![]() ![]() ![]() In management decisions of water structures, a risk-based approach should be used where errors that result in under-preparedness are considered as well as those resulting in over-preparedness. ![]() Design life level is another concept that can be used in a nonstationary context. Design concepts such as return period and hydrological risk should be redefined in a changing world. Annual maxima or peaks-over-threshold series can be analyzed incorporating a trend component to the parameters. Frequency analysis of nonstationary processes can be made by fitting a trend to the parameters of the probability distribution. In some cases, it is more important to increase the power so that errors of estimation that may lead to damages due to inadequate protection are prevented. The power of a test depends on the chosen level of significance, sample size and the accuracy of prediction of trends. Some authors criticized the use of significance levels in statistical tests and recommended using confidence intervals around the estimated effect size. Long-term persistence in hydrological processes also affects the results of the test. The statistical significance of a trend can be detected by means of statistical tests such as the nonparametric Mann-Kendall test, which must be modified when there is serial correlation, possibly by prewhitening. The estimation of extremes (floods and low flows) is more important but also much more difficult. It is attempted to generate synthetic nonstationary time series of future climates by means of a global climate model, which are then used in water resources optimization under uncertainty. A stationary model is sometimes preferable to a nonstationary one when the evolution in time of hydrological processes cannot be predicted reliably. It must be remembered, however, that all hydrological systems include a stationary element, at least in the form of a random component. Detailed climate models and long hydrological records are needed to predict the future conditions in a changing world. Climate change as well as low-frequency climate variability and human intervention in river basins violate the assumption of stationarity, which is claimed to be dead by some researchers. Water resources for hydropower, flow duration curves, productivity of power plants, environmental flows.Recent climate change due to global warming has given an impetus to trend analysis of hydrological time series. Water resources in agriculture, actual evapotranspiration, vegetation and water stress, irrigation Rainfall-runoff models, design hyetographs and flood hydrograph, kinematic model, IUH Įnergy balance of soil surface, potential evapotranspiration, evaporation from free surface Morphology of river basins, relevant characteristics, hypsographic curve (iv) Rainfall-runoff transformation (10 h) Water in porous media, Richard’s equation, infiltration models Įffective rainfall, basin-scale water balance models, SCS-Curve Number model. Principles of soil-water interactions, hydraulic properties of soils, retention curves Statistical models for precipitation, IDF curves. Physical principles, measurement and instruments, assessment of areal rainfall and spatial interpolation Introduction to statistical tests, goodness-of-fit tests, definition of design values Probabilistic models, methods for parameter estimation Advanced and innovative aspects of hydrology will be introduced where possible, for an up-to-date formation of future engineers.ĭefinition of variables and basic statistical concepts, data analysis, statistical inference Different processes of the water cycle, from precipitation formation to soil water infiltration and vegetation evapotranspiration, will be studied to give an appropriate physical background to the theories and techniques that are used in practice. Traditional hydrologic problems, such as quantifying design discharge values for civil infrastructures, assessing the return time of extreme events, or evaluating the water resources for hydropower or irrigation purposes, will be tackled from both a theoretical and a practical point of view. Mathematical and statistical tools that are suitable to face common tasks in hydrology will be presented and their practical use illustrated with examples. The course of Hydrology gives all civil engineers a basic knowledge about the physical processes governing the water cycle and the quantitative techniques to model and estimate the relevant variables, such as precipitation and river discharge. ![]()
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