Preparation of Water Induced Hazard Map of Rangoon River

Project Description

The scope of the proposed Water-Induced Hazard Maps preparation shall be in two parts
• Survey and Data collection by topographic survey of the designated area and the water-induced hazard susceptible areas and submission of the reports
• Preparation and submission of Water-induced Hazard Maps of the Rapti River Basin based on the field survey aerial photo interpretation and GIS Analysis
The work include but not be limited to the following designated areas
• The rivers under the proposed consulting job shall be all the rivers that lie from the upstream of the confluence of Arjun Khola (including Arjun Khola) and Rapti River within the Rapti River Basin. All the sub-basins of the primary tributary of Rapti River shall be delineated and prioritized under the basis of water induced hazard severity.
• Topographical survey should be conducted to draw the cross-sections of the Rapti River along the following locations The cross section shall be taken at 200 m interval sufficient width to cover the probable hazard area and width, sufficient to cover the natural flow regime The data shall be used to assess the flood inundation, and bank erosion hazard map.
• From Arjun Khola and Rapti River confluence to 4 km upstream of Bhaluwan Bridge of Mahendra Highway along Rapti River.
• From the confluence of Ransin Khola and Rapti River upto 3 km upstream of Ransin Khola.
• From the confluence of Kundara Khola and Jhimruk Khola (near Aap Chaur and Dhudi) upto the confluence of Jihimruk Khola and Chudndari Khola (near Kuti Chaur) including Jhimruk hydropower project along Jhimruk Khola.
• From the confluence of Lungri Khola and Madi Khola to the downstream to the confluence of Bhitin Khola and Madi Khola along Madi Khola.
• From the confluence of Lungri and Madi Khola to the confluence of Deukhuri Khola and Lungri Khola along Lungri Khola
• From the confluence of Hiron Khola and Madi Khola upstream to Chalenetar, Judadpata.
• Survey shall be conducted to draw all the major landslides and debris flow area within the Basin as well as along the road sector from Bhaluwan, Dang to Liban. Rolpa district and Bhaluwan to Khlanga to Chunjathati, Asurkot as well as the Machhi road sector in Pyuthan Road. The data shall be presented in the Topographical maps of 1:25000 scale produced by the Department of Survey.
• Detailed slope map of the debris flow prone settlements and landslide prone settlements should be prepared in 1:25000 scale maps. This map should show details about occurrence area, flow area and deposition area of the debris flow.
• The consultant shall update the database associated with the digital maps with the identification of the river in the area and additional fields incorporating information collected during the study.
• The consultant should propose the minimum required width of all the rivers under natural condition within the Rapti River Basin.
• Each hazard maps should clearly indicate the existing settlements and infrastructure under threat delineating the administrative boundaries.

Assignment Description

The scope of the proposed Water-Induced Hazard Maps preparation shall be in two parts • Survey and Data collection by topographic survey of the designated area and the water-induced hazard susceptible areas and submission of the reports • Preparation and submission of Water-induced Hazard Maps of the Rapti River Basin based on the field survey aerial photo interpretation and GIS Analysis The work include but not be limited to the following designated areas 1. The rivers under the proposed consulting job shall be all the rivers that lie from the upstream of the confluence of Arjun Khola (including Arjun Khola) and Rapti River within the Rapti River Basin. All the sub-basins of the primary tributary of Rapti River shall be delineated and prioritized under the basis of water induced hazard severity. 2. Topographical survey should be conducted to draw the cross-sections of the Rapti River along the following locations The cross section shall be taken at 200 m interval sufficient width to cover the probable hazard area and width, sufficient to cover the natural flow regime The data shall be used to assess the flood inundation, and bank erosion hazard map. • From Arjun Khola and Rapti River confluence to 4 km upstream of Bhaluwan Bridge of Mahendra Highway along Rapti River. • From the confluence of Ransin Khola and Rapti River upto 3 km upstream of Ransin Khola. • From the confluence of Kundara Khola and Jhimruk Khola (near Aap Chaur and Dhudi) upto the confluence of Jihimruk Khola and Chudndari Khola (near Kuti Chaur) including Jhimruk hydropower project along Jhimruk Khola. • From the confluence of Lungri Khola and Madi Khola to the downstream to the confluence of Bhitin Khola and Madi Khola along Madi Khola. • From the confluence of Lungri and Madi Khola to the confluence of Deukhuri Khola and Lungri Khola along Lungri Khola • From the confluence of Hiron Khola and Madi Khola upstream to Chalenetar, Judadpata. 3. Survey shall be conducted to draw all the major landslides and debris flow area within the Basin as well as along the road sector from Bhaluwan, Dang to Liban. Rolpa district and Bhaluwan to Khlanga to Chunjathati, Asurkot as well as the Machhi road sector in Pyuthan Road. The data shall be presented in the Topographical maps of 1:25000 scale produced by the Department of Survey. 4. Detailed slope map of the debris flow prone settlements and landslide prone settlements should be prepared in 1:25000 scale maps. This map should show details about occurrence area, flow area and deposition area of the debris flow. 5. The consultant shall update the database associated with the digital maps with the identification of the river in the area and additional fields incorporating information collected during the study. 6. The consultant should propose the minimum required width of all the rivers under natural condition within the Rapti River Basin. 7. Each hazard maps should clearly indicate the existing settlements and infrastructure under threat delineating the administrative boundaries.