A virtual water network of the Roman world

Abstract

Abstract. The Romans were perhaps the most impressive exponents of water resource management in preindustrial times with irrigation and virtual water trade facilitating unprecedented urbanisation and socioeconomic stability for hundreds of years in a region of highly variable climate. To understand Roman water resource management in response to urbanisation and climate variability, a Virtual Water Network of the Roman World was developed. Using this network we find that irrigation and virtual water trade increased Roman resilience to climate variability in the short term. However, urbanisation arising from virtual water trade likely pushed the Empire closer to the boundary of its water resources, led to an increase in import costs, and reduced its resilience to climate variability in the long-term. In addition to improving our understanding of Roman water resource management, our cost-distance based analysis illuminates how increases in import costs arising from climatic and population pressures are likely to be distributed in the future global virtual water network.

Global hydrology 2015: State, trends, and directions

“…To capture this nonpredictability, the stylized models of sociohydrology [e.g., Di Baldassarre et al, 2009;Van Emmerik et al, 2014;Srinivasan, 2015] should be extended with stochastic perturbations. Alternatively, agent-based modeling approaches could be used [e.g., Dermody et al, 2014;Arnold et al, 2015]. It would not be feasible or realistic to define such models globally for each GHM grid cell.…”

The effects of network topology, climate variability and shocks on the evolution and resilience of a food trade network

“…Food trade also provides a buffer against local variability in food resources because regions can import when they have a deficit and export when they have a surplus. The redistribution of resources from regions with surplus to regions with deficit effectively increases the carrying capacity of a trading network [ 8 ]. The reason is that under multi-year to decadal climate variability, the carrying capacity of a non-trading region is limited by the food availability in the periods with the lowest yield.…”

“…However, when regions with heterogeneous climate are connected via a trade network, the carrying capacity approaches the average carrying capacity of all trading nodes. Trade can thus increase the carrying capacity of a trade network without any increase in production [ 8 ]. However, the interdependency of food supply via trade means that changes in one part of a trade network may have implications for food supply in another part of the network.…”

“…wildfires, droughts) which led to a reduction of food on global markets leading to an increase in food prices for trading nations [ 10 ]. A study of virtual water trade in the ancient world demonstrated that trade can save resources on average [ 8 ], but other studies show that increased reliance on trade increases vulnerability to food shortages in the real world trading network [ 9 ; 11 ]. The challenge of food supply will be complicated even further by anthropogenic climate change, which alters the frequency and amplitude of climate variables such as rainfall and temperature patterns [ 12 ].…”

Finding history: the locational geography of Ashokan inscriptions in the Indian subcontinent

“…2013: 7979), and has been used to model large-scale scenarios as diverse as ancient Roman water networks (Dermody et al . 2014) and the effects of pre-modern rice agriculture on methane levels (Fuller et al . 2011).…”