THEORY EXAMINATION (SEM–VIII) 2016-17 GROUNDWATER MANAGEMENT

SECTION – A

Explain the following (Short Answer Type)

Aquifers are underground layers of permeable rock or soil that store and transmit groundwater. The main types include confined aquifers, unconfined aquifers, semi-confined aquifers, and perched aquifers.

A hydro-geologist is a specialist who studies groundwater sources, movement, quality, and availability beneath the earth’s surface.

Dupuit’s theory assumes that groundwater flow is horizontal, steady, and uniform, and it neglects vertical flow components.

Confined aquifers are bounded between impermeable layers and contain pressurized water, while unconfined aquifers have a free water table and are open to the atmosphere.

A water well is a structure drilled or dug into the ground to extract groundwater for domestic, agricultural, or industrial use.

Types of tube wells include shallow tube wells, deep tube wells, strainer tube wells, and artesian tube wells.

Groundwater modelling techniques include mathematical modelling, numerical simulation, physical modelling, and computer-based modelling.

Groundwater drainage refers to removing excess groundwater to prevent waterlogging and improve soil productivity.

Groundwater management models help in sustainable water use, efficient planning, and prevention of over-extraction.

Remote sensing helps in groundwater management by locating aquifers, mapping water resources, and monitoring water levels.

Questions (Section A)

List types of aquifers.

Who is a hydro-geologist?

What are limitations of Dupuit’s theory?

What is groundwater drainage?

What is the use of remote sensing?

SECTION – B

Attempt any five (Long Answer Type)

Groundwater occurs due to infiltration of rainwater into soil and rocks, forming aquifers below the earth’s surface. Its occurrence depends on geology, rainfall, and permeability.

Flow net construction represents groundwater flow using equipotential lines and flow lines. It helps analyze seepage and water movement.

Well losses occur due to friction, turbulence, and resistance near the well screen. These reduce pumping efficiency.

Tube well design involves calculating yield, drawdown, aquifer thickness, and permeability to ensure adequate water supply.

Well construction includes drilling, casing installation, and screen placement. Completion involves cleaning and testing the well.

Artificial recharge adds water to aquifers using recharge pits, while artificial discharge removes groundwater using pumping systems.

Groundwater budgeting calculates water inflow and outflow to maintain sustainable usage.

Rainwater harvesting collects rainwater for storage and groundwater recharge, especially in urban areas.

Questions (Section B)

Explain occurrence of groundwater.

What is flow net construction?

What are well losses?

What is artificial recharge?

Explain rainwater harvesting methods.

SECTION – C

Attempt any two (Detailed Explanation)

Steady-state discharge from a well in an unconfined aquifer can be derived using Darcy’s law by considering assumptions of horizontal flow and constant water table conditions.

Geophysical exploration techniques include electrical resistivity, seismic, magnetic, and gravity methods used to locate groundwater sources.

The hydrologic cycle describes the continuous movement of water through evaporation, condensation, precipitation, infiltration, and runoff.

Movement of contaminated groundwater occurs due to processes like diffusion, dispersion, adsorption, and chemical reactions.

Groundwater modelling uses mathematical equations and computer simulations to predict groundwater behavior, while GIS helps analyze spatial groundwater data.

Questions (Section C)

Explain hydrologic cycle.

What is groundwater modelling?

What are geophysical exploration methods?