Using Simulation Models and Ethnography to Understand Changing Livelihoods Among Samburu Pastoralists

Background and Purpose. African pastoral livestock systems are adapted to the semi-arid conditions in which they exist, enabling people to survive in harsh, risky environments. During the 20^th century, government policies altered pastoral livelihood systems, reducing access to grazing land and critical resources by limiting mobility and creating national parks and forests. In Kenya, adjudication of land rights established a patchwork of land tenure including state-owned land, group-owned land, and private land. This study is part of a long-term research project investigating processes and outcomes of changes in land rights and use on pastoral livelihoods at household and community level. We use computer simulation models of the physical environment and households combined with ethnographic interviews and observations to understand how emerging rules of land use translate into environmental and household impacts. Specifically, we aim to understand how privatizing communal land alters land use rules and practices and what effects these changes have on household and environmental well-being.

Methods. We used ecological (rainfall, soils, vegetation, etc.) and household survey data (n=160) collected from two study communities in Samburu County, Kenya, to construct a computer simulation model of the environment (SAVANNA) and an agent-based model of household behavior (DECUMA). In-depth interviews (n=30) focused on existing and emerging land use rules and practices on private and communal land. Once the models were built, 20-year scenarios were run based on manipulations of variables in the model to simulate the new land use rules and practices observed in the communities. We also held discussions with community members to elicit scenarios that they would like to see modeled. Eight scenarios have been developed including land fragmentation, increased cultivation, changing veterinary care, and improved goat production. Here, we present results from two scenarios—the impact of land fragmentation and increases in cultivation.

Results. Our interviews and observations indicate conflicting visions of the future among our participants, particularly those owning private land. Older and wealthier pastoralists want to continue extensive pastoralism with large herds, requiring access to large tracts of land. Others, often those who own fewer livestock and have more formal education, want to combine cultivation with fewer livestock and utilize only their private land, prohibiting access to others.

The simulation model of land fragmentation shows that reducing access to grazing land reduces livestock numbers over time. As grazing orbits reduce in size, numbers of livestock owned by households go down.  The simulation model of increasing crop cultivation shows increased income from crop sales and more energy available to households from consuming crops. In this scenario, more cultivation leads to increases in household livestock holdings because livestock sales decline and more are purchased using income from crop sales.

Conclusions and Implications. Combining the scenarios suggests contradictory possibilities. Increasing cultivation reduces access to pasture leading to reduction in livestock numbers over time, while increasing income from crops potentially increases household livestock holdings through purchase. Actual outcomes depend on household decision-making regarding investments in livestock and cultivation. Models may inform such decisions by illustrating likely outcomes under different conditions.