The impact of natural disasters is most apparent in the Saraswathy valley...
You may note the dried up river bed of the lost Saraswathy river.Today the land has become a desert.The Capture of its main tributary Yamuna by the Ganges river due to tectonic upheavals around 1900 BC doomed the hundreds of cities and towns that depended on the river
Hundreds of cities and towns lay buried under the sands for over 4000 years .
In the picture below, note how the majority of the sites are along the Saraswathy and not the Indus
https://sites.google.com/site/sarasv...o-channels.pdf
The obove site explains thus :
River Saraswati originated in Himalayas and dried up during
2500-1500 BC, due to tectonic and palaeo-climatic changes. Varying number of courses of the
river have been suggested by the different workers. The obscured channels of the river could be
seen on the images from present day satellites. Using multi-spectral data from new generation
(Indian) satellites/ Sensors Efforts are made to reconstruct
the true course of the river and validate the same through a variety of scientific data generated
under the project by different agencies viz. Remote sensing data, data from core drillings and isotopic studies; data on ground water quality, yield, depth and age of ground water; litholog and sedimentological data, archeological finds, geomorphological data, historic maps etc. Reasons esponsible for disappearance of Saraswati are also analyzed.
Results indicate different reasons responsible for its disappearance. Analysis indicate that “Rise in Himalayas and consequent displacements in the Siwaliks and its foot Hills region (in the form of Yamuna and Satlej tear faults”) and not the “Rise along Delhi-Hardwar Ridge and movements along Kuchchh fault and Luni-Sukari lineaments with resultant westward slope changes” as suggested / believed by earlier workers was the main cause for ultimate drainage desiccation in the north-western Indian region. The results indicate that the river Sarasvati drained through present day river Ghaggar and did not drain along the Aravali hills in Rajasthan.
Also it did not shift its course drastically and continuously from east to west, as suggested by earlier workers. The image anomalies indicate that river Sarasvati flowed parallel to the river Indus as an independent river system (closer to the north-western Indian border) but did not flow through present course of river Nara. The mapped courses of Saras wati runs about 850-900 kms east, parallel to the Indus river course.