Ancient water harvesting in the Old World Dry Belt – Synopsis and outlook.

More than 50 years after the first comprehensively designed projects, the significance of research on past societies and their interactions with landscapes has even increased: Studying arid landscapes opens many areas of general interest about adapted lifestyles and livelihoods, since aridity touches upon problems of desertification and climate change, decentral water and food security. This synoptical paper sheds light onto the premises, functionalities and questions of water harvesting systems in antiquity and asks about the implications of runoff-based economies and societies in the Old World Dry Belt. By comparing results and considerations of the individual contributions to this special issue on ancient water management in general, and water and soil harvesting in particular and other relevant studies, it aims at extracting commonalities and differences between the interlinkages of environmental conditions and human intervention. Moreover, it embeds the various approaches, methods and results of the special issue's authors into overarching considerations oriented towards achieved results, application-oriented aspects and towards focal open questions. Differential analysis of the studied cases, i.e. systematic evaluation of the differences and similarities increases the understanding of the complex issues of runoff agriculture under various environmental and socio-economic conditions. The relevance of the models of ancient water-harvesting based systems evolved during the last decades for modern challenges is given special regard. • Interdisciplinary research in drylands models ancient resource management and livelihoods on a local and regional scale. • Potentials and dynamics of agro-ecosystems are outlined on basis of ancient water harvesting systems. • Studies of ancient resource management are relevant for actual development, sustainability and resilience objectives. • Comparative and complementary analysis of different studies and regions enhances understanding of issues at question. [ABSTRACT FROM AUTHOR]