| One of the solutions for current and future periods with an excess or shortage of water is the storage of water in flood control areas for example and in the case of high water, in the large rivers. In all of these cases, more room is needed for water (temporarily). As room is scarce, policymakers look for multiple use of the same areas, namely by combining water storage and nature. To implement these ideas, it is necessary to research the effects of inundation of surface water on terrestrial vegetation. The development of vegetation is influenced by many environmental factors. The abiotic conditions which eventually determine which type of vegetation will grow are called site factors. In 2003 and part of 2004 a literature study was conducted to determine the effects of flooding on site factors. At the moment, there is primarily only information available with regard to average situations. In other words, the relationships are based on conditions which occur during a long period (often 20 years). An important difference in the knowledge needed for the assessment of the effects of water storage is that in cases of water storage, it is not an average situation but more an occasional event. The collected knowledge in the literature study has been described in a concept article. In 2004 we also worked on the preparation of this knowledge in ecohydrological model systems, such as HABITAT. This was done in cooperation with the Sava-project. The objective of this study is to assess different flood control strategies for the Lonjsko Polje detention area with regard to safety against floods, ecosystem development and nutrient trapping. For these purposes, a vegetation succession model was developed. The methodology is based on ecohydrological knowledge rules demonstrating a relationship between the local inundation duration, land use and vegetation succession rate. Several flood control scenarios were explored to determine their effect on the vegetation development. This resulted in a recommendation for flood management of the central Sava river basin. Results are described in the article: Flood detention, nature development and water quality in a detention area along the lowland river Sava, Croatia. Furthermore, this project contributed to the EU 5th project ECOFLOOD by contributing to the guideline on how to combine water storage and flood control - Ecoflood -, towards natural flood reduction strategies. |
