Abstract

While carrying out environmental surveys in Songkhla Province, South Thailand in the 1980s, my research group and I identified a number of ancient canals and storage tanks on aerial photographs. Their existence was verified by ground truthing and further research uncovered an extensive irrigation system covering some 800 sq. km. Most of these works were heavily sedimented and no longer functional, exceptions being small areas of the storage tanks which were being exploited as beds for rice seedlings. Eventually my group cored all parts of this system so as to establish the original profiles of depth, breadth and, where possible, significant stages of their history of maintenance and neglect. This work included measurements of slope, rainfall and calculations of probable water movement. We prepared new maps of this area with corrections to place names, topography and representing the ancient irrigation system. These maps were immediately adopted by the Royal Thai Ordinance Survey Department and attracted the attention of the King of Thailand. He provided funds for the initial reconstruction of a segment of the irrigation system; the work was completed recently by the Irrigation Department of the Ministry of Agriculture in cooperation with myself. Its resurrection has had a major impact on the harvests obtained by the farming families of these districts.