Morphometry of Lebir River using the geographic information system (GIS) application

Morphometry is defined as understanding of the physical behaviour of the catchments by the evaluation of basin characteristics from the morphometric parameters with respect to floods. This study was conduct at the Lebir River, Kelantan, Malaysia. It is a stream in the peninsular Malaysia. Lebir River is the main and large tributaries of the Kelantan River. Lebir River has 130.18 km of basin length and 3274.6 km2 of catchment area. Lebir River is the main water sources and flood disaster causes on 2014 for local people due to the water catchment. Proper management of river catchment area have to be done by applying morphometry analysis that can assist in future planning and able to predict the events which may happen through hydrology and geomorphology. The studies need a reading of topographical map. All the data from the linear, aerial and relief aspect are collected using Geographic Information System (GIS) at the Lebir River catchment area. Findings of the study, linear aspect of Lebir River catchment area have a stream order 1 to order 8. The total number of stream is 18,440 river which is total length is 1 1,531.83 km. Length of 15‘ order to 8“‘ order are 7093.32 km, 2109.15 km, 1128.33 km, 544.68 km, 292.20 km, 249.75 km, 59.83 km and 54.56 km respectively. The mean stream length for the Lebir catchment area is 0.63 km. The highest stream length ratio is 0.91 km and the lowest is 0.24 km. Catchment area river is strongly distort by the geologic structures which is 6.10, high value of bifurcation ratio. Afterward, the aerial aspect for the catchment area resulted 3.52 km-1 of drainage density, 5.63 km-2 of stream frequency, 45.36 km-1 of drainage texture, 0.19 of fonn factor, and 0.25 of circulatory ratio, 0.49 of elongated ratio and 0.49 of length of the overland flow. This indicates that Lebir River has a weak or impermeable subsurface material, sparse vegetation and mountainous relief, high relief condition and low infiltration causes more water flow during the period of high intensity rainfall capacity, mature topography and elongated shape basin. Relief ratio of the catclunent is 16.60 m/km-1, indicate that the watershed is more vulnerable to severe erosion and steeper slope which is higher relief ratio. Relative relief of the catchment is 5.31 lead to low relative relief. The using of GIS is very assistance in this study to compute all the morphometry parameter. To finish, this study can be provide information to the local community around the catchment and especially to the local authorities. The early sustainable precaution measure and management can be done through this study and create the sustainable development awareness of Lebir River basin area.