Palaeo-channel bisecting Puri town, Odisha: vestige of the lost river 'Saradha'?

摘要

Puri, an ancient town located on the Odisha (Orissa) coast in eastern India, is associated with the 12th century ce Jagannath Temple. Many ancient and historical texts mention a mythical river named Saradha that flowed across the present Grand Road (Badadanda) between the Jagannath and Gundicha temples in Puri, dividing the town into two parts. This study traces the trail of a palaeo-channel beyond and within the heart of Puri town through an integrated study of geology, satellite imagery and ground-penetrating radar (GPR) survey. Various satellite imagery manipulation techniques - band combination, NDVI, MNDWI, linear spectral unmixing algorithm, density slice and spatial profiling - indicate the existence of water components along with vegetation bands, and the presence of a sinusoidal palaeo-channel trace with a V-shaped topographic outline. This is interpreted to represent the remnants of an extinct river valley. GPR survey also suggests that a subsurface river valley, about 128 m wide, existed across parts of the Grand Road. A large, sinusoidal water body near the sea beach at Puri, may represent the last remains of the dried-up channel. Integration of all these features suggests that a river once existed between Jagannath and Gundicha temples in Puri town. The constructed palaeo-channel trail may be that of the lost Saradha river described in ancient texts. The study develops a sequential methodology for identifying palaeo-channels even in urbanized localities like Puri.