Socio-ecological resilience to soil erosion in East-Africa ... Wynant… · –Poverty and...

Socio-ecological resilience to soil erosion in East-Africa:

an interdisciplinary approach

Maarten Wynants, William H. Blake, Anna Rabinovich, Claire Kelly, Kelvin Mtei, Linus Munishi, Mona

Nasseri, Aloyce Patrick, David Gilvear, Neil Roberts, Geoff Wilson, Patrick Ndakidemi

email: maarten.wynants@plymouth.ac.uk

Soil erosion, the FWE nexus and SDG challenges in East Africa

Interdisciplinary approach to ‘wicked problem’ of soil erosion

Funded by UKRI GCRF (2016-2017)

& NERC [Follow On] (2017-2019)

• Natural high vulnerability due to distinct topography, semi-arid climate, disequilibrium vegetation and fragile soils.

• Indigenous systems of intercropping, shifting cultivation, nomadic pastoralism co-evolved with and adapted to local environment.

• Colonial alteration to human-environment relationships within western systems of market-led agricultural and resource management. Displacement, coercion, marginalisation and exclusion of local communities enforced from centralised power structure

• Post-independence nation-states build on colonial borders and principles of modernity. Continuing same processes but with different political justifications. African socialism, liberalisation and globalisation

• Current social economic and political drivers of soil erosion:– Poverty and population increase => Malthusian trap? Why no escape?

– Governance and political representation

– Land rights and access

– Limited access to the market, services and modern capital

Wynants et al. 2018- In prep.

Land degradation in East-Africa: a complex timeline of disruption

Assessing soil vulnerability

to erosion past and present

Exploring socio-

cultural drivers and

challenges

Sedimentary evidence of

baselines and rates of change

Lake Manyara catchmentSubcatchment Sediment contribution (%)

Dudumera (f) 8

Endabash (h) 7.6

Kirurumo (b) 5.3

Makuyuni (d) 59.3

Mto Wa Mbu (c) 7.4

Simba (c) 5.3

Tarangire (e) 7.2

Pinpointing areas of increased soil erosion risk following land cover change (1988-2016)

Wynants et al. 2018- Int J Appl Earth Obs Geoinf 71: 1-8

Loss of vegetation cover [drough, grazing, deforestation] exposes and weakens soil

Image: Blake

Reduced infiltration leads to OLF and sheet erosion

Photo: Carey Marks/University of Plymouth

OLF converges with natural topography and along trackways…

Photo: Carey Marks/University of Plymouth

Incision and gully network development increases connectivity

Photo: Carey Marks/University of Plymouth

socio-ecological system at a tipping point?

Applied environmental diagnostics tools: sedimentary evidence of landscape change

‘If we don’t change the environment may force us to change... and then it might be too late’

Enhanced runoff is a basin-wide problem

Photo: Carey Marks/University of Plymouth

Sediment is being washed to downstream ecosystems threatening

biodiversity, health, economy and livelihoods

Adding complexity to the problem….

But… ‘overgrazing’ and ‘land cover change’ are symptoms of wider environmental and social dynamics and transitions

Population growth

Sedentarisation/ migration

Changing rainfall patterns

Governance change

Shifts in land ownership

communities locked in?

Realising change: barriers and opportunities

Cultural importance of cattle & cattle as ‘savings account’

skills and knowledge to diversify or change livelihood?

Who takes responsibility for protecting common land?

Harmony in community versus environmental protection

Education is valued

Recognition that environment may

force change

Cohesive communities

Co-designing pathways to change through a shared community vision for the future

New tools to support behaviour change and policy co-design in 2018-19 With Carey Marks (designer)

“I’m glad that you have come to ask important things that are concerned about environmental degradation in this community. I’m very happy about your coming in this village because other researchers do come and after getting done with their activities they go and forget us without coming back.

So are you also same as them or there is a way that you are going to help us in saving our environment from soil erosion problems?”

Farmer, Emaerete

Meeting the community's challenge: impact ambitions 2018-2019

Knowledge exchange to elucidate community-led solutions

Co-design of village-specific byelawsDemonstration restoration plots

to catalyse behaviour change

The interdisciplinary Jali Ardhi [Care for the Land] Project

SEI