Mapping of land cover/ use changes for the evaluation of ecosystems and their services in the Mediterranean River catchments, (W. Greece)

Rivers provide direct benefits to human wellbeing by supporting a number of regulating, provisioning and cultural ecosystem services. However, human activities have altered river ecological integrity especially, in the Mediterranean region, mainly through the effects of land cover/ use (LCLU) changes, global climate change, and biodiversity. Thus, understanding and predicting response of rivers to LCLU changes is critical for managing aquatic resources and ecosystem services. During recent decades, agricultural practices and hydromorphological alterations have impacted the natural river ecosystems and the adjusted land of Western Greece. In the current research an integrated approach for assessing the impact of human intervention to river landscapes of W. Greece was conducted by incorporating different aspects of ecological integrity such as habitat quality, species biodiversity, and trophic status. The proposed analysis focuses on the use of the normalized difference vegetation index (NDVI), which represents one of the most sensitive landscape components to environmental degradation. Landsat-TM imagery, air photos and remote-sensing techniques for detecting the spatiotemporal dynamic patterns of LCLU changes, were applied. The utmost goal of the study was the examination of the degree in which LCLU changes affect the ability of the riverine ecosystems to deliver ecosystem services. We used as appropriate ecosystem services indicators for ecosystem condition assessment; water chemistry (pH, conductivity, dissolved oxygen), nutrients of nitrogen and phosphorus, as well as for the overall ecological quality assessment (WFD 2000/60/EC) as Key indicators the presence/ abundance of macrophyte species, the total number of taxa; the invasive species; and IBMR trophic index. Our aim was to gain understanding of natural driven mechanisms causing changes to the riparian ecosystems and water quality of the area. The current research provided a methodological reference to map ecosystem services, through applying remote sensing and assessment of ecological status of the water /riparian area which are of great importance to sustainable use of the riparian landscape and to halt the loss of biodiversity. The results from the spatio-temporal analysis show that during recent decades the LCLU changes were associated with human activities that have changed the river beds, increased landscape fragmentation, and led to the degradation and loss of wetland habitats. Land use disturbances in the catchment’s area are more intense in the riparian buffer zone, with maximum habitat integrity recorded in the upper river reaches. Monitoring and evaluating the ecosystem service function and its changes could contribute to better understanding the human-environment interaction and support decision-making for regional ecological protection and restoration programs.