Hydrological water quality modelling of nested meso scale catchments Von der Fakultät Architektur, Bauingenieurwesen und Umweltwissenschaften der Technischen Universität Carolo-Wilhelmina zu Braunschweig zur Erlangung des Grades eines Doktoringenieurs (Dr.-Ing.) genehmigte Dissertation von Sanyuan Jiang geboren am 04. November 1983 in Hubei, China Eingereicht am: 14.02.2014 Disputation am: 10.04.2014 Berichterstatter: Prof. Dr.-Ing. Günter Meon PD Dr. Michael Rode 2014 Acknowledgment The objectives of this research project would not have been met without the support of several people. Thus, here I would like to express my gratitude for many interesting comments and suggestions as well as for the encouragement I have received during my thesis in connection with the data analysis and the model application. Most importantly, I would like to thank my supervisor PD Dr. Michael Rode from Department Aquatic Ecosystem Analysis and Management, Helmholtz Centre for Environmental Research-UFZ for his strong encouragement, support and especially for his endless patience in discussing the results and improving my writing. His guidance, remarks and critical comments on my work have played a crucial role in both the contents and presentation of this thesis. Moreover, the regular intensive scientific discussion significantly improved my physical understanding of the water and nutrient transport processes at catchment scale and helped foster the development of a scientific attitude in my work. Finally, I am deeply thankful to Dr. Rode for his continual help, understanding and for his belief in me. I would also like to give thanks to my supervisor Professor Günter Meon from Leichtweiß-Institute for Hydraulic Engineering and Water Resources, Technische Universität Braunschweig for his expertise and interest in my work and support on my thesis. His useful comments and feedbacks on the results of this study were beneficial to the project. Additionally, I want to express my thanks to Professor Dietrich Bor- chardt from Department Aquatic Ecosystem Analysis and Management, Helmholtz Centre for Environ- mental Research-UFZ for his interest and support on my work. For excellent collaboration and scientific discussions and, even more, for their friendship, I would like to thank my colleagues Dr. Seifeddine Jomaa and Dr. Olaf Büttner. I shall not forget my colleagues at the group hydrological and water quality modelling for their technical support and guidance. Moreover, I would like to extend my gratitude to the secretary, Martina Klapputh, for the facilities and helps that she gave me during my study. I would also like to thank my colleagues Philipp Theuring and Melanie Hartwig, Dr. Muhammad Rehan Anis, Gundula Paul, Andrew Kaus, Julia Vanessa Kunz for their friendship and the constructive atmos- phere created in the office. I shall not forget my colleague and friend Dr. Sumit Sinha for the interesting discussions and help on improving my English writing. Finally, I would like to express my thanks to my family and my wife’s family, especially to my wife Xia Chen for their consideration and support on my life. i Tables of contents Acknowledgment............................................................................................................................................ ii Zusammenfassung .......................................................................................................................................... v Abstract ........................................................................................................................................................ vii Chapter 1: Introduction ................................................................................................................................. 1 1.1 Problem statement ............................................................................................................................. 1 1.2 State of art ......................................................................................................................................... 2 1.2.1 Hydrological and nutrient transport processes ................................................................................. 2 1.2.2 Hydrological water quality modeling ............................................................................................... 5 1.2.3 Applicability of hydrological water quality models ........................................................................ 8 1.2.4 Model calibration and uncertainty analysis ...................................................................................... 9 1.2.4.1 Uncertainty sources ....................................................................................................................... 9 1.2.4.2 Model calibration and uncertainty analysis methods .................................................................. 13 1.2.5 Step-wise calibration vs. multi-objective calibration ..................................................................... 17 1.2.6 Effects of spatial and temporal resolution of calibration data on model identification .................. 18 1.3 Knowledge gaps .............................................................................................................................. 20 1.4 Objectives ........................................................................................................................................ 22 1.5 Structure of Dissertation .................................................................................................................. 22 Chapter 2: Materials and Methodologies ................................................................................................... 25 2.1 Selke catchment ............................................................................................................................... 25 2.2 Weida catchment ............................................................................................................................. 29 2.3 Hydrological water quality model (HYPE) ..................................................................................... 31 2.3.1 Hydrological processes ................................................................................................................... 33 2.3.2 Nitrogen processes ......................................................................................................................... 36 2.3.3 Input data ........................................................................................................................................ 38 2.3.4 Model parameter set and parameterization ..................................................................................... 39 2.4 Model calibration and uncertainty analysis approaches .................................................................. 41 2.4.1 PEST ............................................................................................................................................... 41 2.4.1.1 Parameter estimation .................................................................................................................. 41 2.4.1.2 Sensitivity analysis ...................................................................................................................... 41 2.4.1.3 Predictive analysis ...................................................................................................................... 42 ii 2.4.2 DREAM(ZS) ..................................................................................................................................... 42 2.5 Model setup and evaluation ............................................................................................................. 44 2.5.1 HYPE model set up ........................................................................................................................ 44 2.5.1.1 Model setup at Selke catchment .................................................................................................. 44 2.5.1.2 Model setup at Weida catchment ................................................................................................. 44 2.5.2 Model performance evaluation ....................................................................................................... 45 2.5.2.1 Inorganic nitrogen loads calculation .......................................................................................... 45 2.5.2.2 Model performance evaluation criteria ....................................................................................... 45 2.6 Multi-site and multi-objective calibration ....................................................................................... 47 2.7 Step-wise calibration and multi-objective calibration ..................................................................... 47 2.8 Effects of spatial and temporal resolution of calibration data on model identification ................... 48 2.8.1 Single-site vs. Multi-site calibration............................................................................................... 48 2.8.2 Bi-weekly vs. Daily IN measurements ........................................................................................... 49 Chapter 3: Multi-site and multi-objective calibration of integrated catchment model HYPE .................... 51 3.1 Model calibration, hydrological and IN simulation results at Selke catchment .............................. 51 3.1.1 Model parameter calibration