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Reflections on GEOtop, NewAge and other modeling

Reflections on GEOtop, NewAge and other modeling

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Rr reflections Rr reflections Presentation Transcript

  • GEOtop, NewAge and Beyond Montpellier, October 21, 2011 Cezanne, Pine Tree near Aix R. Rigon, G. FormettaMonday, October 24, 11
  • Introduction The good old Hydrological cycle                                               2 Rigon et al., Montpellier, October 21, 2011Monday, October 24, 11
  • Introduction Every Hydrologist would like to have THE MODEL of IT But in reality everybody wants just to investigate a limited set of phenomena: for instance the discharge in a river. Or landsliding , or soil moisture distribution. Any problems requires its amount of prior information to be solved: some problems needs more detailed information of others 3 Rigon et al., Montpellier, October 21, 2011Monday, October 24, 11
  • Introduction So we use different models 4 Rigon et al., Montpellier, October 21, 2011Monday, October 24, 11
  • Introduction So we use different models GEOtop Fully distributed Grid based 4 Rigon et al., Montpellier, October 21, 2011Monday, October 24, 11
  • Introduction So we use different models GEOtop NewAge Anthropic Infrastructures Fully distributed Large scale modelling Hillslope - Stream Grid based 4 Rigon et al., Montpellier, October 21, 2011Monday, October 24, 11
  • IntroductionMonday, October 24, 11 Fully distributed Grid based GEOtop Large scale modelling Hillslope - Stream Anthropic Infrastructures Rigon et al., Montpellier, October 21, 2011 NewAge Fully Coupled Subsurface- Surface Grid Based Boussinesq So we use different models 4
  • IntroductionMonday, October 24, 11 Fully distributed Grid based GEOtop Large scale modelling Hillslope - Stream Anthropic Infrastructures Rigon et al., Montpellier, October 21, 2011 NewAge Fully Coupled Subsurface- Surface Grid Based Boussinesq So we use different models GIUH Peak floods PeakFlow 4
  • Introduction So we use different models GEOtop NewAge Boussinesq PeakFlow Anthropic Infrastructures Subsurface- Surface Fully distributed Peak floods Large scale modelling Fully Coupled Hillslope - Stream Grid based GIUH Grid Based The complexity arrow 4 Rigon et al., Montpellier, October 21, 2011Monday, October 24, 11
  • Introduction Every one of them: Perform the mass budget (and preserves mass) Make hypotheses on momentum variations Simplify the energy conservation (and its dissipation) to a certain degree (Implicitly delineates a way to entropy increase) 5 Rigon et al., Montpellier, October 21, 2011Monday, October 24, 11
  • Questions A first question: • How can we manage the set of activities behind all of this modeling ? (-; doing the models using sound science, modern informatics, validating them against data, assessing their uncertainty ;-) •Without reinventing the wheel any time 6 Rigon et al., Montpellier, October 21, 2011Monday, October 24, 11
  • GEOtop GEOtop (Rigon et al., Jour. Hydromet., 2006) This model focuses on the water and energy budgets at few square meters scale with the goal of describing catchment hydrology including (a reasonable parameterization) all known processes. (Whatever this means) 7 Rigon et al., Montpellier, October 21, 2011Monday, October 24, 11
  • Remarks We are aware that: “ You cannot deny that our universe is not a chaos; we discern in it beings, things, stuff that we name with words. These beings or things are forms, structures endowed with a certain stability; they fill a certain portion of space and perdure for a certain time ...” R. Thom, Structural stabity and morphogenesys,1975 And therefore a fully reductionist approach is stupid. However facing with the fundamental law teaches us many thing about the reduction of complexity with scales that naive intuition or pedestrian simplification does not allow. 8 Rigon et al., Montpellier, October 21, 2011Monday, October 24, 11
  • GEOtop structure 1. Radiation - distributed model - sky view factor, self and cast shadowing, slope, aspect, drainage 2. Water balance 6. vegetation interaction - effective rainfall - surface flow (runoff and channel - multi-layer vegetation routing) scheme - evapotranspiration 3. Snow-glaciers - multilayer snow scheme 5. soil energy balance - soil 4. surface energy balance temperature - freezing soil - radiation - boundary-layer interaction 9 Rigon et al., Montpellier, October 21, 2011Monday, October 24, 11
  • GEOtop structure Why this complexity ? snow, ice, permafrost water cycle in complex terrain Endrizzi 2007 Dall’Amico 2010 Rigon et al., 2006 Endrizzi et al, 2010a,b in preparation evapo-transpiration, landsliding energy fluxes Bertoldi et al., 2006 Simoni et al 2008 Bertoldi et al 2010 Lanni et al, 2010 10 Rigon et al., Montpellier, October 21, 2011Monday, October 24, 11
  • GEOtop structure GEOtop, NewAge For each time step Boussinesq Al the models the same strategy but with different Meteo amount of information flowing Rainfall/Snow Radiation Atm. Turbulence Snow/Energy budget 11 Rigon et al., Montpellier, October 21, 2011Monday, October 24, 11
  • GEOtop structure GEOtop Richards ++ Surface flows Channel flow Next time step 12 Rigon et al., Montpellier, October 21, 2011Monday, October 24, 11
  • GEOtop structure What I mean with Richards ++ First, I would say, it means that it would be better to call it, for instance: Richards-Mualem-vanGenuchten equation, since it is: ⇤⇥ ⇥ C(⇥) = ⇥ · K( w ) ⇥ (z + ⇥) ⇤t ⇧ ⇤ ⇥ m ⌅2 K( w ) = Ks Se 1 (1 Se ) 1/m n Se = [1 + ( ⇥) )] m ⇤ w () w r C(⇥) := Se := ⇤⇥ ⇥s r 13 Rigon et al., Montpellier, October 21, 2011Monday, October 24, 11
  • GEOtop structure What I mean with Richards ++ First, I would say, it means that it would be better to call it, for instance: Richards-Mualem-vanGenuchten equation, since it is: ⇤⇥ ⇥ C(⇥) = ⇥ · K( w ) ⇥ (z + ⇥) Water balance ⇤t ⇧ ⇤ ⇥ m ⌅2 K( w ) = Ks Se 1 (1 Se ) 1/m n Se = [1 + ( ⇥) )] m ⇤ w () w r C(⇥) := Se := ⇤⇥ ⇥s r 13 Rigon et al., Montpellier, October 21, 2011Monday, October 24, 11
  • GEOtop structure What I mean with Richards ++ First, I would say, it means that it would be better to call it, for instance: Richards-Mualem-vanGenuchten equation, since it is: ⇤⇥ ⇥ C(⇥) = ⇥ · K( w ) ⇥ (z + ⇥) Water balance ⇤t ⇧ ⇤ ⇥ m ⌅2 Parametric K( w ) = Ks Se 1 (1 Se ) 1/m Mualem n Se = [1 + ( ⇥) )] m ⇤ w () w r C(⇥) := Se := ⇤⇥ ⇥s r 13 Rigon et al., Montpellier, October 21, 2011Monday, October 24, 11
  • GEOtop structure What I mean with Richards ++ First, I would say, it means that it would be better to call it, for instance: Richards-Mualem-vanGenuchten equation, since it is: ⇤⇥ ⇥ C(⇥) = ⇥ · K( w ) ⇥ (z + ⇥) Water balance ⇤t ⇧ ⇤ ⇥ m ⌅2 Parametric K( w ) = Ks Se 1 (1 Se ) 1/m Mualem n Parametric Se = [1 + ( ⇥) )] m van Genuchten ⇤ w () w r C(⇥) := Se := ⇤⇥ ⇥s r 13 Rigon et al., Montpellier, October 21, 2011Monday, October 24, 11
  • GEOtop structure What I mean with Richards ++ Extending Richards to treat the transition from saturated to unsaturated zone. Which means: 14 Rigon et al., Montpellier, October 21, 2011Monday, October 24, 11
  • Landsliding Landsliding After Lanni et al, 2010 submitted 15 Rigon et al., Montpellier, October 21, 2011Monday, October 24, 11
  • Landsliding Landsliding dry case - low intensity precipitation After Lanni et al, 2010 submitted 16 Rigon et al., Montpellier, October 21, 2011Monday, October 24, 11
  • Landsliding Landsliding wet case - high intensity precipitation After Lanni et al, 2010 submitted 17 Rigon et al., Montpellier, October 21, 2011Monday, October 24, 11
  • Landsliding Landsliding The experiments also show that triggering happens when approximately the same critical weight of water has been stored in the hillslope, and that the antecedent soil moisture condition and rainfall intensity determine the rainfall duration needed to achieve this critical volume of water. 18 Rigon et al., Montpellier, October 21, 2011Monday, October 24, 11
  • GEOtop structure What I mean with Richards ++ Extending Richards to treat the phase transition. Which means essentially to extend the soil water retention curves to become dependent on temperature. Freezing Unsaturated starts unfrozen Unsaturated Freezing Frozen procedes 19 Rigon et al., Montpellier, October 21, 2011Monday, October 24, 11
  • GEOtop structure What I mean with Richards ++ Soil water retention curve + thermodynamic equilibrium (Clausius Clapeyron) + Freezing = drying hypothesis pw pressure head: ⇥w = w g Unfrozen water content w (T ) = w [⇥w (T )] M. Dall’Amico et al., The Cryosphere, 2011 20 Rigon et al., Montpellier, October 21, 2011Monday, October 24, 11
  • GEOtop structure What I mean with Richards ++ m Total water = ⇥r + (⇥s ⇥r ) · {1 + [ n · ⇤w0 ] } content: ⇤ ⇥n ⌅ m liquid water ⇥w = ⇥r + (⇥s ⇥r ) · 1 + ⇤w0 Lf (T T ⇥ ) · H(T T ⇥) content: g T0 ⇥w ⇥ ice content: i = w ⇥i depressed g T0 T := T0 + melting Lf w0 point M. Dall’Amico et al., The Cryosphere, 2011 21 Rigon et al., Montpellier, October 21, 2011Monday, October 24, 11
  • Freezing = Drying What I mean with Richards ++ Unsaturated Freezing unfrozen starts Unsaturated Freezing Frozen procedes 22 Rigon et al., Montpellier, October 21, 2011Monday, October 24, 11
  • Freezing = Drying What I mean with Richards ++ M. Dall’Amico et al., The Cryosphere, 2011 23 Rigon et al., Montpellier, October 21, 2011Monday, October 24, 11
  • Freezing = Drying What I mean with Richards ++ M. Dall’Amico et al., The Cryosphere, 2011 24 Rigon et al., Montpellier, October 21, 2011Monday, October 24, 11
  • Freezing = Drying Tot Water profile: comparison with Hansson et al 0 after 50 hours ● Sim −20 ● ● ● Meas −40 ● ● −60 ● ● −80 ● soil depth [mm] ● ● ● −120 ● ● ● ● −160 ● ● ● ● −200 ● 0.25 0.30 0.35 0.40 0.45 0.50 0.55 water content [−] M. Dall’Amico et al., The Cryosphere, 2011 25 Rigon et al., Montpellier, October 21, 2011Monday, October 24, 11
  • Runoff on Frozen Soil Obviously this makes it possible to simulate a lot of new phenomenologies Endrizzi et Al., JHR, 2010 Sisik, river in the artic tundra 26 Rigon et al., Montpellier, October 21, 2011Monday, October 24, 11
  • Runoff on Frozen Soil thaw depth: T(z,t)=0 water table depth: ψm(z,t)=0 44 Stefano Endrizzi, William Quinton, Philip Marsh, Matteo Dall’Amico, 2010 in preparation 27 Rigon et al., Montpellier, October 21, 2011Monday, October 24, 11
  • Runoff on Frozen Soil: main result Runoff on frozen soil The model allows to show that the runoff properties of a basin dramatically change when soil freeze. 28 Rigon et al., Montpellier, October 21, 2011Monday, October 24, 11
  • Snow generated runoff Frozen soil can be combine with the snow module Arabba Pordoi Ornella Saviner Caprile Pescul Malga Ciapela 29 Rigon et al., Montpellier, October 21, 2011Monday, October 24, 11
  • Snow generated runoff Frozen soil can be combine with the snow module 30 Rigon et al., Montpellier, October 21, 2011Monday, October 24, 11
  • Snow generated runoff We have to work more here! Discharge at Saviner year 2006−2007 14 GEOtop measured 12 10 Discharge [m3/s] 8 6 4 2 0 01/10 01/12 01/02 01/04 01/06 01/08 01/10 Date (dd/mm) 31 Rigon et al., Montpellier, October 21, 2011Monday, October 24, 11
  • Questions A second set of questions: •Is Richards equation true ? •Is the van Genuchten-Mualem theory true ? •What actually means “true” ? •Where is “structure” (beside texture) in soil parametrization ? •Are there methods for accounting the spatial and temporal variability of soil hydraulic characteristics ? •Soil thermodynamics .... what is it ? 32 Rigon et al., Montpellier, October 21, 2011Monday, October 24, 11
  • Well, The perfect model does not exist ! Picasso, Dora Maar Deconstructing models 33 Rigon et al., Montpellier, October 21, 2011Monday, October 24, 11
  • JGrass-NewAGE JGrass-NewAGE (Formetta et al., GTD, 2011) This model focuses on the hydrological budgets of medium scale to large scale basins as the product of the processes averaged at the hillslope scale with the interplay of the river network. 34 Rigon et al., Montpellier, October 21, 2011Monday, October 24, 11
  • The structure of NewAge JGrass-NewAge (Formetta et al., GTD, 2011 Hillslope Storage Dynamics Surface flows Aggregation Channel flow Next time step 35 Rigon et al., Montpellier, October 21, 2011Monday, October 24, 11
  • The structure of NewAge JGrass-NewAge (Formetta et al., GTD, 2011 Calibration tools Input Data treatment Goodness of fit Next time step 36 Rigon et al., Montpellier, October 21, 2011Monday, October 24, 11
  • The structure of NewAge JGrass-NewAge (Formetta et al., GTD, 2011 Data assimilation Input Data treatment Goodness of fit Next time step 37 Rigon et al., Montpellier, October 21, 2011Monday, October 24, 11
  • The structure of NewAge JGrass-NewAge (Formetta et al., GTD, 2011 Evapotranspiration Hillslope Storage Dynamics Radiation Surface flows Aggregation Channel flow Next time step 38 Rigon et al., Montpellier, October 21, 2011Monday, October 24, 11
  • The structure of NewAge Someone call them Hydrologic Runoff UnitsRinaldo, Geomorphic Flood Research, 2006 we call them hillslope-link partition of the basin 39 Rigon et al., Montpellier, October 21, 2011 Monday, October 24, 11
  • The structure of NewAge For each of the variable of the hydrological cycle a statistics is made for each hillslope and a single value is returnedRinaldo, Geomorphic Flood Research, 2006 so, we have 5 values of the prognostics quantities here, that are space time-averages of what happens inside each hillslope 40 Rigon et al., Montpellier, October 21, 2011 Monday, October 24, 11
  • The structure of NewAge They are estimated for each hillslope •mean rainfall •mean radiation (we exploit some old idea by Ian Moore) •mean evapotranspiration •mean snow cover •mean runoff production 41 Rigon et al., Montpellier, October 21, 2011Monday, October 24, 11
  • The structure of NewAge When runoff is collected then is routed, for small basins, with a modification of the Muskingum-Cunge algorithm, or directly with a semi-implict solver of the de Saint-Venant 1D 42 Rigon et al., Montpellier, October 21, 2011Monday, October 24, 11
  • The structure of NewAge Thus we have discharges Rinaldo, Geomorphic Flood Research, 2006 Here, Here ... and here again 43 Rigon et al., Montpellier, October 21, 2011Monday, October 24, 11
  • And the complexity of Richards equations ? Remind that, in general, you cannot assume constant flow velocity through the network in all conditions of flow. So the simplifications that brings to the W-GIUH (Rinaldo et al., 1991,1995; Saco and Kumar, 2002; D’Odorico and Rigon, 2003) cannot be made. 44 Rigon et al., Montpellier, October 21, 2011Monday, October 24, 11
  • And the complexity of Richards equations ? Observe, that I did not mention the complexity implies by the Richards equation. WHERE IS IT NOW ? 45 Rigon et al., Montpellier, October 21, 2011Monday, October 24, 11
  • And the complexity of Richards equations ? IT WAS ASSUMED more than DERIVED* - that something averages out* - that the same averages modify the structure of the equations and the parameters (which could possibly vary seasonally) Can we built a statistical theory that rigorously derives the simplified equations ?for a derivation of part of it see Cordano and Rigon, 2008 46 Rigon et al., Montpellier, October 21, 2011Monday, October 24, 11
  • The need for a statistical theory A rigorous statistical theory would be needed that allows for •doing rigorously such simplifications*, not just on the basis of the personal Art of modelling^; •quantify the uncertainty remained after the simplifications** *for a derivation of part of it see Cordano and Rigon, 2008 and BTW compare it with the abstract view Reggiani et al., 1999 ^This will be remain, however ... ** The distribution around the mean quantities could not be sharp. Variances can be important ... 47 Rigon et al., Montpellier, October 21, 2011Monday, October 24, 11
  • The need for a statistical theory However, the more “reductionist” GEOtop could be used to test the solutions implemented in the simplified NewAGE and evaluate the non-acceptable behaviors. Obviously, this is not as simple as it can be, because GEOtop itself comes with its simplifications and errors 48 Rigon et al., Montpellier, October 21, 2011Monday, October 24, 11
  • The structure of NewAge Assume that now a reservoir Rinaldo, Geomorphic Flood Research, 2006 is made here 49 Rigon et al., Montpellier, October 21, 2011Monday, October 24, 11
  • The structure of NewAge Well, you can have the discharges also there Rinaldo, Geomorphic Flood Research, 2006 once you embeds the characteristics of the reservoirs in the model 50 Rigon et al., Montpellier, October 21, 2011Monday, October 24, 11
  • The structure of NewAge However for doing it seamlessly you need to made a topological description of the networkand capture it in a suitable object-oriented-geographic infrastructure. NewAge DOES it! details in the upcoming papers and manual 51 Rigon et al., Montpellier, October 21, 2011Monday, October 24, 11
  • Modeling by component The modeling by component paradigm was adopted This interface was automatically created from OMS v3 annotations automagically inside the udig GIS 52 Rigon et al., Montpellier, October 21, 2011Monday, October 24, 11
  • Modeling by component The modeling by component paradigm was adopted The Object Modeling System OMS is a modular modeling framework that uses an open source software approach to enable all members of the scientific community to address collaboratively the many complex issues associated with the design, development, and application of distributed hydrological and environmental models. Products Development Tools OMS Knowledge Base Resources OMS3 can be found at: http://www.javaforge.com/project/ http://www.javaforge.com/project/oms 53 Rigon et al., Montpellier, October 21, 2011Monday, October 24, 11
  • Questions Is the mean value for a hillslope enough ?from the point of view of the prognostic variable it could be. It Depends on whatthe observer is looking for and for what.from the point of view of the input data, inferring the space-time mean could notbe enogh. In fact:•for evaluating evapotranspiration properly we need for accountng of thesubgrid variability of soil moisture distribution, vegetation and radiation.•for evaluating the snow pack evolution we need to account, at least, for thevariability of radiation 54 Rigon et al., Montpellier, October 21, 2011Monday, October 24, 11
  • The structure of NewAge So Any hillslope is subdivided in - zone of about the same elevation (elevation classes) - areas that receives the same amount of radiation (radiation classes) - soil cover classes An this subgrid variability is used to estimated the mean values for each hillslope. 55 Rigon et al., Montpellier, October 21, 2011Monday, October 24, 11
  • Questions A third set of questions: • Is it possible (and how) to identify sets of spatial points that behave hydrologically in a similar way ? (a question that pervades Hydrology since many years: google hydrological symilarity) •What is explained by the form, topology, and geometry of catchments ? •What we can do to characterize uncertainties in hydrological modeling ? And which is the acceptable degree of confidence to say that a model is a good model ? •Is really possible to work cooperatively building, we dwarfs, on the shoulder of each other, and maybe of some giant ? Or is hydrology condemned to an endemic dilettantism ? (e.g Klemes, WRR, 1986) 56 Rigon et al., Montpellier, October 21, 2011Monday, October 24, 11
  • Peakflow Peakflow (Rigon et al., HESS, 2011) Is a “minimalistic effort” when compared to the others. It is an event based GIUH (width function flavor) model of rainfall runoff which try to use the topographic information for appropriate modeling. Hokusai, 1829-32 57 Rigon et al., Montpellier, October 21, 2011Monday, October 24, 11
  • The structure of Peakflow Peakflow (a W-GIUH) model (Rigon et al., HESS, 2011) Effective rainfall Surface flows Aggregation (Width function) Diffusive wave 58 Rigon et al., Montpellier, October 21, 2011Monday, October 24, 11
  • The structure of Peakflow The main news is that during flood peaks •Radiation and evapotranspiration are neglected (what is relevant is included in the iniital conditions) •you can assume very simplified mechanisms of runoff production •flood wave celerity can be kept constant (as a first approx.) •the most of the variance of flood hydrograph is explained by the geometry and topology of the basin (and the space-time variation of rainfall 59 Rigon et al., Montpellier, October 21, 2011Monday, October 24, 11
  • The structure of Peakflow The main news is that during flood peaks •Radiation and evapotranspiration are neglected (what is relevant is included in the iniital conditions) •you can assume very simplified mechanisms of runoff production •flood wave celerity can be kept constant (as a first approx.) •the most of the variance of flood hydrograph is explained by the geometry and topology of the basin (and the space-time variation of rainfall • well, I did not talk about the runoff coefficient 59 Rigon et al., Montpellier, October 21, 2011Monday, October 24, 11
  • The structure of Peakflow You can assume very simplified mechanisms of runoff production Well, more based on heuristics, since evidence shows that initial condition for large floods (don’t want to talk of return period!) in a basin, and rainfall space-time distribution (but mostly timing counts, Rinaldo et al., 200X) are similar for a given basin. 60 Rigon et al., Montpellier, October 21, 2011Monday, October 24, 11
  • The structure of Peakflow Flood wave celerity can be kept constant (as a first approx.) Leopold and Maddock, 1953 61 Rigon et al., Montpellier, October 21, 2011Monday, October 24, 11
  • The structure of Peakflow Flood wave celerity can be kept constant (as a first approx.) Follows also from theory of minimum energy dissipation: - Rodriguez-Iturbe et al., Energy dissipation, runoff production and the three-dimensional structure of river networks, WRR, 1992 - Rodriguez-Iturbe and Rinaldo, Fractal River Basin, CUP 1997 - Rinaldo et al., Channel Networks, Rev. Earth and Plan. Sciences, 1998 62 Rigon et al., Montpellier, October 21, 2011Monday, October 24, 11
  • The structure of Peakflow The most of the variance of flood hydrograph is explained by the geometry and topology of the basin (and the space- time variation of rainfall) - Rinaldo et al., Geomorphological Dispersion, WRR, 1992 - Rinaldo et al, Can you gauge the shape of a basin ? , WRR, 1995 - D’Odorico and Rigon, Hillslope and channel contributions to the hydrologic response, WRR, 2003 63 Rigon et al., Montpellier, October 21, 2011Monday, October 24, 11
  • Results with Peakflow Good results Fort Cobb, OK USA 05/26/2008 After Perathoner, 2011 64 Rigon et al., Montpellier, October 21, 2011Monday, October 24, 11
  • Results with Peakflow Less good result* Little Washita, OK 19/06/2007 After Perathoner, 2011 * On Little Washita we had also good results 65 Rigon et al., Montpellier, October 21, 2011Monday, October 24, 11
  • Results with Peakflow Less good result Passirio, Italy 23/07/2008 After Perathoner, 2011 66 Rigon et al., Montpellier, October 21, 2011Monday, October 24, 11
  • Results with Peakflow Observations There was a big trick: the runoff coefficient was estimated “a -priori” and was: Fort Cobb <- 0.14 Little Washita <- 0.7 Passirio <- 0.2 67 Rigon et al., Montpellier, October 21, 2011Monday, October 24, 11
  • Results with Peakflow Observations It seems that in some situations there is a delayed production of runoff which produces large recession curves with local maxima of discharges that do not correspond to rainfall impulses. Therefore the “tricky runoff coefficient” could be different from surface and subsurface flows. In the case of Passirio, it could be snow melting. PBIAS is always negative, meaning that a systematic underestimation of flow discharge. 68 Rigon et al., Montpellier, October 21, 2011Monday, October 24, 11
  • Questions A fourth set of questions •How, the hell, can you estimated that damned runoff coefficient ? •Is there really there the minimal information for forecasting floods or can we do even better ? •We used everywhere (with some tricks but with ) with success. Why we did not systematize the parameters choice ? •Can we modify the model structure to include spatial variability of storms ? •Which storms should be use for envisioning extreme events ? 69 Rigon et al., Montpellier, October 21, 2011Monday, October 24, 11
  • GEOFRAME GEOFRAME 201* Vision Out R JGrass-udig- NWW OMS3- NetCDF GEOtop NewAge Boussinesq PeakFlow Models SHALSTAB GEOtop-FS The Horton Machine In JGrass-udig- OMS3- NetCDF METEO /IO Environmental Data Center Data (Postgres/Postgis/Ramadda/H2) 70 Rigon et al., Montpellier, October 21, 2011Monday, October 24, 11
  • Find this presentation at http://www.slideshare.net/GEOFRAMEcafe/rr-reflections Ulrici, 2000 ? Other material at http://abouthydrology.blogspot.com 71 Rigon et al., Montpellier, October 21, 2011Monday, October 24, 11
  • Thank you for your attention From the work "the thousand rivers” (i mille fiumi) by Arrigo Boetti and Anna-marie Sauzeau-Boetti classification by order of magnitude is the most common method for classifying information relative to a certain category, in the case of rivers, size can be understood to the power of one, two, or three, that is, it can be expressed in km, km2, or km3 (length, catchment area, or discharge), the length criterion is the most arbitrary and naive but still the most widespread, and yet it is impossible to measure the length of a river for the thousand and more perplexities that its fluid nature brings up (because of its meanders and its passage through lakes, because of its ramifications around islands or its movements in the delta areas, because of man’s intervention along its course, because of the elusive boundaries between fresh water and salt water...) many rivers have never been measured because their banks and waters are inaccessible, even the water spirits sympathize at times with the flora and the fauna in order to keep men away, as a consequence some rivers flow without name, unnamed because of their untouched nature, or unnamable because of human aversion (some months ago a pilot flying low over the brazilian forest discovered a “new” tributary of the amazon river). other rivers cannot be measured, instead, because they have a name, a casual name given to them by men (a single name along its entire course when the river, navigable, becomes means of human communication; different names when the river, formidable, visits isolated human groups); now the entity of a river can be established either with reference to its name (trail of the human adventure), or with reference to its hydrographic integrity (the adventure of the water from the remotest source point to the sea, independently of the names assigned to the various stretches), the problem is that the two adventures rarely coincide, usually the adventure of the explorer is against the current, starting from the sea; the adventure of the water, on the other hand, finishes there, the explorer going upstream must play heads or tails at every fork, because upstream of every confluence everything rarefies: the water, sometimes the air, but always one’s certainty, while the river that descends towards the sea gradually condenses its waters and the certainty of its inevitable path, who can say whether it is better to follow man or the water? the water, say the modern geographers, objective and humble, and so the begin to recompose the identity of the rivers, an example: the mississippi of new orleans is not the extension of the mississippi that rises from lake itasca in minnesota, as they teach at school, but of a stream that rises in western montana with the name jefferson red rock and then becomes the mississippi-missouri in st louis, the number of kilometres upstream is greater on the missouri side, but in fact this “scientific” method is applied only to the large and prestigious rivers, those likely to compete for records of length, the methodological rethinking is not wasted on minor rivers (less than 800km) which continue to be called, and measured, only according to their given name, even if, where there are two source course (with two other given names), the longer of the two could be rightly included in the main course, the current classification reflects this double standard, this follows the laws of water and the laws of men, because that is how the relevant information is given, in short, it reflects the biased game of information rather than the fluid life of water, this classification was began in 1970 and ended in 1973, some data were transcribed from famous publications, numerous data were elaborated from material supplied non-european geographic institution, governments, universities, private research centres, and individual accademics from all over the world, this convergence of documentation constitutes the the substance and the meaning of the work, the innumerable asterisks contained in these thousand record cards pose innumerable doubts and contrast with the rigid classification method, the partialness of the existing information, the linguistic problems associated with their identity, and the irremediably elusive nature of water all mean that this classification, like all those that proceeded it or that will follow, will always be provisional and illusionary Anne-marie Sauzeau-Boetti (TN the text is published without capital letters) 72 Rigon et al., Montpellier, October 21, 2011Monday, October 24, 11