Morphometric Analysis of Madurai Basin –A case study of Cauvery sub watershed region of Tamil Nadu -India

Abstract

The morphometric analysis of the drainage basin and channel network play a vital role in understanding the
hydro-geological behavior of drainage basin and expresses the prevailing climate, geology, geomorphology and structure. It
provides a quantitative description of the basin geometry to understand its slope, structural controls, geological and
geomorphic history of drainage basin. In the present case study, geomorphometric analysis of Madurai drainage basins (A
part of Cauvery sub watershed region of Tamil Nadu in India) investigates the influence of relief, slope, geologic structure,
tectonic uplift and climate change on basin geometry, pattern of drainage network, landform evolution and basin hy drology.
The geomorphometric analysis includes quantitative measurement and analysis of topography and drainage characteristics
like, altitude variation (relief and slope), channel network morphometry (stream order, stream number, stream length,
bifurcation ratio etc.) and drainage basin morphometry (drainage density and frequency, basin shape, drainage texture,
constant of channel maintenance etc.). On the basis of stream order, stream number, stream length and bifurcation ratio, the
stream denotes the normal geomorphic characteristic i.e. order wise the number, length and bifurcation ratio is decreasing
which is a clear indication of normal tectonically undisturbed landform. The drainage frequency and drainage density values
show little bit abnormality i.e . for the range of 2.1 to 4.0 and 2 – 4 for drainage density and drainage frequency respectively,
hike in the area as compared to the lower and higher range is the important point of study of this particular category. The
absolute relief indicates the abnormality in the second category which ranges from 2.1 to 3 towards the higher order. In
addition to this the absolute relief values for category 4, 5 and 6are decreasing. The kinds of lower and higher repetition
indicate the influence of the tectonic activity in the study area. Geomorphologically the terrain occupies very little high relief
area where steep slope occurs, while rest of the area shows the normal landform conditions.