Morphometry of Pergau River Catchment Area

Morphometry is the measurement of form and pattern. The study of morphometry is fundamental to the study of hydrology, geomorphology, the study of land use, water resources, and so on. It is used to describe the characteristics and geometry parameters of a river basin so that it is more objective and meaningful. In the present paper, the research has been made to study the detail morphometry characteristic of Pergau River catchment area. Pergau River is important to the surrounding environment and the society living along of this river because this river is one of the important water reservoir and resources for the local people and also among the river that supply freshwater fish. The study of morphometry analysis of Pergau River catchment area was carried out by employing topographical map and field observation techniques. For detail study, Geographical Information System (GIS) was used in evaluation of linear, aerial and relief aspects of morphometric parameters. Pergau River has been found basin length with 99.74 km. The total stream length of all stream segments under stream order 1 ( 1 st order) to order 7 (7th order) are found to be 3,159.960 km, 1,029.248 km„ 511.917 km, 238.777 km, 166.628 km, 76.441 km and 25.992 km respectively. The total length of all streams for the entire water catchment area has thus been found to be 5,208.963 km with 7 stream order. The highest bifurcation ratio is found to be 19.40 and mean of bifurcation ratio is 6.373, which fall under the category of normal basin. The study focused on selected morphometrical aspects of the rivers basins namely drainage density, drainage pattern, stream frequency, elongation ratio, circulatory ratio, form factor and length of overland flow. Result of the study shows that the river basin has drainage density of 3.795 km/sq.lcm and the stream at the study area mostly poses dendritic drainage pattern. Pergau River has stream frequency value of 11.480, texture ratio of 76.568, elongation ratio of 0.419 and circulatory ratio of 0.407. The relief ratio was 0.019 and it has been observed that areas with low to moderate relief and slope are characterized by high value of relief ratios. Geographical Information System (GIS) could be effectively used for the computation of these morphological characteristics with a greater efficiency and accuracy. The study will provide the local people a good knowledge and information so that they can utilize the resources for sustainable development of the basin area.