Aim: Understanding the relative importance of climatic and non‐climatic distribution drivers for co‐occurring, functionally similar species is required to assess potential consequences of climate change. This understanding is, however, lacking for most ecosystems. We address this knowledge gap and forecast changes in distribution for habitat‐forming seaweeds in one of the world's most species‐rich temperate reef ecosystems.Location: The Great Southern Reef. The full extent of Australia's temperate coastline.Methods: We assessed relationships between climatic and non‐climatic environmental data known to influence seaweed, and the presence of 15 habitat‐forming seaweeds. Distributional data (herbarium records) were analysed with MAXENT and generalized linear and additive models, to construct species distribution models at 0.2° spatial resolution, and project possible distribution shifts under the RCP 6.0 (medium) and 2.6 (conservative) emissions scenarios of ocean warming for 2100.Results: Summer temperatures, and to a lesser extent winter temperatures, were the strongest distribution predictors for temperate habitat‐forming seaweeds in Australia. Projections for 2100 predicted major poleward shifts for 13 of the 15 species, on average losing 78% (range: 36%–100%) of their current distributions under RCP 6.0 and 62% (range: 27%–100%) under RCP 2.6. The giant kelp (Macrocystis pyrifera) and three prominent fucoids (Durvillaea potatorum, Xiphophora chondrophylla and Phyllospora comosa) were predicted to become extinct from Australia under RCP 6.0. Many species currently distributed up the west and east coasts, including the dominant kelp Ecklonia radiata (71% and 49% estimated loss for RPC 6.0 and 2.6, respectively), were predicted to become restricted to the south coast.Main conclusions: In close accordance with emerging observations in Australia and globally, our study predicted major range contractions of temperate seaweeds in coming decades. These changes will likely have significant impacts on marine biodiversity and ecosystem functioning because large seaweeds are foundation species for 100s of habitat‐associated plants and animals, many of which are socio‐economically important and endemic to southern Australia.

Flooding is the most widespread hydrological hazard worldwide that affects water management, nature protection, economic activities, hydromorphological alterations on ecosystem services, and human health. The mitigation of the risks associated with flooding requires a certain management of flood zones, sustained by data and information about the events with the help of flood maps with sufficient temporal and spatial resolution. This paper presents the potential use of the Sentinel-1 SAR (Synthetic Aperture Radar) images as a powerful tool for flood mapping applied in the event of extraordinary floods that occurred during the month of April 2018 in the Ebro (Spain). More specifically, in this study, we describe accurate and robust processing that allows real-time flood extension maps to be obtained, which is essential for risk mitigation. Evaluating the different Sentinel-1 parameters, our analysis shows that the best results on the final flood mapping for this study area were obtained using VH (Vertical-Horizontal) polarization configuration and Lee filtering 7 × 7 window sizes. Two methods were applied to flood maps from Sentinel-1 SAR images: (1) RGB (Red, Green, Blue color model) composition based on the differences between the pre- and post-event images; and (2) the calibration threshold technique or binarization based on histogram backscatter values. When comparing our flood maps with the flood areas digitalized from vertical aerial photographs, done by the Hydrological Planning Office of the Ebro Hydrographic Confederation, the results were coincident. The result of the flooding map obtained with the RADAR (Radio Detection and Ranging) image were compared with the layers with different return periods (10, 50, 100, and 500 years) for a selected zone of the study area of SNCZI (National Flood Zone Mapping System in Spain). It was found that the images are consistent and correspond to a flood between 10 and 50 years of return. In view of the results obtained, the usefulness of Sentinel-1 images as baseline data for the improvement of the methodological guide is appreciated, and should be used as a new source of input, calibration, and validation for hydrological models to improve the accuracy of flood risk maps.