This 2-year project (2022-2024), funded by a H2020 Marie Skłodowska-Curie Individual Fellowship (H2020-MSCA-IF-2019), employed novel remote sensing methodologies based on freely available optical and radar satellite data, to map and monitor the fractional woody cover over South African savannah regions. The main researcher/fellow working for the project was Dr Christina Karakizi supervised by Dr Elias Symeonakis at the host institute of Manchester Metropolitan University.

​

Drylands cover approximately 40% of the land surface of the Earth and support roughly one-third of the global human population. The savannah biome in particular covers 50% of the African continent and 20% of the global land surface, while also representing around a third of terrestrial net primary production, and comprising a critical regulating component of the land carbon sink. Over the last decades, savannahs have been under pressure from human activities, exacerbated by climate change, with dramatic shifts in vegetation distribution and, consequently, alterations of their function, threatening the ecosystem services provided to some of the continent’s most vulnerable populations. Therefore, monitoring the process and evolution of land degradation in these ecosystems is considered of great importance for the scientific community, regional and national governments, as well as international organizations and institutions, such as the United Nations Convention to Combat Decertification (UNCCD). 

​

​

​

 

 

 

 

 

 

 

 

 

 

 

 

 

 

​​​​

​

Land degradation in savannahs has often been associated with the encroachment or densification of its woody component at the expense of grasses. Savannahs in Africa are vital ecosystems that support millions of pastoralists whose livelihoods are increasingly threatened by woody encroachment. This encroachment involves the proliferation of bushes that displace palatable grasses, leading to significant economic hardship. Pastoralists not only lose livestock due to the reduced availability of grazing land but also incur substantial costs in managing the encroached land and attempting to halt the progression of this encroachment.

 

​​​

​

​

​

​

​

​

​

​

​

​

​

​

​

Monitoring the woody component of savannah land cover is, therefore, needed to enhance the understanding of broad-scale changes in savannahs and their relationship with ecosystem degradation. Over large scales, this can only be achieved in a cost-effective manner using Earth Observation (EO) technologies. The development of the Horizon 2020 SAV-EO project employed novel remote sensing methodologies based on freely-available EO optical and radar satellite data for the mapping and monitoring of fractional woody cover over South African savannah regions.

 

The specific objectives and final contributions of the SAV-EO project were:

1. Development of a pipeline that monitors bush encroachment over South African (SA) savannah environments through accurately mapping of fractional woody vegetation cover and its progress across the years, employing satellite optical (Landsat, Sentinel-2) and SAR (Sentinel-1) data.

2. Development of a pipeline that monitors bush encroachment at the species level over SA savannah environments through accurately mapping of fractional woody vegetation cover at the species level, employing satellite optical multispectral (Sentinel-2) and hyperspectral (EnMAP) data and multispectral drone date for producing training datasets.

3. Development of a savannah degradation monitoring web-tool assessing vegetation maps and contributors (bioclimatic, soils, burn frequency and topographic/land use information) of degradation processes in SA savannah drylands.

4. Development of an intercommunication basis between EO scientist and local stakeholders and population in SA savannah regions in order to develop and update the derived monitoring tools targeted to their current needs.

​

To date, no study has combined pixel-based compositing, multi-sensor (multispectral, hyperspectral, radar satellite & multispectral drone), multi-season (dry and wet season) data, machine and deep learning classification methods and dense time-series analysis to propose an innovative solution for mapping and monitoring savannah woody vegetation cover and discriminate savannah woody vegetation species. Earth Observation efforts to monitor and map savannah encroachment have primarily focused on producing land cover or fractional cover maps that distinguish between woody and grass components. Communication with local stakeholders and farmers has revealed a crucial aspect of woody encroachment: not all bushes have a negative impact on the land's services. Therefore, monitoring woody cover at the species level is essential for realistic assessments of savannah land degradation and holds significant importance for local populations.

​

​

​

​

​

​

​

​

​

​

​

​

The development of the SAV-EO project is strongly connected with the studies on the effects of Climate Change in drylands. The project’s EO-based frameworks were developed in a way that will make them transferable to other transitional ecosystems of high heterogeneity and could, therefore, inform the existing general framework for assessing land degradation and achieving the UN Sustainable Development Goal (SDG) of reaching Land Degradation Neutrality (LDN) by 2030, contribute towards the EC ‘The European Green Deal’ priority and also increase European research visibility in the ‘Environment & Combat Climate Change’ field, a priority area of H2020.

​

​

​

​

​

​

​

​

​

​

​

​

​

​

​

​​

​

​

​

The project’s results could be significantly useful in the research and scientific communities that address Climate Change impacts in drylands, but also to intergovernmental and governmental policy makers and local stakeholders that will use it as baseline data/tools for the development of sustainable management strategies and for assessing the effects of management decisions. SAV-EO has already developed an intercommunication basis/platform between EO scientist and local stakeholders and population in SA savannah regions (SA universities, CSIR, local farmers) through which shares the developed mapping products and land degradation monitoring tools and customizes them based on their current suggestions and needs.

​

​

​

​

​

​

​

​

​

​

​

​

​

​

​

​

​

​

​​

For more information or any other request please contact Dr Christina Karakizi at: chr.karakizi(at)gmail.com

​

​

​

​