TOVS资料真实性检验和偏差订正方案的设计   总被引：2，自引：1，他引：1  

韩桂荣  张菊芳  陈必云  冯民学  周曾奎 《气象》1998,24(7):40-44

具有空间高分辨率的卫星垂直探测（ＴＯＶＳ）资料应用于业务时,应对反演资料的偏差分布进行检验、统计、分析,以利于选取误差稳定且较小的区域（或指标点）作为寻求和归纳预报条件时可应用于业务的反演资料;同时,进一步研究和设计了误差订正方案,经比较分析,单点指标站经回归订正后误差能得到满意的改善,而经采用变分分析后的格点场质量能得到显著提高  相似文献   

北京暴雨与旱涝关系的分析   总被引：11，自引：1，他引：10       下载免费PDF全文

吴正华  储锁龙 《应用气象学报》1998,9(4):492-495

根据北京近百年的逐日降水资料,分析了汛期暴雨与汛期旱涝的关系。指出:汛期暴雨多少和强度对汛期降水丰歉具有决定性作用;在给出的3种暴雨指数中,相当暴雨日数与旱涝级别的相关性最好。文中还讨论了旱涝短期气候预测与暴雨过程的短期气候预测相结合的必要性。  相似文献   

“地气图”方法用于省级旱涝预测的实践     

郭维栋  赵红岩  李栋梁  郭英香 《干旱气象》1998,(4)

简要介绍用“地气图”方法进行降水预测的基本思路,总结此方法的预报实践,指出省级尺度旱涝预测需要解决的几个关键问题,强调除加密观测外,上游地热涡增强的能量频散作用是下游地热涡发展的重要原因  相似文献   

甘肃中部雨养农业区土壤水分预测模式的研究   总被引：5，自引：0，他引：5  

杨兴国  柯晓新  张旭东  万信 《干旱气象》1998,(4)

采用联合国粮农组织（ＦＡＯ）最新推荐的计算农田蒸散量的彭曼－蒙蒂斯公式（ＦＡＯ－ＰＭ）,选取甘肃中部雨养农业区定西１９８０～１９９５年的常规气象资料和１９９０～１９９５年固定地段０～１００ｃｍ的土壤湿度资料,对水平衡和Ｙ．Ｍ安格斯坦土壤水分预测模式进行对比分析,认为后者适宜于本地区的土壤水分预测,并分析了误差原因  相似文献   

Numerical weather prediction relevant to the monsoon problem     

T. N. Krishnamurti  John Molinari  Hua-Lu Pan  Vince Wong 《Pure and Applied Geophysics》1977,115(5-6):1357-1372

In this short paper we have identified some of the modelling groups that have the capability of simulating or carrying out short range numerical weather prediction over the monsoon belt. We have next outlined some of the important and desirable ingredients for a multilevel primitive equation model over the tropics, with most of the emphasis on the present version of Florida State University's Tropical Prediction Model. Finally, we present briefly some important results based on the present version of our prediction models that relate to the NWP efforts over the monsoon belt. Here we have identified the importance of mountains, convection, the radiative heating balance of the earth's surface, and the planetary boundary layer over the Arabian Sea.  相似文献   

STUDY OF RED TIDE PREDICTION MODEL FOR THE CHANGJIANG ESTUARY     

王正方  吕海燕  张庆  卢勇  曾江宁  周青松 《中国海洋湖沼学报》2000,18(4):350-354

ＩＮＴＲＯＤＵＣＴＩＯＮＡｑｕｉｃｕｌｔｕｒｅａｒｅａｒｅｄｔｉｄｅｓｉｇｎａｌｓｏｃｅａｎｐｏｌｌｕｔｉｏｎａｎｄｄｉｓａｓｔｅｒ.Ａｌｔｈｏｕｇｈｅｎｖｉｒｏｎｍｅｎｔｓｃｉｅｎｔｉｓｔｓｈａｖｅｃｏｎｄｕｃｔｅｄｍａｎｙｉｎ ｄｅｐｔｈｒｅｓｅａｒｃｈｅｓｏｎｔｈｅｃａｕｓｅａｎｄｆｏｒｍａｔｉｏｎｍｅｃｈａｎｉｓｍｏｆｒｅｄｔｉｄｅ ,ｍａｎｙｏｆｉｔｓａｓｐｅｃｔｓａｒｅｓｔｉｌｌｕｎｋｎｏｗｎｂｅｃａｕｓｅｒｅｄｔｉｄｅｉｓａｃｏｍｐｌｅｘｐｈｅｎｏｍｅｎｏｎａｎｄｔｈｅｅｃｏｌｏｇｉｃ…  相似文献   

A systematic approach to the input determination for neural network rainfall–runoff models     

Gwo‐Fong Lin  Guo‐Rong Chen 《水文研究》2008,22(14):2524-2530

Input determination has a great influence on the performance of artificial neural network (ANN) rainfall–runoff models. To improve the performance of ANN models, a systematic approach to the input determination for ANN models is proposed. In the proposed approach, the irrelevant inputs are removed. Then an adequate ANN model, which only includes highly relevant inputs, is constructed. Unlike the trial‐and‐error procedure, the proposed approach is more systematic and avoids unnecessary trials. To demonstrate the effectiveness of the proposed approach, an application to actual typhoon events is presented. The results show that the proposed ANN model, which is constructed by the proposed approach, has advantages over those obtained by the trial‐and‐error procedure. The proposed ANN model has a simpler architecture, needs less training time, and performs better. The proposed ANN model is recommended as an alternative to existing rainfall–runoff ANN models. Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   

最短独立闭合环与附合路线的快速搜索方法     

游为  范东明  付淑娟 《测绘科学》2009,34(4)

提出了一种间接平差误差方程转化为条件平差条件方程的快速且易实现自动化的方法,同时采用矩阵分析理论,通过对条件方程进行特殊的矩阵分块及变换,自动搜索出水准网或GPS网的最短独立闭合环与附合路线,并自动解算出闭合差。上述方法有别于传统的图论理论,不依赖于任何信息文件,算法简单,自动化程度高。  相似文献   

Internal testing of a numerical model of hillslope–channel coupling using laboratory flume experiments     

Katerina Michaelides  John Wainwright 《水文研究》2008,22(13):2274-2291

The numerical model COUP 2D simulates the hydrological coupling between hillslopes and the river channel during a rainfall event. In order to test the numerical model, a 1:100 scaled laboratory flume which was modified to incorporate lateral hillslope elements, was used to run a series of experiments in which hillslope angle, channel angle, hillslope discharge and channel discharge were the varying parameters. Overall, there were 18 different experimental configurations with three replicates carried out for each condition, leading to a total of 54 experiments. These conditions were then used to parameterize and run COUP 2D. Internal model outputs of flow depth and flow velocity at four cross‐sections in the channel were compared to the measurements made in the physical model for the same parameter conditions. Statistical comparisons of the measured and modelled data were carried out for each experiment and across all experiments, using two goodness‐of‐fit measures—root mean square error and Nash–Sutcliffe coefficient of efficiency—in order to assess the performance of the model over an entire simulation as well as over all the simulations. The main effects on the goodness‐of‐fit measures for flow depth of each experimental variable, as well as the interactions between variables, were evaluated using statistical modelling. The results show that the model captures flow‐depth variations in response to changing channel and hillslope parameters. Statistical modelling suggests that the main effects on model error are cross‐section position, channel angle and channel discharge. Significant interactions also occur between all the channel variables and between the channel variables and hillslope discharge. The results of the testing procedure have significant implications for the consideration of different model components and for the interaction between data‐ and model evaluation. Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   

浅谈三轮区划与地理信息系统     

李文鑫 《南方国土资源》1999,12(4):612

文章简单介绍了三轮区划的工作任务和技术要求 ,以及在三轮区划工作中运用地理信息系统实现多学科矿产综合预测的工作方法。  相似文献