DocumentCode :
728223
Title :
Adjoint-method-based estimation of Manning roughness coefficient in an overland flow model
Author :
Van Tri Nguyen ; Georges, Didier ; Besancon, Gildas
Author_Institution :
Gipsa-Lab., Univ. Grenoble Alpes, St. Martin-d´Hères, France
fYear :
2015
fDate :
1-3 July 2015
Firstpage :
1977
Lastpage :
1982
Abstract :
An optimal estimation approach for distributed Manning roughness coefficient in an overland flow based on the adjoint method is here proposed. Through some appropriate assumptions and simplifications, the governing equation describing the system is derived from the first continuity equation of the well-known one-dimensional Saint-Venant equations. In this equation, the empirical Manning parameter is considered to be unknown and can be estimated through a new parameter called K which is approximated by a Radial Basis Function Network (RBFN) with specified weighting factors. Estimation of distributed Manning coefficient can be reduced to estimation of weighting factors of RBFN. Infiltration process is also taken account in this work via the so-called Green-Ampt model. For the optimization, the adjoint model is obtained by means of a variational approach. Because of their non-linearity and complexity, the system and adjoint equations are numerically solved by using nonlinear implicit Preissmann schemes. Using steepest decent method and backtracking line search method, the cost functional is optimized in order to estimate the mentioned weighting factors from a set of lumped observation values. Finally, the method is illustrated on a simulated example with a simple overland flow and infiltration over a variable rainfall period.
Keywords :
estimation theory; geophysical fluid dynamics; hydrological techniques; radial basis function networks; rain; variational techniques; Preissmann schemes; RBFN; adjoint-method-based estimation approach; backtracking line search method; distributed Manning roughness coefficient; empirical Manning parameter; first continuity equation; infiltration process; numerical solution; one-dimensional Saint-Venant equations; overland flow model; radial basis function network; rainfall period; steepest decent method; system complexity; weighting factor estimation; Approximation methods; Cost function; Estimation; Mathematical model; Numerical models; Soil; Green-Ampt infiltration model; Infinite dimensional system; Inverse problem; Manning roughness coefficient; Overland flow; Parameter estimation; Saint-Venant equations;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
American Control Conference (ACC), 2015
Conference_Location :
Chicago, IL
Print_ISBN :
978-1-4799-8685-9
Type :
conf
DOI :
10.1109/ACC.2015.7171023
Filename :
7171023
Link To Document :
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