THESIS ABSTRACT

Abstract

There are so many infrastructure development programs in different parts of the nation. One of the concentrated areas of infrastructure development is the northeast part of the Koshi Province of Nepal which demands large-scale construction materials. Although there are many quarry sites established as a source of raw materials in different parts of Nepal, there is a shortfall in that sector. Some source of construction raw materials includes boulder, aggregate, sand is alluvial deposit in the River floodplain. Tamor River is one of the main tributaries of the Koshi River in Koshi Province, Nepal. Sedimentation in Koshi River is also contributed by Tamor River and this bed load sediment can also be used as raw material in construction work. However, it is not possible to enter at any point of the river easily and extract material due to varying river morphology. The material quality of alluvial deposit also varies, that needs to be tested for physical properties to identify whether it falls within the acceptance level of specification. Since the material extraction has also an adverse effect on the river and surroundings, it needs prior study to identify the probable adverse effect of extraction and mitigation measures to overcome the adverse effect. This study aims to identify a suitable source of construction material in the Tamor River. The objective of this study is to find a suitable location in Tamor River that yield construction material, the location is suitable for material extraction; the material available in the flood plain of Tamor River has physical property suitable for use in construction work and adverse effect of material extraction that can be mitigated with proper measures to overcome adverse effect. A field visit for observation of 85 km stretch of Tamor River from Dovan to Mulghat was conducted for a week. Primary data were collected by field observation and structured interviews with the people in the vicinity and people involved in Tamor corridor road construction work at the bank of Tamor River. The questionnaire was used to collect the experience and perception of Engineers of the office of Local Government, the Office under DoR, and Division Irrigation Office. Consultation was made with the expert of DoR vii offices and the Division Irrigation Office for KII to collect information about the material extraction in Tamor River and compare the outcome of this study. Field visit and material sampling for testing was conducted at five Tamor River locations at each tributary's main confluence. The test result of the material has been compared with Indian Standards and Specifications for Roads and Bridge, Nepal. Alluvial deposit material has been found in all sections of the river. A suitable location for the quarry site is from Majhitar downward in the wider valley of the Tamor River Basin. The physical property of the sample material is acceptable from Limbunighat to Phalametar. The quality of material at the lower section was found to be of inferior quality. There is a least probability of adverse effects of material extraction that can be controlled by mitigation measures. Hence it is concluded from the study, that the river bed material from Tamor River can be extracted for a small-scale quantity of work for road sub base, base course, and ordinary concreting work for any kind of structure with preventive plan from Majhitar to Phalametar. It is recommended to use alluvial deposit material from the Tamor River extracted from 2 km downstream of Majhitar to Phalametar far apart from the residential area and up to deposited depth only with a prior confirmatory test. Further study of the main tributary of the Tamor River is recommended.

Keywords

Material Extraction, Adverse effect, Mitigation measure, Alluvial deposit material, Physical property, etc.