Drainage Morphometry of Flood Prone Rangat Watershed, Middle Andaman, India- A Geospatial Approach
Shiva Shankar1, Dharanirajan2

1Shiva Shankar, Department of Disaster Management, Pondicherry University, (Port Blair), India.
2K.Dharanirajan, Assistant Professor, Department of Disaster Management, Pondicherry University, (Port Blair), India.
Manuscript received on 6 April 2014 | Revised Manuscript received on 17 April 2014 | Manuscript Published on 30 April 2014 | PP: 15-22 | Volume-3 Issue-11, April 2014 | Retrieval Number: K15630431114/14©BEIESP
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© The Authors. Blue Eyes Intelligence Engineering and Sciences Publication (BEIESP). This is an open access article under the CC-BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)

Abstract: Floods is one of the wide spread global geo-epidemics frequently causing extensive loss of life and property, flood induced disease, hampering of socio-economic activity including transport and communication. Rangat watershed in middle Andaman is not an exception for that instance. Morphometric analysis of Rangat watershed using Geographic Information System (GIS) and remote sensing indicates that it is susceptible to flooding during extreme meteorological events. The watershed exhibit dentritic drainage pattern and has a perennial Rangat river of 4th order. The computed values of drainage density (2.76 Km/ Km2), stream frequency (5.66 no. streams/ Km2), drainage texture (6.26), infiltration number (15.62), form factor (0.35), elongation ratio (0.19) and Compactness constant (1.51) of the Rangat watershed articulates that it is elongated sub-circular having moderate relief and low infiltration capacity due to impervious sub-surface resulting rapid storm response giving rise to a higher runoff resulting in downstream flooding. Rangat River has the highest stream order (4th order) associated with greater discharge and higher velocity of the stream flow indicating the watershed is highly susceptible to floods during monsoon.
Keywords: Floods, Drainage Morphometry, Geographic Information System, Remote Sensing, Rangat River, Andaman

Scope of the Article: Disaster Management