These slides come to highlight the work of Jost von Hardenberg (GS), Elisa Palazzi (GS), Silvia Terzago and others in downscaling the projection of GCMs in order to obtain very local statistics of climate suitable to be applied, for instance, at the scale of river Adige or its main tributaries. One interesting strategy they follow is to use WRF, i.e. a weather forecast models, to obtain such projections. We think to use their expertise to drive our hydrologic simulations in the project.
Thursday, June 25, 2015
Downscaling of climate projections and sources of uncertainties
This is (actually the second) seminar of the series of CLIMAWARE's. The report of the first one will follow soon. The topic is: Observations and modelling of precipitation and the hydrological cycle: uncertainties and downscaling and is all about the local impacts of Climate Change.
These slides come to highlight the work of Jost von Hardenberg (GS), Elisa Palazzi (GS), Silvia Terzago and others in downscaling the projection of GCMs in order to obtain very local statistics of climate suitable to be applied, for instance, at the scale of river Adige or its main tributaries. One interesting strategy they follow is to use WRF, i.e. a weather forecast models, to obtain such projections. We think to use their expertise to drive our hydrologic simulations in the project.
These slides come to highlight the work of Jost von Hardenberg (GS), Elisa Palazzi (GS), Silvia Terzago and others in downscaling the projection of GCMs in order to obtain very local statistics of climate suitable to be applied, for instance, at the scale of river Adige or its main tributaries. One interesting strategy they follow is to use WRF, i.e. a weather forecast models, to obtain such projections. We think to use their expertise to drive our hydrologic simulations in the project.
Friday, June 5, 2015
A few topics for a challenging Master thesis
It is quite a long time that I am thinking to assign some master thesis around GEOtop 3.0.
A Master Thesis could be done even on the "simple" Richards equation. In this case the idea would be implementing the nested-Newton Casulli-Zanolli's method (on unstructured grids).
Time ago I assigned a little grant on this topic, but unfortunately, the work was not completed/ The material produced, in any case, is here. (I have also some other material, in FORTRAN, anyway). In this case, the idea would be to use Java and develop further what already made by Francesco Serafin in his thesis.
My outstanding colleague Michael Dumbser already promised to help me to complete the precedent work, and, at that point the main work would be to translate the procedural concepts into a object-oriented framework. In any case, who does it, would place one of the first stones of GEOtop 3.0.
Just thinking loudly, once started the Richards' work (which constitutes, however, well defined and challenging enterprise) one could think how to implement coherently different flavours of the equation, for using bimodal or other water retention curves; for extending Richards analysis to integrate also the groundwater 3D equation, or studying the coupling with the evaporation/transpiration sink. All alternatives that are interesting either from the numerical and the physical point of view.
The original problem I had in mind when I started this post, was the more ambitious one connected with the numerics and the physics of soil freezing (see Matteo Dall'Amico Ph.D. Thesis). Our reference paper in the topic is the 2011 Dall'Amico et al. In the thesis and in the paper we wrote the equations in 3D but solved them in 1D with a not so particularly elegant method, which the nested-Newton algorithm could surpass by far.
Working on the cryospheric side of Richards equation open a series of opportunity and especially the collaboration with Stephan Gruber (with Carleton we have an exchange agreement, and the candidate could also stay for a few months there).
Actually all these topics suggest that a very basic trial could be made to envision a scheme and an infrastructure that can accomodate all of these Richards variants by minimising code rewriting. But this would be probably a theme that could be completely developed in a Ph.D. In fact all these topics' task can clearly produce journal papers, if completed, and certainly open the road to some Ph.D. carrier.
Someone can think that everything is too much challenging, and actually, it is. However, all the topics are pretty mature in my mind, and the path to the solution is pretty well designed.
Someone can think that everything is too much challenging, and actually, it is. However, all the topics are pretty mature in my mind, and the path to the solution is pretty well designed.
Wednesday, May 27, 2015
Ecosystem Services
Everybody talks about ecosystem services (ESs). But what are they ? As part of a conversation, I already talked about, I asked to Bilal Adem Esmail and Marika Ferrari to get an informed answer. Both of them pointed my attention to the Millennium Ecosystem Assessment (2005) of which a picture is presented below. In principle, any discipline can find its place in the diagram and try to understand with whom it can profitably dialogate.
Bilal wrote of the subsequent “Cascade Model”, in which a distinction is made among structures, biophysical processes, functions and ecosystem services (as in the scheme below). This to make evident the anthropocentric nature of ESs, and their, in a sense, utilitarian nature. The cascade model, in fact, point to the benefits ESs produces and on their estimation (not excluding their economics). The Model, besides, tries to make clear the role of Institutions and policies in the management of the feedbacks among the social and ecological systems.
Bilal says: “Between saying and doing is half of the sea … or better there is to learn”, learn how to concretise these holistic concepts in reality. As an example he reports what Cowling et al. (2008) draw in their scheme below.
And here we go back to the issues discusses in the previous post. The scheme shows that the biophysical assessment is a fundamental starting point of the mainstream concept of ESs. per promuovere il mainstreaming del concetto dei SE (see the scheme below).
If we try to specify more to the basins or hydrology management, many studies call for a paradigm shift. Pahl-Woostls (2007,2008,2011) summarise the paradigms-shifts that you can see in the table below
More in general, the community talks about “Sustainability Transition” which, in turn, is the scope of the “Sustainability Science”. Citing Clark (2007) “Sustainability Science has emerged over the last two decades as a vibrant field of research and innovation. Today, the field has developed a core research agenda, an increasing flow of results, and a growing number of universities committed to teaching its methods and findings. Like ‘‘agricultural science’’ and ‘‘health science,’’ sustainability science is a field defined by the problems it addresses rather than by the disciplines it employs. In particular, the field seeks to facilitate what the National Research Council has called a ‘‘transition toward sustainability,’’ improving society’s capacity to use the earth in ways that simultaneously ‘‘meet the needs of a much larger but stabilizing human population, . . . sustain the life support systems of the planet, and . . . substantially reduce hunger and poverty’’
To conclude, and balance the novel you presented in the previous post, here it is a video, you will certainly enjoy.
References
References
Braat, L., and R. de Groot. 2012. The ecosystem services agenda: bridging the worlds of natural science and economics, conservation and development, and public and private policy. Ecosystem Services 1(1):4–15.
Cowling, R. M., B. Egoh, A. T. Knight, P. J. O’Farrell, B. Reyers, M. Rouget, D. J. Roux, A. Welz, and A. Wilhelm-Rechman. 2008. An operational model for mainstreaming ecosystem services for implementation. Proceedings of the National Academy of Sciences of the United States of America 105(28):9483–9488.
De Groot, R. S., R. Alkemade, L. Braat, L. Hein, and L. Willemen. 2010. Challenges in integrating the concept of ecosystem services and values in landscape planning, management and decision making. Ecological Complexity 7(3):260–272.
Millennium Ecosystem Assessment. 2005. Ecosystems and human well-being: Synthesis. Island Press, Washington, DC.
Pahl-Wostl, C., M. Craps, A. Dewulf, E. Mostert, D. Tabara, and T. Taillieu. 2007. Social learning and water resources management. Ecology and Society 12(2).
Pahl-wostl, C., E. Mostert, and D. Tàbara. 2008. The Growing Importance of Social Learning in Water Resources Management and Sustainability Science. Ecology and Society 13(1).
Pahl-Wostl, C., P. Jeffrey, N. Isendahl, and M. Brugnach. 2011. Maturing the New Water Management Paradigm: Progressing from Aspiration to Practice. Water Resources Management 25(3):837–856.
Monday, May 18, 2015
Bimodal pore size distribution and hillslope stability
This post is to highlight the work of Fabio Ciervo, a Ph.D. student of Mariolina Papa that I co-advised with Vincente Medina. His thesis had the merit to put together two nice aspects of the recent research on soils. The first came from the work of Nunzio Romano [1] and co-workers, who show consistently that many soils present a bi-modal distribution in porosity, with effects in the form of the soil-water-retention curves (SWRC), and hydraulic conductivity, once Burdine or Mualem's [2] theory is applied. The other is the novel theory of hillslope stability coming out from the joint work of Lu, Likos, and Godt (e.g. [3]).
Who wants to enjoy his thesis can find it here: Fabio Ciervo, Modeling hydrologic response of structured soil, University of Salerno, 2015.
The code, developed in Java, that solves Richards 1D equation using these bimodal SWRC can instead be found on Github.
The Thesis produced a first paper which is under review in Vadose Zone Hydrology Journal.
Some References (others in the Dissertation)
[1] -Romano, N., Nasta, P., Severino, P., and Hopmans, J.W., Using bimodal lognormal function to descrivbe soil hydraulic properties, Soil. Sci. Soc. Am. J., 75(2), 468-480, 2011
[2] - Roth, K., Soil Physics, Institute of Environmental Physics, Heidelberg University,
D-69120 Heidelberg, Germany, 2012
[2] - Lu, N., and Godt, J., Hillslope hydrology and stability, Cambridge University Press, 2013
Who wants to enjoy his thesis can find it here: Fabio Ciervo, Modeling hydrologic response of structured soil, University of Salerno, 2015.
The code, developed in Java, that solves Richards 1D equation using these bimodal SWRC can instead be found on Github.
The Thesis produced a first paper which is under review in Vadose Zone Hydrology Journal.
Some References (others in the Dissertation)
[1] -Romano, N., Nasta, P., Severino, P., and Hopmans, J.W., Using bimodal lognormal function to descrivbe soil hydraulic properties, Soil. Sci. Soc. Am. J., 75(2), 468-480, 2011
[2] - Roth, K., Soil Physics, Institute of Environmental Physics, Heidelberg University,
D-69120 Heidelberg, Germany, 2012
[2] - Lu, N., and Godt, J., Hillslope hydrology and stability, Cambridge University Press, 2013
Friday, May 15, 2015
La teoria dell'idrogramma Istantaneo Unitario
L'idrogramma instantaneo unitario è una teoria semplificata dell'aggregazione e propagazione dei deflussi. Ecco nel seguito, le mie lezioni (per il corso di Costruzioni Idrauliche per Ingegneri Civili a Trento). In 2016 I restructured it in parts, and according to new pieces of theory that I developed with Marialaura Bancheri and finding new inspiration form works by Gianluca Botter, Enrico Bertuzzo and Andrea Rinaldo on travel times. A good review is certainly Rigon et al., 2015. Unfortunetely slides are (so far) in Italian.
1 - Introduction
3 - Alternative heuristics (demonstration of equivalence by travel time distribution -TTD- and IUH)
5 - A couple of examples (uniform and exponential TTD and their names in classical iterpretation)
6 - The geomorphologic instantaneous unit hydrograph GIUH
7 - The width function unit hydrograph WFIUH (for this see also this post on the width function)
9 - Geomorphological dispersion (coming soon)
10 - Hillslope and channel contributions (coming soon)
Slides e Audio:
1 - Introduzione allo IUH. Audio 2014 (31.1 MB); Audio 2015 (19.5 Mb);
2 - Alcune distribuzioni dei tempi di residenza (5.8 Mb); Audio 2015: Alcune distribuzione per tempi di residenza (7.2 Mb).
3 - Idrogramma Istantaneo unitario Geomorfologico. Audio 2014 (16.8 Mb). Audio 2015 (20.3 Mb)
4 - Portate massime. Audio 2014 (17.4 Mb).
5 - L'idrogramma istantaneo unitario basato sulla funzione di ampiezza.
The even older ones:
All the old slides together: La teoria dell'idrogramma istantaneo unitario e dell'idrogramma istantaneo unitario
Generazione del deflusso (Runoff Generation)
Questa parte include l'analisi della formazione dei deflussi superficiali e, sebbene da me non amati, vari metodi più o meno empirici per calcolare l'infiltrazione.
1 - La generazione del deflusso. Audio 2014 (27.9 Mb). Audio 2015 (36.5 Mb).
2 - Il Topmodel. Audio 2015 (14.8 Mb). YouTube2017.
3 - La generazione del deflusso nel modello ARNO/XINJANG. YouTube2017 (Part I, Part II)
4 - Il modello del Soil Conservation Service
Ecco alcuni modelli semplificati di infiltrazione. Ma perchè usarli, quando si possono usare semplificazioni dell'equazione di Richards (see point 10) ?
5 - The good-old- Horton model of Infiltration
6 - The Green-Ampt model of infiltration
Altri Vecchi Audio (2014)
2b-5b - Audio metodi semplificati per il calcolo del deflusso superficiale o dell'infiltrazione (escluso SCS - 23.4 Mb)
1 - La generazione del deflusso. Audio 2014 (27.9 Mb). Audio 2015 (36.5 Mb).
2 - Il Topmodel. Audio 2015 (14.8 Mb). YouTube2017.
3 - La generazione del deflusso nel modello ARNO/XINJANG. YouTube2017 (Part I, Part II)
4 - Il modello del Soil Conservation Service
Ecco alcuni modelli semplificati di infiltrazione. Ma perchè usarli, quando si possono usare semplificazioni dell'equazione di Richards (see point 10) ?
5 - The good-old- Horton model of Infiltration
6 - The Green-Ampt model of infiltration
Altri Vecchi Audio (2014)
2b-5b - Audio metodi semplificati per il calcolo del deflusso superficiale o dell'infiltrazione (escluso SCS - 23.4 Mb)
Monday, May 11, 2015
Use and Perception of Science's Results
I asked to Bilal Adem Esmail, one of our Ph.D. students, working on the relation existing between ecosystem services and the water cycle to comment my previous post on ecosystems and hydrology from his point of view. Here below, please find his answer related to the use of models.
He says (my comments in italics):
“If I understood well your thesis, you support the idea that a good understanding and capacity of modelling biophysical phenomena are fundamental for making decisions, for instance about soil (my note: here used with the planners meaning), that are based on solid foundations. Specifically, it is needed to a correct quantification of the various phenomena, avoiding to use approaches too poorly approximate.
I agree with this thesis, which must be pursued with conviction by all, scientists and anyone. However, we do not have to go beyond a reasonable complexity, and fall in the Borges paradox to reproduce the Empire with a map the coincides identically with the Empire itself (see also here).
We can try to set these limits by considering two crucial elements: the use that will be done of the scientific knowledge (to disseminate, decide or, for instance, negotiate), and (not disjoint by the first), the perception of the same knowledge according to the users of the knowledge (see the scheme below). If perception is wrong nothing can be done.
Cash et al. (2013) and Clark et al (2011) suggest to consider the following three fundamental criteria referring to the perception of users of scientific knowledge: the perception of credibility (the scientific rigor perceived), relevance (of the specific problem), legitimacy (i.e. the capacity of inclusion of more points of view) of the sources.
We can take as an example of the Stanford's Natural Capital Project (NCP (http://www.naturalcapitalproject.org/) in the Water Fund in Latin America. These support governance mechanism and financial investments that guarantee clean water to downhill communities involving uphill communities. This works, more in general, by favouring collaboration among the stakeholder. NCP started to support scientifically the Water Funds, only after that first phase, by using a series of physical models of increasing complexity, called Tier1, Tier2, and Tier 3.
NCP approach is also transdisciplinary (Jahn et al., 2012, see also below^1) and includes at any stage of the process the stake holder. which is, actually considered the qualifying aspect of the process. In the experience of Water Funds, stakeholders were unable to understand the more complex biophysical models, and NCP had to implement simpler models called Tier0, ceasing the using of the complex models^2^3
This shows that in practice accepted scientific theories can find unespected difficulties, in relation to cognitive perceptions. "
References
Notes
^1 Transdisciplinarity is a critical and self-reflexive research approach that relates societal with scientific problems; it produces new knowledge by integrating different scientific and extra scientific insights; its aim is to contribute to both societal and scientific progress; integration is the cognitive operation of establishing a novel, hitherto non-existent connection between the distinct epistemic, social–organizational, and communicative entities that make up the given problem context. (Jahn et al 2012)
^2 - This use of the simplest models is also diffuse in science, even if not always justified. Because some aspects of science are very specialistic, even specialists are not able to understand the reasons of complexity which goes beyond their strict domain of expertise, even they tend to favour the use of the simplest model, even when they are too simple (see Einstein citation). Everyone of us should remember that if what s/he does not understand an explanation of a phenomenon in a snap, not necessarily the explanation is to throw away, but possibly require more application to be understood. Obviously sometimes model complexity was produced just because the Occam’s razor was not applied: this is the case when complexity is not welcomed.
^3 - In my opinion, there is a basic cognitive limitation. To understand complexity (of even new paradigms) time and domestication is necessary. Aristotelians who looked inside Galileo’s telescope were not really able to see what Galileo saw. Their cognitive attitudes (their brains) were simply not prepared to, and they could not. Even scientists, supposed to be rational, in face of unwanted results simply refuse to see them, and it is not uncommon the very famous colleagues died without accepting scientific statements against their own views, even if supported by overwhelming facts.
“If I understood well your thesis, you support the idea that a good understanding and capacity of modelling biophysical phenomena are fundamental for making decisions, for instance about soil (my note: here used with the planners meaning), that are based on solid foundations. Specifically, it is needed to a correct quantification of the various phenomena, avoiding to use approaches too poorly approximate.
I agree with this thesis, which must be pursued with conviction by all, scientists and anyone. However, we do not have to go beyond a reasonable complexity, and fall in the Borges paradox to reproduce the Empire with a map the coincides identically with the Empire itself (see also here).
We can try to set these limits by considering two crucial elements: the use that will be done of the scientific knowledge (to disseminate, decide or, for instance, negotiate), and (not disjoint by the first), the perception of the same knowledge according to the users of the knowledge (see the scheme below). If perception is wrong nothing can be done.
Cash et al. (2013) and Clark et al (2011) suggest to consider the following three fundamental criteria referring to the perception of users of scientific knowledge: the perception of credibility (the scientific rigor perceived), relevance (of the specific problem), legitimacy (i.e. the capacity of inclusion of more points of view) of the sources.
We can take as an example of the Stanford's Natural Capital Project (NCP (http://www.naturalcapitalproject.org/) in the Water Fund in Latin America. These support governance mechanism and financial investments that guarantee clean water to downhill communities involving uphill communities. This works, more in general, by favouring collaboration among the stakeholder. NCP started to support scientifically the Water Funds, only after that first phase, by using a series of physical models of increasing complexity, called Tier1, Tier2, and Tier 3.
NCP approach is also transdisciplinary (Jahn et al., 2012, see also below^1) and includes at any stage of the process the stake holder. which is, actually considered the qualifying aspect of the process. In the experience of Water Funds, stakeholders were unable to understand the more complex biophysical models, and NCP had to implement simpler models called Tier0, ceasing the using of the complex models^2^3
This shows that in practice accepted scientific theories can find unespected difficulties, in relation to cognitive perceptions. "
References
- Cash, D. W., W. C. Clark, F. Alcock, N. M. Dickson, N. Eckley, D. H. Guston, J. Jäger, and R. B. Mitchell. 2003. Knowledge systems for sustainable development. Proceedings of the National Academy of Sciences of the United States of America 100:8086–8091.
- Clark, W.C. et al., 2011. Inaugural Article: Knowledge Systems for Sustainable Development Special Feature Sackler Colloquium: Boundary work for sustainable development: Natural resource management at the Consultative Group on International Agricultural Research (CGIAR). Proceedings of the National Academy of Sciences.
- Jahn, T., M. Bergmann, and F. Keil. 2012. Transdisciplinarity: Between mainstreaming and marginalization. Ecological Economics 79:1–10.
Notes
^1 Transdisciplinarity is a critical and self-reflexive research approach that relates societal with scientific problems; it produces new knowledge by integrating different scientific and extra scientific insights; its aim is to contribute to both societal and scientific progress; integration is the cognitive operation of establishing a novel, hitherto non-existent connection between the distinct epistemic, social–organizational, and communicative entities that make up the given problem context. (Jahn et al 2012)
^2 - This use of the simplest models is also diffuse in science, even if not always justified. Because some aspects of science are very specialistic, even specialists are not able to understand the reasons of complexity which goes beyond their strict domain of expertise, even they tend to favour the use of the simplest model, even when they are too simple (see Einstein citation). Everyone of us should remember that if what s/he does not understand an explanation of a phenomenon in a snap, not necessarily the explanation is to throw away, but possibly require more application to be understood. Obviously sometimes model complexity was produced just because the Occam’s razor was not applied: this is the case when complexity is not welcomed.
^3 - In my opinion, there is a basic cognitive limitation. To understand complexity (of even new paradigms) time and domestication is necessary. Aristotelians who looked inside Galileo’s telescope were not really able to see what Galileo saw. Their cognitive attitudes (their brains) were simply not prepared to, and they could not. Even scientists, supposed to be rational, in face of unwanted results simply refuse to see them, and it is not uncommon the very famous colleagues died without accepting scientific statements against their own views, even if supported by overwhelming facts.
Subscribe to:
Comments (Atom)