Embedded Scribd iPaper - Requires Javascript and Flash Player
SDL FORMALIZATION OF A HYDROLOGIC MODEL
Jeaneth López C., Pau Fonseca i Casas, Josep Casanovas
Outline
§ § § § § § Hydrologic Models Simulation Formalisms GIS data Cellular automaton SDL Specification of the model. Discussion
Hydrologic Models
IPCC estimates that there are four places in the earth with high risk to reduce the availability of hydrologic resources and present abrupt climate changes. Spain (south of Europe), California (EEUU), South Africa, North east of
Greenhouse effects
Hydrologic resource
Rise Sea level Natural disastres
•Cyclones •Droughts •Floods •Frost •Etc…
Human Migration
Rise Temperature
Water Availability
Increase of population Precipi tation Contami nation Waste water
Human Consume Agricul ture
Available Water
Industry Ecosystems
Hydro. model – Sim. Formalisms – GIS Data – Cel. Automaton - SDL
Hydrologic Models

Watershed modeling, or hydrologic model (rainfall-runoff modeling) began in the 1950s and 1960s with the evolution of the digital computer. The Stanford Watershed Model (SWM) was one of the first watershed hydrologic model. (Crawford and Linsey 1966). LSSMs (Large-scale Spatial Models)(Watson et al., 1999) DHSVM (Distributed Hydrology-Soil-Vegetation Model) (Wigmosta 1997, 2002) LSHWM (Large-Scale Hybrid Watershed Modeling)(Aral and Gunduz, 2003), MHM (Macroscale Hydrological Model using Variable Infiltration Capacity VIC 3-layer)(Srinivasan2003) The VIC-3L model, is based on a 3-layer Soil Vegetation Atmosphere Transfer scheme to model different surface conditions. L-THIA (Long Term Hydrologic Impacts Assessment) (Lim et al., 2006) Hydrological model SHALL3 (Zimmermann, 2002) (Haan et al.,1982, Singh, 1988, Singh and Frevert, 2006)
 
 
   

Hydro. model – Sim. Formalisms – GIS Data – Cel. Automaton - SDL
Hydrologic Models

The SWAT (Soil and Water Assessment Tool) was developed by modifying the models specified below. All of this models use the SCS Curve Number Method, an empirical formula for predicting runoff from daily rainfall.
GLEAMS
pesticide compone nt daily rainfall hydrology component Crop Growth compone nt
QUAL2 E
Instream kinetics
Example SWAT adaptations
ESWAT SWATG SWIM
SWRRB
(multiple subbasins, subbasins, other other
CREAMS
SWRRB (multiple
SWAT
routing structur e
components)
EPIC
ROTO
Schematic of SWAT developmental history, including selected SWAT
1970s
Hydro. model – Sim. Formalisms – GIS Data – Cel. Automaton - SDL
Nowada ys
Simulation Formalisms
§ Petri Nets
§ Introduced by Carl Adam Petri (1960). Also known as a Place/Transition
§ DEVS (Discreet Event System Specification)
§ In the 70s Bernard Zeigler proposed a mathematical formalism.
§ SDL (Specification and Description Language)
§ The semantics of SDL was defined formally in 1988.
Hydro. model – Sim. Formalisms – GIS Data – Cel. Automaton - SDL
Petri Nets
RdP=(P,T,A,W,M0)
  
P = Finiteset of nodes Places T = Finiteset of nodes Transitions A C(PxT) and T. (TxP): subset of cartesianproduct between nodes P
 
W = a {1,2,3,..}: weigh of arcs M0 = Pi {1,2,3,..} node Pi: number ok tokens initials in each place
Hydro. model – Sim. Formalisms – GIS Data – Cel. Automaton - SDL
DEVS Formalism
M=<X, S, Y, δint, δext, λ, ta> where:  X: set of input values.  S: set of states values.  Y: set of output values.  δint: internal transition function.

δint :S
S
 
δext: external transition function. δext Q x X S , on
 
Q={(s,e)|sS, 0≤e≤ta(s)} set of states. e elapsed time from the last transition.
 
λ : output function: λ : S Y ta : time advance function.

ta: S
R+0∞
DEVS Processor example
         
M=<X, S, Y, δint, δext, λ, ta> on: X={job1, job2, .., jobn} S={job1, job2,.., jobn}U[Ø]xR+0∞ Y={y(job1), y(job2),.. Y(jobn)} δint(job,σ)=(Ø, ∞) δext(job,σ,e,x)= if job= Ø (x,tp,(x)) else (job, σ-e) λ(job, σ)=y(job) Ta(job, σ)= σ
SDL formalism


Object-oriented, formal language defined by The International Telecommunications Union as recommendation Z.100. Intended for the specification of complex, event-driven, real-time, and interactive applications involving many concurrent activities that communicate using discrete signals.
Hydro. model – Sim. Formalisms – GIS Data – Cel. Automaton - SDL
SDL Formalism

The semantics of SDL was defined formally in 1988.
 Standard  Formal  Graphical
and symbol-based  Object-oriented (OO)
Hydro. model – Sim. Formalisms – GIS Data – Cel. Automaton - SDL
GIS Data
Hydro. model – Sim. Formalisms – GIS Data – Cel. Automaton - SDL
Celular automaton


Each cell xi(t) represent a state of the cell i in the instant t. k = {Empty, Static and Dynamic}
xi
Hydro. model – Sim. Formalisms – GIS Data – Cel. Automaton - SDL
Game of life

The Game of Life is a cellular automaton devised by the British mathematician John Horton Conway in 1970. It is the best-known example of a cellular
Hydro. model – Sim. Formalisms – GIS Data – Cel. Automaton - SDL
Method
§ Cellular Automaton Structure
§ Evolution Rules
§ Precipitation phase § Settlement phase
• Data layers
Hydro. model – Sim. Formalisms – GIS Data – Cel. Automaton - SDL
Model
Soil (Ground)
•Return Flow •Kind of soil •Saturate •Kind of soil use •Non-Saturate •Percolation
•Runoff •Humidity •Evapo-trans piration •Temperature •Rainfall •Precipitation
Hydrologic resource
Meteorology
Factors/variables which affects hydrologic resource
Hydro. model – Sim. Formalisms – GIS Data – Cel. Automaton - SDL
Model
Where:
        
SWt is the total quantity of water in the soil (basin) (mm), SWi is the initial quantity of water in the soil (mm) Ri (rainfall) is the quantity of rain in the period of analysis(mm) Qi is the quantity of runoff (mm) ETi is the evapotranspiration (mm) Pi is the percolation (mm) QRi return flow(mm) t is the time expressed in days i is the index of cell
Hydro. model – Sim. Formalisms – GIS Data – Cel. Automaton - SDL
Model


This expression gives us the water volume existing in each cell of our cellular automaton in a specific time t. In the expression, one position of the cellular automaton matrix [xi,xj] is represented by the cell xi.
Hydro. model – Sim. Formalisms – GIS Data – Cel. Automaton - SDL
System diagram
Hydro. model – Sim. Formalisms – GIS Data – Cel. Automaton - SDL
States diagram
Update Receive
Send
Dynamic
Receiv e
Static
d en S te/ ei ec R ve
Update Receive
Receive
Send
Up
da
Send Update
Empty
Hydro. model – Sim. Formalisms – GIS Data – Cel. Automaton - SDL
Process diagram: Static state
Hydro. model – Sim. Formalisms – GIS Data – Cel. Automaton - SDL
Process diagram: Empty state
Hydro. model – Sim. Formalisms – GIS Data – Cel. Automaton - SDL
Process diagram: Dynamic state
Hydro. model – Sim. Formalisms – GIS Data – Cel. Automaton - SDL
Discussion and future work




This slides depicts the first and more important step to construct a discrete hydrologic simulator based in a cellular automaton. It shows the specification of hydrologic model with the aim of simulate the behaviour of water in a river basin. The use of the cellular simplifies the mathematical expressions and helps us to maintain a structured view of the geographical data needed to represent the model. The use of SDL formalism simplifies the understanding of the behaviour of model thanks its graphical structure. The model is based in the hydrologic balance equation which permits calculate the quantity exist in each cell of the cellular automaton
Hydro. model – Sim. Formalisms – GIS Data – Cel. Automaton - SDL
References






[1] L. Ma, L.R. Ahuja, and R.W. Malone. Systems Modeling for Soil and Water Research and Management: Current Status and Needs for the 21st Century. ASABE, 1907-2007. [2] IPCC Intergovernamental Panel on Climate Change. Report IPCC. 2007. [3] J. Samper, M.A. Garcia, B. Pisani, D. Alvares, A. Varela, and J.A. Losada. Modelos Hidrologicos y Sistemas de Informacion Geografica para la Estimacion de Recursos Hidricos:. Confederacin Hidrologica del Ebro, VII, 2005. [4] E. Guzman, J. Bonini, and D. Matamoros. Modelo Hidrologico SWAT (Soil Water Assessment Tool) Prediccin de Caudales y Sedimentos en una Cuenca. Revista Tecnologica, 17:152–161, 2004. [5] Erik D. Zimmermann. Modelo Hidrologico Superficial y Subterraneo. Centro Universitario rosario de Investigaciones Hidroambientales. [6] A. López, D. Sauri, and Jose M. Galán. Urban Water
References
 



 


[8] P. Pea and J. Alirio. Sobre las redes de petri r-difusas. Divulgaciones Matemticas, 7:87–99, 1999. [9] Gabriel Wainer. Applying cell-devs methodology for modeling the environment. SIMULATION, 82:635, 2006. [10] Liu Qi and Gabriel Wainer. Parallel environment for devs and cell-devs models. SIMULATION, 83:449, 2007. [11] Fonseca P. and Casanovas J. 2005. ESS205, Simplifying GIS data use inside discrete event simulation model through m_n-AC cellular automaton; Proceedings ESS 2005. [12] ITU-T Telecommunication Standardization Sector of ITU. Languages and general software aspects for telecommunication systems. TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU, 2007. [13] Zeigler, B. P.; H. Praehofer; D. Kim. 2000. Theory of Modeling and Simulation. Academic Press. [14] Petri, Carl A. 1962. "Kommunikation mit Automaten". Ph. D. Thesis. University of Bonn. [15] Recalde, L.; Teruel, E.; Silva, M. 1999. Autonomous
Thanks!
Pau Fonseca i Casas pau@fib.upc.edu
Technical University of Catalonia Barcelona School of Informatics Computing laboratory Barcelona Jordi Girona 1-3 (+34)93401773