## Wednesday, February 15, 2023

### The Hydrology Class 2023 - The Foreseen Schedule

This post contains the foreseen schedule of the course. Material uploaded is subject to modifications prior to the schedule date. All the lectures will be to students present in blended format. Meaning that students can be either present or attend remotely. All of them will be recorded and uploaded to web.

Go to the Software Installation page

Topics in bold are definitive. Topics in normal characters are still subject to modifications.  All the 2022 videos will be available at this Vimeo Showcase.

2023-02-27 - Introduction to the course and to hydrology

Complementary References

2023-02-28 - Ground based Precipitations and their statistics Separation snow-rainfall - measure of precipitation

In this part of the class we describe where it rains and how much it rains using statistical concept. One important objective is to understand what are the extreme precipitations for their importance in engineering.
2023-03-06 - 2023-03-13  - Statistics of extreme precipitations

Some reviews on statistics - Return Period
Extreme precipitations  (Storyboard2020)
Distributions Storyboard2020

Determination of Gumbel's parameters
Extreme precipitations  II
2023-03- 14 -Beyond Gumbel
A summary about the extreme precipitation estimations (Whiteboard)

2023-03- 14 - Water in soil and aquifers. Darcy-Buckingham. Hydraulic conductivity. Soil water retention curves (Storyboard2020)

Once precipitations arrive to the ground surface they either infiltrate or generate runoff. We first state how they infiltrate and, actually how water behave in the soil and in the ground. We talk about the complexity of the Earth surface that contains life and call it, the Critical Zone. To study infiltration we introduce the Darcy and Richards equations of which we explain the characteristics.
2023-04-03/04

2023 - 03- 21
- The Richardson-Richards equation  (Storyboard 2020)
2023-03-27
2021-04-20- Runoff Generation and propagation (Summary 2020)

Once the rainfall gains the terrain, it can infiltrate or producing runoff. In the next we discuss the main mechanisms that produce runoff.
Q&A - Runoff - Runoff 2022

2022-05-03 - The surface water propagation (a brief Storyboard 2021)

Runoff moves on the surface of the terrain according to the de Saint-Venant equation. In the following the equation is derived in the 1D case.

Evaporation generalities
(Storyboard2020)

A consistent part of root zone and surface water evaporates and returns to the atmosphere to eventually form clouds and precipitation again. The process follows quite complicate routes and is different when happening from liquid surfaces, soil or vegetation (and BTW animals).  In this group of lectures we try to figure out the physical mechanisms that act in the process and give some hint on methods to estimate evaporation and transpiration with physically based models.
2022-05-08
2022-05-15  -  Evaporation and Transpiration Formulas
2022-05-15 -  After all radiation moves it all

### The Hydrology Class 2023 - Index

Go to the foreseen schedule

Go to the Software Installation page

Go to the lab page

## What the Hydrology Course is About

To have an idea about this class, please look at the Syllabus  slides in first lecture.  This year the class will be 90% similar to the one of the last year.  Laboratory work will be (mostly) concentrated in May and June. March and April up to Easter will be mostly spent to develop the theoretical parts.
Lectures  and lab classes will be recorded and uploaded on my VIMEO channel. Old videos are also in my on my YouTube channel.

The intermediate exam will be written (or oral *) with 3 questions about the topics treated.  The students will be asked to answer with text, figures and formulas. The final exam will be a discussion of the exercises provided by the students int the form of Jupyter notebooks. Each of the exercises will be discussed separately by booking an appointment with the professor before the formal date of the exam or at the day of the final exam.

This Hydrology class aims to explain the physics (meaning the mathematical equations and their phenomenology) and, in some cases, the statistics (i.e. the distribution) of the basic hydrological processes (precipitation, runoff, infiltration, evaporation and transpiration)
Students will be required to:
•  being able to derive and comment the hydrological equations above mentioned and
• to do some statistics on hydrological data. Particular attention will be dedicated to the derivation of the statistics of extreme rainfall.
• Besides students will be requested to get some basics of the tools that will be used to estimate the hydrological fluxes (using a GIS, Python, and other tools, among those in GEOframe).
They will be required to be able, by means of some models provided by the instructors the main hydrological fluxes and represent them at catchment scale.

This is intended to serve as a basis for getting further knowledge and
• prevent, manage, control floods, landslides and snow-avalanches
• manage irrigation
• estimate water availability for hydropower production
• estimate soil, roads, or snow temperature
• forecast snow water equivalent and snow height
Assuming that the student will take a master in Environmental Engineering at Trento University, Acquedotti e fognature, Modelli idrologici, Ingegneria fluviale, are classe that request the knowledge communicate in this Hydrology class.

The first part of the course, until April 3, will be dedicated to the presentation and discussion of theoretical concepts through lectures that will be videotaped and uploaded on the course's Vimeo channel. The lessons will cover 4 of the five hours per week. The fifth hour will be devoted to simple exercises with Python and Jupyter lab and to the preparation of the data necessary for the projects to be completed in the second part of the course in groups of two or three students.
The student must take care to understand the hydrological concepts and discuss them with the lecturer. The first twenty minutes of each lesson will be devoted to the discussion of the topics covered in the previous lesson. Each group will have to prepare one question or comment to which the teacher will answer. A summary of the lesson will follow, followed by the actual lesson. The second part of the course will take up the theoretical themes of the first part and using the tools made available to the GEOframe system. Students, in groups of two or three, will have to:

• Analyze a series of rainfall and hydro-meteorological data with the use of Python
• Estimate the intensity-duration-frequency curves with the methods presented in the first part of the course using the data of a hydro-meteorological gauge station
Besides, they have to accomplish two of the following three tasks under the supervision of the tutor and the teacher:
• Design and run some infiltration simulations in complex soils and discuss the results.
• Design and perform the calculation of evaporation and transpiration in a chosen site
• Studying the coupled transpiration and infiltration in one site.
* The exam  about the theory part will be written.

References

The lessons will be video recorded and made available. Each lesson will be given through slides in English which will be delivered to students in advance. When necessary, the lessons will be accompanied by appropriate in-depth articles. There is no real text because the course, even when it is fully in the hydrological tradition, elaborates the concepts in a contemporary way and uses innovative tools.

As general reference texts we recommend:
• Bras, R.L, An introduction to Hydrologic Science, ISBN-13: 978-0201059229, 1989 - ISBN-10: 0201059223, Addison-Wesley (July 1, 1989)
• Brutsaert, W., Hydrology: an introduction, ISBN-13: 978-0521824798 - ISBN-10: 0521824796, Cambridge University Press, 2005
• Dingmann, L., Physical Hydrology, ISBN-13: 978-1478611189, ISBN-10: 1478611189, Third Edition, Waveland Press, 2015
• Freeze, A. ; Cherry, J., Groundwater, 1979
• Lu, N. and Godt, J.W., Hillslope Hydrology and Stability, Cambridge University Press, ISBN-13: 978-1107021068, ISBN-10: 11070210652010, 2013

These books represent a shareable review of phenomena and hydrological modeling but the methods they present are not necessarily those used in the course. The course, also for reasons of time, presents a selected and limited perspective of the subject that the texts cited dissect from various points of view.

### The Hydrological Modelling Class 2023 - the foreseen schedule

Index

Go to:

Foreseen Schedule (up to Easter)

(boldface dates are those with definitive material, I or directly written in Italian  in for Italian,  unspecified for English. All slides are in English)

To understand better what is below:
• storyboard is a summary, usually in Italian, of the lecture
• A whiteboard is an explanation of a particular topic made on the whiteboard (using Notability on the iPad)
• Slides are commented in English (since 2021)
• Additional  information (only for the brave or the curious) and references are in italics

The 2023 Videos can be found also at here in this Vimeo Showcase

2023-02-27 - I
- Syllabus - Introduction 2 Hydrological Modelling

Here  I introduced the class. Its learning by doing philosophy (altered by the necessity due to COVID-19 times that impose to do first the all the theoretical parts and subsequently all the practical parts hoping that they can be done in presence).
Geomorphometry   - Discussion of previous lesson topics. Summary of the lecture in Italian. (This will be always done, each lesson, but for now on omitted). The rational of introducing these concepts  is that catchments are spatially extended and in this course we are interested to deal with catchments hydrology.

In this first part we deal with the geometrical (differential) characteristics of the topography. Elevations, slopes, curvatures. They will be necessary later to extract the river network and the parts of a catchment.
In this class we define also what the drainage directions are and how they are computed in the case of DEMs (a topography discretized over a regular grid).  From drainage directions are determined the total contributing areas in each point of  a DEM. These two characteristics are eventually used to determine  the channels head and extract the river networkIn turn, the extraction of the channel network allows for the extraction of hillslope and a first definition of  the Hydrologic Response Units (HRU).
2023-03-02
2023-03-06
Q&A -

2023-03-02 -  Interpolations
This lecture, assuming that now you have at least the concepts of what a catchment is and theoretically you know how to extract it and subdivide it in parts, deals with the data to feed catchments hydrology models. Because catchments have a spatial distribution, then also the driving data must be distributed. We need therefore methods of interpolation.

2023-03-09 -  Interpolations part II.
In this class we try to understand how to estimate the errors over the estimates. Besides we introduce a method (the Normal Score) to avoid to obtain negative values when positive interpolated values are required.
Q&A -
Spatial Interpolation (Vimeo2023)

Hydrological Models. This is a class about hydrological models, so what are they ?

The title is self-explanatory. A theoretical approach to modelling is necessary because we have to frame properly our action when we jump from the laws of physics to the laws of  hydrology. Making hydrology we do not have to forget physics but for getting usable models we have to do appropriate simplifications and distorsions. The type of model we will use in the course are those in the tradition are called lumped models. Here we also introduce a graphical tool to represent these models.
Hydrological Models
2023-03-13 - Hydrological Models - II
2023-03-16
2023-03-20
Linear Models for HRUs

Once we have grasped the main general (and generic) ideas, we try to draw the simplest systems. They turn out to be analytically solvable, and we derive their solutions carefully. From the group of linear systems springs out the Nash model, whose derivation is performed.  Obviously, it remains the problem to understand how much the models can describe "reality". However, this an issue we leave for future investigations.
2023-03-23 -
A little more on the IUH and looking at the variety of HDSys models

We introduced previously without very much digging into it the concept of Instantaneous Unit Hydrograph. Here we explain more deeply its properties, Then we observe that there are issues related to the partition of fluxes and we discuss some simple models for obtaining them. Not rocket science here. The concept that we need those tools is more important than the tools themselves. We also observe that linearity is not satisfactory and we give a reference to many non linear models. Finally we discuss an implementation of some of the discussed concepts in the System GEOframe.
2023-03-30
2023-04-06

Travel Time, Residence Time and Response Time
Here below we started a little series of lectures about a statistical way of seeing water movements in catchments. This view has a long history but recently had a closure with the work of Rinaldo, Botter and coworkers. Here it is presented an alternative vie to their concepts. Some passages could be of some difficulty but the gain in understanding the processes of fluxes formation at catchment scale is, in my view, of great value and deserves some effort.  The way of thinking is the following: a) the overall catchments fluxes are the sum of the movements of many small water volumes (molecules); b) the water of molecules can be seen through 3 distributions: the travel time distribution, the residence time distribution and the response time distributions; c) the relationships between these distributions are revealed; d) the relation of these distributions with the the treatment of the catchments made through ordinary differential equations is obtained through the definition of age ranked distributions; e) The theory this developed is a generalizations of the unit hydrograph theory.
2023-04-20

Digressions I - A Glimpse on distributed process-based models

Digressions III

### The Hydrological Modelling Class - 2023 Index

Index

Go to:

Introduction

The Hydrological Modeling course aims to teach to simulate the hydrological cycle at various spatial scales in order to be able to adequately manage the water resource and to prevent the risk of floods. The importance of these two issues is widely covered by the EU 2000/60 framework directives or "Water directive" and EU 2006/60, "Flood directive". Based on the hydrological knowledge acquired in the course of Hydrology at the Bachelor of Engineering for the Environment and the Territory, the hydrological processes, analyzed as punctual phenomena are extended to the water catchment areas.

Precipitation is analyzed as a measured statistical data, both from ground stations and from remote sensing; the other processes are suitably modeled, as briefly described below. At the end of the course, a student must be able to independently model the flow rates, evaporation and transpiration in a river basin of various sizes, after having delineated it starting from digital terrain data. Of course, the student will have to demonstrate that he has critically understood the concepts that underlie the hydrological modeling presented.
The knowledge acquired may be used in the River Engineering course for the design of defense works. Hydrological modeling also introduces concepts that are used in the course of Aqueducts and Sewers for the calculation of stormwater networks. The course is partly useful for the Hydraulic Protection of the Territory course.  A more condensed part of the version of the course can be found @GWS.
An overview of the topics (in Italian) can be found on the seminar done for the District Authority of river Po (here)

The lectures of the course will be held in English, according to the methods already followed in the Numerical Modeling course (i.e. with summary in Italian at the beginning of the lesson, lessons in English, questions and explanations in Italian). The first part of the course, until on April 3, will be dedicated to the presentation and discussion of theoretical concepts. The lectures will be recorded and uploaded on the course's YouTube channel (or Vimeo). The lessons will cover 4 of the five hours per week. The fifth hour will be dedicated to the preparation of the data necessary for the projects to be completed in the second part of the course.

Students must take care to understand the hydrological concepts and discuss them with the lecturer. The first twenty minutes of each lesson will be devoted to the discussion of the topics covered in the previous lesson and the problems that arose in the preparation of the data (in Italian). Every group had to prepare an appropriate question or comment to which the lecturer will replay. A summary, again in Italian, of the lesson and then the actual lesson will follow.
The second part of the course will use the theoretical themes of the first part and using the tools made available by the GEOframe system (https://abouthydrology.blogspot.com/2015/03/jgrass-newage-essentials.html). Students, in groups of two or three, will have to estimate hydrological flows and quantities over a significant period of time and with an hourly time step using a time series of hydro-meteorological data in inputs for period long enough to allow adequate calibration of the models. With the help of the tutor and the reader, students will face problems of missing data, validate the models, discuss and implement an adequate configuration of the GEOframe hydrological system in order to get the hydrological water balance of the basin.

The following works by Abera can be taken as an example of the outcomes expected :
References

The lessons will be video recorded and made available. Each lesson will be given through slides in English which will be delivered to students in advance. When necessary, the lessons will be accompanied by appropriate in-depth papers. There is no real text because the course, even in the hydrological tradition, elaborates the concepts in a contemporary way and uses innovative tools.
As general reference texts we recommend:

• Beven, K. - Raifall-runoff, the primer, ISBN 10: 047071459X, ISBN 13: 978047071459, Second Edition, Wiley-Blackwell, 2012
• Dingmann, L., Physical Hydrology, ISBN-13: 978-1478611189, ISBN-10: 1478611189, Third Edition, Waveland Press, 2015
• Lu, N. and Godt, J.W., Hillslope Hydrology and Stability, Cambridge University Press, ISBN-13: 978-1107021068, ISBN-10: 11070210652010, 2013
• Bonan, G., Ecological Climatology, concepts and applications, ISBN-13: 978-1107619050, ISBN-10: 110761905X, 2016

These books represent a shareable review of the phenomena and hydrological modeling but the methods they present are not necessarily those used in the course. The course, cause of time constraints, presents a selected and limited perspective of the subject that the texts cited dissect from various points of view often complementary to the one of the course.

## Monday, February 6, 2023

### Glimpses of Environmental Engineering for the students of QUADRI Lyceum High School

Looking for excellent students of our degrees in Environmental Engineering, last Wednesday, February 1, I went to the QUADRI Lyceum High School in Vicenza to talk about Environmental Engineering, Flood prevention and all of this. With me dr. Paolo Ronco of Viacqua made also an excellent presentation the work they do for water supply and water resource protection in Veneto (Italy). Here below you can find my presentations.

The slides cover these topics (click on the links for the PDFs: