Unit HYDROGEOLOGICAL RISK
- Course
- Geosciences for risk and environment management
- Study-unit Code
- A000942
- Curriculum
- Geologia applicata alla salvaguardia e alla pianificazione del territorio
- Teacher
- Daniela Valigi
- Teachers
-
- Daniela Valigi
- Hours
- 42 ore - Daniela Valigi
- CFU
- 6
- Course Regulation
- Coorte 2021
- Offered
- 2021/22
- Learning activities
- Caratterizzante
- Area
- Discipline geomorfologiche e geologiche applicative
- Academic discipline
- GEO/05
- Type of study-unit
- Obbligatorio (Required)
- Type of learning activities
- Attività formativa monodisciplinare
- Language of instruction
- Italian
- Contents
- Hazard and Risk. Landslide and hydraulic risk. Risk legislation. The Hydrogeological Management Plan (PAI). Soil slope stability analysis with the limit equilibrium method. Mapping of the areas exposed to floods and landslides. Identification the main protection actions to reduce or to remove the hydrogeological risk: structural and non-structural measures (e.g. flood forecasting system and land-use planning).
- Reference texts
- Pranzini G. & Tanzini M. (2018) - Rischio Idraulico e Idrogeologico. Previsione, prevenzione e progettazione degli interventi per la riduzione dei rischi. Dario Flaccovio Editore.
Gisotti G. (2012) - Il dissesto idrogeologico. Previsione, prevenzione e mitigazione del rischio. Dario Flaccovio Editore, Palermo.
Frumento S. (2014) - Il rischio idrogeologico in Italia. Guida pratica, Cause del dissesto, Strumenti e tipologie di intervento. Wolters Kluwer Italia.
Caivano A. M. (2003) - Rischio idraulico e idrogeologico. Procedure di pianificazione, verifica, controllo e gestione delle emergenze. Epc (Roma).
Ciabatti M. (1982) Elementi di Idrologia Superficiale. Coop. Libraria Univ. Ed. Bologna.
Copies of the slides presented in class by the teacher. - Educational objectives
- The course aims to provide students with theoretical and practical knowledge for the understanding of hydrogeological phenomena and related risks.
In detail, students will acquire knowledge on:
- Triggering factors of landslides;
- Hydrogeological risk assessment;
- Monitoring techniques for selecting the most appropriate and reliable alert systems according to the type of phenomenon;
- Management of emergency phases during extreme rainfall events related to the on-going climate of the Mediterranean area.
Main skills:
- Be able to interpret thematic cartography and critically analyze geological and hydro-meteorological data;
- Be able to interact with Local and National Authorities (Civil Protection, Region, Prefecture, etc.), aiming to activate operative protocols during crisis situations induced by hydro-meteorological event. - Prerequisites
- In order to follow this course with profit, the student must have basic knowledge of applied geology and hydrogeology useful to understand the effect of the human impact, produced by the main engineering works, on environmental systems.
- Teaching methods
- Teaching consists of classroom lectures and field trips. Some technicians of local government authorities dealing with the hydrogeological risk will be involved by specific seminars.
Following a brief description of teaching methods:
- Classroom lectures: the topics are presented to students who are stimulated and involved during the lessons with questions and opinions on the issues discussed, also through the illustration of selected case studies.
- Field trip: students are involved in some field concerning hydrogeological instability and monitoring. - Other information
- The attendance of teaching activities is optional but strongly advised. - Students will have to use spreadsheet and perform exercises in the computer room.
- Learning verification modality
- The exam consists of an oral test aiming to ascertain the knowledge, skills, and abilities of the student in communicating and solving the problems related to the hydrogeological risk. The questions concern the different topics discussed during the course, taking into account both theoretical and practical aspects.
Information for students with disabilities are available at http://www.unipg.it/disabilita-e-dsa - Extended program
- Definition of Risk.
Flood and landslide risk regulations. Hazard and Risk Maps. Illustration of the Central Apennine Flood Risk Management Plan (PGRAAC). VAS and ARS. Hydrogeological development plan of the F. Tiber basin (PAI).
1) Hydraulic risk
Estimation of short-term maximum rainfall. Extreme Values of Precipitation. River regimes.
Estimation of the peak discharge with empirical and semi-empirical methods. Rational formula. Definition of the runoff coefficient. Analyses of annual maximum series of peak discharge with statistical-probabilistic methods (Gumbel). Return time.
Analysis of the flood hydrogram. Separation of baseflow, interflow and surface runoff. Rainfall-runoff models. The Unit Hydrograph.
Estimation of effective rainfall with the ¿ method and the Soil Conservation Service - Curve Number method based on the type of soil, the use of the soil and the soil moisture conditions before to the flood event. Estimation of the peak discharge with the SCS-CN method.
Identification the main protection actions to reduce or to remove the hydrogeological risk: structural and non-structural measures. Flood mitigation works (dams, river diversion, embankments, bridles, brushes, walls). Water protection plans.
2) Landslide risk
AVI project, IFFI project. Introduction to slope stability analysis with the limit equilibrium method. Safety factor. The infinite slope and the methods of slices: Fellenius method, Bishop method, Janbu method, Spencer method, Morgenstern-Price method. Examples of solutions with SLOPEW commercial software. The NTC 2018: Safety factor in seismic areas, excavation fronts, natural slopes. Taylor's abacus: application cases, critical height in Drained and Undrained conditions, numerical examples. Description of some mitigation and stabilization techniques. Stabilization by drainage systems: sub-horizontal drains and draining trenches.