Simulation Of Hydrological Response Research Articles

Chance-constrained overland flow modeling for improving conceptual distributed hydrologic simulations based on scaling representation of sub-daily rainfall variability

Lack of hydrologic process representation at the short time-scale would lead to inadequate simulations in distributed hydrological modeling. Especially for complex mountainous watersheds, surface runoff simulations are significantly affected by the overland flow generation, which is closely related to the rainfall characteristics at a sub-time step. In this paper, the sub-daily variability of rainfall intensity was considered using a probability distribution, and a chance-constrained overland flow modeling approach was proposed to capture the generation of overland flow within conceptual distributed hydrologic simulations. The integrated modeling procedures were further demonstrated through a watershed of China Three Gorges Reservoir area, leading to an improved SLURP-TGR hydrologic model based on SLURP. Combined with rainfall thresholds determined to distinguish various magnitudes of daily rainfall totals, three levels of significance were simultaneously employed to examine the hydrologic-response simulation. Results showed that SLURP-TGR could enhance the model performance, and the deviation of runoff simulations was effectively controlled. However, rainfall thresholds were so crucial for reflecting the scaling effect of rainfall intensity that optimal levels of significance and rainfall threshold were 0.05 and 10 mm, respectively. As for the Xiangxi River watershed, the main runoff contribution came from interflow of the fast store. Although slight differences of overland flow simulations between SLURP and SLURP-TGR were derived, SLURP-TGR was found to help improve the simulation of peak flows, and would improve the overall modeling efficiency through adjusting runoff component simulations. Consequently, the developed modeling approach favors efficient representation of hydrological processes and would be expected to have a potential for wide applications.

Hydrologic-response simulations for the North Fork of Caspar Creek: second-growth, clear-cut, new-growth, and cumulative watershed effect scenarios

This study demonstrates that comprehensive hydrologic-response simulation can be a useful tool for studying cumulative watershed effects. The simulations reported here were conducted with the Integrated Hydrology Model (InHM). The location of the 473 ha study site is the North Fork of the Caspar Creek Experimental Watershed, near Fort Bragg, California. Existing information from a long-term monitoring programme and new soil-hydraulic property measurements made for this study were used to parameterize InHM. Long-term continuous wet-season simulations were conducted for the North Fork catchments and main stem for second-growth, clear-cut and new-growth scenarios. The simulation results show that the increases and decreases, respectively, for throughfall and potential evapotranspiration related to clear-cutting had quantifiable impacts on the simulated hydrologic response at both the catchment and watershed scales. Model performance was best for the new-growth simulation scenarios. To improve upon the simulations reported here would require additional soil-hydraulic property information from across the study area. Although principally focused on the integrated hydrologic response, the effort reported here demonstrates the potential for characterizing distributed responses with physics-based simulation. The search for a comprehensive understanding of hydrologic response will require both data-intensive discovery and concept-development simulation, from both integrated and distributed perspectives. Copyright © 2013 John Wiley & Sons, Ltd.

Assessing the detail needed to capture rainfall‐runoff dynamics with physics‐based hydrologic response simulation

Concept development simulation with distributed, physics‐based models provides a quantitative approach for investigating runoff generation processes across environmental conditions. Disparities within data sets employed to design and parameterize boundary value problems used in heuristic simulation inevitably introduce various levels of bias. The objective was to evaluate the impact of boundary value problem complexity on process representation for different runoff generation mechanisms. The comprehensive physics‐based hydrologic response model InHM has been employed to generate base case simulations for four well‐characterized catchments. The C3 and CB catchments are located within steep, forested environments dominated by subsurface stormflow; the TW and R5 catchments are located in gently sloping rangeland environments dominated by Dunne and Horton overland flows. Observational details are well captured within all four of the base case simulations, but the characterization of soil depth, permeability, rainfall intensity, and evapotranspiration differs for each. These differences are investigated through the conversion of each base case into a reduced case scenario, all sharing the same level of complexity. Evaluation of how individual boundary value problem characteristics impact simulated runoff generation processes is facilitated by quantitative analysis of integrated and distributed responses at high spatial and temporal resolution. Generally, the base case reduction causes moderate changes in discharge and runoff patterns, with the dominant process remaining unchanged. Moderate differences between the base and reduced cases highlight the importance of detailed field observations for parameterizing and evaluating physics‐based models. Overall, similarities between the base and reduced cases indicate that the simpler boundary value problems may be useful for concept development simulation to investigate fundamental controls on the spectrum of runoff generation mechanisms.

Using simulated hydrologic response to revisit the 1973 Lerida Court landslide

Hydrologically driven mass wasting in the form of landslides on steep slopes is a worldwide occurrence. High-profile events in, for example, Brazil, Chile, the Philippines, Puerto Rico, and Venezuela during the last three decades all clearly illustrate, based upon significant losses of life and property, that hydrologically driven slope instability in developed (urban) areas can be a major geologic/environmental hazard. The focus of this study is the 1973 hydrologically driven Lerida Court landslide in Portola Valley, CA, USA. Physics-based hydrologic-response simulation, with the comprehensive Integrated Hydrology Model, was employed to forensically estimate the spatiotemporal pore pressure distributions for the Lerida Court site. Slope stability, driven by the simulated pore pressure dynamics, was estimated for the Lerida Court site with the infinite slope/Factor of Safety approach. The pore pressure dynamics for the Lerida Court site were reasonably captured by the hydrologic-response simulation. The estimated time of slope failure for the Lerida Court site compares well with field observations. A recommendation is made that hydrologically driven slope stability estimates including variably saturated subsurface flow be standard protocol for development sites in steep urban settings.

Towards a simple dynamic process conceptualization in rainfall–runoff models using multi‐criteria calibration and tracers in temperate, upland catchments

AbstractEmpirically based understanding of streamflow generation dynamics in a montane headwater catchment formed the basis for the development of simple, low‐parameterized, rainfall–runoff models. This study was based in the Girnock catchment in the Cairngorm Mountains of Scotland, where runoff generation is dominated by overland flow from peaty soils in valley bottom areas that are characterized by dynamic expansion and contraction of saturation zones. A stepwise procedure was used to select the level of model complexity that could be supported by field data. This facilitated the assessment of the way the dynamic process representation improved model performance. Model performance was evaluated using a multi‐criteria calibration procedure which applied a time series of hydrochemical tracers as an additional objective function. Flow simulations comparing a static against the dynamic saturation area model (SAM) substantially improved several evaluation criteria. Multi‐criteria evaluation using ensembles of performance measures provided a much more comprehensive assessment of the model performance than single efficiency statistics, which alone, could be misleading. Simulation of conservative source area tracers (Gran alkalinity) as part of the calibration procedure showed that a simple two‐storage model is the minimum complexity needed to capture the dominant processes governing catchment response. Additionally, calibration was improved by the integration of tracers into the flow model, which constrained model uncertainty and improved the hydrodynamics of simulations in a way that plausibly captured the contribution of different source areas to streamflow. This approach contributes to the quest for low‐parameter models that can achieve process‐based simulation of hydrological response. Copyright © 2009 John Wiley & Sons, Ltd.

Rapid simulated hydrologic response within the variably saturated near surface

AbstractColumn and field experiments have shown that the hydrologic response to increases in rainfall rates can be more rapid than expected from simple estimates. Physics‐based hydrologic response simulation, with the Integrated Hydrology Model (InHM), is used here to investigate rapid hydrologic response, within the variably saturated near surface, to temporal variations in applied flux at the surface boundary. The factors controlling the speed of wetting front propagation are discussed within the Darcy–Buckingham conceptual framework, including kinematic wave approximations. The Coos Bay boundary‐value problem is employed to examine simulated discharge, pressure head, and saturation responses to a large increase in applied surface flux. The results presented here suggest that physics‐based simulations are capable of representing rapid hydrologic response within the variably saturated near surface. The new InHM simulations indicate that the temporal discretization and measurement precision needed to capture the rapid subsurface response to a spike increase in surface flux, necessary for both data‐based analyses and evaluation of physics‐based models, are smaller than the capabilities of the instrumentation deployed at the Coos Bay experimental catchment. Copyright © 2007 John Wiley & Sons, Ltd.

Near-surface hydrologic response for a steep, unchanneled catchment near Coos Bay, Oregon: 2. Physics-based simulations

The comprehensive physics-based hydrologic-response model InHM was used to simulate 3D variably-saturated flow and solute transport for three controlled sprinkling experiments at the Coos Bay 1 (CB1) experimental catchment in the Oregon Coast Range. The InHM-simulated hydrologic-response was evaluated against observed discharge, pressure head, total head, soil-water content, and deuterium concentration records. Runoff generation, tensiometric/piezometric response in the soil, pore-water pressure generation, and solute (tracer) transport were all simulated well, based on statistical and graphical model performance evaluation. The InHM simulations reported herein indicate that the 3D geometry and hydraulic characteristics of the layered geologic interfaces at CB1 can control the development of saturation and pore-water pressures at the soil-saprolite interface. The weathered bedrock piezometric response and runoff contribution were not simulated well with InHM in this study, most likely as a result of the uncertainty in the weathered bedrock layer geometry and fractured-rock hydraulic properties that preclude accurate fracture flow representation. Sensitivity analyses for the CB1 boundary-value problem indicate that: (i) hysteretic unsaturated flow in the CB1 soil is important for accurate hydrologic-response simulation, (ii) using an impermeable boundary condition to represent layered geologic interfaces leads to large errors in simulated magnitudes of runoff generation and pore-water pressure development, and (iii) field-based retention curve measurements can dramatically improve variably-saturated hydrologic-response simulation at sites with steep soil-water retention curves. The near-surface CB1 simulations reported herein demonstrate that physics-based models like InHM are useful for characterizing detailed spatio-temporal hydrologic-response, developing process-based concepts, and identifying information shortfalls for the next generation of field experiments. The field-based observations and hydrologic-response simulations from CB1 highlight the challenges in characterizing/simulating fractured bedrock flow at small catchments, which has important consequences for hydrologic response and landslide initiation.

Near-surface hydrologic response for a steep, unchanneled catchment near Coos Bay, Oregon: 1. sprinkling experiments

Sprinkling systems are frequently used to simulate rainfall for process-based investigations of near-surface hydrologic response without measuring or accounting for spatial variability. Data analyses from three sprinkling experiments at the Coos Bay 1 experimental catchment (CB1) demonstrate considerable spatial variability in sprinkling. Furthermore, simulated rainfall from sprinklers was found to be more heterogeneous than natural storms at CB1. Water balance calculations and evapotranspiration estimates indicate that evaporation of airborne droplets is a significant portion of applied sprinkling rates, although still less than the amount blown off the field site by strong winds. Incorporation of spatial variability in sprinkling input and soil-water storage did not significantly change water balance calculations. Saturation patterns within the near-surface soil profile and the timing of tensiometric response are affected by sprinkling heterogeneity. Pore-water pressure and saturation development at the soil-saprolite interface are primarily controlled by convergent surface / subsurface topography and bedrock fracture flow, but are also sensitive to sprinkling spatial variations. The analyses presented herein suggest that incorporating spatial variability in sprinkling rates is important when conducting hydrologic-response modeling of sprinkler experiments. This paper is the first-part of a two-part series focused on CB1. The data analyses in this paper are used to parameterize comprehensive physics-based hydrologic-response simulations of three CB1 sprinkling experiments reported in the companion paper.

Simulation of hydrological response of land use change in Taihu Basin

以城市化快速发展的太湖流域为研究对象, 采用1985、1995和2000年TM/ETM土地利用解译资料, 应用区域尺度单元格网分布式水文模型, 进行长序列水文模拟, 定量评估太湖流域土地利用变化及其水文响应特征, 为流域用地规划、水资源管理以及灾害防治提供决策参数。研究显示, 自1985年到2000年, 太湖流域城镇面积扩展了40.38%, 增加量占太湖流域总面积的3.88%。在1980-2000年的雨情下, 全流域土地利用变化导致产流量平均增加4.11%, 约为7.56×10⁸m³, 最高值为11.76%, 约为10.0×10⁸m³。受土地利用变化空间差异影响, 产流量增加具有较大区域差异, 城镇快速扩展的苏锡常地区和浦东浦西地区, 土地利用变化导致产流量平均增加为10.07%和7.03%, 最高增量达20%-30%。;Land use changes alter the hydrological characteristics of the land surface, and have significant impacts on hydrological cycle and water balance. Therefore, it’s very important to study hydrologic response of land use changes for analyzing the complex effects of human activities on natural systems and improving water resource management and flood control. The distributed hydrological model is the key tools that can be used to give insight in the hydrological impacts of land use changes. This paper selects Taihu Basin as study area, with high-speed urbanization. Historical iand use scenarios for 1985, 1995, and 2000 were analyzed to track land use change by TM/ETM image explanation and spatial analysis of Arcgis software. The STREAM model, a cell-based distributed hydrological model, was applied to estimate hydrological response of land use changes by simulating the monthly and annual runoff using long-term rain records from 1980 to 2000. For the entire basin between 1985 and 2000, the urban area increased about 40.38%, about 3.88% of the whole basin area. The land use changes result in an increase of 7.56 x 10⁸m³ on average and 10.0 x 10⁸m³ on maximum, about 4.11% and 11.76% of the whole basin runoff volume respectively. Hydrological response varies according to the extent of land use changes in different parts of the basin. In Suzhou-Wuxi-Changzhou and Pudong-Puxi sub-region, with more extent of land use changes, the land use changes result in an increase of 10.07% and 7.03% respectively on average, and 20%-30% on maximum.

Physics‐based hydrologic‐response simulation: Seeing through the fog of equifinality

Physics‐based hydrologic‐response simulation: Seeing through the fog of equifinality

Simulated effect of a forest road on near‐surface hydrologic response: redux

AbstractIn the work reported here the comprehensive physics‐based Integrated Hydrology Model (InHM) was employed to conduct both three‐ and two‐dimensional (3D and 2D) hydrologic‐response simulations for the small upland catchment known as C3 (located within the H. J. Andrews Experimental Forest in Oregon). Results from the 3D simulations for the steep unchannelled C3 (i) identify subsurface stormflow as the dominant hydrologic‐response mechanism and (ii) show the effect of the down‐gradient forest road on both the surface and subsurface flow systems. Comparison of the 3D results with the 2D results clearly illustrates the importance of convergent subsurface flow (e.g. greater pore‐water pressures in the hollow of the catchment for the 3D scenario). A simple infinite‐slope model, driven by subsurface pore‐water pressures generated from the 3D and 2D hydrologic‐response simulations, was employed to estimate slope stability along the long‐profile of the C3 hollow axis. As expected, the likelihood of slope failure is underestimated for the lower pore pressures from the 2D hydrologic‐response simulation compared, in a relative sense, to the higher pore pressures from the 3D hydrologic response simulation. The effort reported herein provides a firm quantitative foundation for generalizing the effects that forest roads can have on near‐surface hydrologic response and slope stability at the catchment scale. Copyright © 2006 John Wiley & Sons, Ltd.

Physics-based hydrologic-response simulation: foundation for hydroecology and hydrogeomorphology

Two emerging and important disciplines within the large science of hydrology are hydroecology (Eagleson, 2002; Rodriguez-Iturbe and Porporato, 2004) and hydrogeomorphology (Sidle and Onda, 2004), each requiring an integrated understanding of hydrologic response at the surface and within the variably saturated subsurface. Obviously, the most useful tool for understanding ecological or geomorphic processes within a given hydrologically driven system is careful observation via detailed field measurements/experiments (e.g. Montgomery et al., 2002; Loheide and Gorelick, 2005). However, simulation of hydrologic response with comprehensive physics-based models can provide a strong foundation for concept development in both hydroecology and hydrogeomorphology. The simulation of hydrologic response has received considerable attention in the last half century (see Beven (2000, 2002) and Singh and Woolhiser (2002)). In an often cited paper, Freeze and Harlan (1969) proposed a blueprint for a distributed physically based hydrologic model, based upon numerical solution to the coupled partial differential equations that describe water movement on the surface and within the variably saturated subsurface. At least three hydrologic-response models have been developed in the true spirit of the Freeze and Harlan blueprint: (i) InHM (VanderKwaak, 1999), (ii) MODHMS (Panday and Huyakorn, 2004), and (iii) HydroGeoSphere (Sudicky et al., 2005). The Integrated Hydrology Model (InHM) was designed to estimate quantitatively, in a fully coupled first-order approach, three-dimensional (3D) variably saturated flow and solute transport in porous media, 3D variably saturated flow and solute transport in macropores, and two-dimensional (2D) flow and solute transport over the land surface and in open channels. Successful applications of InHM include those of VanderKwaak and Loague (2001) and Loague et al. (2005). Obviously, not all hydrologic-response simulations can (or should) be conducted with comprehensive physics-based models. Potentially the most effective use of physics-based simulation, related to hydroecology and hydrogeomorphology, is in the design of data collection strategies and identifying the next hypothesis-testing field experiment.

Physics‐based hydrologic response simulation: platinum bridge, 1958 Edsel, or useful tool

Physics‐based hydrologic response simulation: platinum bridge, 1958 Edsel, or useful tool

Land-use impacts on storm-runoff generation: scenarios of land-use change and simulation of hydrological response in a meso-scale catchment in SW-Germany

Abstract The impact of land-use change impacts on storm-runoff generation is presented based on a simulation study composed of three parts: (1) generation of spatially explicit land-use scenarios; (2) spatially distributed and process based hydrological modelling of runoff generation; (3) application of this procedure and demonstration of results for a predominantly agricultural meso-scale catchment in a loessy-soil landscape in SW Germany. Land-use scenarios are a prerequisite for assessing the influence of potential changes of land-use and/or land-cover on runoff generation. The land-use change modelling kit (LUCK) provides a method for the spatial transformation of overall trends of land-use into spatially distributed scenarios of land-use patterns, taking into account their topology in a true position mode. The assignment of land-use categories to each grid cell is realised in a spatially explicit manner, dependent on an evaluation of the site characteristics as well as its neighbourhood relationships. Based on these land-use scenarios, the influence of altered land-use characteristics on flooding is simulated using a modified version of the physically based hydrological model WaSiM-ETH. In order to extend the model's capabilities with respect to adequate representation of land-use related runoff generation mechanisms, some additional mechanisms have been introduced: (1) A macropore module accounting for fast infiltration processes; (2) A siltation module decreasing hydraulic conductivity of the soil surface as a function of precipitation intensity and vegetation coverage. (3) Sub-grid variability considering the impervious and sealed portion of a grid cell. The location and lateral interaction of landscape elements within a catchment is captured by spatially explicit modelling on the basis of gridded information provided by the scenarios. The whole simulation procedure is applied to a meso-scale catchment in SW Germany. The results show that the influence of land-use conditions on storm-runoff generation depends greatly on the rainfall event characteristics and on the related spatial scale, i.e. the influence is only relevant for convective storm events with high precipitation intensities in contrast to long-lasting advective storm events with low precipitation intensities. However, convective events—and thus land-use conditions—are of very minor relevance for the formation of floods in large river basins because this type of rainfall event is usually restricted to small-scale occurrence.

Muddy Water and American Agriculture: How to Best Control Sedimentation From Agricultural Land?

The role of agricultural sediment in water quality is well documented. While numerous policies have been advocated and initiated, it still appears to be a significant problem. The present analysis concentrates on the outcome of several policy alternatives in terms of sediment delivery and project costs. These results are obtained by combining social science investigation of probable farmer behavior under a variety of scenarios with a hydrologic simulation model which predicts the sediment delivery with different land uses. This integration of social science behavioral research with the hydrologic response simulation model provides a framework to assess the environmental effectiveness of alternative policies aimed at reducing sedimentation. While the results presented here are preliminary, this approach seems to offer great promise as a tool for federal, state and local conservation agencies in their efforts to efficiently and effectively use their limited resources to reduce soil loss.