Thursday 3rd of july- from 10:30 to 18:30
Session B6: River restoration: what lessons to be learned?
Water, Soil, Air: Regenerating Urban Ecosystems on the Jukskei River Green Corridor
STANDER Romy
South Africa
This poster abstract details the works of “Water For The Future” (WFTF), a citizen-led independent initiative demonstrating a scalable model for urban regeneration through ecological restoration and community empowerment along Johannesburg’s Jukskei River. Our visual centrepieces, isometric maps with key details, will vividly illustrate the project’s multi-faceted interventions across five distinct city blocks, from where the Jukskei river daylights, highlighting achieved successes and future ambitions that are scalable for impact.
Session B7 : Riparian environments. To revegetate or not to revegetate? That’s the question
Assessment of Riparian Ecosystems for Sustainable Management in the Face of Climate Change: A Practical and Interdisciplinary Approach
DOPIERALA Romain, FORET Arnaud, JOËT Océane, VERNAY Antoine, MOATAR Florentina, VALETTE Laurent, MAZAGOL Pierre-Olivier
France
Short abstract : Riparian ecosystems are vital for maintaining ecological balance, regulating water quality, and supporting biodiversity. However, these ecosystems are increasingly vulnerable due to climate change and anthropogenic pressures, which intensify water stress, alter hydrological regimes, and heighten the need for effective restoration and renaturation efforts. In response to these challenges, the SAGE Loire in the Rhône-Alpes region has advocated for interdisciplinary approaches to mitigate these threats and promote sustainable management. This project aims to assess the health and functionality of riparian vegetation, integrating spatial, ecological, and hydrological perspectives to inform restoration and management strategies in the face of climate change. By combining geomatics, ecology, and hydrology, the project will create a comprehensive interdisciplinary database and develop an index to characterize riparian vegetation. This index will incorporate GIS-based spatial mapping, ecological indicators of vegetation water stress, and hydrological data on water temperature, providing a holistic tool for effective riparian ecosystem management and restoration.
Byte and rates: multiple combinations of different remote sensing data for biogeomorphic interaction of river system
RUSNÁK Miloš, GOGA Tomáš, AFZALI Hamid, OPRAVIL Šimon, MICHALEJE Lukáš, MD Ashraf
Slovakia
Short abstract : River channels play a crucial role in maintaining landscapes by transferring energy, matter, and nutrients. Nowadays, modern fluvial geomorphology emphasizes the integration and complex understanding of the mutual relationship between river processes and floodplain ecology with an emphasis on riparian vegetation. For this study, the braided-wandering river system of the Belá River was selected for assessment. This river system is a rare and valuable wetland ecosystem affected by morphological degradation and incision. A combination of old historical aerial images (1949-2018) with 50 centimetres accuracy and modern low-resolution (10 meters) satellite data (from 2016) was used for the evaluation and monitoring of biogeomorphological interaction. For extraction of environmental variables (height above the channel, morphometry, vegetation cover), the study used surface and terrain elevation models derived from lidar data. The spatial extent of vegetation was automatically classified from historical black-and-white aerial imagery (1949-1992), RGB orthophotos (2002-2006) and RGB+NIR orthophotos (2009-2018). Monitoring and response to geomorphic adjustment were analysed based on vegetation and moisture indices were calculated from Sentinel-2 satellite data. The spatial distribution of vegetation and moisture indices was found to be independent of the distance from the channel, with notable differences observed across different channel platforms. Seasonal variations in vegetation and moisture indices followed the local hydrological conditions and the annual phenology curve.
Unlocking vegetation age estimation and the identification of biogeomorphic floods in a braided river
CRIVELLARO Marta, BELLETTI Barbara, ZOLEZZI Guido, PIEGAY Herve, BERTOLDI Walter
Italy
Short abstract : This study investigates the integration of remote sensing (RS) and cloud computing (CC) to estimate vegetation age and to gain insights on biogeomorphic floods in braided rivers, using the Tagliamento River, Italy, as a case study. A novel algorithm, implemented using Landsat Surface Reflectance and Sentinel-2 products on Google Earth Engine, reconstructs vegetation age dynamics at the pixel scale. Validation with field data and high-resolution imagery highlights spatial overestimations (15%) and temporal underestimations (7 years) due to RS limitations. The analysis of historical flood data reveals the role of low-recurrence interval floods in vegetation turnover and recruitment. Results provide insights into riparian vegetation dynamics and their interactions with hydrogeomorphic processes, underscoring the utility of RS in advancing riverine ecosystem studies.
Machine Learning for Long-Term Riparian Vegetation Monitoring Using Historical Aerial Imagery
AFZALI Hamid, RUSNÁK Miloš
Slovakia
Short abstract : The study evaluates a machine learning-based method for detecting spatial-temporal patterns in braided-wandering multichannel systems using historical aerial imagery, focusing on riparian vegetation.
Towards a panel of indicators for monitoring the alluvial wetlands of the Garonne river
QUINTIN Pauline, LE MÉTAYER Nolwenn, DAMIEN Alexianne, OLICARD Ludovic
France
Short abstract : As part of the multi-site management plan for alluvial wetlands led by the Nature En Occitanie association, one of the targeted actions is to develop a panel of monitoring indicators. The aim of this panel is to harmonise monitoring across the Garonne river and to propose reliable indicators that are easy to monitor over the long term and at an appropriate cost. The indicators allow to assess conservation management measures and the conservation status of key habitats. A bibliography of existing indicators applicable to the alluvial context served as a methodological basis. The monitoring objectives were then chosen according to the ecological and hydromorphological issues raised in the site diagnostics. This panel is currently made up of 14 indicators that meet 3 major monitoring objectives : to assess the state of conservation of alluvial forests ; to assess changes in the state of conservation of alluvial grasslands; and to assess changes in the state of conservation of fluvial appendages (aquatic and amphibious vegetation). A fourth objective, to assess changes in the hydromorphological parameters that influence alluvial environments, is currently being discussed with the partners, with the aim of integrating abiotic indicators into this panel.
Impact of river channelization structures on the floodplain vegetation state in a mountain river valleys
ZIELONKA Anna, HAJDUKIEWICZ Hanna, HAJDUKIEWICZ Maciej, WALUSIAK Edward
Poland
Short abstract : Riparian ecosystems are highly sensitive to anthropogenic disturbances, particularly river channel modifications, which alter hydromorphology and floodplain vegetation. Channelization and incision create drier floodplain conditions, favoring the dominance of invasive species while reducing native species diversity. As part of the project, we are studying the condition of riparian vegetation along both channelized and unmanaged river sections in the Polish Carpathians. Our findings indicate that the natural sections exhibit greater species diversity, denser vegetation, and a higher proportion of younger plant age classes. Channelized river sections experienced reduced flooding, which has allowed forests to reach a mature stage and increased the presence of invasive species that outcompete native ones. Multispectral UAV data indicated that invasive species exhibited higher NDRE (Normalized Difference Red Edge Index) values in early spring, stronger temperature correlations and resilience to precipitation variability, unlike native and non-native species, which depended on 20–30 days of cumulative rainfall. These findings highlight the adaptability of invasive species to hydrological and climatic changes in regulated rivers, with climate warming likely accelerating their spread. Restoring natural river channels and flooding regimes is critical to supporting riparian forest resilience and controlling invasive species.