The improvement of the conceptual hydrological model METQ with the urban hydrological response unit and GHG emission modelling = Konceptuālā hidroloģiskā modeļa METQ pilnveide urbānās hidroloģiskās atbildes vienības izveidei un SEG emisiju modelēšanai

Abstract

More than half of the world's population live in urban areas. Increasing population and urbanisation levels make it more and more likely to think about the management of sustainable resources, including water, and adaptation to climate change. Changing the use of land, particularly urbanisation, has a significant impact on hydrological processes. Urban areas not only create additional pollution pressures and reduce water resources, but also build water supply and sewer infrastructure and develop flood protection systems. In the EU, flood risk mitigation measures are set out in Flood Directive 2007/60/EC, which requires Member States to carry out flood risk assessments and mapping of endangered areas. Awareness of the hydrological regime of urban areas is currently being developed and developed using monitoring data and modelling capabilities, but at least two decades of hydrological daily observation data is needed to use modelling tools. The modelling of the hydrological processes of the urban catchment areas is complicated due to the fragmented environment, the specific hydrological regime and the rain regime in the urban environment. In the world, hydrological models are often used in the modelling of ecological components. In the context of the Paris Agreement and the European Green Deal, it is necessary to develop modeling capabilities for GHG emissions in Latvia. In the research, it is hypothesised that the urban hydrological response unit can be integrated into the conceptual hydrological model METQ, and the conceptual hydrological model METQ can be used to simulate GHG emissions from soils. The aim of the study is to improve the conceptual hydrological model METQ by integrating the urban hydrological response unit and to prepare a database and conceptual solution for modelling GHG emissions from soils using the hydrological calculation included in the conceptual hydrological model METQ of the active layer of soil, groundwater and the associated capillary take-off layer. Theoretical research provide an in-depth insight into the changes in hydrological cycle components in urban environments, as well as the theoretical basis for the development of various modeling algorithms in urban hydrological response units. In addition, GHG modelling capabilities have been analysed using hydrological models enabling the development in the near future of nitrous oxide, carbon dioxide gas and methane modeling tools that will allow the methodology for calculating GHG emissions to go to the Tier3 approach (national models on GHG emissions), which takes into account regional, climatic and geomorphological conditions. A practical role in the modelling of hydrological processes is provided by the urban hydrological response unit built into the conceptual hydrological model, which allows the model to be used to address complex water management issues, such as the cumulative impact quantification of climate change and land use patterns, thereby providing a theoretical basis for the renewal of regulatory frameworks regulating hydrotechnical structures, which include: adaptation to climate change. The developed conceptual solutions to modelling GHG emissions from soils allow for the development of a modelling tool that will allow the assessment of soil GHG emissions and the assessment of the effectiveness of various soil-reducing GHG emissions measures, as well as the carrying out of a complex assessment of the soil GHG emissions balance.