Journal
NATURAL HAZARDS
Volume 97, Issue 2, Pages 535-553Publisher
SPRINGER
DOI: 10.1007/s11069-019-03657-6
Keywords
Glacial lake outburst flood (GLOF); 1D and 2D hydrodynamic modeling; Mountain hazard; Himalaya; HEC-RAS; Hydropower station
Funding
- MHRD
- MoES (IMPRINT)
- DST INSPIRE fellowship
Ask authors/readers for more resources
The existence of numerous lakes in the higher reaches of the Himalaya makes it a potential natural hazard as it imposes a risk of glacial lake outburst flood (GLOF), which can cause great loss of life and infrastructure in the downstream regions. Hydrodynamic modeling of a natural earth-dam failure and hydraulic routing of the breach hydrograph allow us to characterize the flow behavior of a potential flood along a given flow channel. In the present study, the flow hydraulics of a potential GLOF generated due to the moraine failure of the Satopanth lake located in the Alaknanda basin is analyzed using one-dimensional and two-dimensional hydrodynamic computations. Field measurements and mapping were carried out at the lake site and along the valley using high-resolution DGPS points. The parameters of Manning's roughness coefficient and terrain elevation were derived using satellite-based raster, the accuracy of which is verified using field data. The volume of the lake is calculated using area-based scaling method. Unsteady flood routing of the dam-break outflow hydrograph is performed along the flow channel to compute hydraulic parameters of peak discharge, water depth, flow velocity, inundation and stream power at a hydropower dam site located 28km downstream of the lake. Assuming the potential GLOF event occurs contemporaneously with a 100-year return period flood, unsteady hydraulic routing of the combined flood discharge is performed to evaluate its impact on the hydropower dam. The potential GLOF resulted in a peak discharge of2600 m(3)s(-1) at the dam site which arrived 38min after the initiation of the moraine-failure event. The temporal characteristics of the flood wave analyzed using 2D unsteady simulations revealed maximum inundation depth and flow velocity of 7.12m and 7.6ms(-1), respectively, at the dam site. Assuming that the control gates of the dam remain closed, water depth increases at a rate of 4.5m per minute and overflows the dam approximately 4min after the flood wave arrival.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available