Bathymetric, Topographic and GPR Survey of Glacial Lakes

Bathymetric, Topographic and GPR Survey of Glacial Lakes

Project: Glacial Lakes Study

Assignment: Bathymetric, Topographic and GPR Survey of Glacial Lakes

Location: Dolakha District and Sankhuwasabha District

Client: Department of Hydrology and Meteorology

Duration:  March 2021 to December 2021

Project Description: DHM (Department of Hydrology and Meteorology) is continuously involved in preparing the Bathymetric and Topographic map of different glacier lakes of Nepal in order to plan for proper mitigation measures from GLOFs and giving continuation to this task, DHM has planned to perform Bathymetric and Topographic survey of Tsho Rolpa and Lower Barun.
Tsho Rolpa is one of the biggest glacial lakes in Nepal. The lake, which is located at an altitude of 4,580 metres in the Rolwaling Valley, Gaurishankar Rural Municipality, Dolakha District, Bagmati Province has grown considerably over the last 50 years due to glacial melting in the Himalayas. It is situated in between 86°27’50” E 27°52’10” N to 86°29’18” E, 27°52’10” N. Lower Barun Glacial lake is located in upper reach of Barun river which lies in Makalu Rural Municipality, Sankhuwasabha district, Province 1 of Nepal. Geographically the lake is situated at 27°47’45” N and 87°06’10” E about 4550 masl.

Scope of Services:

1.  Scientific study of Glacial lakes
   • Collect and review of previous study reports, manuals, standards, guidelines, maps, drawings etc.
   • Conduct desk study, analyze the available data and identify data gap of previous study & recommend the further additional study        needed to prepare report
   • Conduct engineering survey and field investigation for
    o Bathymetric survey of the lakes
    o Topographical surveys including L-section & X-section survey
    o Hydrological studies and sediment studies and water quality study
    o Ground Penetrating Radar Survey at the end moraines, at the locations of seepage, cracks etc
   • Compile, analyze outcome of field survey and investigation
   • Prepare a complete report on scientific study of the Glacial lakes
   • Prepare a detailed bathymetric map, topographic map of the Glacial lakes
2.  Study for the maintenance of Built Structures of Tsho Rolpa
   • Collect and review of previous study reports, manuals, standards, guidelines, maps, drawings etc.
   • Visual inspection and thorough observation of the built structures at Tsho Roi pa Glacial Lake with special focus on Micro-                     hydropower plant, detailed inspection and measurements of damaged parts of the structures, photograph and videos of the                 various components.
   • Conduct longitudinal profile survey from the intake to the powerhouse
   • Suggest necessary repair/maintenance/replacement works also stating the order of priority for maintenance
   • Prepare of detailed design, drawings, specifications, cost estimate and tender document for the procurement of maintenance              works of such structures.