Impact of water allocation oversight in irrigation systems: an agent-based model approach

Abstract

As access to water is a right of all people, government agents are responsible to allocate water to guarantee its sustainable use for multiple users. However, deciding the best allocation strategy is not a straightforward task. In complex systems, which depend on a collection of individual decisions by people, water policies may have unpredictable impacts. Considering the water allocation in a water canal, we present an agent-based model that allocates water and incorporates an agents’ adaptability behaviour strategy of overriding the manager's decision when water right is denied. We compared scenarios of farmers' override susceptibility and of water availability on the Canal do Sertão in the state of Alagoas, northeastern Brazil. In the scenario of reduced water capacity, agents with water rights in the last segments of the canal were unable to withdraw water due to agents who withdrew illegally. The sustainability of the system proved to be sensitive to the level of susceptibility of capturing water illegally, deserving attention and investments in the oversight sector. Besides this effect, the model can be applied to assess and compare advantages and impacts on the water levels for different water policies such as financial subsidies or different water allocation strategies.