Journal of Hydrologic Engineering

Potential effects of climate change on streamflow and soil moisture in Vermilion basin, Illinois, are investigated using a spatial distributed hydrological model (WetSpa). The model results show good agreement between observed and simulated discharges at the Leonore gauge station and soil moisture at the Stelle soil moisture recording site. Climate scenarios are derived by statistical downscaling of regional climate predictor variables for two climate scenarios and four time periods. The downscaled local climate variables are used as inputs to the WetSpa model. The results of the hydrological simulations show that streamflow in the Vermilion basin may decrease substantially, especially in summer, as a result of less precipitation but primarily due to increased evapotranspiration. Predictions also indicate that reduced precipitation in summer combined with a substantial increase in evaporative demand may lead to soil moisture deficits in the fall, which could have a negative impact on the natural vegetation and rainfed crop growth.

The impact of climate change on water resources is a major issue for regions in the world. Climate parameters such as temperature and precipitation are expected to change in the future and could significantly impact available water resources. This paper assesses long-term water availability over the North Platte River watershed, Wyoming, by utilizing the variable infiltration capacity (VIC) hydrologic model and developing streamflow projections under anthropogenic climate change conditions. Uncertainties in the scenarios of climate change and global climate models are assessed by utilizing ensemble multiple models and multiple scenarios from the World Climate Research Programme’s database. The simulated streamflows are compared using an intermodel interscenario approach. Based on streamflow projections, there is a possibility of increased annual streamflow for this region through 2100, with maximum streamflow during 2085–2090. The simulated annual streamflows for future periods vary from −20 to 62% with respect to the baseline period (1971–2000). In the simulations, the wet months are getting wetter, whereas the summer months are found to be growing drier. The streamflow projections and the range of streamflow can be utilized by decision makers in future water supply and demand management study.

Acoustic discharge measurement devices (ADM) based on transit time measurements are widely used to measure water flow rates in channels and closed conduits for hydropower applications. In addition to making velocity and discharge measurements, the ADM simultaneously records the speed of sound and the attenuation of the acoustic pulse through the water-sediment mixture. This information can be used to estimate characteristics of the suspension such as the volume fraction of the sediment. Such information is crucial in hydropower plants because of the negative effects solid particles can have on the equipment. In this work, the Atkinson-Kytömaa model for monodisperse particles is applied to analyze the effect of solid particles and other operating parameters on the sound speed and attenuation in water suspensions. This model has been selected because it is suitable for the interested range of applications. The model has been validated by measurements with different particle material (glass, quartz, calcium carbonate), size, size distribution, shape, and concentration. Moreover, the sensitivity of the model to the particle parameters has been investigated and the critical parameters for monitoring applications have been identified.

In this paper, a distributed numerical model is proposed on the basis of (1) a hydrologic model for the water exchange laws; (2) a surface runoff model based on a hybrid two-dimensional (2D) diffusive/kinematic wave approximation able to calculate flow over all kinds of wet/dry ground surface slopes; (3) a groundwater flow model based on the 2D Darcy law for both saturated and partly saturated zones; (4) a 2D hillslope erosion model for the sediment transport; and (5) a explicit finite-volume discretization with specific schemes according to the characteristics of the flow equations, upwind for the hyperbolic equations and centered for the parabolic equations. The resulting model offers a variable time step, ensuring numerical stability with the time step size sensitive to the grid cell size in the diffusive wave case and an entropy correction of the upwind fluxes to ensure conservative solutions near local maxima in the slopes controlling the water movement. The validation and practical application of the model is presented in Paper II, in which the potential usefulness of the proposed model is demonstrated.

The development of a distributed two-dimensional (2D) hydrologic-hydraulic simulation model was presented in Paper I. The simulation model combined overland flow (kinematic/diffusive wave models), hillslope sediment transport, and groundwater flow apart from the water exchange mechanisms between zones. Particular attention was paid to the upwind discretization of the surface flow equations. In this paper, the proposed model is validated by using four test cases with exact solutions, one academic test case, and two laboratory test cases. The model adequately reproduced front advance over dry beds of any slope and water table evolution in simple cases. As practical application of the model, the simulation of real events in two experimental basins is also presented. The work is focused on the influence of the choice of the empirical parameters on the model results concerning solid and liquid discharges. Also, because of the lack of information referring the boundary and initial conditions of the groundwater flow in real basins, it is difficult to evaluate the accuracy of the complete model.

A flood forecasting system has been developed using MIKE11 river-modeling software modules rainfall-runoff (RR) [or Nedbor-Afstromnings model (NAM)], hydrodynamic (HD), and flood forecasting (FF) for the Jamuneswari river catchment of the northwestern part of Bangladesh. The 3-arc second shuttle radar topography mission (SRTM) digital elevation model (DEM) version 4.0 and the D8 method of ArcGIS9.3 have been used to delineate river network and catchment bounderies, which are required for MIKE 11 model setup. The European Centre for Medium-Range Weather Forecast (ECMWF) model-forecasted rainfall data have been used in MIKE 11 NAM-HD modules to increase the forecast lead time to 72 h. Errors in forecast results have been assessed by computing efficiency index, coefficient of correlation, volume error, peak error, and peak time error. Integration of the MIKE 11 HD module with the MIKE NAM module has improved the result by 10.84% for efficiency index, 20.7% for volume error, 25.61% for peak error, and 95.83% for peak time error. The MIKE 11 FF module was applied along with the integrated MIKE 11 NAM and HD modules to minimize error in the forecasted result. The efficiency index, volume error, peak error, and peak time error of the hindcast result, before updating by MIKE 11 FF, were calculated as 0.803, 0.505%, 2.58%, and 2 h, After updating by the MIKE 11 FF module, results were calculated as 0.989, $-0.005\%$, 0.158%, and 0.00 h. Inputting the ECMWF-forecasted rainfall, the updated forecasting system determined the efficiency index, volume error, peak error, and peak time error as 0.92, 0.008%, 0.87%, and 0.00% for 24 h; 0.87, 0.231%, 0.507%, and 0.00 h for 48 h; and 0.84, 0.519%, and 0.000 h for 72 h. The steps for developing the flood forecasting system described in this case study are generic and can be applied under similar geographic conditions in other locations worldwide. In Bangladesh, decision makers will have more time to develop responses to imminent the flooding as a result of the increased forecast lead time provided by the analysis method described in this case study.

The curve number (CN) method is widely used as a technique for estimating surface runoff depth from rainstorms. This simply lumped method is based on the main parameter CN, which represents the lumped expression of basin absorption, and on a parameter that represents interception, infiltration during the early part of a storm, and surface depression storage, called initial abstraction. In this paper, CN is evaluated at the basin scale from rainfall-runoff multiday events, in the observation period 1940–1997 (recorded length mean equal to 20 years) for 61 Sicilian basins with three different methods: NEH4 method, asymptotic fitting method, and a least-squares method. A first analysis of Sicilian watershed behavior indicates a major occurrence of standard CN response (43 basins), as opposed to a complacent response (10 basins), and a few cases of violent behavior (3 basins). For basins with complacent behavior a modified formula of a runoff CN equation is proposed. The original assumption of the initial abstraction ratio ($\mathrm{Ia}/S$ or $\lambda$) equal to 0.20 is investigated for watersheds with standard and violent CN response, using “natural” and “ordered” rainfall-runoff data. Results indicate a median $\lambda$ value of 0 for natural data and 0.05 for ordered data, according to recent worldwide studies. CN seasonal preliminary analysis indicates higher CNs in the dormant season versus in the growing season, whereas $\lambda$ seasonal analysis indicates values close to 0 in both the dormant and growing seasons.

Preliminary site design, emergency response, or engineering operations in remote locations may require a rapid hydrologic analysis to provide decision-support information on a site’s suitability for various improvements. This paper describes a procedure for conducting such analyses using widely available Internet-based data and tools. The purpose of this paper is to introduce the reader to the steps necessary to execute a hydrologic analysis remotely. The analysis presented was conducted using programs typically found on any computer or that can be downloaded on short notice from the Internet. Freely available online geospatial data were used to create a database of hydrologic conditions at remotely identified points of interest. These points of interest were compared to actual hydrologic databases for sections of Interstate 25 in New Mexico and State Route M-131 in Michigan. The results of the remote hydrologic analysis correctly identified and analyzed 78% of actual physical locations of culverts for the New Mexico site. Due to increased difficulty of visual identification caused by the density of land cover in a more humid climate, the remote hydrologic analysis technique correctly identified 55% of actual physical locations of culverts for the Michigan site. Potential methods to improve the accuracy of the technique are discussed.