Remote Sensing for Monitoring Water Use and Stress in Savannas: A Handbook

  • 2017/07/14     Dresden, Germany

    Image: UNU-FLORES/Ana Andreu Mendez

    Image: UNU-FLORES/Ana Andreu Mendez

    By Atiqah Fairuz Salleh, Communications and Advocacy

    Savannas are among Africa’s most productive multifunctional landscape – supporting wildlife, livestock, crops, and livelihoods – but experience frequent droughts. This is made worse by climate change and other human-induced changes. To maintain ecosystem productivity, there is a need to develop a mechanism for monitoring water availability and vegetation dynamics in savannas.

    Due to the interlinkages between resources, and between resources and society, their sustainable management requires a holistic perspective. Taking things together, we need to rely on an integrated management and monitoring of resources as embodied by the Nexus Approach. This necessitates integrated tools that are capable of addressing and reducing uncertainties associated with resources management with the use of timely and precise information on ecosystem dynamics.

    One way is to make use of Earth Observation (EO) data and technologies. Especially in developing countries where ground data is scarce, monitoring networks unreliable, and data access restricted, scientific open data sources are essential for monitoring ecosystems. Open-source software, like the Water Observation Information System (WOIS) developed by the TIGER Initiative, is valuable in this regard.

    In a newly launched publication, UNU-FLORES’s TIGER Savanna Tool Handbook: On Remote Sensing of Water Use and Water Stress in African Savanna Ecosystems from Local to Regional Scale (2017) provides guidance on EO techniques and the topic of remote sensing in theory, as well as sheds light on the tools such as WOIS in practice. A how-to manual at the end also guides practitioners through the steps implementing the equations, and deriving information from data gathered.

    TIGER Initiative and Project 410

    In December 2015 UNU-FLORES, together with the University of Limpopo and the University of Western Cape (South Africa), were selected as one of the ten TIGER Water for Agriculture teams for conducting joint research for integrated water management, within project 410 “Remote Sensing of Water Use and Water Stress in African Savanna Ecosystem from Local to Regional Scale: Implications for Land Productivity”. The TIGER initiative, launched by the European Space Agency (ESA) in 2002, promotes the use of Earth Observation (EO) data to improve Integrated Water Resources Management in Africa, while strengthening the scientific collaboration between African and European partners. The handbook is co-authored by the European lead of the project, Dr Ana Andreu Mendez, and the African lead, Dr Timothy Dube.

    Covering both the theoretical bases and practical application of the EO tools, the handbook serves to support stakeholders and practitioners in accounting for African savannas’ water use and water stress using EO data. This is envisioned to provide accurate and timely information to support decision-making processes at different scales. Information gathered can be used to assist agricultural authorities to determine areas of vulnerability, for instance, and enable their sustainable management. It is hoped that the results will improve our understanding of water use and water stress evolution over a key multifunctional African ecosystem, and taking it further, help improve productive savanna management through increased ecosystem productivity and resilience.


    In order to derive information that can cover stakeholders’ needs, and in furthering the Nexus Approach, the integration of stakeholders’ perspectives within the framework of the project is promoted and Capacity Development actions reinforced. Contribution towards improving the integration of the savanna water use and water stress tool in rangeland management is welcomed via an online survey as we seek to continuously develop tools to facilitate this development for stakeholders and practitioners.

    Focusing on safeguarding ecosystem services and livelihoods in Southern Africa, a region that is prone to water scarcity and where climatic change projections show that the ratio of temperatures/precipitation will progressively increase, it is hoped that the tools introduced in this handbook come handy amidst the trends of global change. It is hoped that the TIGER tools will be taken up widely for resources management in African savannas and developed further for additional applications in other regions.