A model for distributed GIUH‐based flow routing on natural and anthropogenic hillslopes          下载免费PDF全文

Dennis W. Hallema  Roger Moussa 《水文研究》2014,28(18):4877-4895

Attempts to reduce the number of parameters in distributed rainfall–runoff models have not yet resulted in a model that is accurate for both natural and anthropogenic hillslopes. We take on the challenge by proposing a distributed model for overland flow and channel flow based on a combination of a linear response time distribution and the hillslope geomorphologic instantaneous unit hydrograph (GIUH), which can be calculated with only a digital elevation model and a map with field boundaries and channel network as input. The spatial domain is subdivided into representative elementary hillslopes (REHs) for each of which we define geometric and flow velocity parameters and compute the GIUH. The catchment GIUH is given by the sum of all REH responses. While most distributed models only perform well on natural hillslopes, the advantage of our approach is that it can also be applied to modified hillslopes with for example a rectangular drainage network and terrace cultivation. Tests show that the REH‐GIUH approach performs better than classical routing functions (exponential and gamma). Simulations of four virtual hillslopes suggest that peak flow at the catchment outlet is directly related to drainage density. By combining the distributed flow routing model with a lumped‐parameter infiltration model, we were also able to demonstrate that terrace cultivation delays the response time and reduces peak flow in comparison to the same hillslope, but with a natural stream network. The REH‐GIUH approach is a first step in the process of coupling distributed hydrological models to erosion and water quality models at the REH (associated with agricultural management) and at the catchment scale (associated with the evaluation of the environmental impact of human activities). It furthermore provides a basis for the development of models for large catchments and urban or peri‐urban catchments. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   

Field investigation and modelling of coupled stream discharge and shallow water‐table dynamics in a small Mediterranean catchment (Sardinia)          下载免费PDF全文

Marcello Niedda  Mario Pirastru 《水文研究》2014,28(21):5423-5435

In the semi‐arid Mediterranean environment, the rainfall–runoff relationships are complex because of the markedly irregular patterns in rainfall, the seasonal mismatch between evaporation and rainfall, and the spatial heterogeneity in landscape properties. Watersheds often display considerable non‐linear threshold behavior, which still make runoff generation an open research question. Our objectives in this context were: to identify the primary processes of runoff generation in a small natural catchment; to test whether a physically based model, which takes into consideration only the primary processes, is able to predict spatially distributed water‐table and stream discharge dynamics; and to use the hydrological model to increase our understanding of runoff generation mechanisms. The observed seasonal dynamics of soil moisture, water‐table depth, and stream discharge indicated that Hortonian overland‐flow was negligible and the main mechanism of runoff generation was saturated subsurface‐flow. This gives rise to base‐flow, controls the formation of the saturated areas, and contributes to storm‐flow together with saturation overland‐flow. The distributed model, with a 1D scheme for the kinematic surface‐flow, a 2D sub‐horizontal scheme for the saturated subsurface‐flow, and ignoring the unsaturated flow, performed efficiently in years when runoff volume was high and medium, although there was a smoothing effect on the observed water‐table. In dry years, small errors greatly reduced the efficiency of the model. The hydrological model has allowed to relate the runoff generation mechanisms with the land‐use. The forested hillslopes, where the calibrated soil conductivity was high, were never saturated, except at the foot of the slopes, where exfiltration of saturated subsurface‐flow contributed to storm‐flow. Saturation overland‐flow was only found near the streams, except when there were storm‐flow peaks, when it also occurred on hillslopes used for pasture, where soil conductivity was low. The bedrock–soil percolation, simulated by a threshold mechanism, further increased the non‐linearity of the rainfall–runoff processes. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   

A hydrologic routing model suitable for climate‐scale simulations of arctic rivers: application to the Mackenzie River Basin          下载免费PDF全文

R.E. Beighley  K. Eggert  C.J. Wilson  J.C. Rowland  H. Lee 《水文研究》2015,29(12):2751-2768

In this study, the Hillslope River Routing (HRR) model was modified for arctic river basin applications and used to route surface and subsurface run‐off from the Community Land Model (CLM) in the Mackenzie River Basin (MRB) for the period 2000–2004. The HRR modelling framework performs lateral surface and subsurface run‐off routing from hillslopes and channel/floodplain routing. The HRR model was modified here to include a variable subsurface active layer thickness (ALT; permafrost) to enable subsurface water to resurface, a distributed surface storage component to store and attenuate the rapid generation of snowmelt water, compound hillslopes to account for the low relief near rivers and floodplains, and reservoir routing to complete the total surface and subsurface water storage accounting. To illustrate the new HRR model components, a case study is presented for the MRB. The basin is discretized into 5077 sub‐basins based on a drainage network derived from the global digital elevation model (DEM) developed from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) sensor on board NASA's Terra satellite and river widths extracted from LandSat images. The median hillslope land area is 68.5 km² with a flow length of 2.8 km. Gridded CLM surface and subsurface run‐offs are remapped to the HRR model's irregular sub‐basins. The role of each new model component is quantified in terms of peak annual streamflow (magnitude and timing) at select locations and basin‐wide total water storage anomalies. The role of distributed surface storage is shown to attenuate the relatively rapid generation of snowmelt water, impact the annual peak hydrograph (reduced peaks by >30% and detailed peak by >20 days), and account for 20% of the monthly total water storage anomalies averaged over the year and ranging from 14 to 25% (?10 to 30 mm) throughout the year. Although additional research is needed to dynamically link spatially distributed ALT to HRR, the role of ALT is shown to be important. A basin‐wide, uniform 1 m ALT impacts the annual peak hydrograph (reduced peaks by 9% and detailed peak by 8 days) and trends in total water storage anomalies. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   

Simulating streamflow on regulated rivers using characteristic reservoir storage patterns derived from synthetic remote sensing data          下载免费PDF全文

Yeosang Yoon  Edward Beighley 《水文研究》2015,29(8):2014-2026

This study presents a method to estimate streamflow in rivers regulated by lakes or reservoirs using synthetic satellite remote sensing data. To illustrate the approach, the new reservoir routing method is integrated into the Hillslope River Routing model, and a case study is presented for the highly regulated river in the Cumberland River basin (46,400 km²). The study period is April–May 2000, which contains a significant flood event that occurred in 1–2 May 2000. The model is shown to capture storage/release characterises in eight reservoirs with a mean normalized root mean square error (NRMSE) of 20% for entire simulation period and 27% for the May flood event. These errors are 69 and 75%, respectively, less than the NRMSE if reservoirs are not included in the model. Given the limitations of satellite missions, the impacts of the revisit cycles and operational periods are quantified. We used 26 observation sets of satellite altimetry over Cumberland River basin that are generated by considering both repeat cycles and satellite operation periods. For the revisit cycles, increasing the interval of repeat cycle leads to a corresponding increase of mean NRMSE from 27 to 59% as a result of sampling fewer flood events and smoothing of the change in storage signal as a result of longer intervals between visits. For the operation periods, the impact of data periods is limited because of the strong seasonal pattern of reservoir operations. Overall, the results suggest that the generalized routing model derived from reservoir stage observations can be used to simulate reservoir operating conditions, which can be used in forecasting hydrologic impacts of land cover or climate change. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   

An automated routing methodology to enable direct rainfall in high resolution shallow water models     

Christopher C. Sampson  Paul D. Bates  Jeffrey C. Neal  Matthew S. Horritt 《水文研究》2013,27(3):467-476

Recent high profile flood events have highlighted the need for hydraulic models capable of simulating pluvial flooding in urban areas. This paper presents a constant velocity rainfall routing scheme that provides this ability within the LISFLOOD‐FP hydraulic modelling code. The scheme operates in place of the shallow water equations within cells where the water depth is below a user‐defined threshold, enabling rainfall‐derived water to be moved from elevated features such as buildings or curbstones without causing instabilities in the solution whilst also yielding a reduction in the overall computational cost of the simulation. Benchmarking against commercial modelling packages using a pluvial and point‐source test case demonstrates that the scheme does not impede the ability of LISFLOOD‐FP to match both predicted depths and velocities of full shallow water models. The stability of the scheme in conditions unsuitable for traditional two‐dimensional hydraulic models is then demonstrated using a pluvial test case over a complex urban digital elevation model containing buildings. Deterministic single‐parameter sensitivity analyses undertaken using this test case show limited sensitivity of predicted water depths to both the chosen routing speed within a physically plausible range and values of the depth threshold parameter below 10 mm. Local instabilities can occur in the solution if the depth threshold is >10 mm, but such values are not required even when simulating extreme rainfall rates. The scheme yields a reduction in model runtime of ~25% due to the reduced number of cells for which the hydrodynamic equations have to be solved. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   

Hydrologic procedures of storm event watershed models: a comprehensive review and comparison     

Deva K. Borah 《水文研究》2011,25(22):3472-3489

Currently, many watershed models are available that have various complexities, strengths, and weaknesses. The basic mathematical foundations of these mathematical models are often overlooked due to high demands on convenient applications with graphical user interfaces. Although this and other factors are important while selecting a model, the mathematical foundation should also be taken into account, as performance or efficiency and accuracy of a model depend on its simplicity or complexity. A comprehensive review of 14 storm event watershed models was conducted. Hydrologic procedures (rainfall excess, flow routing, and subsurface flow) of the models are presented and compiled. Among the procedures, flow routing has the most influence on model performances (speed and accuracy). Overland and channel flow routing procedures using different flow‐governing equations, having various approximations and solved by different methods, are compared based on their relative levels of physical bases, complexities, and expected accuracies in simulating the dynamics of water flow. Models using more mathematical terms in the flow‐governing equations are more physically based and expected to be more accurate than models using approximations, however, are more complex due to more intensive but approximate numerical schemes (inefficient). Models using approximate equations with analytical solutions may provide a balance between complexity and accuracy. The review and comparisons are useful to modellers, water resources managers, and researchers in understanding the basic foundations of the models and making informed selections for practical applications or further developments. Other factors such as data intensiveness, user friendliness, and resource requirements are also important considerations. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

Nash瞬时单位线推演河道汇流的完整公式   总被引：1，自引：0，他引：1  

闫宝伟  郭生练  周建中 《水科学进展》2014,25(3):428-434

Nash瞬时单位线是基于零初始条件而得到的,没有反映河道汇流的完整过程。通过拉普拉斯变换和数学归纳,推导出了考虑初始槽蓄量退水过程的完整Nash河道汇流公式。分析讨论了公式各项的物理含义,出口断面的流量应是河槽初始槽蓄量的退水过程与上游入流演算结果的叠加,据此建立了一种具有物理概念的河道洪水演算实时校正模型,通过实例分析验证了公式的实用性和合理性。完整公式是更为一般情形下的Nash河道汇流模型,一定程度上丰富和发展了现有Nash汇流理论,并可适当提高河道洪水演算的精度。  相似文献   

GPSRTK技术在繁华城区管网三维数据采集中的应用研究   总被引：5，自引：1，他引：4  

马洪滨 《测绘科学》2006,31(2):119-121

GPSRTK技术在三维数据采集中的应用越来越多,但在繁华城区内工作一直被认为是一个不可逾越的鸿沟,强遮挡问题、电磁波干扰问题、多路径问题、精度问题等使人们望而却步。本文通过沈阳市自来水管网图文信息系统建设项目将GPSRTK技术应用到繁华城区的数据采集,通过实际应用总结出,只要注意解决本文结论中提出的几个问题,GPSRTK技术不但可在繁华城区应用,而且能收到比较理想的结果。  相似文献   

MED路由策略研究     

张卫国  尹霞  吴建平 《中国海洋大学学报(自然科学版)》2008,(Z1)

边界网关协议是目前用于广域网中最主要的域间分布式动态路由协议,具有丰富的路由控制机制。MED属性的使用不当通常会引起热土豆路由和MED振荡。介绍热土豆路由和MED振荡,总结分析了避免热土豆路由和MED振荡的方法,并针对广域网和专网分别提出了整体的MED路由策略,最后利用仿真软件加以验证。  相似文献   

全国警用空间信息服务互联互通的关键技术     

伍胜  杨崇俊 《地理信息世界》2011,9(6):12-16

针对大型空间信息服务平台构建过程中的数据互联互通和信息集成问题,从集成框架体系结构、技术路线和关键技术3个方面进行研究,提出了分布式地理空间信息集成框架的5层体系结构模型和原子空间信息服务概念;通过研究分布式空间查询路由算法和虚拟四叉树模型等关键技术,探索实现分布式环境下的空间信息的互联互通.  相似文献