Surface water resources
Topic: Water Resources of India: Availability, Use and Conservation · NCERT: Class 12, Ch 4 "Water Resources"
Meaning
Surface water resources are the water in rivers, lakes, ponds and tanks. India has about 10,360 rivers longer than 1.6 km, and together they carry about 1,869 cubic km of water a year. Only about 690 cubic km (32%) of this can actually be used. The rest cannot be held back, because the land is too steep or uneven and because most rain falls in a few monsoon months and quickly runs off to the sea.
Example
The Ganga, Brahmaputra and Barak basins cover about one-third of India's area but hold about 60% of its surface water. Much of this water is still not tapped. In contrast, the Godavari, Krishna and Kaveri in peninsular India are already heavily used.
Don't confuse with
- Groundwater: water stored underground in soil pores and rock layers (aquifers). NCERT puts India's replenishable groundwater at about 432 cubic km. Surface water flows or stands above the ground.