Sources of Freshwater and Hydrological Cycle

Study Notes

Freshwater is primarily derived from precipitation, surface runoff, and groundwater.
Surface runoff refers to water that flows over land surfaces into bodies of water after rainfall.
Groundwater is sourced from aquifers, which are underground layers of water-bearing rock.

Water is classified as a renewable resource because it is continuously replenished.
The hydrological cycle is a key process where water circulates between the hydrosphere, atmosphere, and lithosphere.
Throughout the hydrological cycle, water changes its state (e.g., evaporation, condensation).

Water availability fluctuates based on geographical location and seasonal variations.
Annual and seasonal precipitation differences impact the distribution and accessibility of freshwater resources.

Rapid population growth increases water demand, leading to unequal access and scarcity.
Food production needs drive over-exploitation of water resources for irrigation to support higher agricultural yields.
Excessive use of wells and tube-wells by farmers leads to diminished groundwater levels, affecting water availability and food security.
Urbanization and industrialization place stress on existing freshwater sources due to increased water and energy demands.
Urban centers with dense populations utilize their own groundwater pumps, leading to further depletion of groundwater reserves.

Even with abundant water resources in India, many regions face scarcity due to quality issues.
Pollution from domestic and industrial waste deteriorates the quality of available water.
Toxicity concerns arise from improper waste disposal, agriculture runoff, and chemicals contaminating water supplies.
Major rivers like the Ganga and Yamuna are heavily polluted due to human activities, including urban development and agricultural practices.