Reservoirology #2

Because, as we already noticed, often modelling the hydrological cycle is studying the mutual interactions of "reservoirs" of something (which I named "reservoirology"), I tried with my students to have a clean way to represent reservoirs. As we said in the slides below, we try to represent them in a way that, if it is not in a one to one correspondence with the equations that can be derived from the graphs, we are as close as possible to it. This post, left for saving the history, is, however, superseded by the new post reservoirology #3.

Please find above this graphic collection and help us to improve it. One thing to notice is that our representation is mappable, with different expressivity of the concepts to the Petri Networks algebra, which puts in our hands several studies in mathematics, computer sciences, biology and other sciences. 

Freezing-thawing processes studying with numerical models

This is the presentation given by Niccolò Tubini at the Carleton University last October 6th. Niccolò in his Master Thesis is working for a new implementation of the theory of freezing and thawing already covered by Matteo Dall'Amico in his Ph.D. Thesis and in Dall'Amico et al., 2011.

This work is part of the GEOtop project and its new implementations (see also here). The intention is to use the new numerical method implemented by Casulli and Zanolli (2010, 2011) of the extended Richards equation (see also the video here). The new method promise to be faster than the older one, more stable, and implemented for unstructured grids, while at present, GEOtop 2.0 uses a structured grid. Hopefully, the new development will be made in OMS3. 

References

Casulli, V., & Zanolli, P (2010). A nested newton-type algorithm for finite colume methods solving Richards' equation in mixed form. SIAM J. SCI. Comput., 32(4), 2225–2273.

Casulli, V., & Zanolli, P. (2012). Iterative solutions of mildly non linear systems, Journal of Computational and Applied Mathematics, 236(16), 3937–3947. http://doi.org/10.1016/j.cam.2012.02.042

Dall'Amico, M., Endrizzi, S., Gruber, S., & Rigon, R. (2011). A robust and energy-conserving model of freezing variably-saturated soil. The Cryosphere, 469–484. http://doi.org/10.5194/tc-5-469-2011

Networks

Networks are pervasive in our world and represent often the way energy is dissipated from large to small scale. I have some past in the topics, especially if we look at river networks, for which a all-time reference is Rodriguez-Iturbe and Rinaldo book.
The news is that my research on networks could have some future. We are using networks for commanding our JGrass-NewAGE model, but with the idea that we can, by means of a chain of models, follow energy dissipation across the hydrological cycle.

John Baez  works on the mathematical theory of networks, seen under different perspectives. His blog, Azimuth, is a source of really exciting ideas brought with extreme competence and he and coworkers have interest in networks. This blog post is to bring attention  his page on network theory which is a huge font of information to be read.

Non-equilibrium Thermodynamics

I am starting to rewrite S.R. de Groot and P. Mazur, (dGM) Non-equilibrium thermodynamics book. Better, at the moment, I am trying the rewrite its PART A. What do I mean for rewriting ? Mostly two things: the first that I want to learn what it says, driving a slower dance with it, and the second is that I do not fully endorse what I understand so far from it. My differentiation is especially about the role of entropy, which, I think, is treated in a way that strongly derives from the idiosyncrasies of the equilibrium thermodynamics. I already wrote jointly with Matteo Dall’Amico something about thermodynamics, and possibly the two flows could merge in one final product. My goal is not thermodynamics, per se, but the thermodynamics of the hydrological cycle, of which I am a scientist. I believe that thermodynamics has to evolve towards a science of dynamical structures that allows for describing fluxes of information, besides energy and mass, with the final goal to understand ”life organisation”. The latter, however, is for future people. I will attack only water movements, and, maybe, some related cycles, as the carbon cycle. However water flows through plants, an plants are life. So let’s see where I will could arrive in the next fifteen years.

In what follows, what between ” ” is a verbatim transcription of dGM book. I believe their material is copyrighted, however, mine is distributed under CC license 3.0

You can follow the growth of the book while I am writing it, and comment it, if you like. To this scope I am using the Authorea tools. So:

Non-equilibrium Thermodynamics

1 - Introduction and motivation
2 - Conservation of mass
3 - Conservation of momentum
4 - Conservation of Energy

Other chapters will follow.

EPAs for water

EPA, in this case, stands for Environmental Protection Agency (of the United States).
We use a couple of models developed there, especially in my class of Hydraulic Constructions.
These products are:

• Epanet   (see also this post)
• SWMM (see also this post)

and they are available as open source.

There is  an organization of people gathering who are interested in working on them.  You can join them at:

https://github.com/OpenWaterAnalytics

http://wateranalytics.org/

I do not endorse them as the best models ever. But they are there, opens source, and have a community. I see them as a starting point for injecting new ideas and extensions.

The hydrologist's toolbox

One is doing hydrology, s/he is a hydrologist, and asks to me how to increase his/her knowledge.
I answered that s/he should be proficient in:

• GIS
• Some hydrological model (more than one indeed)
• Databases
• Treating data
• Instrumentation

Being specific, and following the above points: 

•  We  are looking at gvSIG (but QGIS and GRASS are good choices). 
•  People use are SWAT, Topkapi-X, HEC-RAS, and in Urban contexts, SWMM (see also here). I have mine JGrass-NewAGE and GEOtop that give a lot of answers that the other models do not give. 
•  First choice is R. Then, it could be Python that has a vibrant community (Software Carpentry, Python for hydrologists, Python for Geoscientists) (for my models I use Java -see also here- and C/C++; my colleagues use the good-old FORTRAN: but these languages have a higher degree and complexity than R and Python. The latter can be used for the 90% of hydrological tasks that do not involve specific "complex" hydrological modeling).
• Learning SQL could be necessary. Postgres plus Postgis offer a professional answer. SQlite plus Spatialite can be a handy solution. See also this post.
• On this I cannot say much. But I will add information soon. 

A hydrologist should then look for classes and courses on the above topics. This blog has a lot of information about the above topics. Please keep an eye on it.  My lectures on hydrology (in Italian) are available here.

The Adige database or the database NewAGE

This is to introduce the Adige database that collects as many possible data about the Adige river.  It is the result  of many years of work (involving Alberto Bellin (GS, RG), myself (GS, RG), Bruno Majone (GS), Francesca Villa, Hydrologis and many others), across various projects the latter of which are the CLIMAWARE project and GLOBAQUA ones . It contains geometries (it is a spatial database), time series, intakes and outakes data. It is a gold mine for whom wants to dig into it.

The presentation is due to Stefano Tasin, one of my master students, and it is in Italian.  However the slides could be understandable also by those who have a knowledge of SQL or want to get it, after some little effort. Clicking on the figure above you access his presentation pdf. Tables in the database are documented here. 

The database is in sqlite and spatialite, expandable and, I hope to find someone who can legally maintain it and offer it as open data.  The whole DB is contained in a ~1.5 GB file called NewAgeDB.sqlite.