Morphometric Analysis of Kakoi River Watershed for Study of Neotectonic Activity Using Geospatial Technology

Francis Sangma,Guru Balamurugan

doi:10.4236/ijg.2017.811081

Abstract

Morphometric analysis is defined as the quantitative measurement of landscape shape. Morphometric studies of a watershed helps the researcher to compare different landform and calculate the geomorphic indices that may be useful for identifying a particular characteristic such as the level of neotectonic activity in a watershed. The present study has been carried out in Kakoi River Watershed which is a part of Lower Subansiri River Basin in Assam. The study area is geo-dynamically unstable region characterized by active faults, continuing crustal movements and complicated structural region which fall under the seismic zone V of India. In recent century, the Lower Suabsiri River Basin has gone tremendous morphological changes due to active tectonics activities. After the Assam Earthquake of 1950, some of the rivers like Subansiri and its tributaries Dirgha, Kadam and Kakoi suddenly changed their channels giving birth to new channels. The present study is to examine the neotectonic domains and the changes of river course. The geomorphic indices such as Hypsometric Integral (HI), Elongation ratio (Re), Asymmetry Factor (AF), Stream-length Gradient Index (SI), Mountain Front Sinuosity (Mfs), Basin shape index (Bs), Ratio of Valley floor width to Valley Height (Vf) and Channel sinuosity (S) etc. have been studied from remote sensing data. The results shows that the study area is under active tectonic area based on Vf (0.301), Rl (0.461), Bs (3.6), Sl (165.73) and other parameters such as S (1.38) and Mfs (2.02) indicated as moderate active tectonic region. Utilization of geospatial technology and remote sensing data in the present study becomes more reliable and helpful in analyzing, monitoring and understanding the landform changes in a watershed.

Highlights

Morphometry is the mathematical and geometrical representation of earth’s surface and shape dimension of earth’s landform [1] [2] [3]
The results shows that the study area is under active tectonic area based on valley floor (Vf) (0.301), Rl (0.461), Basin shape index (Bs) (3.6), Stream length-gradient index (Sl) (165.73) and other parameters such as S (1.38) and Mountain Front Sinuosity (Mfs) (2.02) indicated as moderate active tectonic region
The Kakoi river is 5th order basin which traverse through high land, mid land and low land

Summary

Introduction

Morphometry is the mathematical and geometrical representation of earth’s surface and shape dimension of earth’s landform [1] [2] [3]. After the Assam Earthquake of 1950, some of the rivers like Subansiri and its tributaries Dirgha, Kadam and Kakoi suddenly changed their channels giving birth to new channels destroying villages, agricultural fields or tea-plantation [26]. Geospatial technologies such as GIS and remote sensing data have been used successfully to evaluate the terrain and morphometric parameters of a watershed with easier and better accuracy [27]. The analysis for the present study is carried out by GIS and remote sensing data to calculate the geomorphic indices of the watershed digitally and precisely This helps to generate data to understand the watershed characteristics and changes of the landform. The main objectives of the morphometric analysis of the Kakoi River watershed are: ● To examine the active tectonic domains in the watershed; ● To examine the river course changes due to the active tectonic activities using geospatial technology

Study Area

Materials and Methodology

Data Analysis and Results

Discussion and Conclusions