Author(s): Tamas Kramer; Janos Jozsa
Linked Author(s): János Józsa
Keywords: Wetland; Numerical modelling; Storm surge; Flooding; Calibration
Abstract: The paper deals with a 100 ha wetland in an estuary of the capital area of Finland. The area has gone through major changes in the last decades due to land based and river borne nutrient loads, resulting in unfavourable living conditions for aquatic birds. In order to restore the overgrown areas, opening inner ponds and brook channels by dredging is planned, in combination with dam construction. A survey of geological, hydrological and hydrodynamic conditions in the wetland has been made as a basis for the planned measures. Numerical models were used to assess the impacts of the dredging work on the water exchange and water levels in the wetland. The hydrodynamic model calculates the wetting and drying as well as water exchange due to the sea level variations. A simplified water balance model estimates the long-term impacts of rainfall-runoff, evapotranspiration and infiltration. The paper presents results of planning scenarios, where alternative pond and brook channels have been designed, controlled by dams with various crest height.
Year: 2001