MSc thesis topic: Monitoring wetland changes in recent years using Sentinel 1 and 2 data

To protect wetland ecosystem, the 1971 Ramsar Convention aims to support the maintenance of wetland ecology. To maintain wetlands ecological functions as well as food security functions, spatially explicit information on wetland distribution and extent is vital. It is further needed for a variety of purposes from regional wetland and biodiversity management to understanding wetland roles on climate change at continental or global scales.

Remote sensing provides opportunities to characterize and monitor wetland areas and many studies previously attempted to characterize wetland areas at different scales. However, there are considerable uncertainty about their distribution and extent as existing wetland area estimations at large scales differ significantly while increasing the uncertainty of its effect on climate change.

Wetland areas can have different types of natural vegetation such as grassland, shrubs and forests and it can differ in terms flooding frequency such as waterlogged or regularly flooded. While different vegetation types can be mapped with optical remote sensing data, flooding frequency can be better mapped using radar data.

ESA’s Sentinel satellite program has significant potential uses. The Sentinel-1 satellite includes a radar system with the capability of collecting cloud-free water- and moisture-specific data. Sentinel-2 incorporates a fine spatial resolution 10-meter multispectral sensor and will orbit with a short, five-day revisit time. The combination of these radar and optical systems holds great promise for wetland mapping, particularly in monitoring changes in wetland areas.

Building up on the work of Slagter et al (2020), different wetland areas will be characterized using Sentinel 1 and 2 data and then the yearly variations in wetlands areas will be monitored. The study will be done in Santa-Lucia wetland area in South Africa.

Objectives

• To monitor recent changes in wetland areas in St Lucia wetlands, South Africa

Literature

• Esther Amler, Michael Schmidt and Gunter Menz: Definitions and Mapping of East African Wetlands: A Review
• Slagter, B., Tsendbazar, N.-E., Vollrath, A., & Reiche, J. (2020). Mapping wetland characteristics using temporally dense Sentinel-1 and Sentinel-2 data: A case study in the St. Lucia wetlands, South Africa. International Journal of Applied Earth Observation and Geoinformation, 86, 102009

Requirements

• R and GEE scripting skills

Theme(s): Integrated Land Monitoring