Engineering and environmental geological investigations in Butwal area

Abstract

The Butwal town lies at the junction of the Siddhartha and Mahendra highways. It is endangered by landslides and floods every year during the monsoon season.

The area consists of the Tertiary sedimentary rocks (Siwaliks) in the north and Quaternary sediments (Terai Plain) in the south. The Main Frontal Thrust (MFT) marking the contact between the Siwaliks and Terai runs along the topographic break, north of the main settlement of Butwal.

Landslide at Jyotinagar (north of Butwal) triggered after the heavy monsoon of 27th August 1998 is considered as one of the main geo-hazard in the area. Wide-open cracks are marked around the crown of the slide with the slope of 40-60 degrees. Infiltration and percolation of water through these cracks is further aggravating the situation.

Engineering and environmental geological investigations were carried out in the area with an objective to prepare the engineering and environmental geological map at 1:15,000 scale. This map would be a great help to engineers, urban planners and decision- makers particularly in urban planning, landuse planning, infrastructure development, hazard mitigation, sustainable utilization of natural resources and environmental management. The types of information included in the map are lithological description of rocks and sediments, geo-hazards, mineral resources, features of environmental significance, riverbed mining, landfill site, landuse and urban geology.