Document Type : Original Research Article
Department of Water Engineering and Management, Tarbiat Modares University, Tehran, Iran
Department of Biodiversity and Ecosystem Management, Environmental Sciences Research Institute, Shahid Beheshti University, Tehran, Iran
Department of Physical Geography, Faculty of Earth Sciences, Shahid Beheshti University, Tehran, Iran
River ecosystems face numerous human pressures that can lead to certain impacts on the environment. However, there is limited information available regarding the prevalence, spatial patterns, mutual impacts, and simultaneous occurrences of these pressures. In this study, we aimed to identify and assess various types of human pressures at different scales within the Talar River catchment. In this regard, a total of 43 sites within the Talar River catchment were selected for investigation. We employed a comprehensive approach by selecting 30 key indicators that represent major human pressures on river ecosystems. These indicators were combined to create a pressure index. The findings revealed that 93% of the studied sites experienced land use pressure, indicating significant human modification in those areas. Additionally, 69% of the sites were subjected to connectivity pressure, 88% to morphological pressure, 86% to water quality pressure, and 41% finally exhibited hydrological pressure. Importantly, our analysis also revealed complex interactions between multiple human pressures. Approximately 8.4% of the sites were affected by two distinct human pressures, while 2.3% experienced three overlapping pressures. Moreover, an overwhelming majority (92%) of the sites were impacted by combinations of more than three human pressures, emphasizing the cumulative impacts of all pressures. These findings underscore the need for comprehensive and systematic consideration of multiple factors when undertaking integrated river basin management and restoration efforts. In other words, effective management and restoration strategies should account for the different scales within the catchment and address the specific combinations of human pressures present.