干旱区生态环境知识资源中心

Understanding the processes of ravine formation and estimates of Specific Sediment Yields (SSY) of these regions help in formulating mitigation policies significantly. Upto now, in the Ganga Plain, the work done on ravine formation, erosion and SSY estimates has been speculative. Here, utilizing (i) high resolution Digital Elevation Models (DEMs) prepared from Real Time Kinematic (RTK) survey and CARTOSAT images of ravined zones and (ii) luminescence chronology, we provide the first estimate of SSY from the ravines. The results indicate that SSY in the Marginal Ganga Plain (MGP) ravines may range between 600 +/- 100 t/km(2)/yr and 1600 +/- 200 t/km(2)/Yr.

The correspondence between the orientations of fractures and that of first order ravine suggests that the ravine growth is genetically related to extensional stress regime of the peripheral forebulge. Further, the clay sedimentology indicates that besides regional tectonics, action of swelling clays may have accelerated development of the badlands. The geomorphic relationship between the length of ravined catchments and incision in the trunk channels indicates that the river-incision associated base level change is not playing an overarching role in the ravine formation in the MGP.