Hydrological threats for riparian wetlands of international
importance – a global quantitative and qualitative analysis
Christof Schneider1, Martina Flörke1, Lucia De Stefano2, and Jacob D. Petersen-Perlman31Center for Environmental Systems Research, University of Kassel, Kassel, Germany 2Department of Geodynamics, Complutense University of Madrid, Madrid, Spain 3Department of Geography, Western Oregon University, Monmouth, Oregon, USA
Abstract. Riparian wetlands have been reportedly disappearing at an accelerating rate. Their ecological integrity as well as their vital ecosystem services for mankind depend on regular inundation patterns of natural flow regimes. However, river hydrology has been altered worldwide. Dams cause less variable flow regimes and water abstractions decrease the amount of flow so that ecologically important flood pulses are often reduced. Given growing population pressure and projected climate change, immediate action is required. Adaptive dam management, sophisticated environmental flow provisions, water use efficiency enhancement, and improved flood management plans are necessary for a sustainable path into the future. Their implementation, however, is often a complex task. This paper aims at identifying hydrological threats for 93 Ramsar sites, many of which are located in transboundary basins. First, the WaterGAP3 modeling framework is used to quantitatively compare current and future modified flow regimes to natural flow conditions. Results show that current water resource management seriously impairs riparian wetland inundation at 29 % of the analyzed sites. Further 8 % experience significantly reduced flood pulses. In the future, Eastern Europe, Western Asia as well as central South America could be hotspots of further flow modifications due to climate change. Second, impacts on riparian wetland flooding are qualitatively assessed. New dam initiatives in the upstream areas were compiled to estimate the potential for future flow modifications. They currently take place in one third of the upstream areas and are likely to impair especially wetlands located in South America, Africa, Asia and the Balkan Peninsula. Further qualitative results address the capacity to act for each site by evaluating whether upstream water resource availability and the existing legal and institutional framework could support the implementation of conservation measures.
Schneider, C., Flörke, M., De Stefano, L., and Petersen-Perlman, J. D.: Hydrological threats for riparian wetlands of international
importance – a global quantitative and qualitative analysis, Hydrol. Earth Syst. Sci. Discuss., doi:10.5194/hess-2016-350, in review, 2016.