD 北大核心 2021年第1期159-163,170,共6页
云贵高原地理环境复杂,气温与降水空间差异显著,研究其气温与降水空间分布特征具有重要意义。基于1981—2010年云贵高原180个气象站的平均气温、降水数据,利用克里金法、反距离权重法、样条函数法等插值方法,探究了气温与降水空间分布... 云贵高原地理环境复杂,气温与降水空间差异显著,研究其气温与降水空间分布特征具有重要意义。基于1981—2010年云贵高原180个气象站的平均气温、降水数据,利用克里金法、反距离权重法、样条函数法等插值方法,探究了气温与降水空间分布特征及其影响因素。结果表明:(1)云贵高原气温空间分布总体南高北低,乌蒙山区和云南西北部的横断山区气温相对较低。(2)云贵高原降水空间分布总体在云南南部较高,云南东北和贵州西北降水相对较少,降水在局部地区受地形影响明显。(3)云贵高原气温与降水分布的各种插值平均百分比误差中,误差依次为SPLINE>TREND>OK>KED>IDW(降水),SPLINE>TREND>IDW>KED>OK(气温),气温OK,降水IDW插值精度高,效果好。(4)云贵高原海拔每上升1000 m,气温下降范围在6.2~3.3℃,哀牢山(无量山)—横断山沿线海拔对气温的影响程度较高,但海拔对降水的影响相对复杂。 展开更多
关键词 气温 降水 空间插值 影响因素 云贵高原
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文章速递喀斯特地区降水量空间插值方法对比——以贵州省为例 认领
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作者 莫跃爽 索惠英 +5 位作者 焦树林 赵宗权 张洁 赵梦 刘炜 李银久 《水土保持研究》 CSCD 北大核心 2021年第1期164-170,共7页
利用贵州省17个气象站1960—2018年降水资料,采用反距离权重法(IDW)、普通克里金法(OK)、样条函数插值法(Spline)、趋势面插值法(Trend)4种方法,按多年平均、月平均、最大3个月及最小3个月不同降水量指标进行分析,对贵州省降水量空间插... 利用贵州省17个气象站1960—2018年降水资料,采用反距离权重法(IDW)、普通克里金法(OK)、样条函数插值法(Spline)、趋势面插值法(Trend)4种方法,按多年平均、月平均、最大3个月及最小3个月不同降水量指标进行分析,对贵州省降水量空间插值模拟结果进行了交叉检验。结果表明:4种方法的年均降水插值精度和最大3个月降水插值精度为Spline>OK>Trend>IDW;最小3个月降水量插值结果显示OK法的插值结果最好,IDW法效果最差;月降水量插值结果的MAE,MRE和RMSE的变化都呈现出明显的季节性,平均绝对误差(MAE)和均方根误差(RMSE)表现为秋冬两季误差低于春夏两季,平均相对误差(MRE)的值在春季和秋季较高,4种插值方法误差值排序为IDW>Trend>Spline>OK,OK法的插值结果较好,随着降水量的增加,模拟的降水量插值情况变差。(3)贵州省年降水量在空间上变化较大,总体上由南向北减少,年降雨量最高区域主要位于西南部,毕节地区降水最少;采用Spline法对年均降水量进行插值,出现渐变平滑条带现象,其插值结果较为均匀准确,在空间分布上符合贵州省的实际情况,空间插值较好。 展开更多
关键词 喀斯特山区 降水量 空间插值 贵州省
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文章速递基于TRMM数据的祁连山大气降水时空分布特征 认领
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作者 薛健 李宗省 +1 位作者 李宗杰 桂娟 《水土保持研究》 CSCD 北大核心 2021年第1期204-210,共7页
根据TRMM3B43卫星检测的大气降水数据信息,同时结合祁连山地区气象站点实测数据信息,分析两者相关系数和误差等指标进行TRMM降水数据的精度检验,并结合Mann-Kendall突变检验分析祁连山大气降水的变化特征。最后检验结果表明:(1)TRMM3B4... 根据TRMM3B43卫星检测的大气降水数据信息,同时结合祁连山地区气象站点实测数据信息,分析两者相关系数和误差等指标进行TRMM降水数据的精度检验,并结合Mann-Kendall突变检验分析祁连山大气降水的变化特征。最后检验结果表明:(1)TRMM3B43数据在该地区整体上精度较高,适用性良好,其中TRMM降水数据同该地区气象站点的测量数据在年尺度下相关系数为0.79,在月尺度下的相关系数为0.74,季尺度下的整体精度略低,在冬季的相关系数仅为0.44,有明显的低值高估现象;(2)祁连山地区降水的空间分布大致上呈自东向西递减的趋势且年内季节分配不均;(3)通过Mann-Kendall突变检验,发现近21年内研究区的年均降水量和季均降水量均变化复杂,并在近几年呈现上升的趋势。 展开更多
关键词 TRMM 时空变化 精度检验 降水量 祁连山
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1961—2017年华北地区降水气候特征分析 认领
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作者 杨若子 邢佩 +3 位作者 杜吴鹏 党冰 轩春怡 熊飞麟 《地理科学》 CSSCI CSCD 北大核心 2020年第9期1573-1583,共11页
基于华北地区1961—2017年的均一化降水数据,从降水量、降水强度、降水日数和降水量贡献率等方面揭示了华北地区降水的气候特征。结果表明:1961—2017年华北地区年降水量以3.2 mm/10a的速率减少,其主要原因是夏季降水的减少。空间上,降... 基于华北地区1961—2017年的均一化降水数据,从降水量、降水强度、降水日数和降水量贡献率等方面揭示了华北地区降水的气候特征。结果表明:1961—2017年华北地区年降水量以3.2 mm/10a的速率减少,其主要原因是夏季降水的减少。空间上,降水量大值区的降水趋势变化呈减少特征;降水强度呈增大趋势,降水的时间分布更加集中;小雨、暴雨和大暴雨及以上量级降水日数和贡献率呈减小趋势,而中雨和大雨则有所增加;分析各等级降水对华北地区空间分布的贡献率,小雨事件对华北地区西部降水的贡献最主要,大雨、暴雨和大暴雨对华北东南部地区降水量的贡献最为主要,这进一步解释了小雨、暴雨和大暴雨及以上量级降水量的减少造成了华北地区西部和东南部地区降水总量的下降。华北地区降水气候特征研究可为区域气候变化以及暴雨、干旱等灾害应对提供科学支撑。 展开更多
关键词 华北地区 降水量 降水强度 降水日数 降水量贡献率
Study on the Effects of Extreme Precipitation for Seven Growth Stages of Winter Wheat in Northern Weihe Loess Plateau, China 认领
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作者 Ouk Sereyrorth Baowen Yan +2 位作者 Khem Chunpanha Porn Lybun Pich Linvolak 《水资源与保护(英文)》 2020年第4期358-380,共23页
The research on the characteristic frequency of precipitation is a great significance for guiding regional agricultural planning, water conservancy project designs, and drought and flood control. Droughts and floods o... The research on the characteristic frequency of precipitation is a great significance for guiding regional agricultural planning, water conservancy project designs, and drought and flood control. Droughts and floods occurred in northern Weihe Loess Plateau, affecting growing and yield of winter wheat in the area. Based on the daily precipitation data of 29 meteorological stations from 1981 to 2012, this study is to address the analysis of three different frequencies of annual precipitation at 5%, 50%, and 95%, and to determine the amount of rainfall excess and water shortage during seven growth stages of winter wheat at 5%, 10%, and 20% frequencies, respectively. Pearson type III curve was selected for this study to analyze the distribution frequency of annual rainfall and rainfall amount following seven growth stages of winter wheat crop in 29 stations of Northern Weihe loess plateau. As a result of our study, annual precipitation is gradually increasing from southwest to northeast of Northern Weihe loess plateau. The highest amount of annual precipitation occurred in the Baoji area and the lowest precipitation covered by the northwest area of Northern Weihe loess plateau. Moreover, the amount of rainfall of seven growth stages indicates that excessive rainfall occurs not only in the first stage (sowing to tillering) and seventh stage (flowering to ripening) but also in second stage (tillering to wintering). In the seventh stage, a large amount of excessive rainfall occurred in Changwu, Bin, Qianyang, Fengxiang, Baojiqu, and Baojixian. Moreover, water shortage is distributed in the third stage (from wintering to greening), the fourth stage (from greening to jointing), the fifth stage (from jointing to heading), and the sixth stage (from heading to flowering). Furthermore, the worst water shortages occurred in Hancheng, Heyang, Chengcheng, Pucheng, Dali, Tongchuan, and Fuping in the fourth stage (greening to jointing stage). Even though we study the crop water requirement under extreme rainfall conditions, the am 展开更多
关键词 Extreme PRECIPITATION Annual PRECIPITATION SEVEN Growth Stages Winter Wheat Crop Rainfall Excess Water SHORTAGE NORTHERN Weihe Loess Plateau
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中国区域三源融合降水产品的改进效果评估 认领
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作者 孙帅 师春香 +5 位作者 潘旸 谷军霞 白磊 苏传程 韩帅 孙金森 《水文》 CSCD 北大核心 2020年第6期10-15,23,共7页
高质量、高时空分辨率的网格降水产品对于智能网格预报、水循环、地气相互作用以及防灾减灾具有重要意义。国家气象信息中心对原三源降水CMPAS(CMA Multi-source merged Precipitation Analysis System)进行了升级,进一步融合了质控后... 高质量、高时空分辨率的网格降水产品对于智能网格预报、水循环、地气相互作用以及防灾减灾具有重要意义。国家气象信息中心对原三源降水CMPAS(CMA Multi-source merged Precipitation Analysis System)进行了升级,进一步融合了质控后的国家级非考核站降水信息,研发了新的三源降水产品CMPAS_new。利用中国气象局的站点观测数据和水利部降水观测数据对CMPAS和CMPAS_new降水产品进行检验评估,并与CMORPH、GPM降水产品进行对比。结果表明:CMORPH、GPM、CMPAS和CMPAS_new降水产品都能够合理地反映出中国地区降水的空间分布;使用中国气象局逐小时站点观测进行检验评估,从误差时间序列可以看出,融合了非考核站降水观测的CMPAS_new优于CMPAS;使用水利部日降水观测数据进行检验评估,从误差时间序列、均方根误差空间分布可以看出,CMPAS_new优于其他三种降水产品,CMPAS优于GPM,GPM优于CMORPH,未来可将三源降水的背景场CMORPH替换为GPM。从个例分析看,CMPAS_new较好地监测到了四川中北部地区的降水,在广东省惠东县高潭镇强降水监测上,CMPAS_new与站点观测更为接近,能够较好地反映出高潭镇此次极端降水。 展开更多
关键词 降水 CMORPH GPM CMPAS 非考核站
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Spatial Rainfall Variability and an Increasing Threat of Drought, According to Climate Change in Uttaradit Province, Thailand 认领
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作者 Muhammad Farhan Ul Moazzam Byung Gul Lee +1 位作者 Ghani Rahman Tahir Waqas 《大气和气候科学(英文)》 2020年第3期357-371,共15页
This study presents the work commenced in northern Thailand on spatial and temporal variability of rainfall. Thirty years (1988-2017) rainfall data of eight meteorological stations were used for assessing temporal var... This study presents the work commenced in northern Thailand on spatial and temporal variability of rainfall. Thirty years (1988-2017) rainfall data of eight meteorological stations were used for assessing temporal variability and trend analysis. The results showed decreasing trend in rainfall from its first half of the observed study period (1988-2002) to last half of the time period (2003-2017) in total average annual as well as monsoonal average rainfall by 14.92% and 15.50% respectively. It was predicted from linear regression results that by 2030 the average annual and monsoonal rainfall will drop by 35% and 34.10% respectively. All stations showed negative trend except Fakara met-station in annual rainfall. In the seasonal trend analysis, the results showed decreasing trend almost in all met-stations. Mann-Kendall trend test was applied to assess the trend. All met-stations show significant negative trend. To assess drought in the study area, Standardized Precipitation Index (SPI) was applied to 12-month temporal time period. The results predicted meteorological drought in the near future. The spatial distribution of rainfall presented changing phenomena in average annual, monsoonal, winter, and summer seasons in both analyzed periods. 展开更多
关键词 Climate Change Temporal Variability Meteorological Drought Mann Kendall Test Standardized Precipitation Index
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Temporal and Spatial Characteristics of Summer Extreme Precipitation in Eastern China and Possible Causalities 认领
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作者 Yahan Zhong Mengzhou Yang Chaoxia Yuan 《地球科学和环境保护期刊(英文)》 2020年第6期36-46,共11页
In the past decades, with the increasing frequency of extreme weather and climate events, the world has suffered huge losses. Based on NCEP/NCAR reanalysis data and China regional precipitation data provided by China ... In the past decades, with the increasing frequency of extreme weather and climate events, the world has suffered huge losses. Based on NCEP/NCAR reanalysis data and China regional precipitation data provided by China Meteorological Administration, the extreme precipitation events in eastern China are defined by relative threshold method, and the temporal and spatial characteristics of summer extreme precipitation in eastern China from 1961 to 2016 are analyzed by empirical orthogonal function (EOF), and the reverse distribution of extreme precipitation in the middle and lower reaches of the Yangtze River and south China by Indian Ocean warm pool is revealed influence. The results show that the total amount and frequency of extreme precipitation in summer are concentrated in the Yangtze River Basin and south China. EOF1 decomposition of extreme precipitation reflects the interannual oscillation characteristics of reverse spatial distribution in the Yangtze River Basin and south China. The time series corresponding to EOF1 has significant interannual characteristics. The Pacific-Japan (PJ) teleconnection pattern is a circulation system that significantly affects the spatial-temporal pattern of extreme precipitation in southern China. When the PJ pattern is in the positive phase, the anticyclone controls the south China region, and restrains the convective activity, which results in the decrease of extreme precipitation. The anomalous southwest wind to the south of 30<span style="font-size:10.0pt;font-family:;" "=""><span style="font-family:Verdana, Helvetica, Arial;white-space:normal;background-color:#FFFFFF;">&#176</span></span>N and the anomalous northerly wind to the north of 30<span style="font-size:10.0pt;font-family:;" "=""><span style="font-family:Verdana, Helvetica, Arial;white-space:normal;background-color:#FFFFFF;">&#176</span></span>N converge in the middle and lower reaches of the Yangtze River. Combining with the sufficient water vapor carried by the anomalous southwest airflow at the edge of anticyclo 展开更多
关键词 Extreme Precipitation Pacific-Japan Pattern Indian Ocean Warm Pool
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Enhancing asphaltene precipitation modeling by cubic-PR solid model using thermodynamic correlations and averaging techniques 认领
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作者 Aktham E.Shoukry Ahmed H.El-Banbi Helmy Sayyouh 《石油科学:英文版》 SCIE CAS CSCD 2020年第1期232-241,共10页
Cubic equation-of-state solid models are one of the most widely used models to predict asphaltene precipitation behavior.Thermodynamic parameters are needed to model precipitation under different pressures and tempera... Cubic equation-of-state solid models are one of the most widely used models to predict asphaltene precipitation behavior.Thermodynamic parameters are needed to model precipitation under different pressures and temperatures and are usually obtained through tuning with multi asphaltene onset experiments.For the purpose of enhancing the cubic Peng–Robinson solid model and reducing its dependency on asphaltene experiments,this paper tests the use of aromatics and waxes correlations to obtain these thermodynamic parameters.In addition,weighted averages between both correlations are introduced.The averaging is based on reported saturates,aromatics,resins,asphaltene(SARA)fractions,and wax content.All the methods are tested on four oil samples,with previously published data,covering precipitation and onset experiments.The proposed wax-asphaltene average showed the best match with experimental data,followed by a SARA-weighted average.This new addition enhances the model predictability and agrees with the general molecular structure of asphaltene molecules. 展开更多
关键词 ASPHALTENE PRECIPITATION ASPHALTENE ONSET pressure ASPHALTENE PRECIPITATION MODELING ASPHALTENE THERMODYNAMICS CUBIC equation of state
1961-2018年青海高原昼夜雨量时空变化特征分析 认领
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作者 刘义花 马元仓 +2 位作者 杨延华 李斌春 朱宝文 《冰川冻土》 CSCD 北大核心 2020年第3期996-1006,共11页
基于青海高原1961-2018年47个气象站昼夜雨量数据,分析了青海高原及各生态功能区的昼夜雨量及雨日的时空变化特征。结果表明:近58年来,青海高原昼夜雨量空间分布基本一致,总体表现为东南向西北减少,夜雨日多于昼雨日分布。青海高原昼夜... 基于青海高原1961-2018年47个气象站昼夜雨量数据,分析了青海高原及各生态功能区的昼夜雨量及雨日的时空变化特征。结果表明:近58年来,青海高原昼夜雨量空间分布基本一致,总体表现为东南向西北减少,夜雨日多于昼雨日分布。青海高原昼夜雨量总体均呈增多趋势,昼雨量的增加速率大于夜雨量;从空间分布来看,柴达木盆地西部、东部农业区大部及青南牧区南部少数地区昼夜雨量呈减少趋势,而柴达木盆地东部、环青海湖地区、青南牧区大部昼夜雨量均呈增多趋势。青海高原昼雨日略有增加,夜雨日有减少趋势;在地域上,柴达木盆地昼夜雨日增多趋势明显,而东部农业区昼夜雨日减少趋势明显。青海高原昼夜雨量分别呈2a、3a的周期。近58年来,青海高原、东部农业区、环青海湖地区、柴达木地区昼雨量均无明显的突变现象,仅青南牧区昼雨量在2003年前后存在明显突变现象;青海高原、东部农业区、青南牧区夜雨量无明显突变现象,环青海湖地区、柴达木盆地夜雨量分别在1979年、2003年出现了突变现象。 展开更多
关键词 雨量 雨日 昼夜 时空变化 青海高原
山东夏季极端降水时空分布及环流特征分析 认领
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作者 时晓曚 王志轩 +2 位作者 孙即霖 孙雅文 顾瑜 《海洋湖沼通报》 CSCD 北大核心 2020年第3期45-51,共7页
本文利用2000-2018年山东省大气监测自动站的降水观测资料以及美国国家环境预报中心与美国国家大气研究中心(NCAR/NCEP)再分析的高空月平均资料、降水月平均资料以及逐日降水资料,分析了不同季节山东省极端降水的时空分布的基本特征,以... 本文利用2000-2018年山东省大气监测自动站的降水观测资料以及美国国家环境预报中心与美国国家大气研究中心(NCAR/NCEP)再分析的高空月平均资料、降水月平均资料以及逐日降水资料,分析了不同季节山东省极端降水的时空分布的基本特征,以及异常大气环流对极端降水的影响。结果表明,极端降水对山东降水的影响主要集中在夏季,山东省的东南沿海地区表现更为明显。在500hPa上,极端降水次数偏多季的环流形势表现为AO负位相,在50°N的中纬度西风上波动较为显著,降水概率随之增大。根据极端降水持续时间,将极端降水分为第一类和第二类极端降水,若200hPa上南亚高压偏东,500hPa上副高西伸,中纬度西风带的槽脊振幅明显偏大;同时,在850hPa上,高纬度波长较长,有利于冷空气直接南下和暖湿的水汽输送带交汇于山东省上空,则有利于产生第一类极端降水,反之,则易产生第二类极端降水。 展开更多
关键词 降水 极端降水 异常大气环流 时空分布
Study on Climate Changes for Flue-Cured Tobacco Growth in Chenzhou City of Hunan Province 认领
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作者 Xiangzhen Kong Decheng Li +2 位作者 Wujin Li Hongguang Li Yansong Xiao 《农业科学(英文)》 2020年第5期487-499,共13页
Chenzhou city is the most typical region of Nanling Hill Ecological Zone of flue-cured tobacco with of aroma style of burnt sweet and pure sweet in China and is the largest planting region of flue-cured tobacco in Hun... Chenzhou city is the most typical region of Nanling Hill Ecological Zone of flue-cured tobacco with of aroma style of burnt sweet and pure sweet in China and is the largest planting region of flue-cured tobacco in Hunan province. It is of significance to study the changes of climatic parameters with time because climate is the most important factor in determining the growth, yield and quality of flue-cured tobacco. In this study, the data of climatic parameters including cumulative sunshine hours(S), mean temperature (T) and cumulative precipitation (P)from 1952 to 2018 in Chenzhou were used to analyze their changes at the scales of year, whole field period and growing period of flue-cured tobacco. The results showed that at the scale of year, the cumulative S, mean T and cumulative P were ranged from 1029.0 h to 2072.1 h, from 17.1°C to 19.5°Cand from 897.1 mm to 2244.6 mm, with the means of 1449.7 h, 18.1°C and 1482.5 mm, respectively. At the scale of whole field period of flue-cured tobacco, the cumulative S, mean T and cumulative P were ranged from 298.1 h to 807.2 h, from 21.2°C to 23.9°C and from 416.7 mm to 1102.7 mm, with the means of 514.8 h, 22.3°C and 719.0 mm, respectively. At the scale of growing period of flue-cured tobacco, the annual cumulative S were ranged from 70.0 h to 257.2 h, from 77.3 h to 322.5 h and from 131.2 h to 300.3 h in the periods of rooting, flourishing and maturing with the means of 127.8 h, 190.4 h and 197.2 h, respectively. The mean temperatures were ranged from 14.2°C to 18.9°C, from 22.2°C to 26.1°C, and from 25.8°C to 29.6°C with the means of 16.4°C, 24.1°C and 28.0°C, respectively. The annual cumulative P were ranged from 69.9 mm to 553.9 mm, from 133.1 mm to 485.6 mm and from 46.4 mm to 356.8 mm in the periods of rooting, flourishing and maturing with the means of 262.5 mm, 299.9 mm and 153.9 mm, respectively. At the year scale, cumulative S annually decreased by 7.587 h, mean T annually increased by 0.02°C, while cumulative P changed irregularly with insig 展开更多
关键词 SUNSHINE Hours TEMPERATURE PRECIPITATION Flue-Cured TOBACCO Chenzhou
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1956—2018年中国降水特征的时空分布规律研究 认领
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作者 徐东坡 李金明 +3 位作者 周祖昊 刘佳嘉 严子奇 汪党献 《水利水电技术》 北大核心 2020年第10期20-27,共8页
基于中国2424个气象站点1956—2018年逐日降水数据,采用Mann-Kendall趋势性分析法、Pettitt突变分析法和小波分析法对全国及分区域的降水量演变特征进行分析,研究了全国及区域上的多种降水演变特征的时空分布规律。研究结果表明,从全国... 基于中国2424个气象站点1956—2018年逐日降水数据,采用Mann-Kendall趋势性分析法、Pettitt突变分析法和小波分析法对全国及分区域的降水量演变特征进行分析,研究了全国及区域上的多种降水演变特征的时空分布规律。研究结果表明,从全国尺度上来看:1956—2018年中国降水量呈现不显著的增加趋势,在整个系列年中无显著突变点,且仅存在以20 a为周期的一级主周期。从区域尺度上来看:(1)全国大部分区域降水量无显著的趋势性变化和突变特征,其中华南地区、华中大部、华东大部、黑龙江省以及四川省和宁夏回族自治区等地均呈现不显著的增加趋势,而华北地区和东北地区的吉林省、辽宁省,以及西南地区的云南省和贵州省等少部分地区降水量呈现不显著的减少趋势,大部分区域第一主周期为20 a左右(±2 a);(2)我国西北西部地区和西藏自治区等部分区域的降水量存在显著的增加趋势,均在80年代和90年代发生显著突变,而西北西部地区的第一主周期基本为6 a左右(±2 a),西藏地区第一主周期基本为10 a左右。 展开更多
关键词 中国 降水量 降水特征 时空分布规律
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