Automata Theory in the WEFW nexus: Experience from the cities in the Global South

The major societal interests among the urban community at the moment represent a wide array of sustainable energy, climatic regulation, proper water use and sustainable production and consumption of renewable resources. As people migrate to urban areas, and more than half of the world population now live in cities, more pressure is put on the Water-Energy-Food-Waste (WEFW) systems. Devoid of plans for sustainable provision of WEFW services, cities may suffer water stress, starvation, load shedding and choked with waste. In this regard, among the dilemmas faced by urban managers is which methodologies would appropriately fix these problems and why. They can either (i) treat each of these problems individually or (ii) address them as one complex problem. This paper adopts the Automata Theory (AT) to explain how these options are affected by the nature of WEFW nexus, in what way the effects are transferred in the states and the opportunities and cautions from this nexus that affect the management of urban dynamics. A total of 16 articles analysing WEFW nexus and 20 articles covering interactions between WEFW elements were reviewed. Results show that the management of the interconnections between the WEFW elements contributes to either the realization or the breakdown of the urban systems. Empirical studies to establish resultant interactions between nexus sub-systems and developing integrated planning tools for inclusive policy processes that consider the vast array of this nexus in the current complex systems is fundamental