Dynamical Models of Interactions between Herds Forage and Water Resources in Sahelian Region

Figure 3

Chronological evolution and phase portrait of the herd individuals and forage resources of System (1) when 𝑟₀₁=200 kgDM/ha, 𝑟₀₂=55 kgDM/ha, 𝑟₁=80 kgDM/ha, 𝐾=30--600 kgDM/ha, 𝑒=0.05/day, 𝑎=0.013/ha, 𝑞=0.4/day, and 𝛾=0.07/day. Global stability of equilibrium 𝐸₁=(𝐾,0) for System (1). This illustrates the case when pastoralists decide to migrate for reasons different from unavailability of forage resources.