Sources of Freshwater and Hydrological Cycle

Sources of Freshwater

• 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.

Renewable Nature of Water

• 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).

Variability of Water Availability

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

Causes of Water Scarcity

• 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.

Qualitative Aspects of Water Crisis

• 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.