Lecturer: Gabriella Petaccia  

Course name: Idrologia (mn)
Course code: 062101
Degree course: Ingegneria per l'Ambiente e il Territorio
Disciplinary field of science: ICAR/02
The course relates to:
University credits: CFU 6
Course website: n.d.

Specific course objectives

The courses focuses in giving the student the necessary knowledge to cope with hydrologic problems that commonly arise in engineering such as: water supply, flood analysis. It gives also the statistic notions necessary to design works for an assigned risk level. Each lesson lasts 2 hours.

Course programme

Rainfalls
Origin and classification of rainfalls. Thunderstorms, hurricanes. The pluviometric regime, and the italian regimes.

Measurement of Rainfall
Rain gauges, sources of rainfall data. Space-Time characteristics of Rainfall, Interpolation of rainfall records ( Thiessen diagrams, Isohyetal maps)

Statistical and probability analysis of hydrological data
Statistical variables, random variables, frequency, probability and statistical distributions

The drainage basin:
Definition and main features, time of concentration

Statistical and probability analysis of hydrological data
Statistical distributions and parameters. Return period. Binomial distribution.

The hydrologic losses
Evaporation, measurement of evaporation, real and potential evaporation. Infiltration

Continuous random variable probability distributions
Normal distribution, Gamma distribution, Poisson distribution, Pearson distribution, Extremal distribution, Lognormal distribution.

Determination of runoff from precipitation
Runoff coefficient, SCS method, Curve number.

Choice of the probability distribution
Probability paper, plotting of data, curve fitting, reliability of analysis, Statistical Inference

Stream flow measurements
Determination of stage: Stage indicators . Velocity measurements: the rotating meter. Discharge measurements. The hydrometric station, stage discharge relation.

Statistical tests.
Introduction, Pearson Test.

Flood characteristics and determination, statistical analysis
Flood hydrograph analysis. Statistical local analysis, relation between maximum yearly peak discharges and average daily discharge.

Quantitative determination of urban storm water runoff
Depth duration curve, the hydrograph method: IDF, Chicago, Sifalda and ISWS methods

Rainfall-Runoff modelling.
Rational method, Linear and stationary systems. Instantaneous unit hydrograph, conceptual methods, Linear reservoir, linear channel, series and parallel of linear systems, Nash’s model

practical classes

exercise 1 Statistical bases: Return period, Cumulative probability. Exercise 2 Drainage basin, Hypsometric analysis, average height, concentration time, average slope, Horton constants: Exercise 3 The hydrologic losses Exercise 4 Discharge evaluation Exercise 5 Evaluation of a discharge for assigned return period Exercise 6 Depth duration curve evaluation Exercise. 7 Pearson Statistical Test Exercise.8 Design hydrograph method Exercise.9 Instantaneous unit hydrograph: linear reservoir and linear channel Exercise. 10 Instantaneous unit hydrograph GIUH Exercise 11 rainfall runoff analysis: series and parallel of linear systems

Course entry requirements

Course structure and teaching

Lectures (hours/year in lecture theatre): 32
Practical class (hours/year in lecture theatre): 27
Practicals / Workshops (hours/year in lecture theatre): 0
Project work (hours/year in lecture theatre): 0

Suggested reading materials

Chow, V.T.; Maidment, D.R.; Mays L.. Applied Hydrology,. WNew York, Mc Graw-Hill Book Company, 1988..

Maione, U.; Moisello, U.:. Elementi di statistica per l. Pavia, la Goliardica Pavese, 1993..

Moisello, U.. Idrologia tecnica. Pavia, La Goliardica Pavese, 1998..

Testing and exams

THE EXAM WILL TAKE PLACE USING PERSONAL COMPUTERS