Come on MESS around. Developing a long-term Modelling approach to study Emerging Societal Systems in ancient southern Mesopotamia.
Creators: name: Ertsen, Maurits
name: Lang, Dengxiao
name: Cushing, Reggie
name: Diblen, Faruk
name: Lyashevska, Olga
name: Rost, Stephanie
name: van Nooyen, Ronald R.P.
Publisher: name: Zenodo
Year: 2024

description: Early Southern Mesopotamia is well-known for its complex history of expansion of (irrigated) farming in relation to urban developments and changing landscapes. In several older studies, irrigated farming was (usually implicitly) conceptualized as an entity that had been realized on larger scales in relatively short period of time – hence the need for more central control of labor and irrigation activities. In line with the research also mentioned in the workshop call in terms of “a steady increase in the number of anthropological and archaeological studies that look into the human-environment interactions and resource management practices of Indigenous and local populations”, Mesopotamian discussions suggest more and more that gradually developing water systems over longer time periods (centuries if not millennia) were fundamental to the development of Mesopotamian society (Altaweel 2019; Rost 2017; Wilkinson et al 2015). Recent scholarship suggests that these urban-based societies developed within an emerging network of irrigated areas increasing in size and number, with transport connections to move surplus yields being exploited.  

As is also stated in the workshop call, more interdisciplinary efforts and discussions – including other data sets that are mobilized – “offer new opportunities for enriched approaches to computational modelling that better address important scientific challenges in the study of past human eco-dynamics”. Indeed, we aim to develop further understanding of Mesopotamian’s history by applying different modelling techniques. Within the Water Resources group at Delft University of Technology, an agent-based model (ABM) was developed to explore the development processes that could have taken place in Mesopotamian societies (Lang and Ertsen 2023). The model builds on the dynamics of irrigated sub-areas (farmlands) and irrigation systems in relation to decision-making processes, both on sub-areas (especially irrigating crops) and along canals (especially sharing water). Allowing responses to water scarcity or to high yields is built into the decision-making processes, including options to expand/reduce irrigated sub-areas, move irrigated sub-areas, expand the system, or start a new system. 

The model already shows fascinating results in its generation of various patterns of yields and (expansion) dynamics of irrigated sub-areas and system. These results shows how human decision-making determines the level of influence of and benefits for sub-areas and the overall irrigation system, including degrees of inequality in yields among sub-areas. The model offers a base for further study, by incorporating additional agents into the irrigation system and expanding the spatial-temporal scales of the irrigated landscape, to reach a more comprehensive understanding of the evolutionary dynamics of irrigation systems in Southern Mesopotamia (Ertsen 2016). 

In March 2023, we have started a two-year project with the Water Resources group and the Dutch eScience Center to realize such modelling expansion. Based on the available ABM in NetLogo, this project studies conditions for longer-term growth of irrigated landscapes – again, with longer-term defined as millennia. The purpose of the expanded digital approach is to produce long-term runs as (ensembles of) likely outcomes in terms of increasing/decreasing irrigated areas with associated yields (which may have changed over time per hectare) and transport options – related to water availability (which may have changed over time as well) and water distribution between/decisions by model users to expand and/or move. Given the many choices available to model agents, using calibration data to check model is unfeasible, but we can decide which outcomes are feasible in terms of physical boundaries – including keeping model agents alive. To test different outcomes ABM models need to run repeatedly with different sets of parameters. To facilitate parameter sweep we propose a template-based utility that will leverage existing models and require minimal code changes. In addition to this, we will provide a guide on how to run multiple models on HPC.

This contribution proposes to share the MESS challenges and progress achieved so far and how we plan to proceed, within the workshop theme(s) “anthropogenic impacts on environmental change in the long- and short-term, at smaller and larger spatial scales” and “theoretical and conceptual frameworks for socio-ecological simulations of past human behaviour that go beyond traditional models”.