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(Download) UPSC: Geologist Examination Papers-2020 (Hydrogeology Paper)

(Download) UPSC: Geologist Main Examination Papers-2020

(Hydrogeology Paper)

Exam Name : UPSC Geo-Scientist and Geologist Main Exam

Subject : UPSC Geo-Scientist and Geologist Main Exam Papers 2020 : Hydrogeology Paper

Year : 2020

Hydrogeology Paper

Time Allowed : Three Hours
Maximum Marks : 200

SECTION A

(Compulsory Section)
Q1. Write short notes on the following in not more than 5 sentences each : 5x8=40

(a) Geologic Materials as Aquifers

(b) Isohyets

(d) Residence Time of Groundwater

(e) Reynolds Number

(f) Groundwater Drawdown

(g) Direct Rotary Drilling

(h)Wenner Array in Resistivity Survey

SECTION B

Attempt any one question.

Q2. (a) Derive Darcy's equation for anisotropic materials.

(b) Groundwater flows through an aquifer of cross-section area 10,000 m2 and with a length of 1000 m. Hydraulic heads at the groundwater entry and exit points in an aquifer are 250 m and 200 m respectively. Groundwater from the aquifer discharges into a stream at a rate of 100 m3/day. Calculate the hydraulic conductivity of the aquifer. If the effective porosity of the aquifer is 0·2, what is the linear groundwater velocity ?

Q3. (a) Differentiate between Hydraulic conductivity and Permeability.

(b) An aquifer consisting of 400 m interbedded sandstone and shale has 60% sandstone. The sandstone and shale have hydraulic conductivity of 0.1 m/s each and vertical hydraulic conductivity of 0.01 m/s each. Calculate the ratio of equivalent horizontal hydraulic conductivity and vertical hydraulic conductivity of the aquifer.

(c) If hydraulic conductivity and thickness of an aquifer are 0.5 cm/sec and 25 m respectively, what is the transmissivity of the aquifer ?

SECTION C

Attempt any one question.
Q4. (a) Derive Thiem's method for steady-state flow in a confined aquifer.
(b) Discuss on well completion and development methods.
(c) What is base flow? How is it estimated ?
Q5 (a) What is the difference between aquifer performance test and step drawdown test for sustainable yield of tube-wells ?
(b) Explain the difference between the groundwater level fluctuation due to evaporation and evapotranspiration.
(c) Define slug test. How is transmissivity of aquifer calculated by this test ?

SECTION D

Attempt any one question.
Q6. (a) Explain the technique to infer suitable sites for groundwater exploration by using Resistivity meter.
(b) Explain borehole logging with special reference to Gamma logging in groundwater exploration.
(c) Discuss the drilling methods for groundwater exploration in different geological formations.
Q7. (a) What is DTH drilling for groundwater exploration ?
(b) Using hyperspectral sensor, how is it possible to infer groundwater quality ?
(c) What is Proton Precession Magnetometer ? Discuss the functioning of this instrument in groundwater exploration.

SECTION E

Attempt any one question.
Q8. (a) What are the major chemical constituents of groundwater ? Discuss the factors that may affect the composition of groundwater.
(b) What is Total Dissolved Solids (TDS) in groundwater ? Explain its significance in determining the suitability of groundwater for drinking purposes.
(c) Express 23 mg/L sodium (Na) in mol/L (Atomic wt. of Na = 23).
Q9. (a) Discuss the use of Hydrogen and Oxygen isotopes in the study of groundwater.
(b) What is Artificial groundwater recharge ? Discuss with suitable illustration, Roof-Top Rainwater Harvesting System for recharging the groundwater.
(c) Calculate the total harvestable rainwater from a roof having an area of 40 m2, with total annual rainfall of 60 inches and runoff coefficient 0.9.