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21.
针对TRMM降水数据在中国内陆是否可靠的问题,本研究采用了Xie Pingping根据地面观测站点产生的降水数据、中国气象局公开的759个站点观测降水数据与3B42_V6版本的TRMM降水数据,在中国内陆将地面观测数据同TRMM数据进行了深入对比分析。发现TRMM降水质量受地形影响很大,迎风坡偏小背风坡与山顶偏大,TRMM降水在汛期(夏季与秋季)比站点观测降水大,枯季(冬季与春季)TRMM相对精确。所以本研究建议在对TRMM降水数据进行应用时应该进行地形矫正。 相似文献
22.
资料同化方法研究进展 总被引：3，自引：0，他引：3
数值天气预报模式的不断完善和大气观测探测资料（特别是卫星、雷达等非常规探测资料）的大量涌现,推动着资料同化方法的逐步发展.文章主要回顾了资料同化方法研究的发展过程、目前的应用现状以及对未来同化方法的展望.随着人们对资料同化含义的深入理解,对于资料同化的研究由初始的探索阶段逐步发展到以经验性为主的同化方法,主要包括SCM和nudging;统计方法的引入,成为资料同化方法研究发展道路上具有重要意义的一个里程碑,从而出现了多元统计插值同化,比如OI,3D-Var以及PSAS;针对背景误差协方差固定不变与实际情况的差异,考虑时间维的四维资料同化方法成为目前国际上较为主流的同化研究方法,其中以4D-Var和Kalman滤波为代表;随着计算机技术的进步,更加合理的四维资料同化方法将会成为未来业务预报中主要的资料同化方法. 相似文献
23.
By using Schwarz alternating method, this paper presents a simplified alternating algorithm for the problems of two holes
having arbitrary shapes and arrangements in an isotropic homogeneous linear elastic infinite region, and obtains stress and
displacement fields for random times of iteration. After precision analysis it is found that the results for twenty times
of iteration are of very high precision, and those with higher precision can be acquired if the iteration solving is further
conducted. The comparison of the results from FEM further proves the reliability of the simplified alternating algorithm presented
by this paper. 相似文献
24.
Xin Huang Hongzhuan Tan Jia Zhou Tubao Yang Abuaku Benjamin Shi Wu Wen Shuoqi Li Aizhong Liu Xinhua Li Shuidong Fen Xinli Li 《Natural Hazards》2008,47(1):65-73
Natural and man-made disasters have been increasing and affecting millions of people throughout the world. Floods are the
most common natural disasters affecting more people across the globe than all other natural or technological disasters and
also are the most costly in terms of human hardship and economic loss. In order to explore the total economic loss, components
of economic loss, and factors influencing economic loss during flooding, a retrospective study was carried out in year 2000
in areas that suffered floods in 1998 in Hunan province, China. A total of 10,722 families were investigated using a multistage
sampling method. We found that the total economic loss to the 10,722 families investigated was US$ 8.925 million; translating
into an average economic loss of US$ 832.45 per family and US$ 216.75 per person. Economic loss related to property loss,
income loss, and increased medical cost accounted for 57.38%, 40.00%, and 2.62% of the total economic loss, respectively.
Economic loss was significantly related to a family’s pre-flood income; duration of the flood; severity of flood; and type
of flood. River floods yielded the highest economic loss and drainage problem floods yielded the lowest loss. We recommended
that flood-related preventive measures should focus on the prevention of river floods and shortening the duration of floods
with the view of significantly minimizing economic losses associated with floods. 相似文献
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26.
基于遥感驱动分布式时变增益水文模型 总被引：1，自引：0，他引：1
提出了一个完全采用遥感数据驱动的分布式时变增益水文模型,该模型通过融雪、产汇流等水文过程计算,给出流量的雪盖、蒸散发、径流等水文要素。在拉萨河流域,该模型采用遥感USGS-SRTM的3秒DEM、遥感TRMM(The Tropical RainfallMeasuring Mission)降水、Modis-LST(Land Surface Temperature)数据,建立分布式水文模型,模拟了2001-2008年日水文过程。模拟结果效率系数接近0.7,相关系数接近0.8,水量平衡误差5%以内。说明完全依靠遥感驱动水文模型进行水文水资源模拟可行。该模型为解决高寒山区无资料或缺资料地区水文水资源问题提供了一个新方法。 相似文献
27.
Groundwater quality is of vital importance in groundwater safety especially for the purpose of water supply, its management becomes more and more necessary as groundwater contamination has threaten its safe use in China. The article analyzed the contamination sources of groundwater and impact of contamination on human health and water supply, the knowledge gaps were pointed and recommendations were made for groundwater quality management in China. 相似文献
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29.
Aizhong Ye Qingyun Duan John Schaake Jing Xu Xiaoxue Deng Zhenhua Di Chiyuan Miao Wei Gong 《水文研究》2015,29(10):2438-2453
For water supply, navigational, ecological protection or water quality control purposes, there is a great need in knowing the likelihood of the river level falling below a certain threshold. Ensemble streamflow prediction (ESP) based on simulations of deterministic hydrologic models is widely used to assess this likelihood. Raw ESP results can be biased in both the ensemble means and the spreads. In this study, we applied a modified general linear model post‐processor (GLMPP) to correct these biases. The modified GLMPP is built on the basis of regression of simulated and observed streamflow calculated on the basis of canonical events, instead of the daily values as is carried out in the original GLMPP. We conducted the probabilistic analysis of post‐processed ESP results falling below pre‐specified low‐flow levels at seasonal time scale. Raw ESP forecasts from the 1980 to 2006 periods by four different land surface models (LSMs) in eight large river basins in the continental USA are included in the analysis. The four LSMs are Noah, Mosaic, variable infiltration capacity and Sacramento models. The major results from this study are as follows: (1) a modified GLMPP was proposed on the basis of canonical events; (2) post‐processing can improve the accuracy and reduce the uncertainty of hydrologic forecasts; (3) post‐processing can help deal with the effect of human activity; and (4) raw simulation results from different models vary greatly in different basins. However, post‐processing can always remove model biases under different conditions. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
30.
利用MODIS可见光通道气溶胶光学厚度的卫星遥感和523 nm波长微脉冲激光雷达 (MPL LIDAR) 对气溶胶消光系数垂直分布的观测，分析了珠江三角洲地区2003年6月一次气溶胶污染过程中气溶胶光学厚度的分布特征、气溶胶消光系数廓线的演变，认为这次污染过程是弱高压控制下的区域性污染，而香港地区污染物浓度的上升与区域性输送有直接关系，结果表明卫星和激光雷达的光学遥感方法提供了研究大气污染的可行手段。 相似文献