基于奇异谱分析的江淮降水场预测模型研究   总被引：3，自引：1，他引：3  

章毅之 《气象与减灾研究》2006,29(1):34-37

中国的降水预报主要是对汛期(夏季)的单站降水量或区域的降水型态进行预报,而主要的预报方法为动力学方法和统计学方法。据此,利用江淮地区的月降水量标准化序列,得到江淮地区降水时空分布型态。并在此基础上,利用奇异谱分析和时间序列的分析方法,设计了统计学的降水预测模型,对江淮地区的月降水量进行了预测试验。结果表明,模型能对江淮降水场的趋势作出较好的预报,且递推时间短时预报效果较好。  相似文献   

Controls on the export of C, N, P and Fe from undisturbed boreal catchments, Finland   总被引：2，自引：0，他引：2  

Pirkko Kortelainen  Tuija Mattsson  Leena Finér  Marketta Ahtiainen  Sari Saukkonen  Tapani Sallantaus 《Aquatic Sciences - Research Across Boundaries》2006,68(4):453-468

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西风带系统的异常活动对2003年淮河暴雨的作用机制研究   总被引：5，自引：2，他引：5       下载免费PDF全文

李峰  林建  何立富 《应用气象学报》2006,17(3):303-309

利用NCEP/NCAR再分析资料, 分析了2003年6—7月亚洲中高纬地区阻塞形势对淮河暴雨的作用。结果表明:亚洲北部阻塞高压的建立和维持, 使得500 hPa高度上西风锋区南压, 引导冷空气南下, 造成中纬度地区冷暖空气和能量交换频繁。尤其在2003年6月20日后, 阻塞高压活动加强, 淮河流域北部维持为大气能量锋区, 低层850 hPa副热带锋区也长期停滞在35°N附近。阻塞高压的异常活动通过对大气动量和热量的一次次向南频散, 造成淮河流域连续发生暴雨天气过程。阻塞高压的强度及位置变化与前部低涡的活动密切相关, 并通过西风带基本气流及长波系统的螺旋结构的变化, 激发Rossby波的经向传播来影响副热带高压的南北进退, 从而决定了雨带的位置。  相似文献   

CHARACTERISTICS AND CAUSE ANALYSIS OFWESTERN PACIFIC SUBTROPICAL HIGH DURING THE HUAIHE RIVER FLOODS IN 2003     

金荣花  矫梅燕  徐晶  秦华锋 《热带气象学报(英文版)》2006,12(1):97-98

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Errors and uncertainty in physically-based rainfall-runoff modelling of catchment change effects   总被引：1，自引：0，他引：1  

John Ewen  Greg O&#x;Donnell  Aidan Burton  Enda O&#x;Connell 《Journal of Hydrology》2006,330(3-4):641-650

The error in physically-based rainfall-runoff modelling is broken into components, and these components are assigned to three groups: (1) model structure error, associated with the model’s equations; (2) parameter error, associated with the parameter values used in the equations; and (3) run time error, associated with rainfall and other forcing data. The error components all contribute to “integrated” errors, such as the difference between simulated and observed runoff, but their individual contributions cannot usually be isolated because the modelling process is complex and there is a lack of knowledge about the catchment and its hydrological responses. A simple model of the Slapton Wood Catchment is developed within a theoretical framework in which the catchment and its responses are assumed to be known perfectly. This makes it possible to analyse the contributions of the error components when predicting the effects of a physical change in the catchment. The standard approach to predicting change effects involves: (1) running “unchanged” simulations using current parameter sets; (2) making adjustments to the sets to allow for physical change; and (3) running “changed” simulations. Calibration or uncertainty-handling methods such as GLUE are used to obtain the current sets based on forcing and runoff data for a calibration period, by minimising or creating statistical bounds for the “integrated” errors in simulations of runoff. It is shown that current parameter sets derived in this fashion are unreliable for predicting change effects, because of model structure error and its interaction with parameter error, so caution is needed if the standard approach is to be used when making management decisions about change in catchments.  相似文献   

Spatial variation of effective porosity and its implications for discharge in an upland headwater catchment in Scotland     

L. K. Deeks  A. G. Bengough  D. Low  M. F. Billett  X. Zhang  J. W. Crawford  J. M. Chessell  I. M. Young 《Journal of Hydrology》2004,290(3-4):217-228

Spatial and temporal measurements of shallow sub-surface soil physical properties were made within a 1 km² upland catchment. The surface soil layer of the catchment was organic rich (>70% organic matter) with a corresponding total porosity of 81%. Monthly point observations of volumetric water content (θ) were combined with point estimates of total porosity () and the porosity <50 μm (_residual), to define the ratio of water filled pore volume:pore volume in pores <50 μm (=θ/_residual). Values of θ/_residual were compared with discharge to test whether mass flow occurred when θ/_residual>1. A correlation between water content and discharge was found, with discharge increasing rapidly when θ/_residual approached unity. Similar relationships between water content and catchment discharge were identified for soil units adjacent to the stream when θ/_residual approached unity. These data suggest that soil pores >50 μm are of crucial importance in determining catchment discharge. Spatial and temporal variations in soil properties related to moisture content of the soil were also observed. Under dry conditions, a clear division based on aspect was noted, the west-facing side of the catchment being wettest. In wetter months, total porosity and soil water content were significantly affected by soil type and the spatial pattern of soil water content was more variable than in the dryer months. The physical quantification of soil properties in the shallow sub-surface layer proved important in explaining different initial changes in discharge from the catchment in response to a rainfall event.  相似文献   

淮河流域夏季降水异常与北太平洋海温异常的关系   总被引：18，自引：9，他引：18  

王慧  王谦谦 《南京气象学院学报》2002,25(1):45-54

研究淮河流域降水异常与北太平洋海温异常的相关关系,初步探讨北太平洋海温异常对淮河流域降水的可能影响机制。结果表明:淮河流域夏季降水与上年8-10月北太平洋中部关键海区(162．5~177．5°W,36．5~41．5°N)的SSTA存在持续高的正相关关系;淮河流域夏季降水异常对应着一种大范围的海温异常分布型,而关键海区正好位子其相关最显著地区;正是由于北太平洋大范围持续的海温异常引起了次年夏季大气环流的异常,导致了淮河流域夏季降水异常,这也正是海温与降水具有很好相关的内在原因。  相似文献   

Modeling the impact of groundwater harvesting on the hydro-salinity of a saline catchment in southeastern Australia     

Shahbaz Khan  Muhammad Nadeem Asghar  Tariq Rana 《Hydrogeology Journal》2008,16(4):713-726

Recharge to a saline, unconfined shallow-water-table aquifer is normally considered as an irrecoverable loss of water, but such thinking could be reviewed empirically. The use of an appropriate groundwater harvesting system does not only provide an opportunity to recover this lost water, but can also help in catchment salinity management and improvement. Agricultural-based land-drainage systems such as those that use serial biological concentration (SBC) of salts, provide examples of such harvesting methods. The impact of groundwater harvesting has been assessed on the hydro-salinity of a saline catchment in southeastern Australia through modeling. For both the below average rainfall and very wet years, the “do nothing” scenario resulted in increasing salinization in the catchment. However, after introducing a SBC system, groundwater salinity showed a decreasing trend while hydraulic heads tended to stabilize around the depth of subsurface collector wells. However, for a successful groundwater harvesting system, proper understanding of the groundwater flows and salt mobilization associated with a catchment is necessary. The outcomes of this modelling study have the potential to address similar issues (salinization) and/or needs (water harvesting) existing elsewhere in the world, particularly in semi-arid regions.

Muhammad Nadeem AsgharEmail:

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1961-2018年淮河流域热浪事件时空变化特征   总被引：2，自引：0，他引：2  

王文  胡彦君  徐川怡 《地理科学》2021,41(5):911-921

利用淮河流域1961—2018年逐日最高气温与平均气温格点数据,在对基于绝对阈值和相对阈值的热浪事件识别方法进行改进的基础上,分析了逐年的热浪强度、烈度、频次、最长历时等时空变化特征。结果表明,淮河流域基于固定气温阈值的绝对热浪（>35 ℃）的多年平均强度为10.27 ℃、烈度为1.82 ℃,频次为1.3次;基于热浪指数的相对热浪多年平均强度为2.27、烈度为0.63,频次为1.0次。空间分布上,绝对热浪多发于流域西部除边缘山地的内陆地区（支流沙颖河流域）,相对热浪多发于流域西南地区（淮河干流中上游）,总体上流域东北部丘陵地区及东南近海地区的绝对、相对热浪均较弱（少）;时间变化上,淮河流域的热浪事件具有显著的趋势性突变,在20世纪60年代初至80年代早期（约1982—1985年）呈减弱（少）趋势,此后呈增强（多）趋势。  相似文献   

Assessing the temporal variance of evapotranspiration considering climate and catchment storage factors     

《Advances in water resources》2015

Understanding the temporal variance of evapotranspiration (ET) at the catchment scale remains a challenging task, because ET variance results from the complex interactions among climate, soil, vegetation, groundwater and human activities. This study extends the framework for ET variance analysis of Koster and Suarez (1999) by incorporating the water balance and the Budyko hypothesis. ET variance is decomposed into the variance/covariance of precipitation, potential ET, and catchment storage change. The contributions to ET variance from those components are quantified by long-term climate conditions (i.e., precipitation and potential ET) and catchment properties through the Budyko equation. It is found that climate determines ET variance under cool-wet, hot-dry and hot-wet conditions; while both catchment storage change and climate together control ET variance under cool-dry conditions. Thus the major factors of ET variance can be categorized based on the conditions of climate and catchment storage change. To demonstrate the analysis, both the inter- and intra-annul ET variances are assessed in the Murray-Darling Basin, and it is found that the framework corrects the over-estimation of ET variance in the arid basin. This study provides an extended theoretical framework to assess ET temporal variance under the impacts from both climate and storage change at the catchment scale.  相似文献