Reconstructing the Ancient Mihinthale Tank: A GIS and Remote Sensing Approach to Uncovering Historical Landscapes in Sri Lanka

The study employs Geographic Information Systems (GIS) and Remote Sensing techniques to reconstruct the inundation area of the ancient Mihinthale tank, providing a comprehensive understanding of its historical landscape. The methodology involved several key steps, including the acquisition of Advanced Land Observing Satellite (ALOS) data to create a detailed Digital Elevation Model (DEM) of the study area. The DEM was processed using ArcGIS to generate contour lines and determine the maximum water level. GPS locations of the old tank bund were collected and integrated into ArcGIS to reconstruct the ancient bund. The reconstructed bund and contour lines were then used to delineate the potential inundation area. A comparison of the ancient tank's dimensions and capacities with its present-day counterpart reveals substantial differences. The current tank bund measures approximately 720 meters, while the ancient bund was around 1700 meters. The current tank covers an area of about 0.25 square kilometers, whereas the ancient tank extended over 0.98 square kilometers. The surface volume of the present tank is approximately 1,024,000 cubic meters, compared to about 5,033,000 cubic meters for the ancient tank. The investigation highlights the significance of the Mihinthale tank within the broader context of Sri Lankan monastic and hydraulic infrastructure. Historical evidence suggests that the ancient tank played a crucial role in sustaining the large monastic population in Mihinthale, supporting the hypothesis of an extensive tank bund connecting the Mihinthale monastery and Wasammale.