Morphometric Analysis

Morphometric analysis provides quantitative expression of the drainage basins, and is regarded as one important tool in hydrological analysis (Angillieri, 2008) providing simple and accurate measures to document the drainage systems (Mesa, 2006). Morphometric analysis brings out the basic characters on the geometrical and mechanical aspects of the river basin which in turn would be helpful in understanding the hydrology, sediment characteristics and landscape evolution of basins. The morphometric analysis examines linear and areal aspects of the drainage networks (Nag and Chakraborty, 2003). The basic steps involved in morphometric analysis are defining, measuring and analyzing the quantitative indices related to flow plane geometry and profile,

Therefore documenting basin characteristics using morphometric techniques, well-known since early nineteenth century, are very valuable. The studies by Horton (1945), Strahler (1957 and 1964), and Schumm (1956 and1963) are well known works in the field. Studies conducted by Dade (2001), Singh et al., (2005), Sreedevi et al., (2005), Mesa (2006), Rao et al., (2006), Sarkar and Gundekar (2007), Rudraiah et al., (2008), Angillieri (2008), Thomas et al., (2010) are some of the recent studies. The recent studies make use of the potentials of Geographic Information System (GIS) and Remote Sensing (RS) as the most popular and effective tools to investigate the river morphometry and basin characters. The present study examines the morphometric characteristics of Bharathapuzha River basin using GIS and RS

This indicates the decrease in the slope in the basin’s terrain, it becoming more flattening and tending towards the coastal belt from the higher elevation Western Ghats. It is also observed that the stream length characteristic of the basin follows Horton’s second law, which states that the average length of streams of each of the different order in a drainage basin tends closely to reach a direct geometric ratio (Horton, 1945; Chow, 1964). Mean stream length (Lsm, the ratio of the total number of stream segment of a particular order to the total stream length of the same order) is believed to be a distinctive property of a river channel relating the drainage network components and its associated basin surfaces (Strahler, 1964). The stream length shows an abrupt increase in 4th and higher order for the main river as well as all the tributaries, indicating the pressure exertion from the structural elements especially slope and high amount of rainfall (Thomas et al.,