Water Resources Cheat Sheet
Different Monsoon Seasons
India experiences four main monsoon seasons:
• Southwest Monsoon (June to September): Brings heavy rainfall to most of India.
• Northeast Monsoon (October to December): Brings rainfall to southeastern India.
• Pre-Monsoon (March to May): Marked by rising temperatures and occasional storms.
• Winter Monsoon (December to February): Brings dry and cool weather across most of
India.
Factors influencing monsoons include geography, elevation, and ocean temperatures.
Evaporation Measurement by Lysimeter
A lysimeter is used to measure actual evapotranspiration (evaporation + transpiration).
• It consists of a soil-filled container isolated from surroundings.
• Measures water input (precipitation, irrigation) and soil moisture changes.
• Used for accurate field-based evapotranspiration measurements, aiding water resource
management.
Distribution of Water
Global water distribution:
• Oceans: 97.5%
• Glaciers and ice caps: 2.15%
• Groundwater: 0.31%
• Surface water (lakes, rivers): 0.01%
• Atmosphere: 0.001%
• Biological water: 0.00004%
Most freshwater is in glaciers and ice caps, leaving less than 1% available for direct use.
Hydrological Cycle
The hydrological cycle describes the continuous movement of water:
• Evaporation from water bodies, soil, and plants
• Transpiration from plants
• Condensation in the atmosphere
• Precipitation as rain, snow, or hail
• Surface runoff into rivers, lakes, and oceans
• Infiltration into the ground, moving as groundwater
Subsurface Distribution of Water
Subsurface water exists as:
• Soil moisture: Water in soil pores, available for plants.
• Groundwater: Water in deeper layers, stored in rock formations.
Groundwater is influenced by soil type, geology, and climate.
Aquifers & Types
An aquifer is a geological formation storing and transmitting groundwater:
• Unconfined aquifer: No overlying impermeable layer, allowing direct recharge.
• Confined aquifer: Has an impermeable layer above, storing pressurized water.
• Perched aquifer: A small, isolated aquifer above the main water table.
• Artesian aquifer: A confined aquifer where groundwater rises due to pressure.
Rainwater Harvesting (Roof & Surface)
Rainwater harvesting methods:
• Roof rainwater harvesting: Collects rooftop rainwater into tanks or ponds.
• Surface rainwater harvesting: Collects rainwater from land surfaces into reservoirs.
Benefits include water conservation, groundwater recharge, and flood control.
Water Distribution Scenario in Karnataka
Karnataka faces diverse water challenges due to variable climate:
• Receives rainfall from both southwest and northeast monsoons, but unevenly distributed.
• Groundwater varies in availability and quality across regions.
• Major rivers include the Cauvery, Krishna, and Godavari, with water-sharing disputes.
• Increasing focus on conservation, efficient irrigation, and rainwater harvesting.
