Linking Indigenous Peoples’ stewardship of their land and Terrestrial Moisture Flows to West Africa during the dry season

Abstract

Indigenous Peoples' Lands (IPL) cover approximately one quarter of the Earth’s land surface and play a potentially significant role in sustaining terrestrial moisture flows (TMF). Yet, understanding of how they contribute to regional hydrological cycles remains limited. Building on a global-scale study suggesting a buffering role of IPL in West African precipitation during the dry season, this study identifies the corresponding source region of IPL-sourced moisture and examines whether IPL territories show different land stewardship patterns compared to non-IPL territories. Using the UTrack moisture tracking model, the main terrestrial source region is identified in southern Chad, the Central African Republic, and parts of the Congo Basin. Within this region, IPL and non-IPL territories are compared through spatial and statistical analyses of evapotranspiration, root-zone soil moisture, vegetation productivity, and land degradation, complemented by a qualitative assessment of institutional indicators. Results suggest limited but consistent differences between IPL and non-IPL territories, including land degradation patterns concentrated in areas where formal Indigenous tenure recognition is absent, and examples of sustainable land management practices that effectively sustain soil moisture and land integrity. These findings suggest that Indigenous stewardship practices may contribute to sustaining terrestrial moisture flows and highlight the importance of strengthening Indigenous land rights.

Popular Abstract

Indigenous Peoples manage about one quarter of the Earth’s land surface, living in forests, savannas, wetlands, and drylands that play a crucial role in the global water cycle. When vegetation and soil evaporate water into the atmosphere, this moisture can be transported hundreds of kilometers before falling as rain somewhere else. This process is called terrestrial moisture recycling, and implies that what happens on land in one region can influence rainfall – and therefore water availability – in another. Understanding how Indigenous Peoples manage their lands is essential to acknowledge their role in this process.
This work focuses on West Africa during the dry season, a period of reduced rainfall when soil moisture becomes critical for crops and pastures. Using atmospheric moisture tracking, the main terrestrial source of moisture supplying West African precipitation during this period was identified. Paradoxically, this region includes southern Chad, the Central African Republic, and parts of the Congo Basin, showing that a water-scarce area can still play a critical role in sustaining rainfall elsewhere. It also shows the influence of atmospheric transport patterns, which determine how much moisture evaporates from land and where it
ends up as rain.
The identified source region hosts a wide diversity of Indigenous Peoples. In the tropical rainforests, where land degradation is widespread, Indigenous land rights are largely unrecognised and communities face evictions driven by logging, agribusiness expansion, and infrastructure development. In the Sahel, land improvements are observed and examples of sustainable land management practices directly supporting soil moisture retention and vegetation have been identified. These practices, such as natural regeneration of native vegetation, traditional mulching techniques, and management of pastoral corridors, are part of knowledge accumulated and transmitted across generations about how to preserve and support productivity of land, water, and resources, in areas where water can be limited.
However, mapping and assessing the contribution of Indigenous territories is complex, as they encompass both intact ecosystems and areas under external pressure, and the majority remains without legal recognition. Satellite-based indicators such as evapotranspiration rates, soil moisture and vegetation indexes can capture some biophysical dimensions of land condition, but cannot fully reflect Indigenous land stewardship, which is rooted in guardianship, spiritual relationships with land and water, and intergenerational knowledge
transmission.
The results of this study call for further research and direct dialogue with Indigenous representatives. Recognising Indigenous Peoples as key stakeholders in water governance, as holders of knowledge and rights, is essential for developing strategies to sustain terrestrial moisture flows in a context of intensifying land degradation, water crisis, and climate change.

• author: Berthaud, Maylis
• supervisor: Rolf Larsson; Anna Tengberg; Malin L. Ingemarsson
• organization: Division of Water Resources Engineering
• course: VVRM05 20261
• year: 2026
• type: H2 - Master's Degree (Two Years)
• subject: Technology and Engineering
• keywords: Terrestrial moisture flows, Indigenous Peoples’ Lands, Land stewardship, West Africa, Dry season
• publication/series: TVVR 5000
• report number: TVVR26/5010
• ISSN: 1101-9824
• language: English
• additional info: Examiner; Erik Nilsson
• id: 9236558
• date added to LUP: 2026-06-17 10:30:33
• date last changed: 2026-06-17 10:30:33