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1.
Lawal Billa Hamid Assilzadeh Shattri Mansor Ahmed R. Mahmud Abdul H. Ghazali 《Central European Journal of Geosciences》2011,3(3):309-317
Observed rainfall is used for runoff modeling in flood forecasting where possible, however in cases where the response time of the watershed is too short for flood warning activities, a deterministic quantitative precipitation forecast (QPF) can be used. This is based on a limited-area meteorological model and can provide a forecasting horizon in the order of six hours or less. This study applies the results of a previously developed QPF based on a 1D cloud model using hourly NOAA-AVHRR (Advanced Very High Resolution Radiometer) and GMS (Geostationary Meteorological Satellite) datasets. Rainfall intensity values in the range of 3–12 mm/hr were extracted from these datasets based on the relation between cloud top temperature (CTT), cloud reflectance (CTR) and cloud height (CTH) using defined thresholds. The QPF, prepared for the rainstorm event of 27 September to 8 October 2000 was tested for rainfall runoff on the Langat River Basin, Malaysia, using a suitable NAM rainfall-runoff model. The response of the basin both to the rainfall-runoff simulation using the QPF estimate and the recorded observed rainfall is compared here, based on their corresponding discharge hydrographs. The comparison of the QPF and recorded rainfall showed R2 = 0.9028 for the entire basin. The runoff hydrograph for the recorded rainfall in the Kajang sub-catchment showed R2 = 0.9263 between the observed and the simulated, while that of the QPF rainfall was R2 = 0.819. This similarity in runoff suggests there is a high level of accuracy shown in the improved QPF, and that significant improvement of flood forecasting can be achieved through ‘Nowcasting’, thus increasing the response time for flood early warnings. 相似文献
2.
DPFT is a lumped approach for operational flash flood forecasting, based on the unit hydrograph. Using a multi-event alternating iterative algorithm, it identifies a robust and stable average transfer function and a consistent set of effective rainfall series associated with each event at the same time. This key ingredient allows an objective calibration of different loss functions, relating gauged precipitation and effective rainfall. A case study based on an operational French basin (545 km2) is presented. Three lumped production functions have been calibrated and compared. The results show that more elaborate models of loss functions must be proposed, and some possible directions for this are pointed out. 相似文献
3.
Limitations of real-time models for forecasting river flooding from monsoon rainfall 总被引：1，自引：0，他引：1
Very intense rainfall during the southwest and northeast monsoons causes severe river flooding in India. Some traditional
techniques used for real-time forecasting of flooding involve the relationship between effective rainfall and direct surface
runoff, which simplifies the complex interactions between rainfall and runoff processes. There are, however, serious problems
in deducing these variables in real time, so it is highly desirable to have a real-time flood forecasting model that would
directly relate the observed discharge hydrograph to the observed rainfall. The storage routing model described by Baba and
Hoshi (1997), Tanaka et al. (1997), and Baba et al. (2000), and a simplified version of this model, have been used to compute observed river discharge directly from observed hourly
rainfall. This method has been used to study rainfall–runoff data of the Ajay River Basin in eastern India. Five intense rainfall
events of this basin were studied. Our results showed that the Nash–Sutcliffe efficiency of discharge prediction for these
five events was 98.6%, 94.3%, 86.9%, 85.6%, and 67%. The hindcast for the first two events is regarded as completely satisfactory
whereas for the next two events it is deemed reasonable and for the fifth it is unsatisfactory. It seems the models will yield
accurate hindcast if the rainfall is uniform over the drainage basin. When the rainfall is not uniform the performance of
the model is unsatisfactory. In future this problem can, in principle, be corrected by using a weighted amount if rainfall
is based upon multiple rain-gauge observations over the drainage basin. This would provide some measure of the dispersion
in the rainfall. The model also seems unable to simulate flooding events with multiple peaks. 相似文献
4.
DPFT is a lumped approach for operational flash flood forecasting, based on the unit hydrograph. Using a multi-event alternating iterative algorithm, it identifies a robust and stable average transfer function and a consistent set of effective rainfall series associated with each event at the same time. This key ingredient allows an objective calibration of different loss functions, relating gauged precipitation and effective rainfall. A case study based on an operational French basin (545 km2) is presented. Three lumped production functions have been calibrated and compared. The results show that more elaborate models of loss functions must be proposed, and some possible directions for this are pointed out.Presently at the Institut de Ciences de la Terra Jaume Almera, Apartat 30102, 08080 Barcelona, Spain.Presently at EDF-DTG. Service de Ressources en Eau, BP 4348, 31029 Toulouse Cedex, France. 相似文献
5.
为提高实时洪水预报精度,提出了一种基于动态系统响应曲线洪水预报误差修正新方法。该方法将动态系统响应曲线引入洪水预报误差修正中,建立一种向误差源头追溯的动态反馈修正模型。此修正方法将新安江模型产流以下的部分作为响应系统, 用线性差分近似代替非线性系统响应函数的偏导数值,得到时段产流量所对应的系统响应曲线。用实测流量和计算流量之间的差值作为信息,使用最小二乘估计原理,对产流量进行修正, 再用修正后的产流量重新计算出流过程。该修正方法分别用理想案例和王家坝流域进行检验,结果证明此方法效果比传统二阶自回归模型有明显提高。 相似文献
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由于预报模型的局限性和实时信息的不完善,洪水预报过程存在许多误差,而基于图形交互式修正技术是消除预报误差的有效手段。分析了水文预报过程交互式修正技术在洪水预报工作中的重要性,介绍了过程拟合平滑技术和样条插值技术,基于此基础上研究实现了以橡皮筋形式交互式修正水文预报过程的技术,并应用于洪水预报系统中。研究实例表明,该技术使用方便,有效地提高了洪水预报精度。 相似文献
9.
针对现行流量过程线分割方法中存在着缺乏物理基础和客观的、科学的操作方法，以及其他的一些问题，提出了流量过程线的分割应遵循的三条基本原则，在此基础上提出流量过程线分割的新方法。该法通过流域的降雨资料和出口断面的流量资料，经推导得到Horton下渗能力曲线的三参数，并推导出地下净雨量在非饱和带运行时间公式和地下水汇流公式，从而对流域出口断面流量过程线进行分割。 相似文献
10.
Valérie Estupina Borrell Jacques Chorda Denis Dartus 《Comptes Rendus Geoscience》2005,337(13):1109-1119
Flash-flood events resulting from paroxystic meteorological events concentrated in time and space are insufficiently documented as they produce destructive effects. They are hardly measurable and present single features that are not transposable to another event. In the South of France, the flash flood of November 1999 gives a perfect illustration of these characteristics. The physical complexity of the process and consequently the volume and the variety of the data to take into account are incompatible with the real time constraint allocated to the forecasters confronted to the occurrence of such phenomena. So, we have to make choices to afford acceptable simplifications to the complete mechanical model. MARINE (‘Modélisation de l'Anticipation du Ruissellement et des Inondations pour des évéNements Extrêmes’) is the operational and robust tool we developed for flash-flood forecasting. This model complies with the criterions of real-time simulation. It is a physically based distributed model composed of two parts: first the flood runoff process simulation in the upstream part of the basin modelled from a rainfall–runoff approach, then the flood propagation in the main rivers described by the Saint-Venant equations. It integrates remote sensed data – Digital Elevation Model, land-use map, hydrographic network for the observations from satellites and the rainfall evolution from meteorological radar. The main goal of MARINE is to supply real time pertinent information to the forecasters. Results obtained on the Orbieu River (Aude, France) show that this model is able to supply pertinent flood hydrograph with a sufficient precision for the forecasting service to take the appropriate safety decisions. Furthermore, MARINE has already been tested in the French National Flood Forecasting Service of Haute-Garonne in real conditions. To cite this article: V. Estupina Borrell et al., C. R. Geoscience 337 (2005). 相似文献
11.
针对现有分布式单位线汇流理论未考虑土壤含水量变化引起的时变汇流路径问题,提出动态汇流路径新概念,推求同时考虑降雨强度和土壤含水量时空分布的坡面流速计算公式,引入地形指数刻画流域蓄水能力空间分布,从而获得栅格尺度流域流速分布场,进一步建立不同蓄满状态下流域动态汇流路径集合,最终实现考虑动态汇流路径的时变分布式单位线推求。以龙虎圩和东石流域为实例,通过SCS模型计算产流量,采用本文所提方法进行汇流计算,引入涵盖低流量误差、高流量误差及洪量误差的多目标优化方法率定参数,2个典型流域28场洪水预报结果表明,洪峰流量相对误差在±15%内,峰现时间误差在±6 h之间,纳什效率系数平均值超过0.8,与现有方法相比,所提方法能更加准确地反映汇流时间分布场,提高了洪水预报精度。 相似文献
12.
In real-time flood warning systems, sufficient lead-time is important for people to take suitable actions. Rainfall forecasting is one of the ways commonly used to extend the lead-time for catchments with short response time. However, an accurate forecast of rainfall is still difficult for hydrologists using the present deterministic model. Therefore, a probability-based rainfall forecasting model, based on Markov chain, was proposed in this study. The rainfall can be forecast one to three hours in advance for a specified nonexceeding probability using the transition probability matrix of rainfall state. In this study, the nonexceeding probability, which was hourly updated on the basis of development or decay of rainfall processes, was taken as a dominant variable parameter. The accuracy of rainfall forecasting one to three hours in advance is concluded from the application of this model to four recording rain gauges. A lumped rainfall-runoff forecasting model derived from a transfer function was further applied in unison with this rainfall forecasting model to forecast flows one to four hours in advance. The results of combination of these two models show good performance with agreement between the observed and forecast hydrographs. 相似文献
13.
To study the application of the TOPMODEL and the Xin’anjiang model to rainfall runoff simulation in semi-humid regions, the Holtan excess infiltration runoff module was added to the TOPMODEL structure. The basin of the Heihe Jinpen Reservoir in Shaanxi Province, China, was selected as the study area. Rainfall and runoff data and digital elevation models were collected. The watershed topographic parameters and 21 floods that occurred from 2005 to 2013 were obtained to simulate rainfall runoff. Results show that the improved TOPMODEL and the Xin’anjiang model can effectively stimulate rainfall runoff. The average values of their Nash coefficient are 0.84 and 0.83, respectively, upon calibration, and 0.78 and 0.80, respectively, upon validation. The Xin’anjiang model performs slightly better than the improved TOPMODEL. The results of large flood peaks are better than those of ordinary floods. Both results can be used to simulate the rainfall runoff of a watershed. 相似文献
14.
Precipitation forecasting using classification and regression trees (CART) model: a comparative study of different approaches 总被引：2，自引：0，他引：2
Bahram Choubin Gholamreza Zehtabian Ali Azareh Elham Rafiei-Sardooi Farzaneh Sajedi-Hosseini Özgür Kişi 《Environmental Earth Sciences》2018,77(8):314
Interest in semiarid climate forecasting has prominently grown due to risks associated with above average levels of precipitation amount. Longer-lead forecasts in semiarid watersheds are difficult to make due to short-term extremes and data scarcity. The current research is a new application of classification and regression trees (CART) model, which is rule-based algorithm, for prediction of the precipitation over a highly complex semiarid climate system using climate signals. We also aimed to compare the accuracy of the CART model with two most commonly applied models including time series modeling (ARIMA), and adaptive neuro-fuzzy inference system (ANFIS) for prediction of the precipitation. Various combinations of large-scale climate signals were considered as inputs. The results indicated that the CART model had a better results (with Nash–Sutcliffe efficiency, NSE?>?0.75) compared to the ANFIS and ARIMA in forecasting precipitation. Also, the results demonstrated that the ANFIS method can predict the precipitation values more accurately than the time series model based on various performance criteria. Further, fall forecasts ranked “very good” for the CART method, while the ANFIS and the time series model approximately indicated “satisfactory” and “unsatisfactory” performances for all stations, respectively. The forecasts from the CART approach can be helpful and critical for decision makers when precipitation forecast heralds a prolonged drought or flash flood. 相似文献
15.
A channelized debris flow/flood generally originates from initial gully erosion by superficial runoff that evolves rapidly into massive erosion of the channel bed. Knowledge of the formation conditions of such events is crucial for accurate forecasting, and determination of rainfall and runoff thresholds for such hazards is a primary concern following a strong earthquake. This work proposed a framework for debris flow/flood formation at the watershed scale in two watersheds (area: 2.4 and 32.4 km2) in the Wenchuan Earthquake area (China). The critical runoff and rainfall conditions required for debris flow/flood formation were simulated and their annual variations investigated. Ultimately, the runoff conditions required for debris flow/flood formation in the two studied watersheds were calculated on an annual basis and found to increase in time. Similarly, following consideration of three different rainfall types, critical rainfall conditions were proposed that also showed an increasing tendency. The increase of rainfall and runoff conditions for debris flow/flood formation is attributable to both the recovery of vegetation and the reduction of source materials. In comparison with actual monitored flow behaviors and previously proposed rainfall thresholds, the results showed strong consistency and high forecasting efficiency.
相似文献16.
基于山坡水文试验的新认识, 提出变动产流层概念, 将壤中流的描述从单一的土壤层间拓展到土壤-风化基岩界面, 通过对壤中流形成及发展过程的精细刻画, 实现了蓄满-超渗产流及其转换机制的统一描述。基于变动产流层概念, 根据运动波模型理论, 推导了单元网格的超渗/饱和地面径流、壤中流的计算公式, 利用非线性水库计算地下径流量, 采用二维扩散波进行地表汇流、一维扩散波进行河道汇流, 建立了面向山丘区的变动产流层分布式水文模型(VRGL)。对典型湿润山丘区的屯溪流域2010—2019年共24场洪水进行模拟, 结果显示: 洪峰流量和洪量的相对误差均在±20%内, 确定性系数在0.84左右, 表明VRGL具有较高的精度, 可用于山丘区洪水预报。 相似文献
17.
为了解决由降雨强度引起的径流汇流的非线性问题,提出一种基于SCS(United States Department of Agriculture-Soil Conservation Service)流速公式的时变分布式单位线计算方法。引入参考雨强表征SCS公式中流速系数对应的水力条件。由降雨过程的时段雨强与参考雨强的比值构成一个量纲一因子,将该因子加入SCS公式后使其能够考虑降雨对流速的影响。改进后的流速公式用于计算一次降雨过程中不同降雨时段对应的时变分布式单位线,时变分布式单位线与新安江模型的产流模块构成降雨径流模型,将模型用于裴河流域率定参考雨强。率定后的模型用于谭家河流域进行应用检验,结果显示,确定性系数大于等于0.9的洪水场次,由时不变单位线的42%增大为83%。提出的方法能够显著提高流域水文模型的降雨径流模拟能力。 相似文献
18.
Flash flood disaster is a prominent issue threatening public safety and social development throughout the world, especially in mountainous regions. Rainfall threshold is a widely accepted alternative to hydrological forecasting for flash flood warning due to the short response time and limited observations of flash flood events. However, determination of rainfall threshold is still very complicated due to multiple impact factors, particular for antecedent soil moisture and rainfall patterns. In this study, hydrological simulation approach (i.e., China Flash Flood-Hydrological Modeling System: CNFF-HMS) was adopted to capture the flash flood processes. Multiple scenarios were further designed with consideration of antecedent soil moisture and rainfall temporal patterns to determine the possible assemble of rainfall thresholds by driving the CNFF-HMS. Moreover, their effects on rainfall thresholds were investigated. Three mountainous catchments (Zhong, Balisi and Yu villages) in southern China were selected for case study. Results showed that the model performance of CNFF-HMS was very satisfactory for flash flood simulations in all these catchments, especially for multimodal flood events. Specifically, the relative errors of runoff and peak flow were within?±?20%, the error of time to peak flow was within?±?2 h and the Nash–Sutcliffe efficiency was greater than 0.90 for over 90% of the flash flood events. The rainfall thresholds varied between 93 and 334 mm at Zhong village, between 77 and 246 mm at Balisi village and between 111 and 420 mm at Yu village. Both antecedent soil moistures and rainfall temporal pattern significantly affected the variations of rainfall threshold. Rainfall threshold decreased by 8–38 and 0–42% as soil saturation increased from 0.20 to 0.50 and from 0.20 to 0.80, respectively. The effect of rainfall threshold was the minimum for the decreasing hyetograph (advanced pattern) and the maximum for the increasing hyetograph (delayed pattern), while it was similar for the design hyetograph and triangular hyetograph (intermediate patterns). Moreover, rainfall thresholds with short time spans were more suitable for early flood warning, especially in small rural catchments with humid climatic characteristics. This study was expected to provide insights into flash flood disaster forecasting and early warning in mountainous regions, and scientific references for the implementation of flash flood disaster prevention in China. 相似文献
19.
综述了淮河流域概况，淮河干流洪水预报系统物采用的预报方法。１９９１年淮河干流洪水预报采用了降雨径流预报与上，下游站相应流量预防方法相配合，并注重实时水情分析；在行洪区多，行洪后水面宽广而比降又极小的河段的汇流计算，采用了以实测洪水资料绘制的经验蓄曲线为充分发挥的湖泊洪水演算方法。 相似文献