SOIL EROSION AND FLOOD MITIGATION IN CZ AND UK - COMPARISON, DISCUSSION AND LESSON LEARNED

Abstract

Both the United Kingdom as well as Czech Republic have seen increased impacts due to flooding in recent years. Rural flooding is due to intense and heavy rainfall-runoff events. Runoff brings with it soil erosion and sediment transport, so called ‘muddy floods,’ which causes serious onsite and offsite damages in the landscape or even in settlement area and infrastructure. Long-term observation and measurement is crucial step for understanding of complexity of processes involved in the generation of muddy floods and a requirement for and further calibration and validation of predictive models. In addition, such flooding has a significant impact to the agricultural in both countries. There are differences in initial conditions but similarities in consequences, which leads to degradation of sources (soils) and costs in billions EUR each year. Both countries are investing in research and three complementary projects are highlighted here, as examples. The ‘Quantifying the likely magnitude of nature-based flood mitigation effects across large catchments (Q-NFM)’ project funded by the UK Natural Environment Research Council is dealing with the question “How much can natural measures reduce flooding at large scales?”. The project includes direct measurement of landscape management effect to inform modelling, which can then be used to assess of flood protection and landscape management methods. Mitigation measures may have a synergistic effect and significantly lower the soil erosion and sediment transport, risk of drought or even floods. Modelling of these risks and scenarios of protection has been one of goals of two projects within Czech Rep. First is called Saxon-Czech flood risk management where soil erosion, sediment transport and scenarios of protection on 150km2 catchment is evaluated. Second is called “Erosion losses - increased risk to the inhabitants and water quality” where large scale risk assessment of flash floods was carried out and 150,000 potential risk points identified over area of 79,000 km2.