43-Assessment of sedimentation in Nizamsagar Reservoir using digital remote sensing technique

Abstract

As per recommendations of Working Group for National Action for Reservoir Sedimentation Assessment, National Institute of Hydrology has taken up study on sedimentation for 25 reservoirs in India during X plan period using remote sensing technique. One such study for Nizamsagar reservoir in Godavari basin in Maharashtra for year 1930- 2006 is described here. Reservoir's original utilizable and gross volumes were 841.18 and 375.55 M m3 respectively. Minimum draw down level (MDDL) and full reservoir level (FRL) for reservoir are and 426.87 m respectively. Linear Imaging Self Scanning (LISS)- Ill data of Indian Remote Sensing Satellites (IRS) 1C and 10, covering elevation range between 415.8 and 427.3 m, were used. Normalized Difference Vegetation Index (NDVI) and supervised classification techniques were used to determine water spread area. Revised live storage capacity was 375.55M m3. The silt Index for the live storage area was 2.82 ha m (100 km2 year)-1 (0.73 % of live storage or 6.13 M m3 year- 1). Total live storage lost in sedimentation was 465.63 M m3 (55.4 % of gross storage).