EGU21-9362
https://doi.org/10.5194/egusphere-egu21-9362
EGU General Assembly 2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

An entropy-based investigation on the river recovery potential in a regulated river basin 

Chandan Pradhan, Suman Padhee, Subashisa Dutta, and Rishikesh Bharti
Chandan Pradhan et al.
  • Indian Institute of Technology Guwahati, Civil Engineering, Guwahati, India (c.pradhan@iitg.ac.in)

River recovery is the process that describes the capacity of the river to adjust to the limiting boundary conditions. In the regulated rivers, altered flow-sediment regime controls the trajectory of adjustments along the geomorphic and vegetative attributes. The present study is focused on recovery potential assessment of Mahanadi River, which shows a gradual emergence of in-channel vegetation in the post-dam period. The study area encompasses (i) 10 km reach of Mahanadi River (M1) having bedrock exposed, anabranching channel pattern and (ii) 102 km reach of Ong river (O1) with alluvial, compound channel form. In this study, Google Earth Engine cloud computing platform is used to process the Landsat images (1980-2010) and vegetation, water, and floodplain geomorphic classes are derived by Normalized Difference Vegetation Index (NDVI) and modified Normalized Difference Water Index (mNDWI). Finally, the intensity disorder index (IDI) is computed to represent the ‘system state’ in the post-monsoon periods and the influence of vegetation growth on the channel recovery. The results show that M1 is relatively stable, with cumulative vegetation area increased from 2% in 1980 to 8% in 2010. However, O1 demonstrates an accelerated increase in vegetation area i.e., 10% in 1980 to 30% in 2010. The system state (IDI) varies between 0.2 and 0.6 and follows a decreasing trend along M1 and O1. The findings establish that both regulated reaches may approach channel recovery in the near future, and prevailing boundary conditions indirectly influence the rate and direction of IDI.        

How to cite: Pradhan, C., Padhee, S., Dutta, S., and Bharti, R.: An entropy-based investigation on the river recovery potential in a regulated river basin , EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-9362, https://doi.org/10.5194/egusphere-egu21-9362, 2021.

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