The west-flowing rivers of India, though fewer in number and generally shorter than their east-flowing counterparts, possess distinct characteristics primarily due to their origin, topography, and geological structure. The major west-flowing rivers include the Narmada, Tapi (Tapti), Sabarmati, Mahi, and numerous smaller, swift rivers originating in the Western Ghats.

Here are their salient features:

1. Origin and Direction of Flow: Most significant west-flowing rivers (Narmada, Tapi, Mahi, Sabarmati) originate in the Central Highlands or the Satpura Range and flow westward into the Arabian Sea. A large number of smaller, perennial rivers originate in the Western Ghats and flow westward directly into the Arabian Sea.

2. Rift Valley Flow (Narmada and Tapi): The Narmada and Tapi rivers are unique as they flow through rift valleys. These valleys are formed by faulting, where blocks of the Earth's crust have subsided. This geological feature dictates their straight, linear courses and prevents them from forming deltas.

3. Estuary Formation: Unlike the east-flowing rivers which form extensive deltas, west-flowing rivers typically form estuaries at their mouths. An estuary is a partially enclosed coastal body of brackish water with one or more rivers or streams flowing into it, and with a free connection to the open sea. This is due to their shorter courses, steeper gradients, and the hard rock terrain they traverse, which limits sediment deposition.

4. Shorter Courses and Steeper Gradients: Rivers originating in the Western Ghats are generally short and swift due to the steep western slope of the Ghats. This steep gradient results in high velocity and significant erosional power, often leading to the formation of waterfalls (e.g., Sharavathi River forming Jog Falls).

5. Non-Perennial Nature (mostly): While the larger rivers like Narmada and Tapi are perennial, many of the smaller west-flowing rivers originating in the Western Ghats are largely rain-fed and can experience reduced flow or even dry up during the dry season, especially those with smaller catchment areas.

6. Limited Tributaries: Due to their shorter courses and the rugged terrain, these rivers generally have fewer and shorter tributaries compared to the large east-flowing river systems.

7. Hydroelectric Potential: The steep gradients and swift flow of many west-flowing rivers, particularly those in the Western Ghats, offer significant potential for hydroelectric power generation. Projects like the Koyna Hydroelectric Project (though Koyna flows east, many similar projects exist on west-flowing rivers) harness this energy.

8. Limited Navigability: Their swift currents, rocky beds, and often shallow depths make most of these rivers less suitable for navigation, especially for large vessels.

9. Economic Significance: Despite their shorter lengths, these rivers are vital for irrigation, domestic water supply, and industrial use in the states they traverse (Gujarat, Maharashtra, Goa, Karnataka, Kerala). They also support rich estuarine ecosystems that are important for fisheries and biodiversity.

In summary, the west-flowing rivers of India are characterized by their unique geological settings (rift valleys), steep gradients, short courses, and the formation of estuaries, distinguishing them significantly from the larger, delta-forming east-flowing rivers.