Next Issue
Previous Issue

Table of Contents

Hydrology, Volume 3, Issue 2 (June 2016)

  • Issues are regarded as officially published after their release is announced to the table of contents alert mailing list.
  • You may sign up for e-mail alerts to receive table of contents of newly released issues.
  • PDF is the official format for papers published in both, html and pdf forms. To view the papers in pdf format, click on the "PDF Full-text" link, and use the free Adobe Readerexternal link to open them.
View options order results:
result details:
Displaying articles 1-10
Export citation of selected articles as:
Open AccessArticle
Identification of Streamflow Changes across the Continental United States Using Variable Record Lengths
Received: 23 April 2016 / Revised: 2 June 2016 / Accepted: 9 June 2016 / Published: 17 June 2016
Cited by 28 | Viewed by 1889 | PDF Full-text (4007 KB) | HTML Full-text | XML Full-text
Abstract
The study focused on investigating the presence of change patterns in 600 unimpaired streamflow stations across the continental U.S. at different time intervals to understand the change patterns that can provide significant insight regarding climate variability and change. Each station had continuous streamflow [...] Read more.
The study focused on investigating the presence of change patterns in 600 unimpaired streamflow stations across the continental U.S. at different time intervals to understand the change patterns that can provide significant insight regarding climate variability and change. Each station had continuous streamflow data of at least 30 years (the entire dataset covered a range of 109 years). Presence of trends and shifts were detected in water year and the four seasons (fall, winter, spring, and summer) analyzing the water year and seasonal mean flows. Two non-parametric tests, namely, the Mann-Kendall test and the Pettitt’s test were used to identify the trends and the shifts, respectively. The results showed an increasing trend in the northeast and upper-mid regions, whereas southeast and northwest regions underwent a decrease. Shifts followed similar patterns as trends with higher number of stations with significant change. Fall and spring showed the highest number of stations with increasing and decreasing change, respectively, in the seasonal analyses. Results of this study may assist water managers to understand the streamflow change patterns across the continental U.S., especially at the regional scale since this study covers a long range of years with a large number of stations in each region. Full article
Figures

Figure 1

Open AccessArticle
Is Catchment Classification Possible by Means of Multiple Model Structures? A Case Study Based on 99 Catchments in Germany
Received: 15 April 2016 / Revised: 6 June 2016 / Accepted: 6 June 2016 / Published: 16 June 2016
Cited by 2 | Viewed by 1518 | PDF Full-text (5038 KB) | HTML Full-text | XML Full-text
Abstract
This study investigates how the performance of a set of models depends on the catchments to which these models are applied. It examines (i) whether it is possible to identify a single best model for each of the catchments, or whether results are [...] Read more.
This study investigates how the performance of a set of models depends on the catchments to which these models are applied. It examines (i) whether it is possible to identify a single best model for each of the catchments, or whether results are dominated by equifinality; and (ii) whether the ranking of model performance can be related to a set of predictors, such as climate and catchment characteristics. In order to explore these questions, we applied 12 model structures to 99 catchments in Germany, ranging in size from 10 km2 to 1826 km2. We examined model performance in terms of streamflow predictions, based on various indices. Our results indicate that for some catchments many structures perform equally well, whereas for other catchments a single structure clearly outperforms the others. We could not identify clear relationships between relative model performance and catchment characteristics. This result led us to conclude that for the spatial scales considered, it is difficult to base the selection of a lumped conceptual model based on a priori assessment, and we recommend a posteriori selection based on model comparisons. Full article
Figures

Figure 1

Open AccessArticle
Postprocessing of Medium Range Hydrological Ensemble Forecasts Making Use of Reforecasts
Received: 17 December 2015 / Revised: 19 May 2016 / Accepted: 23 May 2016 / Published: 31 May 2016
Cited by 2 | Viewed by 1510 | PDF Full-text (1356 KB) | HTML Full-text | XML Full-text
Abstract
A hydrological ensemble prediction system is running operationally at the Royal Meteorological Institute of Belgium (RMI) for ten catchments in the Meuse basin. It makes use of the conceptual semi-distributed hydrological model SCHEME and the European Centre for Medium Range Weather Forecasts (ECMWF) [...] Read more.
A hydrological ensemble prediction system is running operationally at the Royal Meteorological Institute of Belgium (RMI) for ten catchments in the Meuse basin. It makes use of the conceptual semi-distributed hydrological model SCHEME and the European Centre for Medium Range Weather Forecasts (ECMWF) ensemble prediction system (ENS). An ensemble of 51 discharge forecasts is generated daily. We investigate the improvements attained through postprocessing the discharge forecasts, using the archived ECMWF reforecasts for precipitation and other necessary meteorological variables. We use the 5-member reforecasts that have been produced since 2012, when the horizontal resolution of ENS was increased to the N320 resolution (≈30 km over Belgium). The reforecasts were issued weekly, going back 20 years, and we use a calibration window of five weeks. We use these as input to create a set of hydrological reforecasts. The implemented calibration method is an adaption of the variance inflation method. The parameters of the calibration are estimated based on the hydrological reforecasts and the observed discharge. The postprocessed forecasts are verified based on a two-and-a-half year period of data, using archived 51 member ENS forecasts. The skill is evaluated using summary scores of the ensemble mean and probabilistic scores: the Brier Score and the Continuous Ranked Probability Score (CRPS). We find that the variance inflation method gives a significant improvement in probabilistic discharge forecasts. The Brier score, which measures probabilistic skill for forecasts of discharge threshold exceedance, is improved for the entire forecast range during the hydrological summer period, and the first three days during hydrological winter. The CRPS is also significantly improved during summer, but not during winter. We conclude that it is valuable to apply the postprocessing method during hydrological summer. During winter, the method is also useful for forecasting exceedance probabilities of higher thresholds, but not for lead times beyond five days. Finally, we also note the presence of some large outliers in the postprocessed discharge forecasts, arising from the fact that the postprocessing is performed on the logarithmically transformed discharges. We suggest some ways to deal with this in the future for our operational setting. Full article
(This article belongs to the Special Issue Hydrological Modeling: Beyond Runoff Calibration)
Figures

Figure 1

Open AccessArticle
An Institutional Analysis of Groundwater Quality Control: Experiences in Hadano, Kanagawa Prefecture, Japan
Received: 29 December 2015 / Revised: 29 April 2016 / Accepted: 4 May 2016 / Published: 18 May 2016
Cited by 1 | Viewed by 1277 | PDF Full-text (2049 KB) | HTML Full-text | XML Full-text
Abstract
A considerable number of studies have been made of institutional arrangements that can prevent excessive groundwater pumping based on Hardin’s seminal work, the “tragedy of the commons.” In contrast, this paper is concerned with groundwater quality control for which policy studies are very [...] Read more.
A considerable number of studies have been made of institutional arrangements that can prevent excessive groundwater pumping based on Hardin’s seminal work, the “tragedy of the commons.” In contrast, this paper is concerned with groundwater quality control for which policy studies are very limited. This paper not only clarifies institutional challenges specific to groundwater contamination, but also demonstrates how government and industry could solve them using a case study of Hadano, Kanagawa Prefecture, Japan, which has pioneered countermeasures for groundwater pollution in Japan. Hadano solved the challenges by enacting an innovative local ordinance with three pillars: Proxy purification by the city government, fundraising for purification activities and a retroactive system. Lessons learnt from the Hadano case will be very useful to policy makers because these problems already occur in other urban areas, or are likely to occur in the near future. Full article
(This article belongs to the Special Issue The Intersection of Society and Watershed Science)
Figures

Figure 1

Open AccessArticle
Comparing One-Way and Two-Way Coupled Hydrometeorological Forecasting Systems for Flood Forecasting in the Mediterranean Region
Received: 19 January 2016 / Revised: 3 April 2016 / Accepted: 25 April 2016 / Published: 7 May 2016
Cited by 11 | Viewed by 2014 | PDF Full-text (5701 KB) | HTML Full-text | XML Full-text
Abstract
A pair of hydro-meteorological modeling systems were calibrated and evaluated for the Ayalon basin in central Israel to assess the advantages and limitations of one-way versus two-way coupled modeling systems for flood prediction. The models used included the Hydrological Engineering Center-Hydrological Modeling System [...] Read more.
A pair of hydro-meteorological modeling systems were calibrated and evaluated for the Ayalon basin in central Israel to assess the advantages and limitations of one-way versus two-way coupled modeling systems for flood prediction. The models used included the Hydrological Engineering Center-Hydrological Modeling System (HEC-HMS) model and the Weather Research and Forecasting (WRF) Hydro modeling system. The models were forced by observed, interpolated precipitation from rain-gauges within the basin, and with modeled precipitation from the WRF atmospheric model. Detailed calibration and evaluation was carried out for two major winter storms in January and December 2013. Then, both modeling systems were executed and evaluated in an operational mode for the full 2014/2015 rainy season. Outputs from these simulations were compared to observed measurements from the hydrometric station at the Ayalon basin outlet. Various statistical metrics were employed to quantify and analyze the results: correlation, Root Mean Square Error (RMSE) and the Nash–Sutcliffe (NS) efficiency coefficient. Foremost, the results presented in this study highlight the sensitivity of hydrological responses to different sources of simulated and observed precipitation data, and demonstrate improvement, although not significant, at the Hydrological response, like simulated hydrographs. With observed precipitation data both calibrated models closely simulated the observed hydrographs. The two-way coupled WRF/WRF-Hydro modeling system produced improved both the precipitation and hydrological simulations as compared to the one-way WRF simulations. Findings from this study, as well as previous studies, suggest that the use of two-way atmospheric-hydrological coupling has the potential to improve precipitation and, therefore, hydrological forecasts for early flood warning applications. However, more research needed in order to better understand the land-atmosphere coupling mechanisms driving hydrometeorological processes on a wider variety precipitation and terrestrial hydrologic systems. Full article
Figures

Figure 1

Open AccessArticle
Surface Runoff in Watershed Modeling—Turbulent or Laminar Flows?
Received: 5 April 2016 / Revised: 20 April 2016 / Accepted: 25 April 2016 / Published: 4 May 2016
Cited by 3 | Viewed by 2027 | PDF Full-text (5288 KB) | HTML Full-text | XML Full-text
Abstract
Determination of overland sheet flow depths, velocities and celerities across the hillslope in watershed modeling is important towards estimation of surface storage, travel times to streams and soil detachment rates. It requires careful characterization of the flow processes. Similarly, determination of the temporal [...] Read more.
Determination of overland sheet flow depths, velocities and celerities across the hillslope in watershed modeling is important towards estimation of surface storage, travel times to streams and soil detachment rates. It requires careful characterization of the flow processes. Similarly, determination of the temporal variation of hillslope-riparian-stream hydrologic connectivity requires estimation of the shallow subsurface soil hydraulic conductivity and soil-water retention (i.e., drainable porosities) parameters. Field rainfall and runoff simulation studies provide considerable information and insight into these processes; in particular, that sheet flows are likely laminar and that shallow hydraulic conductivities and storage can be determined from the plot studies. Here, using a 1 m by 2 m long runoff simulation flume, we found that for overland flow rates per unit width of roughly 30–60 mm2/s and bedslopes of 10%–66% with varying sand roughness depths that all flow depths were predicted by laminar flow equations alone and that equivalent Manning’s n values were depth dependent and quite small relative to those used in watershed modeling studies. Even for overland flow rates greater than those typically measured or modeled and using Manning’s n values of 0.30–0.35, often assumed in physical watershed model applications for relatively smooth surface conditions, the laminar flow velocities were 4–5 times greater, while the laminar flow depths were 4–5 times smaller. This observation suggests that travel times, surface storage volumes and surface shear stresses associated with erosion across the landscape would be poorly predicted using turbulent flow assumptions. Filling the flume with fine sand and conducting runoff studies, we were unable to produce sheet flow, but found that subsurface flows were onflow rate, soil depth and slope dependent and drainable porosities were only soil depth and slope dependent. Moreover, both the sand hydraulic conductivity and drainable porosities could be readily determined from measured capillary pressure displacement pressure head and assumption of pore-size distributions (i.e., Brooks-Corey lambda values of 2–3). Full article
Figures

Figure 1

Open AccessArticle
Impact of Climate Change on Groundwater Resources in the Klela Basin, Southern Mali
Received: 22 March 2016 / Revised: 27 April 2016 / Accepted: 28 April 2016 / Published: 2 May 2016
Cited by 5 | Viewed by 2470 | PDF Full-text (7337 KB) | HTML Full-text | XML Full-text
Abstract
Investigations of groundwater resources in order to understand aquifer system behavior are vital to the inhabitants of the Klela Basin, Mali, because groundwater is the only permanent water resource and is used for drinking water and irrigation. Due to climate change, this vital [...] Read more.
Investigations of groundwater resources in order to understand aquifer system behavior are vital to the inhabitants of the Klela Basin, Mali, because groundwater is the only permanent water resource and is used for drinking water and irrigation. Due to climate change, this vital resource is being threatened. Therefore, MODFLOW was applied in this study to simulate groundwater dynamics. The aim of this study was to evaluate the impact of climate change on groundwater resources in the Klela basin using the RCP4.5 (Representative Concentration Scenario 4.5 W/m2) climate scenario. Climatological, geological, hydrogeological, hydraulic and demographic data were collected and used as model input data. Groundwater recharge was estimated to be approximately 165.3 mm/year using the EARTH (Extended model for Aquifer Recharge and soil moisture Transport through the unsaturated Hardrock) model. Recharge was then used as groundwater model input. The sandstone aquifer in the study area was simulated in steady and transient conditions. The results showed that hydraulic conductivity values varied from 1.1 to 13.9 m/day. The model was used for scenario quantification after model calibration and verification using three different piezometer data sets. The results of the simulated MODFLOW model showed a decrease in groundwater levels over time. Full article
Figures

Figure 1

Open AccessArticle
Evaluation of Multiresolution Digital Elevation Model (DEM) from Real-Time Kinematic GPS and Ancillary Data for Reservoir Storage Capacity Estimation
Received: 1 March 2016 / Revised: 20 April 2016 / Accepted: 21 April 2016 / Published: 27 April 2016
Cited by 2 | Viewed by 1709 | PDF Full-text (5636 KB) | HTML Full-text | XML Full-text
Abstract
This study presents the estimation of reservoir storage capacity using multiresolution Real-Time Kinematic Global Positioning System (RTK-GPS) DEM, in comparison with ASTER and contour-derived DEM. Through RMSE comparisons of the elevation point uncertainty and error analysis, the results shows that the RTK-GPS DEM [...] Read more.
This study presents the estimation of reservoir storage capacity using multiresolution Real-Time Kinematic Global Positioning System (RTK-GPS) DEM, in comparison with ASTER and contour-derived DEM. Through RMSE comparisons of the elevation point uncertainty and error analysis, the results shows that the RTK-GPS DEM gave the best results for the reservoir capacity-area power curve estimation, defined by a convex slope with an exponential deterministic relationship given by V = 0.09 × A 1.435 . The results further show the existence an empirical relationship between the reservoir volume certainty and the GPS point density d i as V e = c × d i ρ . This relationship is dependent on the reservoir terrain, slope and surface area. Validation of the results with in situ data showed the differences between the simulated and observed storage volumes was less than +10%, and using the Nash-Sutcliffe coefficient of efficiency on the storage volumes, an average efficiency of +0.7 on the monthly observed and simulated reservoir storage volume was observed. Full article
Figures

Figure 1

Open AccessArticle
Hydrological Evaluation of TRMM Rainfall over the Upper Senegal River Basin
Received: 12 March 2016 / Revised: 8 April 2016 / Accepted: 8 April 2016 / Published: 15 April 2016
Cited by 11 | Viewed by 2171 | PDF Full-text (2346 KB) | HTML Full-text | XML Full-text
Abstract
The availability of climatic data, especially on a daily time step, has become very rare in West Africa over the last few years due to the high costs of climate data monitoring. This scarcity of climatic data is a huge obstacle to conduct [...] Read more.
The availability of climatic data, especially on a daily time step, has become very rare in West Africa over the last few years due to the high costs of climate data monitoring. This scarcity of climatic data is a huge obstacle to conduct hydrological studies over some watersheds. In this context, our study aimed to evaluate the capacity of Tropical Rainfall Measuring Mission (TRMM) satellite data to simulate the observed runoffs over the Bafing (the main important tributary of the Senegal River) before their potential integration in hydrological studies. The conceptual hydrological model GR4J (modèle du Génie Rural (Agricultural Engineering Model) à 4 paramètres Journalier (4 parameters Daily)) has been used, calibrated and validated over the 1961–1997 period with rainfall and Potential Evapotranspiration (PET) as inputs. Then, the parameters that best reflect the rainfall-runoff relation, obtained during the cross-calibration-validation phase, were used to simulate runoff over the 1998–2004 period using observed and TRMM rainfalls. The findings of this study show that there is a high consistency between satellite-based estimates and ground-based observations of rainfall. Over the 1998–2004 simulation period, the two rainfall data series show quite satisfactorily results. The output hydrographs from satellite-based estimates and ground-based observations of rainfall coincide quite well with the shape of observed hydrographs with Nash-Sutcliffe Efficiency coefficient (NSE) of 0.88 and 0.80 for observed rainfalls and TRMM rainfalls, respectively. Full article
Figures

Figure 1

Open AccessArticle
Variability and Trends in Precipitation, Temperature and Drought Indices in the State of California
Received: 9 February 2016 / Revised: 18 March 2016 / Accepted: 22 March 2016 / Published: 28 March 2016
Cited by 10 | Viewed by 2265 | PDF Full-text (8405 KB) | HTML Full-text | XML Full-text
Abstract
This study presents a comprehensive assessment of the variability and trends of the precipitation and temperature along with the trends in drought indices over the State of California. The non-parametric Mann–Kendall trend test is applied with a trend-free pre-whitening procedure in trend identification. [...] Read more.
This study presents a comprehensive assessment of the variability and trends of the precipitation and temperature along with the trends in drought indices over the State of California. The non-parametric Mann–Kendall trend test is applied with a trend-free pre-whitening procedure in trend identification. A dataset containing 120-year (water years 1896–2015) monthly precipitation, average temperature, maximum temperature, minimum temperature and the Palmer Index for seven climatic regions of the state is used for this purpose. The results confirm previous work indicating that no clear trends are observed in precipitation, while a distinct warming trend is evident in temperature over the state. New findings of this study include: (1) in general, the variability of annual, winter (December–February) and spring (March–May) precipitation shows an increasing tendency, implying intensified frequency of the occurrence of dry or wet extremes; (2) on the annual scale and in the summer, statewide meteorological, hydrological and agricultural drought indices all have decreasing trends, indicating the more frequent occurrence of drought events; and (3) among seven regions, the South Coast Drainage region generally has the most significant warming trend, as well as the most significant declining trends in drought indices. Overall, these findings are highly meaningful from both theoretical and practical perspectives, in the context of providing critical information in developing prediction models and guiding water resources management practices, respectively. Full article
Figures

Figure 1

Hydrology EISSN 2306-5338 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top