Comparing Past and Present Hydrologic Aspects of a Mediterranean Wetland from a Sustainable Management Perspective

Wetlands are significant examples of ecosystems with high biological diversity and ecological reserve. The quantity of water entering a wetland is a major driver that acts on the ecological state and proper functioning of the wetland ecosystem. Flows that contribute to the sustainability of aquatic habitats and water dependent ecosystem processes are often called environmental flows. There are a number of methods ranging from simple hydrologic assessments to holistic approaches for assessing ecosystem requirements and corresponding environmental flow quantities. These mainly differ by approach rationale, data requirements, addressed ecosystem type, computation time and prediction accuracy. This study introduces a methodological framework for assessing environmental flow potential of a river system with reference to natural hydrologic alteration in river hydrology and probable anthropogenic impacts arising from built-in storage and regulation facilities. It is principally aimed to guide water managers in making decisions for allocating water between the competing economic sectors as well as the environment itself for securing sustainable management. The method is applied to a significant Ramsar wetland selected from the Mediterranean transect of Turkey. The results given in terms of the deficit/surplus rates for the environmental flow potential in the river indicate that the change naturally experienced in hydrologic conditions presents a positive appearance with increased potential for environmental allocations. However, this view is completely reversed in the post-damming period as the storage and regulation effects of an operating dam significantly contribute to decrease in the environmental flow potential, while exacerbating the competition for water in the area.