Abigail Schade

Abstract. This global environmental history examines comparisons and connections among ancient and medieval qanat irrigation technologies in arid regions. Qanat systems were traditionally built in arid regions of the mountainous plateau of Iran, using gravity-fed slopes to extract groundwater from higher strata. Techniques of qanat construction and maintenance allowed for irrigation agriculture in arid regions with natural endowments of groundwater. This dissertation examines historical connections across space and time by comparing knowledge about engineering of qanat. The concept of technological diffusion, or technology transfer, signifies connections in this global history. Comparisons are made by examining the long-term environmental history of individual landscapes. I consider long-term continuity and change by reading archaeological reports; through my own geographic observations and analysis; and through historical texts documenting traditional techniques. In an epilogue, this dissertation examines 20th-century changes in irrigation technologies for agriculture, and modernizing notions of expertise for agricultural development in mid-20th-century Iran. Here is a report of her work.