eprintid: 1431
rev_number: 9
eprint_status: archive
userid: 1
dir: disk0/00/00/14/31
datestamp: 2001-02-07 00:00:00
lastmod: 2014-04-03 10:40:48
status_changed: 2012-08-14 15:01:11
type: doctoralThesis
metadata_visibility: show
creators_name: Dieses, Angelika
title: Numerical methods for optimization problems in water flow and reactive solute transport processes of xenobiotics in soils
title_de: Numerische Methoden für Optimierungsprobleme in Wasser- und Stofftransportprozessen von Xenobiotika in Böden
ispublished: pub
subjects: ddc-550
divisions: i-708000
adv_faculty: af-11
keywords: Reduziertes Verallgemeinertes Gauss-Newton Verfahren , Inverse Modellierung , Modellierung von Umweltverhaltenparameter estimation , multiple shooting , optimal experimental design , reduced generalized Gauss-Newton method , environmental fate modelling
cterms_swd: Parameterschaetzung
cterms_swd: Mehrzielmethode
cterms_swd: Optimaler Versuchsplan
cterms_swd: Gauß-Newton-Methode
cterms_swd: Umwelt
abstract_translated_text: Inverse modeling is increasingly used in the modeling of water flow and reactive  solute transport in the unsaturated zone to determine unknown parameters, e.g. degradation rates. In this thesis new contributions are made to the following fields: 1. Modeling of parameter estimation problems and optimal experimental design  problems: Mathematical modeling of water and solute transport processes in the  unsaturated zone leads to instationary partial differential equations (PDEs)  coupled with nonlinear ordinary differential equations (ODEs). 2. ECOFIT: An efficient method for parameter estimation of xenobiotics in soils:  The parameter estimation problem constrained by PDEs and ODEs is transformed by  discretization into a large scale nonlinear constrained least-squares problem.  Finite differences are employed for spatial discretization. Discretization in time  is done by multiple shooting. A reduced Generalized Gauss-Newton method is  presented that exploits that the systems have only few degrees of freedom. Using  directional derivatives for setting up the linearized problems, we end up with  essentially the same computational effort as for the single shooting method while  maintaining the advantages of multiple shooting. For the computation of derivatives  in discretized PDE-systems highly efficient strategies are derived exploiting  structures on several levels. 3. ECOPLAN: An approach for optimizing experimental conditions and sampling schemes:  Embedding the optimal experimental design problem in the framework of optimal control  theory results in an intricate, nonlinear, state-constrained optimization problem  that is solved by a structured SQP-method. 4. Application of ECOFIT and ECOPLAN to column, lysimeter and field studies:  Numerous types of examples are worked out to demonstrate the power and the  possibilities of ECOFIT and ECOPLAN, some of them using hypothetical data, some of  them building on data provided by experiments.
abstract_translated_lang: eng
date: 2000
date_type: published
id_scheme: DOI
id_number: 10.11588/heidok.00001431
ppn_swb: 1643185195
own_urn: urn:nbn:de:bsz:16-opus-14315
date_accepted: 2000-12-15
advisor: HASH(0x558eaa62efb0)
language: eng
bibsort: DIESESANGENUMERICALM2000
full_text_status: public
citation:   Dieses, Angelika  (2000) Numerical methods for optimization problems in water flow and reactive solute transport processes of xenobiotics in soils.  [Dissertation]     
document_url: https://archiv.ub.uni-heidelberg.de/volltextserver/1431/1/diss_final.pdf