JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD B.Tech III WATER RESOURCES ENGINEERING Previous Question Paper (October - 2020 - R16)

Infiltration is the process by which water on the ground surface enters the soil. The primary factors affecting the rate and capacity of infiltration include:

• Characteristics of the soil: Soil texture, structure, and porosity determine the size and connectivity of voids. Sandy soils have higher infiltration rates than clayey soils.
• Initial moisture content: Drier soils exhibit higher initial infiltration rates due to higher matric suction, whereas saturated soils have significantly reduced infiltration capacity.
• Vegetative cover: Vegetation intercepts rainfall, reduces surface runoff velocity, and improves soil structure through root systems, which increases infiltration.
• Surface conditions: Compaction, crusting, or the presence of impervious surfaces (like pavement) drastically reduce infiltration.
• Rainfall intensity: If rainfall intensity exceeds the infiltration capacity of the soil, surface runoff occurs.
• Temperature: Higher temperatures decrease the viscosity of water, which can slightly increase the rate of infiltration into the soil profile.

The hydrological cycle is the continuous movement of water on, above, and below the surface of the Earth. The process can be represented by the following components:

The schematic flow involves the following stages:

• Evaporation and Transpiration: Water from oceans, lakes, and plants enters the atmosphere as water vapor.
• Condensation: Water vapor cools in the atmosphere to form clouds.
• Precipitation: Water returns to the Earth's surface as rain, snow, or hail.
• Infiltration and Percolation: Water enters the soil and moves to groundwater aquifers.
• Runoff: Excess water flows over the land surface into streams, rivers, and eventually back into oceans, completing the cycle.