Spatial pattern dynamics in aquatic ecosystem modelling
On 29 June 2009, Mrs. Hong Li from China successfully defended her PhD thesis and was awarded the doctoral degree cum laude. The PhD research focused on “spatial pattern dynamics in aquatic ecosystem modelling”. Aquatic ecosystems are sensitive to rapid economic development, urbanisation, population growth, and effects of climate change.
This is why e.g. the United Nations Millennium Development Goals and the EU Water Framework Directives are putting emphasis on ensuring environmental sustainability through improved water resources management. In her doctoral research, Mrs. Hong Li showed that Environmental Hydroinformatics tools can contribute greatly to assessing potential impacts and optimising effects of measures.
Modelling approaches
Spatial pattern dynamics can be considered an indicator of the changes occurring inside aquatic ecosystems. In the thesis several modelling approaches are explored to reproduce the proper spatial pattern behaviour at different spatio-temporal scales. A wide range of modelling tools, data-analysis techniques and knowledge-based systems were developed and combined in various ways. It is shown that spatial information from Remote Sensing images can greatly enhance the resolution of harmful algal bloom prediction in open seas. Also, the combination of Cellular Automata and high resolution photographs proved a good approach in accurately representing aquatic plant growth in a confined pond.
Fig.2 Comparisons of chlorophyll-a concentration from RS images with the results from original GEM and GEM model with RS data as input
Fig. 3 Cellular Automata modelling result vs. high resolution photo
Multi-Agent Systems approach
A newly emerged Multi-Agent Systems approach was applied to modelling the interactions between different outcompeting species in shallow lakes. The spatial patterns observed in the field were captured very well.
Fig. 4 GIS density maps vs. Multi-agent system modelling result
Coherent Modelling Framework
A cross-disciplinary synthesis framework was introduced in the thesis, linking physical, chemical, and biological/ecological processes into a coherent modelling framework, as a first step towards a next generation system in aquatic ecosystem modelling. In this way, environmental hydroinformatics can contribute to advancing science and engineering, and help achieving sustainable environmental management strategies.
The defence was held in accordance with the rules and regulations of Delft University of Technology and took place at UNESCO-IHE. Mrs. Li’s promoter was Professor Arthur Mynett of UNESCO-IHE/TU Delft. For Professor Richard Meganck, Vice-Chairman and Rector of UNESCO-IHE this was the last promotion before his retirement.