Assessment of Suitable Flood Mitigation Measures in Tbilisi

This Technology Transfer Advances Georgia's

• Nationally Determined Contribution to improve country’s preparedness and adaptive capacity by developing climate resilient practices that reduce vulnerability of highly exposed communities. Establishment of Early warning systems for climate related extreme events is considered as priority measure by the Government of Georgia.

Context

Flash floods and mudflows occurring on small rivers as a result of heavy rains impact various parts of Tbilisi, causing heavy damage and/or human casualties. Recommendations are needed in order to determine appropriate actions to prevent disastrous consequences of possible floods of the Dukniskhevi River within Tbilisi, as part of climate change adaptation.

Requested CTCN Response

• Rainfall runoff hydrological modelling of Dukniskhevi River catchment, based on analogical extreme rainfall from 2015 Vere River disastrous flood (neighbouring catchment)
• Hydrodynamic modelling of extreme flood water levels for analogical hydrological situation of June 2015 Vere River disaster
• Detailed field surveys and topographical measurements for parameters and data needed for both hydrological and hydraulic modelling 
• Detail flood mapping – production of flood hazard and flood risk maps of Dukniskhevi River floodplains in Tbilisi 
• Calculation and evaluation of necessary parameters of hydraulic structures as for example bridges, piped sections and tunnels, their hydraulic capacity and hydraulic performance
• Recommendations for eventual establishment of regular hydro-meteorological observations and monitoring 
• Proposal for preventive measures (one of which could be flood forecasting and warning system) to prevent or mitigate further flood disasters 
• Training and technology transfer to relevant Georgian institution personnel, which will allow to perform similar hydrological and hydrodynamic modelling analyses

Relevant Technologies and Approaches

• Flood hazard mapping
• Hydrological modelling
• Flood forecasting system

Expected Results

• Appropriate contingency planning for extreme flood events, based on actual flood risk maps
• Planned measures for extreme flood adaptation 
• Proper spatial and land development planning, based on flooding maps, that will help to mitigate flood risk 
• Transferred technology (modelling software) and modelling technique skills of trained personnel will enable future management of flood risk and modelling of various flood scenarios and land development scenarios