Modelling the Economics of Grassland Degradation in Banni, India, using System Dynamics

This is a study of the interactions between the ecology and economy of the Banni grassland, located in the district of Kutch, Gujarat, India. The study focuses on modelling the economic impact of grassland degradation in the Banni from 1992–2015 and simulates future scenarios up to 2030 using system dynamics. The specific sectors being modelled are the area spread of the invasive species Prosopis juliflora, palatable grass, the populations of livestock as well as the livestock and charcoal incomes of Banni. An economic valuation is done by discounting the future earnings of the pastoral (milk, livestock sale, dung manure) and charcoal economy under two scenarios 1) Base case (Business as Usual), i.e. keeping current policies constant and 2) P. juliflora removal policy (PRP) i.e. where a decision is implemented to remove P. juliflora from Banni. Under the BAU scenario, modelling results indicate that the Banni grassland is headed for severe fodder scarcity due to the shrinking area under grassland. Under the PRP scenario, Banni is able to revive its grasslands and increase the present value of future earnings (up till 2030) by 62 per cent. A delay of five years in the decision to remove P. juliflora results in a 28 per cent reduction in earnings indicating the policy’s time sensitivity. The model serves as a test bed for generating what-if scenarios of the Banni grassland.