1.2 - Irrigation and landscape: An interdisciplinary approach

Summary

ABSTRACT

Studying irrigation history is studying the history of civilisation in dry areas where the natural environment and water infrastructure are closely connected. Yet, surprisingly little is known about the ways irrigation provided the material base for civilisations to prosper. Our knowledge how irrigation developed as interplay between hydraulic and humans is limited, presumably because that kind of knowledge is highly interdisciplinary in nature. Several aspects of water use in irrigation systems need to be explored, including timing and distribution, in order to study how water fluxes on different time scales could be incorporated in archaeological research. This paper discusses irrigation in the Zerqa triangle in the Jordan Valley where water tapped from the Zerqa River was transported to the fields through open canals under gravity. The settlement patterns found in the valley suggest close connections to the canal system from the Iron Age onwards. Physical aspects of the irrigated landscape will be explored by basic hydrological and hydraulic modelling.

KEYWORDS

irrigation, Jordan, explorative modelling, water management

INTRODUCTION

A most fascinating aspect of irrigation is the close connection between civilisation and the natural environment in which water infrastructure acts as interplay. Many civilisations of the past have used irrigation to feed their population. Intensified production provided a relatively secure food source for a larger population as it enabled the peasant population to produce a surplus to support the non-peasant population. Food security enabled development of city kingdoms in many regions: Mesopotamia, Egypt, the Indus-valley, China, Mexico and (coastal) Peru (Scarborough 2003). Because of the importance of irrigation, it has been well studied. The well-known Hydraulic Hypothesis is based on manipulation of water from larger streams for irrigating areas without reliable rainfall. Despite this valuable research, what has been stated by one author more than 25 years ago is still a valid comment. ‘Much of the archaeological literature on irrigation canals merely notes their presence at a certain period(s) and records their association with sites. It may describe or even classify the main features of an irrigation system […] but does not fully elucidate the technology, hydraulics or hydrology of the canals. Even where excavations into canals have been carried out, the researchers have not used their data to its full potential […].’ (Farrington 1980).