Q. How do Himalayan rivers maintain their flow throughout the year while peninsular rivers show significant seasonal variations?(150 words)
13 Jan, 2025 GS Paper 1 Geography
Approach
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Himalayan rivers, such as the Ganga, Yamuna, and Brahmaputra, maintain perennial flow, whereas Peninsular rivers like the Godavari, Krishna, and Mahanadi exhibit seasonal variations in their discharge. These differences arise due to distinct geographical, climatic, and hydrological factors that influence their regimes.
Geographical Factors: Himalayan vs Peninsular Rivers' Flow:
Himalayan rivers maintain their perennial nature due to glacial melt, large catchments, and favorable climatic conditions, while peninsular rivers face seasonal variations due to monsoon dependence, geological constraints, and smaller catchments. These differences underline the need for effective water resource management, such as river interlinking, to mitigate disparities and ensure sustainable water availability.
Alternatively, the body section can be presented in tabular format:
Aspect | Himalayan Rivers | Peninsular Rivers |
Source of Origin and Water Supply | Originate from glaciers and snow-fed regions in the Himalayas, ensuring perennial flow. | Rain-fed, relying heavily on the southwest monsoon, resulting in seasonal water supply. |
Examples: Ganga from Gangotri Glacier; Brahmaputra from Chemayungdung Glacier. | Examples: Godavari from Trimbakeshwar; Krishna from Mahabaleshwar. | |
Melting glaciers during summer sustain flow, even with reduced rainfall. | Dry up or experience reduced flow in non-monsoon months due to lack of alternative water sources. | |
Climatic Influence | Humid and subtropical climate ensures steady precipitation, including winter snowfall and monsoon rains. |
Semi-arid to tropical climate leads to pronounced seasonality with high monsoon discharge and dry-season flow. |
Examples: Ganga tributaries (e.g., Kosi) receive rainfall from the Terai region. | Examples: Cauvery and Tungabhadra show significant flow reductions in dry seasons. | |
Catchment and Geology | Large catchments with extensive tributary networks, supported by young, tectonically active Himalayas. | Smaller catchments, originating from ancient, stable geological formations with hard crystalline rocks. |
Examples: Brahmaputra has vast tributaries like Dibang and Lohit, sustaining flow. | Seasonal rainfall drains quickly due to hard terrain and limited permeability. | |
Human Interventions | Perennial flow supports irrigation and hydroelectric projects, enabling flow regulation. | Seasonal flow limits utility for irrigation and drinking water during dry seasons. |
Examples: Tehri Dam on Bhagirathi; Farakka Barrage on Ganga for irrigation and navigation. | Examples: Hirakund Dam on Mahanadi often faces storage issues during dry seasons. |