ASSESMENT OF CHANNEL MIGRATION CHARACTERISTICS OF BHARATHAPUZHA RIVER FROM PALLIPURAM TO PURATHUR REACH USING GIS AND RS

Abstract

A study on Assessment of channel migration characteristics of Bharathapuzha river from Pallipuram to Purathur was conducted in Kelappaji College of Agricultural Engineering and Technology Tavanur. The objective of the study was to identify the changes in the left and right bank reach of Bharathapuzha using GIS and RS and to identify the hot spots for maximum stream bank erosion in this reach. Satellite imagery from USGS Earth Explorer Sentinel 2-A was taken for the pre- monsoon (February) and post-monsoon (October) months of 2017,18,19 and 20. Spatial analysis was done in these data sets to obtain results for the given objectives. The maximum shift on left bank was observed along section C i.e., near Chamravattom and maximum right bank shift along section D i.e., near Perunthallur. The hotsopts were identified near Minipamba Temple, Kuttippuram, near Chamravattom and near Nilayoram Park. More left bank shift was observed in the river channel i.e., more erosion taking place at the left bank of the river channel. The lateral shift and high rate of erosion along some points were observed. The high rate of erosion taking place may be because of the excessive and unpredictable rainfall leading to floods in recent years and excessive sand mining activities taking place in the Bharathapuzha. This had led to considerable shifting and large amount of deposition taking place on the other side of erosion leading to the shrinking of the river. Water level is decreasing due to deepening of the bed. This had also led to change in river morphology and geometry and flood conditions. Hence, with the help of this study the trend in the river channel flow can be predicted and also steps can be taken for the rejuvenation of the Bharathapuzha river.