Evaluating damming effect on eco-hydrological alteration in river and wetland using indicators of hydrological alteration

Abstract

Present work successfully examined the damming impact on the eco-hydrological conditions of the river and wetland. The study found that monthly mean discharge was attenuated by 1.61 to 57% after damming. About 28.57 to 100% flow failure rate was found in the post-dam period and a moderate to the high degree of negative hydrological alteration (HA) for different IHA groups was identified. The flow failure rate in the river was >70% in most of the months while wetland water depth failure rates were 43% in pre-dam to 71% in post-dam, and a low and high negative degree of HA was observed over 20% and 9% of wetland areas respectively during post-monsoon season. The damming effect was found more intensive in the river than in wetlands. The eco-hydro deficit was recorded, which is an indication of growing ecological distress. The current result is used for river and wetland restoration planning.