Drainage Network Analysis and Tectonics Interference of the Reth River, Central Ganga Plain (India) Using Geospatial Technology
Pawan Kumar Gautam, D. Nagesh Kumar, Anoop Kumar Singh, Deepali Singh
Abstract
Abstract The Reth River is a ground water fed river of Central Ganga Plain, ~107 km long and drains ~391.71 km2. It flows through an incised valley until confluences with the Gomati River. Incision of the river valley has been investigated by using a longitudinal profile, escarpment height and morphology of the valley. The study was executed using Toposheet of scale 1 : 50 000 of Survey of India (SOI) and decadal satellite imageries, with GIS techniques to estimate the properties of basins. The mean bifurcation ratio of the basin is 5.49, but variation between the successive stream orders suggests that the study area is tectonically controlled. The drainage density (0.66), stream frequency (0.46), constant of channel maintenance (1.51) and length of overland flows (0.80) indicate of the high surface rock permeability, low surface runoff, high infiltration rate, and least erodible properties respectively. The drainage texture (0.30) suggests a very coarse texture and smooth topography. RHO coefficient value (0.13) indicates the low capacity of water. The elongation ratio (0.45), circulatory ratio (0.28) and form factor (0.16) indicate that the basin is highly elongated due to shallow relief. The downstream variation of escarpment heights indicates an increasing downstream trend of escarpment heights. According to aerial views of 46 years, oxbow lakes are formed through several processes, such as (i) a flow separation zone at the entrance of the channel creating a sediment plug, (ii) sediment sorting by flow gradients and decantation in the ponded areas. The drainage basin shape (3.02) indicates the basin is tectonically active. River longitudinal profile ranges are from 124 to 102 m amsl. This indicates the 4th-order river with dendritic pattern.