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. Mathematical and statistical tools that are suitable to face common tasks in hydrology will be presented and their practical use illustrated with examples. 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. 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. Advanced and innovative aspects of hydrology will be introduced where possible, for an up-to-date formation of future engineers.

After this course, students will be expected to have gained knowledge of the physical processes and principles governing the rainfall formation, the rainfall-runoff transformation, the soil water balance at different temporal and spatial scales. Students will acquire the principles of hydrologic data management and analysis as well as information on the measurement of precipitation and discharge. Students will come to know a set of modeling techniques, with the corresponding hypotheses, merits and limitations, useful to analyze different real problems, to estimate variables and to identify solutions. Expected acquired skills include: the use of probabilistic methods for the definition of rainfall and discharge design values and for the verification of past extreme events; the layout of hydrologic water balances for the estimation of peak floods or available water resources; modeling of soil-water interactions at different temporal and spatial scales.

Students must have taken a course of hydraulics and know the basic principles of hydrostatics, flow dynamics, pressure and force distribution. Knowledge of the fundamentals of probability and statistics is also necessary. In addition, students should have a basic knowledge of informatics and possibly know a programming software (e.g., Matlab) for the development of assignments and exercises. The course attendance requires fluent spoken and written English.

(i) Statistical hydrology (20 h) Definition of variables and basic statistical concepts, data analysis, statistical inference; Probabilistic models, methods for parameter estimation; Introduction to statistical tests, goodness-of-fit tests, definition of design values; (ii) Precipitations (10 h) Physical principles, measurement and instruments, assessment of areal rainfall and spatial interpolation; Statistical models for precipitation, IDF curves. (iii) Water and soil (10 h) Principles of soil-water interactions, hydraulic properties of soils, retention curves; Water in porous media, Richard’s equation, infiltration models; Effective rainfall, basin-scale water balance models, SCS-Curve Number model. (iv) Rainfall-runoff transformation (10 h) Morphology of river basins, relevant characteristics, hypsographic curve; Rainfall-runoff models, design hyetographs and flood hydrograph, kinematic model, IUH; (v) Water resources (10 h) Energy balance of soil surface, potential evapotranspiration, evaporation from free surface; Water resources in agriculture, actual evapotranspiration, vegetation and water stress, irrigation; Water resources for hydropower, flow duration curves, productivity of power plants, environmental flows.

The course will primarily address the Sustainable Development Goal n.6, related to the sustainable use of freshwater resources, but will also briefly discuss issues related to the energy and climate Goals.

The course is organized in lectures and exercise-classes. Lectures are devoted to the presentation of the course topics, in their theoretical aspects and applicative examples, and they will be held mainly by the lecturer. Exercise-classes will focus on numerical exercises and practical hydrologic problems, to be solved individually with the assistance of the course instructors. Students will be asked to prepare a written report for five (5) major assignments, summarizing the development and results obtained. One optional assignment will be proposed that involves a small research or application developed in groups (2-3 people) and presented to the class at the end of the course.

All material that is necessary for the course will be presented and discussed in class. Reference books are: - Kottegoda, Rosso (2008) “Applied Statistics for Civil and Environmental Engineering”, Blackwell Publishing, for the statistical parts, - Chow, Maidments, Mays (1988) “Applied Hydrology”, McGraw-Hill, for the physical hydrology parts. Additional readings can be found in international reference textbooks. Some specific chapters will be provided to the students on the course web page. A useful online reference is: echo2.epfl.ch/VICAIRE/

Modalità di esame: Prova scritta su carta con videosorveglianza dei docenti;

Students will undergo a written exam (duration: 2 hours) including 2-3 exercises and 1-2 open questions. The exercises will have to be solved by hand calculations. They are shorter and occasionally different than the assignments developped during exercises-classes and are aimed at verifying the learning and the understanding of quantitative methods in hydrology. The open questions will focus on topics introduced during the lectures and are aimed at verifying the acquired knowledge about hydrological processes and the theory behind the modeling techniques introduced. The use of assignment reports will NOT be allowed during the exam. The written exam mark will take into account the resolution methods, the correctness of the numerical solutions, the knowledge demonstrated and the clarity of presentation. The maximum mark will be 25/30 and the minimum pass mark will be 18/30. The final mark for the course will be the sum of the written exam mark plus the marks obtained from the evaluation of the assignment reports prepared along the course (a maximum of 5 points, i.e. 5/30) and the marks gained from the (optional) group work presentation delivered at the end of the course (a maximum of 2 points, i.e. 2/30). Marks obtained with the reports and the presentation do not contribute to reach the minimum pass mark; reports’ and presentation’s marks remain valid throughout the whole academic year.

Modalità di esame: Prova scritta (in aula); Prova scritta su carta con videosorveglianza dei docenti;

Students will undergo a written exam (duration: 2 hours) including 2-3 exercises and 1-2 open questions. The exercises will have to be solved by hand calculations. They are shorter and occasionally different than the assignments developped during exercises-classes and are aimed at verifying the learning and the understanding of quantitative methods in hydrology. The open questions will focus on topics introduced during the lectures and are aimed at verifying the acquired knowledge about hydrological processes and the theory behind the modeling techniques introduced. The use of assignment reports will NOT be allowed during the exam. The written exam mark will take into account the resolution methods, the correctness of the numerical solutions, the knowledge demonstrated and the clarity of presentation. The maximum mark will be 25/30 and the minimum pass mark will be 18/30. The final mark for the course will be the sum of the written exam mark plus the marks obtained from the evaluation of the assignment reports prepared along the course (a maximum of 5 points, i.e. 5/30) and the marks gained from the (optional) group work presentation delivered at the end of the course (a maximum of 2 points, i.e. 2/30). Marks obtained with the reports and the presentation do not contribute to reach the minimum pass mark; reports’ and presentation’s marks remain valid throughout the whole academic year.