Geography Indian Physical 3 · Section 7

maturity of the rivers. The Western Ghats running close to the western coast act as the water divide between the major Peninsular rivers, discharging their water in the Bay of Bengal and as small rivulets joining the Arabian Sea. Most of the major Peninsular rivers except Narmada and Tapi flow from west to east. The Chambal, the Sind, the Betwa, the Ken, the Son, originating in the northern part of the Peninsula belong to the Ganga river system. The other major river systems of the Peninsular drainage are – the Mahanadi the Godavari, the Krishna and the Kaveri. Peninsular rivers are characterised by fixed course, absence of meanders and non- perennial flow of water. The Narmada and the Tapi which flow through the rift valley are, however, exceptions. The Evolution of Peninsular Drainage System Three major geological events in the distant past have shaped the present drainage systems of Peninsular India: (i) Subsidence of the western flank of the Peninsula leading to its submergence below the sea during the early tertiary period. Generally, it has disturbed the symmetrical plan of the river on either side of the original watershed. (ii) Upheaval of the Himalayas when the northern flank of the Peninsular block was subjected to subsidence and the consequent trough faulting. The Narmada and The Tapi flow in trough faults and fill the original cracks with their detritus materials. Hence, there is a lack of alluvial and deltaic deposits in these rivers. (iii) Slight tilting of the Peninsular block from northwest to the southeastern direction gave orientation to the entire drainage system towards the Bay of Bengal during the same period. River Systems of the Peninsular Drainage There are a large number of river systems in the Peninsular drainage. A brief account of the major Peninsular river systems is given below: The Mahanadi rises near Sihawa in Raipur district of Chhattisgarh and runs through Odisha to discharge its water into the Bay of Bengal. It is km long and its catchment area spreads over . lakh sq. km. Some navigation is carried on in the lower course of this river. Fifty three per cent of the drainage basin of this river lies in Madhya Pradesh and Chhattisgarh, while per cent lies in Odisha. The Godavari is the largest Peninsular river system. It is also called the Dakshin Ganga. It rises in the Nasik district of Maharashtra and discharges its water into the Bay of Bengal. Its tributaries run through the states of Maharashtra, Madhya Pradesh, Chhattisgarh, Odisha and Andhra Pradesh. It is , km long with a catchment area spreading over . lakh sq. km per cent of this, lies in Maharashtra, per cent in Madhya Pradesh and Chhattisgarh, and the rest in Andhra Pradesh. The Penganga, the Indravati, the Pranhita, and the Manjra are its principal tributaries. The Godavari is subjected to heavy floods in its lower reaches to the south of Polavaram, where it forms a picturesque gorge. It is navigable only in the deltaic stretch. The river after Rajamundri splits into several branches forming a large delta. The Krishna is the second largest east- flowing Peninsular river which rises near Mahabaleshwar in Sahyadri. Its total length is , km. The Koyna, the Tungbhadra and the Bhima are its major tributaries. Of the total catchment area of the Krishna, per cent lies in Maharashtra, per cent in Karnataka and per cent in Andhra Pradesh. The Kaveri rises in Brahmagiri hills ( ,341m) of Kogadu district in Karnataka. Its length is km and it drains an area of , sq. km. Since the upper catchment area receives rainfall during the southwest monsoon season (summer) and the lower part during the northeast monsoon season (winter), the river carries water throughout the year with comparatively less fluctuation than the other Peninsular rivers. About per cent of the Kaveri basin falls in Kerala, per cent in Karnataka and per cent in Tamil Nadu. Its important tributaries are the Kabini, the Bhavani and the Amravati. The Narmada originates on the western flank of the Amarkantak plateau at a height of about , m. Flowing in a rift valley between the Satpura in