Improved unit hydrograph identification for seven Welsh rivers: implications for estimating continuous streamflow at ungauged sites
ABSTRACT A unit hydrograph-based continuous rainfall—streamflow model is applied at daily time step to several catchments in Wales. Two calibration methods are compared for seven catchments. Five of the catchments are among 60 basins in England and Wales for which models were derived by other investigators using the first calibration method, in order to devise a regionalization scheme allowing model parameters to be estimated from catchment properties. The paper shows that in several cases the first calibration method tends to overestimate low flows and give a positively biased estimate for one of the unit hydrograph parameters. It also shows that the second parameter calibration method can often overcome this problem, yielding model parameters more suitable for regionalization with respect to physical catchment properties. Implications of the work are discussed in the context of improving regionalization schemes where the estimation of streamflow in ungauged basins is the major objective.
- SourceAvailable from: Andre Mesquita[Show abstract] [Hide abstract]
ABSTRACT: One of the main obstacles to the socio-economic development of the Brazilian Amazon is the lack of electric energy in the numerous small isolated communities of the region that hampers value-added agricultural production, revenue growth and creation of jobs. One way to solve this problem is by setting up micro-hydro power (MHP) plants under a sustainable development perspective. This paper presents a decision support system (DSS) that analyzes this solution. The system considers the hydrological, topographical, geotechnical, environmental, energy, economic and social aspects of the target site. A detailed analysis is made of the hydrological model that employs a rainfall run-off model for small catchment analysis; the energy planning favors a two-turbine method to determine the maximum energy production during demand peaks, and the economic aspects show that the costs of energy generated by MHP plants are comparable to those from rural grid systems and lower than those from from diesel generators. Thus, the use of the hydro-power resources of the small catchments of Amazonia combined with the minimization of the environmental impacts caused by MHP not only fulfills the energy demand of the small communities of region, but is also viable economically along with job creation and revenue generation, and it supports the perspective of sustainable development.Energy for Sustainable Development 01/2008; 12(3):25-33. · 2.22 Impact Factor
- [Show abstract] [Hide abstract]
ABSTRACT: Employing 1-, 2-, 4-, 6-, 12- and 24-hourly data sets for two catchments (10.6 and 298 km) in Wales, the calibrated parameters of a unit hydrograph-based model are shown to change substantially over that range of data time steps. For the smaller basin, each model parameter reaches, or approaches, a stable value as the data time step decreases, providing a straightforward method of estimating time-step independent model parameter values. For the larger basin, the model parameters also reach, or approach, stable values using hourly data, but, for reasons given in the paper, interpretation of the results is more difficult. Model parameter sensitivity analyses are presented that give insights into the relative precision on the parameters for both catchments. The paper discusses the importance of accounting for model parameter data time-step dependency in pursuit of a reduction in the uncertainty associated with estimates of flow in ungauged basins, and suggests that further work along these lines be undertaken using different catchments and models.Hydrological Sciences Journal-journal Des Sciences Hydrologiques - HYDROLOG SCI J. 01/2008; 53(4):685-695.
- [Show abstract] [Hide abstract]
ABSTRACT: Two types of unit hydrograph (UH) are discussed, with an emphasis on uncertainties. The paper reviews the 1-parameter triangular unit hydrograph (UH) employed to assist with systematic design floo d hydrograph estimation for ungauged United Kingdom catchments. A 6-parameter rainfall-runoff model that incorporates a 3-parameter UH is also discussed. Th e precision and accuracy of characteristic decay ti mes for dominant quick and slow response UHs, derived from the 6-parameter model, are examined in the context of uncertainty in flow regime regionalisation. On the basis that, as argued in the paper, the full potent ial of the 3- parameter UH has yet to be exploited for regionalis ation of flow regimes, there are plans for further work along these lines during the International Associat ion of Hydrological Sciences (IAHS) Prediction in Ungauged Basins (PUB) Decade (2003-2012).06/2004;