Introduction

There used to be Indus Valley Civilization (IVC) also called Harapan civilization flourished along Indus river and its tributaries around 7 ka, but those cities were abandoned around 2 ka (Lemmen et al., 2012). There are many reasons have been proposed to the collapse of the civilization including hostile ethic, flood, earthquake, climatic change etc. (Lahiri, 2000). However it is believed that the drying of the Sarasvati River is the main reason triggered the decline of Indus civilization (Yasphal et al., 1984). Enzel et al 1999 suggested that the lake record in Thar desert shows that there was intense drying after 4.2 ka and this may cause the shortage of the water and thus the collapse of the civilization. The paleo Gaggar-Hakra valley is proposed to be the most possible candidate for the lost Saraswati River (Sharma et al.,2008) yet with geomorphology and geochemistry data Maemoku et al., 2012 suggested the sand dunes formed befeor mature Harapan so that Gaggar-Hakra River can’t be the lost Saraswati river.

 

Objective

The paleo channel is an unsolved myth and it may be related to the ancient civilization and also has something to do with the paleo climate. Though there is no direct evidence to show the collapse of civilization is due to the shortage of water triggered by the climatic change, the paleo channel is acted as the main character to the development of the civilization. This study aims to trace those ancient civil-related paleo channels, the Gaggar-Hakra river with the satellites images.

 

Geological Settings

The Gaggar-Hakra valley is originated in the ephemeral streams from Lower Himalaya of northwestern India and continues to be Hakra River flows from Punjab plain toward the west and disappears into the Thar Desert as the valley turns into the dry riverbed. The Thar Desert is bound in the northwest by the Sutlej River, in the east by the Aravalli range, in the south by the salt marsh known as the Rann of Kachh and in the western side by the Indus valley (Fig.1.).

The Punjab and Haryana plains are composed of alluvial fans at the foot of Himalaya and interfluve of the tributaries of the major rivers as well as the flood plain along the rivers (Naruse, 1985). Sand dunes are several meters high and the stabilized sand dunes in the south near Thar Desert are more than 10 meters in height.