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Portable rainfall simulator for plot-scale investigation of rainfall-runoff,and transport of sediment and pollutants 预览
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作者 Julien Boulange Farag Malhat +2 位作者 Piyanuch Jaikaew Kazuki Nanko Hirozumi Watanabe 《国际泥沙研究:英文版》 SCIE 2019年第1期38-47,共10页
A low-cost,simple to use portable rainfall simulator is developed for use over a 5m2 plot.The simulator is easy to transport and assemble in the field,thereby allowing for necessary experimental replicates to be done.... A low-cost,simple to use portable rainfall simulator is developed for use over a 5m2 plot.The simulator is easy to transport and assemble in the field,thereby allowing for necessary experimental replicates to be done.It provides rainfall intensities of between 20 and 100 mm/h by changing the number and type of silicon nozzles used.The Christiansen coefficient of uniformities obtained in the field are appropriate and vary from 79 to 94%for rainfall intensities ranging from 30 to 70 mm/h.In addition,the median volumetric drop diameters measured for rainfall intensities of 30,50,and 70 mm/h are in the lower range of that of natural rainfall and equal to 1.1070.08,1.6970.21,and 1.6670.20 mm,respectively.The velocities of the raindrops with diameters less than 1.2mm reached terminal velocities,while raindrops less than 2.0mm achieved velocities reasonably close to the terminal velocity of natural rainfall.Furthermore,the average time-specific kinetic energy(KET)for rainfall intensities of 30,50,and 70 mm/h are 257.7,760.1,and 1645.2 J/m2/h,respectively accounting for about 78.0 and 86.5%of the KET of natural rainfall for 50 and 70 mm/h rainfall intensity,respectively.The applicability of the portable rainfall simulator for herbicide transport study is investigated using two herbicides(atrazine and metolachlor);herbicide losses in runoff and sediment samples are in the ranges reported in the literature.As a percentage of the amount of herbicide applied,5.29%of atrazine and 2.15%of metolachlor are lost due to combined water and sediment runoff.The results show that the portable rainfall simulator can be effectively used in studying processes such as pesticide runoff,infiltration mechanisms,and sediment generation and transport at a field plot scale with an emphasis on how surface characteristics such as slope and soil properties affect these processes. 展开更多
关键词 RAINFALL simulator RAINFALL intensity RAINDROP energy RAINDROP size distribution RAINFALL UNIFORMITY
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海南省60多年来降雨量及降雨侵蚀力变化趋势 预览
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作者 孙丽丽 査轩 《亚热带水土保持》 2019年第1期1-6,共6页
为了分析海南省降雨量、侵蚀性降雨量及降雨侵蚀力在不同时间尺度上的变化趋势及其相关性,根据该地区1952~2015年的日降雨量数据资料,采用变异系数、趋势系数和气候趋势率等方法分析不同时间尺度的降雨、侵蚀性降雨和降雨侵蚀力的变化... 为了分析海南省降雨量、侵蚀性降雨量及降雨侵蚀力在不同时间尺度上的变化趋势及其相关性,根据该地区1952~2015年的日降雨量数据资料,采用变异系数、趋势系数和气候趋势率等方法分析不同时间尺度的降雨、侵蚀性降雨和降雨侵蚀力的变化趋势。结果表明:①1952~2015年海南省年平均降雨侵蚀力和降雨量分别为514.96 MJ·mm/(hm~2·h)和1 751.50 mm。降雨侵蚀力和降雨总量年际波动显著,年均侵蚀性降雨量、年均降雨量、年均降雨侵蚀力变异系数分别为24.43%、24.14%、21.71%。且年内变化较大,均主要集中在5~10月。②总体上春冬降雨侵蚀力呈减少趋势,趋势系数分别为-0.008、-0.002,夏秋降雨侵蚀力呈增加趋势,趋势系数分别为0.21、0.14。③月降雨量和降雨侵蚀力的变化趋势基本一致,5、7、8、10月降雨量呈增加趋势,趋势系数分别为0.08、0.22、0.04、0.30;5、7、8、10、12月降雨侵蚀力呈增加趋势,趋势系数分别为0.07、0.34、0.16、0.44、0.10。④相关分析表明,年降雨量、年侵蚀性降雨量和年降雨侵蚀力这三者之间呈极显著正相关,相关系数均大于0.99。本研究结果可为该地区及海南省水土流失防治及土壤侵蚀机理研究提供数据和理论支撑。 展开更多
关键词 降雨量 侵蚀性降雨量 降雨侵蚀力 趋势系数 倾向率
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Characteristics of runoff processes and nitrogen loss via surface flow and interflow from weathered granite slopes of Southeast China
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作者 DENG Long-zhou FEI Kai +3 位作者 SUN Tian-yu ZHANG Li-ping FAN Xiao-juan NI Liang 《山地科学学报:英文版》 SCIE CSCD 2019年第5期1048-1064,共17页
Rainfall intensity and slope gradient are two of the most important factors affecting the variations of runoff nitrogen(N).However,the effects of slope gradient and rainfall intensity on N loss via surface flow and in... Rainfall intensity and slope gradient are two of the most important factors affecting the variations of runoff nitrogen(N).However,the effects of slope gradient and rainfall intensity on N loss via surface flow and interflow on weathered granite slopes are poorly understood.In this study,12 artificial rainfalls(three rainfall intensities and four slope gradients)were simulated to investigate the coupling loss characteristics of surface flow–interflow–total nitrogen(TN),nitrate nitrogen(NO3--N)and ammonia nitrogen(NH4+-N)on weathered granite slopes.The results show that slope gradient has a greater impact on the surface flow when the rainfall intensity is relatively large.The effect gradually weakens with the decrement of rainfall intensity.The interflow yield increases firstly with the prolongation of rainfall duration,then tends to be stable and finally decreases.The total surface flow percentage increases with rainfall intensity while it decreases with increasing slope gradient with a range of 10.88%-71.47%.The TN loss concentration of the surface flow continually decreases with rainfall duration while that of the interflow shows different fluctuations.However,the TN loss loads of both surface flow and interflow increase with increasing rainfall intensity and slope gradient.The NO3--N concentration of interflow is much higher than that of the surface flow.The NH4+-N concentration is always less than that of NO3--N with no significant difference between surface flow and interflow.The percentages of the TN,NO3--N,and NH4+-N total loss load and concentration of surface flow and interflow were analyzed.The results show that N loss via both surface flow and interflow occurs mainly in the form of NO3--N.Most of the N loss is caused by interflow which is the preferential path of runoff nutrient loss.These findings provide data support and underlying insights for the control of runoff and N loss on the weathered granite slopes. 展开更多
关键词 Simulated RAINFALL Nitrogen loss Surface flow INTERFLOW SLOPE GRADIENT RAINFALL intensity Weathered GRANITE SLOPE
Differences between Convective and Stratiform Precipitation Budgets in a Torrential Rainfall Event 预览
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作者 Yongjie HUANG Yaping WANG Xiaopeng CUI 《大气科学进展:英文版》 SCIE CAS CSCD 2019年第5期495-509,共15页
Differences in rainfall budgets between convective and stratiform regions of a torrential rainfall event were investigated using high-resolution simulation data produced by the Weather Research and Forecasting(WRF)mod... Differences in rainfall budgets between convective and stratiform regions of a torrential rainfall event were investigated using high-resolution simulation data produced by the Weather Research and Forecasting(WRF)model.The convective and stratiform regions were reasonably separated by the radar-based convective–stratiform partitioning method,and the threedimensional WRF-based precipitation equation combining water vapor and hydrometeor budgets was further used to analyze the rainfall budgets.The results showed that the magnitude of precipitation budget processes in the convective region was one order larger than that in the stratiform region.In convective/stratiform updraft regions,precipitation was mainly from the contribution of moisture-related processes,with a small negative contribution from cloud-related processes.In convective/stratiform downdraft regions,cloud-related processes played positive roles in precipitation,while moisture-related processes made a negative contribution.Moisture flux convergence played a dominant role in the moisture-related processes in convective or stratiform updraft regions,which was closely related to large-scale dynamics.Differences in cloud-related processes between convective and stratiform regions were more complex compared with those in moisture-related processes.Both liquid-and ice-phase microphysical processes were strong in convective/stratiform updraft regions,and ice-phase processes were dominant in convective/stratiform downdraft regions.There was strong net latent heating within almost the whole troposphere in updraft regions,especially in the convective updraft region,while the net latent heating(cooling)mainly existed above(below)the zero-layer in convective/stratiform downdraft regions. 展开更多
关键词 CONVECTIVE RAINFALL STRATIFORM RAINFALL precipitation BUDGET UPDRAFT REGION downdraft REGION
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Evaluation of a traditional method for peak flow discharge estimation for floods in the Wenchuan Earthquake area,Sichuan Province,China
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作者 GUO Xiao-jun CUI Peng +3 位作者 LI Yong LIU Jin-feng GE Yong-gang WANG Ci-de 《山地科学学报:英文版》 SCIE CSCD 2019年第3期641-656,共16页
Peak discharge of flood in small mountainous watershed is usually calculated using the 'Rainstorm–runoff calculation method in small watersheds in Sichuan Province'(RRM). This study evaluated the RRM calculat... Peak discharge of flood in small mountainous watershed is usually calculated using the 'Rainstorm–runoff calculation method in small watersheds in Sichuan Province'(RRM). This study evaluated the RRM calculation using real-time monitored rainfall and hydrologic data from a small watershed in the Wenchuan Earthquake area of Sichuan Province, China. The results indicated that the discharge values given by the RRM are commonly overestimating the measured discharge. The overestimation rate was discussed and empirical equations were proposed for improving RRM estimations, based on the relationship between calculated and measured discharge values at different watershed scales(2, 30, and 40 km2), under different rainfall probabilities(0.97–0.5, 0.5–0.2, and 0.2–0.002), and for different rainfall durations(0–6, 6–24, and >24 h). The results of this study help contribute to the understanding of water floods formation and help provide more accurate estimations of peak flow discharge in small watersheds in the Wenchuan Earthquake area. 展开更多
关键词 RAINFALL RUNOFF yield INFLUX PEAK DISCHARGE WENCHUAN Earthquake area
黔中喀斯特坡地浅层裂隙土壤机械组成对降雨的响应
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作者 杨宇琼 戴全厚 +1 位作者 严友进 彭旭东 《应用生态学报》 CAS CSCD 北大核心 2019年第2期545-552,共8页
运用野外取样调查结合室内吸管法,分析黔中喀斯特坡地不同土地利用类型浅层裂隙土壤机械组成随降雨的变化特征,以期为该区地下土壤漏失研究提供理论依据和技术支撑.结果表明:黔中喀斯特坡地浅层裂隙土壤粒径含量总体以粉粒为主,约占57%... 运用野外取样调查结合室内吸管法,分析黔中喀斯特坡地不同土地利用类型浅层裂隙土壤机械组成随降雨的变化特征,以期为该区地下土壤漏失研究提供理论依据和技术支撑.结果表明:黔中喀斯特坡地浅层裂隙土壤粒径含量总体以粉粒为主,约占57%.在不同降雨量的作用下,坡耕地裂隙土壤颗粒含量变化整体表现为细砂粒含量的减少和粉粒、黏粒含量的增大.草地裂隙土壤颗粒的变化主要是细砂粒含量的减少和黏粒含量的增加.乔木林地和灌木林地裂隙土壤颗粒的变化不规律.降雨量与土壤砂粒含量变化之间存在正相关关系.随着土层深度的增加,各土地利用类型的裂隙对粉粒和极粗砂粒含量的变化有一定影响,其中,粉粒含量随土层深度的增加而减少. 展开更多
关键词 喀斯特坡地 浅层裂隙 土壤机械组成 降雨 地下土壤漏失
Parameter transferability across spatial resolutions in urban hydrological modelling:a case study in Beijing,China
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作者 Xiaoshu HOU Lei CHEN +2 位作者 Xiang LIU Miao LI Zhenyao SHEN 《地球科学前沿:英文版》 SCIE CAS CSCD 2019年第1期18-32,共15页
This study examined the influence of spatial resolution on model parameterization,output,and the parameter transferability between different resolutions using the Storm Water Management Model.High-resolution models,in... This study examined the influence of spatial resolution on model parameterization,output,and the parameter transferability between different resolutions using the Storm Water Management Model.High-resolution models,in which most subcatchrnents were homogeneous,and high-resolution-based low-resolution models (in 3 scenarios)were constructed for a highly urbanized catchment in Beijing.The results indicated that the parameterization and simulation results were affected by both spatial resolution and rainfall characteristics.The simulated peak inflow and total runoff volume were sensitive to the spatial resolution,but did not show a consistent tendency.High-resolution models performed very well for both calibration and validation events in terms of three indexes:1)the Nash-Sutcliffe efficiency, 2)the peak flow error,and 3)the volume error;indication of the advantage of using these models.The parameters obtained from high-resolution models could be directly used in the low-resolution models and performed well in the simulation of heavy rain and torrential rain and in the study area where sub-area routing is insignificant.Alternatively,sub-area routing should be considered and estimated approximately.The successful scale conversion from high spatial resolution to low spatial resolution is of great significance for the hydrological simulation of ungauged large areas. 展开更多
关键词 SWMM high RESOLUTION low RESOLUTION RAINFALL characteristics PARAMETER transferability
基于时间序列模型的降雨量预测分析 预览
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作者 程敏 张耀文 +2 位作者 姜纪沂 任杰 赵振宏 《水科学与工程技术》 2019年第1期1-5,共5页
为了解济南市未来降雨的变化情况,以济南市1959~2015年降雨量数据为研究对象运用SPSS软件中时间序列模型ARIMA对其进行了建模;拟合1959~2015年的降雨量数据及预测未来5年的降雨量。ARIMA模型预测结果表明了济南市2016~2020年的年降雨量... 为了解济南市未来降雨的变化情况,以济南市1959~2015年降雨量数据为研究对象运用SPSS软件中时间序列模型ARIMA对其进行了建模;拟合1959~2015年的降雨量数据及预测未来5年的降雨量。ARIMA模型预测结果表明了济南市2016~2020年的年降雨量依次为676.5,635.5,689.8,630.7,663.3mm,5年的年平均降雨量为659.2mm,这与过去57年的多年平均降雨量较为接近,可以依此推测济南市未来5年出现干旱及洪涝灾害的可能性较小。可以看出,影响ARIMA模型预测结果的因素有很多,为了更加精准地预测降雨量,应当考虑多种要素并结合当地具体环境,建立符合当地的降水量预测模型。 展开更多
关键词 时间序列模型 ARIMA模型 预测 降雨量 SPSS
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Uncertainty on Design Critical Rainfall for Flash Flood Early Warning : A Case Study of South Branch Watershed of Censhui 预览
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作者 Li Changzhi Zhang Xiaolei +2 位作者 Zhang Miao Sun Dongya Guo Liang 《气象与环境研究:英文版》 CAS 2019年第1期31-38,42共9页
Critical rainfall estimation for early warning of rainstorm-induced flash flood is an inverse rainstorm-0x09runoff process based on warning discharge threshold for a warning station of interest in a watershed;the key ... Critical rainfall estimation for early warning of rainstorm-induced flash flood is an inverse rainstorm-0x09runoff process based on warning discharge threshold for a warning station of interest in a watershed;the key aspects of critical rainfall include rainfall amount and rainfall duration. Antecedent moisture content and storm pattern affects highly the estimation of critical rainfall. Using hydrological modeling technique with detailed sub-basin delineation and manual for design rainstorm-runoff computation, this study first introduced basic concept and analysis methods on critical rainfall for flash flood early warning, and then investigated the responses of flash flood warning critical rainfall to antecedent moisture content and storm pattern. Taking South Branch Watershed of Censhui in Hunan Province as an example, critical rainfall in scenarios of typical antecedent moisture content and storm patterns was estimated at 3 warning stations of interest in this watershed. This research illustrates that both antecedent and storm pattern play important role in the estimation of critical rainfall and enough attention should also be paid to these factors when a decision to be made on whether a warning to be issued or not. 展开更多
关键词 UNCERTAINTY DESIGN critical RAINFALL ANTECEDENT moisture content STORM pattern
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成层性非均质含水土层中柴油运移及重分布过程研究 预览
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作者 杨建丰 俞晔伟 +4 位作者 吴文宇 朱根民 潘玉英 杨金生 田丽娜 《浙江海洋大学学报:自然科学版》 CAS 北大核心 2019年第2期153-160,186共9页
柴油在现代能源中占有重要地位,但其泄漏后对含水土层的污染不容忽视。通过自制物理模型,模拟了柴油在非均质土层的运移和重分布过程,最终对土样进行化学分析,测定代表性点位的含油率和含水率。分析了土壤质地及土质界面对柴油运移范围... 柴油在现代能源中占有重要地位,但其泄漏后对含水土层的污染不容忽视。通过自制物理模型,模拟了柴油在非均质土层的运移和重分布过程,最终对土样进行化学分析,测定代表性点位的含油率和含水率。分析了土壤质地及土质界面对柴油运移范围和速度的影响,水位升降及降雨对柴油在非均质土层中重分布的影响。结果表明:柴油垂向运移速度与土粒孔隙成正比,横向运移范围与土粒孔隙成反比;当柴油运移遇到土质界面时,不会立即向下迁移,而是先在界面处聚集,并在界面处侧向运移,扩大了污染面积;随着水位上升,部分柴油向上迁移,并被土粒吸附扩大污染面积;随着水位下降,柴油下移,污染区域进一步扩大;降雨淋滤及混合稀释作用使污染物分布更均匀。成果可为柴油污染土壤后的治理与修复提供理论支持,具有重要的实际应用价值。 展开更多
关键词 柴油 非均质含水土层 运移 水位波动 降雨
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2016-2017年呼和浩特市影响手足口病发病的气象因素分析
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作者 牛涛 乌兰 +3 位作者 滕跃 张勇 田晓灵 王文瑞 《中国病毒病杂志》 CAS 2019年第1期33-38,共6页
目的探讨2016-2017年呼和浩特市影响手足口病发病的气象因素,为本地区手足口病的防控提供依据。方法收集2016-2017年呼和浩特市手足口病报告病例信息以及同期的气象资料,采用Pearson相关分析来分析各变量间的相关关系。运用主成分分析... 目的探讨2016-2017年呼和浩特市影响手足口病发病的气象因素,为本地区手足口病的防控提供依据。方法收集2016-2017年呼和浩特市手足口病报告病例信息以及同期的气象资料,采用Pearson相关分析来分析各变量间的相关关系。运用主成分分析将气象资料间的若干主成分进行提取,运用多重线性回归分析主成分与手足口病发病数之间的相互依存关系,采用逐步回归法对变量进行筛选,分析得出对手足口病发病有关的主要气象因素。结果 Pearson相关分析结果表明手足口病月发病数与平均气温、最高气温、最低气温、平均相对湿度、最小湿度、降水量呈正相关(r>0且P<0.05),与平均气压、最高气压呈负相关(r<0且P<0.05),与最低气压、平均风速、日照时数无明显的线性相关关系(P>0.05)。与手足口病月发病数相关的8个气象因素纳入主成分回归分析,结果显示主成分Z1、Z2的特征根均大于1,其累计贡献率大于95%,再选取手足口病月平均发病数作为因变量,主成分Z1、Z2作为自变量,采用逐步回归筛选自变量,进行多重线性回归分析,经检验,回归方程(Y=173.833+110.413Z1+102.685Z2)有统计学意义(F=13.084,P=0.002),决定系数R2为0.744。同时标准化残差图显示散点呈带状均匀分布,其绝对值在2以内,Durbin-Watson值为2.158,提示各气象因素之间无相关关系,无异方差性,拟合效果较好。多重线性回归分析结果表明当湿度处于33%~50%,降水量达到2.0~3.0mm,气温为18~28℃时,手足口病发病数趋于发病高峰;而气压处于890~900hPa时,手足口病发病趋于发病高峰。结论气象因素与手足口病发病有着密切的关系,主要因素有湿度、降水量、气温和气压等。对于手足口病的防控工作要结合个人、社会和气象因素等采取综合性措施,最大限度地预防和控制手足口病的发生和疫情的扩大。 展开更多
关键词 手足口病 气象因素 湿度 降水量 气温 气压
宜昌降雨中元素和有机物含量分布及其影响
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作者 杜容山 贺小敏 +1 位作者 郭丽 乔琴 《环境科学与技术》 CAS CSCD 北大核心 2019年第1期164-169,共6页
在宜昌国控酸雨监测点位采用智能降水监测仪收集2016年5月-2017年4月的自然降雨和人工增雨,采用吹扫捕集/气相色谱质谱法检测挥发性有机物含量,石墨板消解/电感耦合等离子体质谱法检测元素含量;使用SPSS等软件制图分析元素和挥发性有机... 在宜昌国控酸雨监测点位采用智能降水监测仪收集2016年5月-2017年4月的自然降雨和人工增雨,采用吹扫捕集/气相色谱质谱法检测挥发性有机物含量,石墨板消解/电感耦合等离子体质谱法检测元素含量;使用SPSS等软件制图分析元素和挥发性有机物含量的变化趋势、自然降雨与人工增雨中待测物含量的不同及城区与郊区降雨中待测物含量的差异,探讨元素和挥发性有机物对地表水的污染状况。结果表明:宜昌降雨中待测物含量最大的时段是秋冬季,不同待测物在城区和郊区降雨中的分布不一致,人工增雨中待测物含量与自然降雨差异较小,所有降雨中待测物均未对地表水造成污染。 展开更多
关键词 降雨 组分 分布 污染
Reactivation of a huge ancient landslide by surface water infiltration
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作者 TU Guo-xiang HUANG Da DENG Hui 《山地科学学报:英文版》 SCIE CSCD 2019年第4期806-820,共15页
An ancient landslide, situated in Deqin County, Yunnan Province, China, was used to investigate the reactivation by water infiltration. This study considers the infiltration process and landslide stability using finit... An ancient landslide, situated in Deqin County, Yunnan Province, China, was used to investigate the reactivation by water infiltration. This study considers the infiltration process and landslide stability using finite-element method(FEM)-based models. The results show that the reactivation of old landslide deposit was triggered by the long-term leakage of diversion ditch before October 2012, and the reactivation was triggered again by the intense rainfall on 7-9 October 2012. The old cracks, which formed in the earlier reactivation of landslide, played a key role for the rainfall infiltration. They offered a preferential path for much more rainfall to infiltrate fast into deep soil, and caused wetting front to move down faster in landslide. The old slip zone with lower permeability was another important factor to cause the infiltrated water to accumulate and form a high pore water pressure above slip zone. Then the high pore water pressure decreased the shear strength of slip zone and triggered the reactivation of the old landslide deposit again. 展开更多
关键词 LANDSLIDE Rainfall INFILTRATION Soil stability Finite-element-method Leakage of DIVERSION DITCH
代县地电阻率降雨影响及数值模拟 预览
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作者 郭文峰 曹志勇 王海龙 《地震地磁观测与研究》 2019年第2期62-70,共9页
多年观测数据表明,代县地电阻率年变受降雨影响比较显著,通过褶积滤波法获取降雨量对视电阻率的影响值,定量分析降雨与视电阻率的相关性。在此基础上,利用代县地电阻率电测深数据及相关地质资料,建立三维有限元模型,模拟降雨对地电阻率... 多年观测数据表明,代县地电阻率年变受降雨影响比较显著,通过褶积滤波法获取降雨量对视电阻率的影响值,定量分析降雨与视电阻率的相关性。在此基础上,利用代县地电阻率电测深数据及相关地质资料,建立三维有限元模型,模拟降雨对地电阻率的影响,进一步确定降雨对视电阻率影响的物理机制。结果表明:降雨是造成代县地电阻率年变的主要因素,且与视电阻率呈正相关性;降雨造成表层介质含水饱和度发生变化,使得相应电阻率下降近10倍,从而引起地电阻率年变幅度发生近1/10的改变。 展开更多
关键词 降雨 褶积滤波 表层介质 电阻率增大系数 视电阻率 数值模拟
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信阳台伸缩仪降雨干扰特征分析 预览
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作者 杨龙翔 薛秀秀 +2 位作者 闫伟 王明亮 阎楷 《大地测量与地球动力学》 CSCD 北大核心 2019年第1期103-106,共4页
利用2013~2016年信阳台伸缩仪观测资料和降雨资料,对每次降雨后伸缩仪的变化进行分析,利用M2波潮汐因子分析仪器格值的变化情况,并对观测资料进行格值归化。最后得到信阳台伸缩仪和降雨之间的回归关系,对排除降雨干扰、识别异常有借鉴... 利用2013~2016年信阳台伸缩仪观测资料和降雨资料,对每次降雨后伸缩仪的变化进行分析,利用M2波潮汐因子分析仪器格值的变化情况,并对观测资料进行格值归化。最后得到信阳台伸缩仪和降雨之间的回归关系,对排除降雨干扰、识别异常有借鉴作用。 展开更多
关键词 降雨 伸缩仪 回归分析
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降雨对巫山县城老林场回填土高边坡的影响研究 预览
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作者 王梓帆 杨鹏 +1 位作者 侯珍珠 夏宇 《山西建筑》 2019年第4期70-72,共3页
降雨对大体积回填土高边坡的影响不容忽视。以巫山县城老林场回填土高边坡为例,基于考虑流固耦合的降雨入渗过程对巫山县城老林场回填土高边坡进行数值试验,得出了巫山县城老林场回填土高边坡的渗流场、位移场、塑性区及稳定性系数变化... 降雨对大体积回填土高边坡的影响不容忽视。以巫山县城老林场回填土高边坡为例,基于考虑流固耦合的降雨入渗过程对巫山县城老林场回填土高边坡进行数值试验,得出了巫山县城老林场回填土高边坡的渗流场、位移场、塑性区及稳定性系数变化特征和规律。 展开更多
关键词 数值试验 渗流场 塑性区 稳定性系数 降雨
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温度和降水对蔬菜烟粉虱的影响 预览
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作者 顾爱祥 张网定 +3 位作者 周福才 邬亚红 张海波 韩杜斌 《环境昆虫学报》 CSCD 北大核心 2019年第2期310-315,共6页
为了探讨温度胁迫和降水对蔬菜烟粉虱种群的影响,分别利用冬季零度以下的低温、夏季高温闷棚,以及降水量和降水程度与烟粉虱种群数量的关系,研究温度和降水对蔬菜烟粉虱的种群影响。结果发现,冬季低温强度和低温时间对翌年烟粉虱的种群... 为了探讨温度胁迫和降水对蔬菜烟粉虱种群的影响,分别利用冬季零度以下的低温、夏季高温闷棚,以及降水量和降水程度与烟粉虱种群数量的关系,研究温度和降水对蔬菜烟粉虱的种群影响。结果发现,冬季低温强度和低温时间对翌年烟粉虱的种群数量有明显的影响,温度越低、低温时间越长,翌年春夏烟粉虱的种群数量越低。翌年春夏烟粉虱的种群数量和低温当量的相关关系符合下列方程:y=-63.16ln(x)+177.2(R^2=0.9102)。夏季高温闷棚后棚内温度迅速上升,闷棚1d后,棚内地面以上10cm的空气最高温度迅速上升到63.97℃,此后5d闷棚期间最高温度一直保持在64℃以上;闷棚1d后,辣椒上烟粉虱的虫口减退率达到60.41%,处理5d后成虫全部死亡。闷棚后棚内土温迅速上升,闷棚1d后,地下20cm处的温度达到了39.53℃,随着闷棚时间的延长,土温一直保持在40℃以上。降雨量和降雨时间对烟粉虱种群数量有明显的影响,降雨量3.33mm/12h的烟粉虱的虫口减退率达到84.72%,11.67mm/12h的烟粉虱的虫口减退率达到96.32%。3.33mm/12h的降雨强度处理下,处理1.5h、2.0h后烟粉虱的虫口减退率分别为92.93%和95.42%。结果表明,冬季低温、夏季高温和降水对蔬菜烟粉虱种群数量有抑制作用。 展开更多
关键词 烟粉虱 低温 高温闷棚 降雨 种群控制
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模拟降雨条件下泥沙荷载随坡面侵蚀过程的变化(英文)
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作者 孙莉英 方海燕 +4 位作者 蔡强国 杨希华 和继军 周俊良 王训明 《地理学报:英文版》 SCIE CSCD 2019年第6期1001-1020,共20页
It is of great significance to quantify sediment load changing with erosion processes for improving the precision of soil loss prediction. Indoor rainfall experiments were conducted in 2 rainfall intensities(90 mm... It is of great significance to quantify sediment load changing with erosion processes for improving the precision of soil loss prediction. Indoor rainfall experiments were conducted in 2 rainfall intensities(90 mm·h-1 and 120 mm·h-1), four slope gradients(17.60%, 26.80%, 36.40%, 46.60%) and 2 slope lengths(5 m, 10 m). Erosion processes are divided into five stages. Results show that sediment yield is mainly sourced from rill erosion, contributing from 54.60% to 95.70% and the duration of which is extended by slope gradients. Sediment load and sediment concentration are significantly different along erosion stages, with the highest values in rill development stage(SIV). Surface flow velocities(interrill and rill) demonstrate less significant differences along erosion stages. Rainfall intensity increases sediment load in all stages, with up to 12.0 times higher when changing from 90 to 120 mm·h-1. There is an increasing trend for sediment load and sediment concentration with the rising slope gradient, however, fluctuations existed with the lowest values on 26.80% and 36.40%, respectively, among different treatments. The slope gradient effects are enhanced by rainfall intensity and slope length. Results from this study are important for validating and improving hillslope erosion modelling at each erosion stage. 展开更多
关键词 RAINFALL simulation EROSION EXPERIMENTS RILL EROSION interrill EROSION sediment load
基于降雨的昆明水库蓄水模式分析及风险研究 预览
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作者 段燕楠 王占良 王顺金 《云南地理环境研究》 2019年第2期13-19,共7页
根据昆明国家基准气候站1988~2017年的降雨资料,以昆明松华坝水库为例,运用统计、比较等方法,通过分析降雨时空分布特征、蓄水地理环境特征等因素,将昆明水库蓄水模式分为雨季降雨最佳蓄水模式、干旱背景蓄水模式、局地强降雨蓄水模式... 根据昆明国家基准气候站1988~2017年的降雨资料,以昆明松华坝水库为例,运用统计、比较等方法,通过分析降雨时空分布特征、蓄水地理环境特征等因素,将昆明水库蓄水模式分为雨季降雨最佳蓄水模式、干旱背景蓄水模式、局地强降雨蓄水模式、秋季连阴雨降雨蓄水模式和冬季降雨降雪蓄水模式5种;从降雨强度、降雨历时、降雨范围3个方面对降雨蓄水风险进行评估,得出昆明由于降雨引发的蓄水风险相对小,蓄水较为安全;昆明可通过开展常态化人工增雨,增加库塘蓄水,同时加强生态环境建设,保护蓄水环境。 展开更多
关键词 降雨 水库 蓄水模式 蓄水风险评估 昆明
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考虑降雨作用的气温升高对多年冻土活动层水热影响机制
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作者 张明礼 温智 +5 位作者 董建华 王得楷 侯彦东 王斌 郭宗云 魏浩田 《岩土力学》 EI CAS CSCD 北大核心 2019年第5期1983-1992,共10页
近50 a青藏高原暖湿化趋势显著,水热边界条件的改变必然影响多年冻土的稳定性和高原生态环境的演变。已有研究主要关注气候升温对冻土温度场的影响,而对升温过程伴随的活动层水分变化研究较少。基于土壤-地表-大气水分和能量平衡的冻土... 近50 a青藏高原暖湿化趋势显著,水热边界条件的改变必然影响多年冻土的稳定性和高原生态环境的演变。已有研究主要关注气候升温对冻土温度场的影响,而对升温过程伴随的活动层水分变化研究较少。基于土壤-地表-大气水分和能量平衡的冻土水-汽-热耦合模型,以青藏高原北麓河地区2013年实测气象资料为模型驱动数据,研究在降雨不变,气温不变、气温升高1℃和升高2℃情况下活动层水热响应机制与过程。结果表明:气候升温通过改变地表能量与水分平衡过程和土壤内部水热运移分量影响多年冻土水热过程。气温升高引起地表净辐射、蒸发潜热和土壤热通量增大,而地表降雨入渗和感热通量减少;气温升高会降低土壤含水率和土壤导水系数,但温度梯度及与温度梯度相关的水分和能量分量相应增大,而与水势梯度相关的水分和能量分量相对减少;升温对土壤温度场的影响比水分场明显,影响范围也更深;随着气温升高,地表蒸发量和活动层厚度增大,气温升高加速了冻土的退化过程,与降雨增加对冻土的热稳定性影响相反。 展开更多
关键词 多年冻土 活动层 水分运移 热传递 气候变化 降雨
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