Investigation of a lysimenter using the simulation tool siwapro DSS and adaptation of this program to vietnamese requirements

® HANOI UNIVERSITY OF SCIENCE DRESDEN UNIVERSITY OF TECHNOLOGY PHAM THI BICH NGOC INVESTIGATION OF A LYSIMETER USING THE SIMULATION TOOL SiWaPro DSS AND ADAPTATION OF THIS PROGRAM TO VIETNAMESE REQUIREMENTS MASTER THESIS Supervisors: Prof Dr Ing habil Peter Wolfgang Graeber Dipl Ing Rene Blankenburg Technical University Dresden Institute for Waste Management and Contaminated Site Treatment Hanoi - 2008 ACKNOWLEDGEMENTS Two years have passed and marked a historical pathway toward my Master degree The two years were full of challenges, hopes, inspiration and wonderful support from many people I would like to thank you all for a big variety of reasons: My first greatest thanks go to my tutors Prof Dr Ing habil Peter Wolfgang Graeber and Dipl Ing Rene Blankenburg for having guided, supported and accom-panied me through the process of this Master thesis Thanks also for having greatly contributed to the thesis with your vast experience and advice Many thanks to Prof Dr Bilitewski, Assc Prof Dr Bui Duy Cam and Assc Prof Dr Nguyen Thi Diem Trang for making great efforts to establish and design the training program frame for this master course and develop it, so I can have a chance to join this course My acknowledgements go also to all teachers from Hanoi University of Sciences in Vietnam and Institute for Waste Management and Contaminated Site Treatment in Germany for giving me lots of valuable and interesting lectures and helping us to understand more clearly and have a thorough grasp of specific knowledge during this master course My grateful thanks to Dr rer nat Axel Fischer, Mr Christian and Mrs Hoang Phan Mai for helping and supporting during my time in Dresden and Pirna, Germany Thanks also to Pham Hai Minh for all administrative support during the Master course time I also would like to express my gratitude to:  The Committee on Overseas Training Project, Ministry of Education and Training for having granted the scholarship that supported this Mater thesis  Hanoi University of Sciences and Institute for Waste Management and Con- taminated Site Treatment (IAA) for providing all materials and equipments that I used during the course  Vietnam National University, Hanoi and Technical University Dresden and German Academic Exchange Service (DAAD) for supporting this Master training program in which I attended Thanks to all the classmates for their nice and warm company for the encouragement and support And last but not least, special huge thanks to my family (my parents in law, my parents, my husband, my son and my brothers and sisters) and all my friends (especially Mrs Ha) and my relatives for thinking of me, helping me, and encouraging me in my pathway to a Master degree I love you all th Hanoi, 10 December 2008 Pham Thi Bich Ngoc SUMMARY The main objective of this thesis is to use SiWaPro DSS to model and simulate the water flow process in the unsaturated zone with the available data from the lysimeter number 302 in Juelich, Germany The unsaturated zone is the portion of the subsurface above the ground water table It contains air as well as water in the pores This zone plays an important roll in many aspects of hydrology, such as infiltration, exfiltration, capillary rise, recharge, interflow, transpiration, runoff and erosion Interest in this zone has been increasing in recent years because the movement of water along with contaminants in this zone have been affecting the groundwater and the subsurface environment Water flow is concerned with movement of water in unsaturated porous media In order to handle water flow process under steady state or transient conditions in the unsaturated zone, a useful computer program is used to model and simulate this process This program combines the simulation module SiWaPro for numerical modeling of water flow and contaminant transport in variably saturated media with additional simulation and parameter estimation tools, data sources for the simulation and a graphical user interface The computer-based decision support system SiWaPro DSS software is a program for modeling and simulating the processes as water flow, solute transport, bio degradation and sorption in variably saturated porous media In SiWaPro DSS, the discretization of the modeling area is realized using finite elements with the GALERKIN method SiWaPro DSS contains the 2D triangular mesh generator EasyMesh 1.4 The mesh generator allows the generation of meshes with varying element sizes and irregular mesh boundaries Currently, the generator allows flexible space quantization at modeling time given by the user To validate SiWaPro DSS, the means of measurement data from a lysimeter experiment are used Lysimeters are devices for measuring the characteristic properties of the soil water balance, amounts of seepage water and their quality In this thesis, lysimeter 302 located in Juelich, Germany is used for calibrating model The Juelich lysimeter 302 was established in August 2001, the monoliths were taken out from Munich-Neuherberg in June 2001 and the installation of the measurement devices occurred and the data logging started on December 10th 2001 This lysimeter is run by the Research Centre in Juelich (FZJ) This lysimeter is a large undisturbed lysimeter with 2m in area and 2,4m in depth including 0,8m of reference material The three suction cups are installed together with tensiometers, TDR and temperature sensors at 3-different depth layers distance from upper edge of the lysimeter in turn as 0,85m; 1,15m and 1,8m To model the water flow of the lysimeter in SiWaPro DSS, the finite element mesh of the lysimeter is constructed with the column of 1,6m in width and 1,6m in height (excluding 0,8m of reference material) The lower boundary condition is a first kind boundary condition that allows outflow only A second type boundary condition is applied at the upper boundary of the column of lysimeter It is a transient boundary condition using time – variable boundary conditions to simulate precipitation in the model Three soil water sampling device layers are applied as first kind boundary condition, and as the lower boundary condition, only outflow is allowed The column of the lysimeter soil is divided into layers; each of the soil layers is described in its hydraulics with 11 parameters To calibrate model, two data sets of 11 soil hydraulic and van Genuchten parameters with different initial pressure head and boundary condition of three suction cup layers as well as different amount of nodes and elements in the mesh are used Because the time is short – besides, one model took from 25 hours to 50 hours for running; some models took much more time, then they were stopped before they finish So there are only 10 models were run After getting the result from simulation of each model, the simulation result was checked and analyzed and then the data set was changed or finite element mesh of the lysimeter was adjusted or the software was reconsidered The simulation results that were shown in diagrams in section 4.1 are the best model, but the results still show some difference of output between simulation and measurement because input data which took from lysimeter station are not well documented and some soil parameters which are estimated by the person who operate the lysimeter are different from the fact The result shows that total inflow and total outflow of lysimeter are in balance That means the model and finite element mesh of the lysimeter is designed well Outflow of the suction cup layer number in the simulation is almost the same as measurement Outflow of the suction cup layer number and lower boundary condition in simulation are the same as measurement in the first year But in the second year, outflow of the suction cup layer number in simulation is higher than measurement; opposite to the outflow of the lower boundary condition the simulation one is lower than measurement Outflow at the suction cup layer number is different increasing by time between simulation and measurement The differences come from the data mentioned as above The SiWaPro DSS program have been introducing to Federal Environmental Bureaus and Consulting Companies in Germany These Bureaus and Companies can use this software tool primarily for leachate forecasts with respect to the German soil protection law In Vietnam it also can be apply similar to Germany, but it takes a bit time for Vietnamese to familiar with it For Vietnamese to apply this software, the GUI and help system were initially translated into Vietnamese Therefore, it can be said that SiWaPro DSS is one of the useful tools for leachate forecast However, it should be applied for a wide variety of contaminants if the software is revised to adapt with not only all available data but also a few available data The lysimeter is good for calibrating the model and will be better if the data is documented well and frequency TABLE OF CONTENTS ACKNOWLEDGEMENTS SUMMARY TABLE OF CONTENTS ABBREVIATIONS LIST OF FIGURES LIST OF TABLES LIST OF DIAGRAMMS INTRODUCTION FUNDAMENTALS OF SOIL HYDROLOGY 2.1Definition of soil and unsaturate 2.2Soil hydraulic parameters 2.3Soil water balance 2.4Soil water flow MATERIAL AND METHODS 3.1Theoretical approaches and meth 3.2Finite element method 3.3Lysimeter 3.3.1 General information about lysimeter 3.3.2 Juelich lysimeter station description 3.3.3 Description of the Juelich lysimeter number 302 3.4Water flow model 3.5Description of the finite element 3.6Description of software SiWaPro 3.6.2.1 Graphical user interface ( 3.6.2.2 Mesh Generator 3.6.2.3 Weather Generator 3.6.2.4 3.6.2.5 3.6.2.6 Import and Export Interfaces 3.6.3 Manual SiWaPro DSS Mesh Generator 3.6.3.1 Create a simple 2D mesh 3.6.3.2 Definition internal curves 3.6.3.3 Inserting a background image as construction basis 3.6.3.4 Boundary condition editor 3.7 Data sets for calibrating the model 3.7.1 3.7.2 3.7.3 3.7.4 3.7.5 RESULTS 4.1 Simulation results 4.2 Extension and adaptation to Vietnam requirements DISSCUSSION AND CONCLUSIONS REFERENCES STATEMENT UNDER OATH APPENDICES Appendix 1: Precipitation using for simulation Appendix 2: Brief of output of simulation for 784 days Appendix 3: Data from measurement Appendix 4: Data from simulation for the days equivalent with measure days ABBREVIATIONS BbodSch G German Soil Protection Law CART Classification and Regression Trees CART Decision Support System DSS Equation Eq Finite Element FE The Research Center in Juelich FZJ Group Method of Data Handling GMDH The National Research Center for Environment and Health GSF Graphical User Interface GUI The North Rhine-Westphalia State Environment Agency LUA NRW National Institute of Plant Protection NIPP PFT SiWaPro SKE SKE SKE SKE TDR Classification and Regression Trees Pedotransfer Function Sickerwasserprognose / Leachate Forecast Soil water sampling device layer at 0,85m distance to upper edge of the lysimeter Soil water sampling device layer at 1,15m distance to upper edge of the lysimeter Soil water sampling device layer at 1,80m distance to upper edge of the lysimeter Saugkerzenebene / Soil water sampling device layer Time domain reflectometry van Genuchten Parameter vGP LIST OF FIGURES Figure 1: The unsaturated zone compares with the saturated zone Figure 2: Division of soil fraction sizes, German (left) and American (right) Figure 3: Dicretization / meshing of area to be modeled Figure 4: Boundary conditions and discetization of a simple model for groundwater flow (from Chris McDermott, 2003) Figure 5: Boundary conditions and discretization for a simple column model Figure 6: Stress applied to the top of the rock column causes deformation Figure 7: Mesh in details Figure 8: Pressing of the stainless steel bottom plate (left) and lifting of a readily filled monolithic lysimeter (right) Figure 9: Lysimeter covered with grass (left), the round surface of the Lysimeter (middle) and lysimeter cellar with complete instrument (right) Figure 10: The lysimeter system at the Büel measurement site Figure 11: Cross-section of a guideline lysimeter surrounded by a control plot Figure 12: The lysimeter station in Munich-Neuherberg Figure 13: The instrument for measuring the wind speed (right) and the rainfall (left)at lysimeter station Figure 14: Simplified sketch of the lysimeter and boundary conditions in the upper, lower and suction cup layers at lysimeter 302 in Juelich Figure 15: The schematic composition and the arrangement of measurement devices Figure 16: Structure of SiWaPro DSS Figure 17: Graphical user interface (GUI) of SiWaPro DSS Figure 18: SiWaPro DSS help system Figure 19: Search options for database access Figure 20: GeODin interface form for data import Figure 21: First start of the mesh generator Figure 22: Define the modeling domain 22 Ward R.C (1975), Principles of Hydrology, McGraw-Hill Book Company (UK) 23 Wösten J H M., Pachepsky Ya A & Rawls W J (2001), “Pedotransfer func- tions: bridging the gap between available basic soil data and missing soil hydraulic characteristics”, Journal of Hydrology, 251, p 123-150 24 Yaron B., Dagan G & Goldshmid J (1984), (edited), “Introductory Com- ments”, Pollutants in Porous Media – The Unsaturated zone between soil surface and groundwater, Springer-Verlag, Berlin, Heidelberg, New York and Tokyo 25 Muller J.C (1996), “un point sur trente ans de lysimétrie en France (1960- 1990)”, Une technique, un outil pour l’étude de l’énvironnement, INRA, editions, Comifer, Paris 78 STATEMENT UNDER OATH I hereby declare that this Master thesis is my own work with the assistance from my tutors and persons who are mentioned in the acknowledgements section And I only used sources listed in References th Hanoi, December 10 , 2008 Pham Thi Bich Ngoc 79 APPENDICES Appendix 1: Precipitation using for simulation Date (lys.operationday) 10/12/01 17/12/01 24/12/01 31/12/01 02/01/02 14/01/02 21/01/02 28/01/02 04/02/02 11/02/02 18/02/02 25/02/02 04/03/02 11/03/02 18/03/02 25/03/02 31/03/02 04/04/02 15/04/02 22/04/02 29/04/02 06/05/02 Date (lys.operationday) 13/05/02 21/05/02 27/05/02 03/06/02 10/06/02 17/06/02 24/06/02 01/07/02 08/07/02 15/07/02 22/07/02 29/07/02 05/08/02 12/08/02 19/08/02 26/08/02 02/09/02 09/09/02 16/09/02 23/09/02 30/09/02 07/10/02 14/10/02 21/10/02 28/10/02 04/11/02 Date (lys.operationday) 11/11/02 13/11/02 25/11/02 01/12/02 09/12/02 16/12/02 23/12/02 30/12/02 06/01/03 14/01/03 20/01/03 27/01/03 03/02/03 10/02/03 17/02/03 24/02/03 03/03/03 10/03/03 18/03/03 24/03/03 31/03/03 07/04/03 15/04/03 21/04/03 28/04/03 05/05/03 Date (lys.operationday) 12/05/03 19/05/03 26/05/03 02/06/03 10/06/03 16/06/03 23/06/03 30/06/03 07/07/03 16/07/03 21/07/03 28/07/03 04/08/03 11/08/03 18/08/03 25/08/03 01/09/03 09/09/03 15/09/03 22/09/03 29/09/03 09/10/03 13/10/03 20/10/03 27/10/03 03/11/03 Date (lys.operationday) 12/11/03 17/11/03 24/11/03 01/12/03 09/12/03 15/12/03 22/12/03 29/12/03 05/01/04 13/01/04 19/01/04 26/01/04 02/02/04 84 Appendix 2: Brief of output of simulation for 784 days Date 10/12/01 17/12/01 24/12/01 31/12/01 07/01/02 14/01/02 21/01/02 28/01/02 04/02/02 11/02/02 18/02/02 25/02/02 04/03/02 11/03/02 18/03/02 25/03/02 01/04/02 08/04/02 15/04/02 22/04/02 29/04/02 06/05/02 13/05/02 20/05/02 27/05/02 03/06/02 10/06/02 17/06/02 24/06/02 01/07/02 08/07/02 15/07/02 22/07/02 29/07/02 Date 05/08/02 12/08/02 19/08/02 26/08/02 02/09/02 09/09/02 16/09/02 23/09/02 30/09/02 07/10/02 14/10/02 21/10/02 28/10/02 04/11/02 11/11/02 18/11/02 25/11/02 02/12/02 09/12/02 10/12/02 16/12/02 23/12/02 30/12/02 06/01/03 13/01/03 20/01/03 27/01/03 03/02/03 10/02/03 17/02/03 24/02/03 03/03/03 10/03/03 17/03/03 24/03/03 31/03/03 07/04/03 Date 14/04/03 21/04/03 28/04/03 05/05/03 12/05/03 19/05/03 26/05/03 02/06/03 09/06/03 16/06/03 23/06/03 30/06/03 07/07/03 14/07/03 21/07/03 28/07/03 04/08/03 11/08/03 18/08/03 25/08/03 01/09/03 08/09/03 15/09/03 22/09/03 29/09/03 06/10/03 13/10/03 20/10/03 27/10/03 03/11/03 10/11/03 17/11/03 24/11/03 01/12/03 08/12/03 15/12/03 22/12/03 Date 29/12/03 05/01/04 12/01/04 19/01/04 26/01/04 02/02/04 88 Appendix 3: Data from measurement Date 04/04/02 06/05/02 03/06/02 08/07/02 12/08/02 09/09/02 14/10/02 13/11/02 16/12/02 14/01/03 17/02/03 18/03/03 15/04/03 12/05/03 16/06/03 16/07/03 11/08/03 89 Appendix 4: Data from simulation for the days equivalent with measurement days 90 ... numerical modeling of water flow and contaminant transport in variably saturated media with additional simulation and parameter estimation tools, data sources for the simulation and a graphical user... Generator Project Database Weather Generator DIN 4220 Database Simulation Module Pollutant Database Graphics Module Output Database Application layer Database layer Figure 16: Structure of SiWaPro. .. a variety of textural, compositional and hydraulic para44 meters Figure 19 shows a form with the search options available for database access Contaminant Databases The contaminant database was