As common goods can be considered as a geographical manifestation of mutual aid (Springer 2016), understanding the origins, conditions, advantages and limitations of cooperation in natural and social systems has motivated many investigations in the biological and social sciences. We propose that cooperative behavior occurs when an agent acts upon one or more resources (or capital) with a beneficial result for at least one resource for the recipient of the interaction and with a selection process for that behavior on the side of the acting agent. With empirical data on irrigation (France/ Cambodia) and a theoretical agent-based model, we explored how variable resources in space and time might provide benefits for cooperative behavior. First, our simulations showed that temporal variability of resources can have a much greater influence on the success of cooperation than spatial heterogeneity in the distribution of resources. Based on those theoretical results we interpret empirical observations looking at the influence of the specificities of the resource in the emergence of mutual aid. Second, the model shows that the factors favoring equity in sharing access to the resource promote the success of cooperation. These results help in understanding the decrease in cooperative behavior in an irrigation context in France. They also raise questions about the low level of cooperation in Preks areas in Cambodia. Finally, our simulations showed the limitations of large group sizes of cooperating agents in the context of a common-pool management system. The possibility of characterizing the potential for the emergence of cooperation through some indicators of the spatial-temporal variability of resources is an interesting research objective for future work.