Showing posts with label Hydrological Modelling 2023. Show all posts
Showing posts with label Hydrological Modelling 2023. Show all posts

Wednesday, February 15, 2023

The Hydrological Modelling Class 2023 - the foreseen schedule

 Index

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 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
    Some References (advanced)

    Digressions I - A Glimpse on distributed process-based models

    Digressions II - Radiation -  After all radiation moves it all.
    Digressions III

    The Hydrological Modelling Class - 2023 Index

     Index

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    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.