Assessing wetland conservation action effectiveness in the Mekong Delta with Sentinel-1 Synthetic Aperture Radar data

Abstract Concerns about the effectiveness of nature conservation efforts have led to the adoption of evidence-based approaches and more rigorous evaluation methods. This is especially relevant to wetlands, which are crucial for ecosystem services and face global threats from human actions. In the present study, 10-m Sentinel-1 synthetic aperture radar (SAR) data, which provide global coverage regardless of cloud cover, are used to assess the effectiveness of wetland restoration activities which aim to promote wetter conditions. These were carried out during 2022-2024 in the Boeung Prek Lapouv area (Mekong delta, Cambodia). A method was developed to separate SAR signals from the dry and wet seasons to infer variations in groundwater level and wetness retention. Analysis of these signals showed that interventions were effective to varying degrees with the construction of new pools, the lowering of grounds and blocking of ditches being the most impactful.