Promoters Prof. Dr. ir Peter Goethals Laboratory of Environmental Toxicology and Aquatic Ecology Department of Applied Ecology and Environmental Biology Dr. Pieter Boets Laboratory of Environmental Toxicology and Aquatic Ecology Department of Applied Ecology and Environmental Biology Dean Prof. dr. ir. G. Van Huylenbroeck Rector Prof. Dr. P. Van Cauwenberge M.Sc. Javier Ernesto Holguin Gonzalez Integrated ecological modelling for decision support in river management Thesis submitted in fulfilment of the requirements for the degree of Doctor (PhD) in Applied Biological Sciences Dutch translation of the title: Geïntegreerde ecologische modellering voor beslissingsondersteunend rivierbeheer. Please refer to this work as follows: Holguin-Gonzalez, J.E., 2013. Integrated ecological modelling for decision support in river management. PhD thesis, Ghent University, Ghent, Belgium. ISBN-number: 978-90-5989-640-6 This research was supported by an exchange funding from the European Union Alfa Project, the WATROPEC Project of the Flemish Government and the Special Research Fund of Ghent University (BOF01/WI0/611 and BOF09/24J/092) in Belgium. The author and the promoters give the authorisation to consult and copy parts of this work for personal use only. Every other use is subject to the copyright laws. Permission to reproduce any material contained in this work should be obtained from the author. Acknowledgements First of all I would like to thank my promoters, Prof. Dr. ir. Peter Goethals and Dr. Pieter Boets at the Laboratory of Environmental Toxicology and Aquatic Ecology at Ghent University in Belgium for their support and guidance during this research. Doing research is only possible when there are enough financial means. Therefore, I am very grateful to the representatives of the ALFA Programme “Latin-American – European Partnership For Water Education And Training (WETNET)”, the Program “Master grants for candidates from developing countries”, for their support of my studies in the Master program in Environmental Sanitation and my thesis research. Moreover, I like to thank the Research Unit of Aquatic Ecology that funded me via the WATROPEC Project of the Flemish Government, and the Special Research Fund of Ghent University (BOF01/WI0/611 and BOF09/24J/092) in Belgium. In Colombia, I would like to thank the Environmental Technical Direction of the Environmental Authority in the Cauca Region (CVC), the Natural Resources and Environmental Engineering School of the Universidad del Valle (EIDENAR-Univalle), the Cauca River Modelling Project (CRMP) and Cinara Institute in Colombia, for the information, which was used to develop the research presented in this document. Special thanks are given to my friends and colleagues in the CRMP where I learned to love modelling. In Belgium and Ecuador, I would like to thank the Flemish Interuniversity Council – University Development Cooperation VLIR-UOS and the Programs VLIR- IUC Cuenca and VLIR SRS, for financing this research in the framework of the Project South-South mobility allowances. Additionally, I would like to thank the Universidad de Cuenca and ETAPA in Ecuador for the opportunity to study their samples. I thank Prof. Gregory J. Pelletier for his valuable suggestions on how to use the software QUAL2Kw and the engineer Sandra Barros from ETAPA for her support in this study. In Croatia, I would like to thank the Water Supply and Sanitation Company in the city of Varaždin in Croatia (VARKOM) for the opportunity to study their samples, the company ECO-TEHPROJECT in Croatia and the WATROPEC Project. i Finally, I would like to thank my wonderful parents for their love and their unconditional support during these long years, who always believed in and supported my choices in life. I cannot forget to say thanks to my friends and colleagues at the Laboratory of Aquatic Ecology in Ghent University. Moreover, my friends in Ghent from different nationalities, with whom I shared the huge pile of extra-ecological knowledge, in particular related to culture, gastronomy, religion, psychology, politics and of course dancing. Thank you guys for your company, good ideas and for your enormous support. ii Contents Table of contents Chapter 1: General introduction 1.1 Research context.........................................................................................................1 1.2 Problem definition......................................................................................................5 1.3 General objective and scope.......................................................................................6 1.4 General methods.........................................................................................................6 1.5 Summary of content..................................................................................................12 Chapter 2: State-of-the-art of integrated ecological modelling of rivers and decision support in river management 2.1 River water quality problems and water quality regulation….................................13 2.2 Integrated ecological river assessment.....................................................................14 2.2.1 Hydromorphological quality...........................................................................14 2.2.2 Physicochemical water quality........................................................................15 2.2.3 Biological water quality..................................................................................17 2.3 Mathematical modelling...........................................................................................22 2.4 Major types of river system models..........................................................................24 2.4.1 Hydraulic modelling........................................................................................24 2.4.2 Physicochemical water quality modelling.......................................................26 2.4.3 Ecological river assessment and river species distribution modelling............29 2.4.3.1 Ecological river assessment..................................................................30 2.4.3.2 River species distribution modelling....................................................31 2.5 The need for an integrated data collection and an integrated ecological modelling approach for decision support in river management.................................................33 2.6 Model uncertainty......................................................................................................36 Chapter 3: Case study 1: Integrated ecological modelling to analyze the impact of wastewater discharges on the ecological water quality of the Cauca river in Colombia 3.1 Introduction..............................................................................................................40 3.2 Materials and methods..............................................................................................43 3.2.1 Study area…....................................................................................................43 3.2.2 Data collection, coupling of data and dataset pre-processing.........................44 3.2.3 Water quality assessment................................................................................46 3.2.4 Water quality modelling techniques................................................................47 3.2.4.1 River water quantity and quality model.............................................48 3.2.4.2 River habitat suitability and ecological assessment models...............49 3.2.5 Simulation of pollution control scenarios.......................................................52 3.3 Results....................................................................................................................54 3.3.1 Water quality assessment and river water quality modelling..........................54 3.3.2 River habitat suitability and ecological assessment models............................54 3.3.3 Integrated ecological modelling and scenario assessment...............................58 3.4 Discussion..............................................................................................................62 3.4.1 Habitat preference and ecological water quality.............................................62 3.4.2 Model performance, uncertainty and validation..............................................63 3.4.3 Implementation of pollution control scenarios................................................65 3.4.4 Evaluation of the integrated ecological modelling framework........................66 3.5 Conclusions............................................................................................................67 iii Contents Chapter 4: Case study 2: Integrated ecological modelling for decision support in the water management of the Cuenca river in Ecuador 4.1 Introduction..............................................................................................................71 4.2 Materials and methods.............................................................................................72 4.2.1 Study area........................................................................................................72 4.2.2 Data collection, coupling of data and dataset pre-processing.........................74 4.2.3 Water quality modelling techniques used........................................................75 4.2.3.1 Hydraulic and physicochemical water quality model.........................76