Earth Observation data as input to a Water-Energy-Food System Dynamics Model in the Songwe River Basin

Abstract:

Data availability is one of the main limitations in the assessment of the Water-Energy-Food (WEF) nexus. Recent advances in Earth Observations (EO) have increased the availability of data across all WEF sectors in data-scarce regions. EO data can play a crucial role in delivering input data for models that are aimed at capturing and quantifying the interactions between the three sectors. The WEF-Tools project proposes the use of EO to fill data gaps (e.g. water quality, electricity access, land-cover/use) in the Songwe river basin to conduct a WEF nexus assessment for the catchments using System Dynamics Modelling (SDM) to quantify nexus-wide impacts. SDM has the advantage of being flexible in integrating sectors and data at different spatial, sectoral and temporal scales. The Songwe river has a catchment area of 4200 km² and forms the boundary between Tanzania and Malawi. The basin is home to mainly rural communities with low access to electricity, water and sanitation and who depend largely on agriculture as a source of livelihood. Over the last decades, population growth and climate change have exerted considerable pressure on land resources, exacerbating food and energy insecurity and poverty. To address these issues, the Songwe River Basin Development Programme (SRBDP) has proposed the construction of multi-purpose dams for ensuring flood control, and water and energy supply. This work demonstrates how EO can contribute to engineering data for different components of the Songwe WEF nexus and subsequently assisting SDM in quantifying and understanding complex interactions, synergies, and trade-offs. The use of EO data in the Songwe WEF nexus analysis is beneficial to support local decision-makers in achieving their commitments to the Sustainable Development Goals (SDGs), particularly SDGs 2, 6, and 7. This study can serve as a reference to other data-scarce areas.