Lecturer: Ugo Moisello  

Course name: Hydrology
Course code: 502527
Degree course: Ingegneria Civile e Ambientale
Disciplinary field of science: ICAR/02
L'insegnamento è caratterizzante per: Ingegneria per l'Ambiente e il Territorio
University credits: CFU 6
Course website: http://www-3.unipv.it/webidra/materialeDidattico/mdidat
tico.htm

Specific course objectives

The aim of the course is to give the basic concepts for solving the most common hydrological problems: water availability and floods. The necessary statistical notions are also given.

Course programme

Hydrology
(30 hours)

• Introduction. Origin and types of precipitations. Storms, hurricanes. Factors affecting the rainfall regime. The rainfall regimes in Italy.
• Rain gauges. Rainfall data published in Italy. Computation of the average rainfall depth over a basin (with the isohyet method and Thiessens's method).
• The basin: definition and main characteristics. Surface runoff, interflow and groundwater discharge. The concentration time.
• Basin losses and different forms of water storage. Depression storage (short reference). Dalton's law. Evaporation factors and time-invariant evaporation rate. Atmometers and evaporation pans. Different evaporation forms (short reference). Actual and potential evapotranspiration. Infiltration (short reference).
• The assessment of basin losses in the engineering practice.
• Discharge and river stage. Staff and automatic recording gauges. Current meters. The discharge measurement.
• The runoff regimes of Italian rivers. Streamflow data published in Italy. The flood hydrograph analysis.
• Statistical analyses of floods. At-site statistical analyses. The relation between peak and daily discharge annual maxima. The probability distribution of the maximum discharge in a period of N years.
• Rainfall depth-duration-frequency curves. The area reduction factor.
• Design hyetographs.
• The rainfall-runoff process. Simple mathematical relations and mathematical models. The rational method. Conceptual and black-box models. Complete models and flood models. The determination of storm runoff and effective rainfall.
• Linear time-invariant systems. The instantaneous unit hydrograph and its application to storm runoff models. The discretization of the instantaneous unit hydrograph.
• Linear time-invariant models arranged in series and in parallel. The linear channel and the time-area method. The linear reservoir and the Nash model.
• The model determination: type selection and parameter estimation. The least squares method and the method of moments.
• Illustration of a series of slides showing measurement instruments and methods.

Statistics
(10 hours)

• Random variables, probability theory axioms, discrete and continuous probability distributions.
• Parameters and moments of probability distributions. Functions of random variables. The return period. The binomial distribution.
• The normal distribution and other continuous distributions.
• The quantile estimation problem. Frequency, sample moments. Estimation of the probability distribution. Probability papers. Parameter estimation. The method of moments.
• Statistical tests. Pearson's test.

Laboratories
(12 hours)

• Determination of the peak discharge with a given return period by means of Gumbel's distribution.
• Determination of the peak discharge with a given return period, by means of a statistical analysis taking into consideration three different probability distributions (Gumbel, two-parameters lognormal and two-parameters Gamma). Determination of the probability distribution of the maximum discharge in a period of N years.
• Determination of the rainfall depth-duration-frequency curve for a single station.
• Determination of some design hyetographs for a given area, based on the rainfall depth-duration data recorded at a station and a table of the area reduction factor.
• Determination of the instantaneous unit hydrograph of a conceptual model by means of the method of moments.

Course entry requirements

MATHEMATICAL ANALYSIS: The concepts of function, limit, derivative, integral. Combinations. The concept of differential equation, particularly linear with constant coefficients. The concepts of multivariate function, partial derivative and partial derivative differential equation. Unconditional maximum of a function of one or more variables. Practical knowledge: computation of simple derivatives and integrals, use of mathematical tables of limits, derivatives, integrals and definite integrals. GEOMETRY AND ALGEBRA: Fundamentals of trigonometry. Fundamentals of analytical geometry in two and three dimensions. The concepts of linear and non-linear scale. Matrices and linear equation systems. Practical knowledge: elementary trigonometry and geometry operations (computation of areas included). Graphical representation of functions, with linear and non linear (particularly logarithmic) scales. PHYSICS: Physical magnitude measurements and measurement units. Fundamentals of aggregation states of matters and physical properties of bodies (density, viscosity, capillarity).

Course structure and teaching

Lectures (hours/year in lecture theatre): 40
Practical class (hours/year in lecture theatre): 12
Practicals / Workshops (hours/year in lecture theatre): 0

Suggested reading materials

Testing and exams

The exam consists of a written and an oral test. The oral test may be taken only after passing the written test, and the final mark is determined by both results. The student can also give up the oral test and use the result of only the written test for passing the exam.