| Abstract: |
Sri Ksetra is the largest site of Pyu civilization in Burma
its emergence as an urbanized site began in the early 1st century BCE about the same time as Beikthano's and Halin's. Located on the southern edge of the Dry Zone of Central Burma, it has an annual rainfall of c. 1200 mm p.a., which is insufficient for secure rice cultivation. Irrigation and drainage works were essential for urban levels of development. In the long season, they served as valuable adjuncts to the natural drainage system, protecting Sri Ksetra from the strong erosive action of water pouring down the slopes of the ridge immediately to the west. This paper presents a new application, developed in Cambridge, to render freely available Remote Sensing images of medium resolution more sensitive to the differential presence of water in the landscape. It documents the sub-surface and surface movement of moisture across the site of Sri Ksetra after the end of a single monsoon season, at three critical moments in the intermediate season from September to February in 2002-2003. The findings are supported by the study of combined resources: the spaceborne multi-spectral and multi-temporal satellite imagery of medium resolution just mentioned, aerial photographs and archaeological maps. They corroborate each other in revealing how surface and sub-surface water still flows along the ancient irrigation channels and gathers in the collection tank at the lowest point of the ancient irrigation/drainage system. In this new application, the satellite images even capture details that compare well with those recorded in the aerial photographs taken sixty years ago in less disturbed conditions. This research technique also demonstrates that parts of the ancient irrigation system, though subject to an unexpected process of sedimentation for about one thousand years, still capture, store and distribute rainwater at subsurface level, resulting in major differences in soil productivity and drainage today. The aims of this paper are several: to present the new insights provided by our treatment of satellite imagery
to relate them to the existing archaeological and environmental evidence on the ancient irrigation works
and to consider the potential value of these research techniques for research on other Southeast Asian archaeological sites.
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