GATE — Environmental Science and Engineering (ES) · India · IITs and IISc on rotation (2026: IIT Guwahati)
Original practice questions written to the published syllabus · not past papersUsing less water to grow food and sharing it fairly: water productivity, water footprint accounting, groundwater depletion, rainwater harvesting and the institutions that govern water. Irrigation system design is in the Agricultural Engineering track; water pricing economics is in the Agribusiness track.
In the exams: ICAR AIEEA-PG Water Science & Technology group; GATE ES Section 4 (water conservation, rainwater harvesting); ICAR AICE subject 71 Unit 1
GATE ES (Section 4) and UGC NET Environmental Sciences
Water scarcity indicators, rainwater harvesting and recharge, groundwater depletion, virtual water and water footprint, wastewater reuse and SAR, IWRM principles.
How our questions for GATE spread across the units of Agricultural Water Conservation, Water Footprint & Governance. Difficulty: 12 easy, 4 medium, 1 hard.
| Water scarcity indicators and the water-food-energy nexus | 2 | |
| Water productivity and 'more crop per drop' | 2 | |
| Water footprint: green, blue and grey water | 2 | |
| Virtual water and trade | 2 | |
| Groundwater depletion and aquifer management | 2 | |
| Rainwater harvesting and managed aquifer recharge | 2 | |
| Wastewater reuse in agriculture: benefits and risks | 1 | |
| Integrated Water Resources Management | 1 | |
| Water rights, allocation and participatory irrigation management | 1 | |
| River basin governance and transboundary water | 1 | |
| Water stewardship standards for agri-food companies | 1 |
Choose an answer, then open the working. Each explanation says why the right answer is right and why the others are not.
1 mm of water over 1 hectare equals:
C. 10 m3
1 ha = 10,000 m2; 0.001 m x 10,000 m2 = 10 m3.
Rainwater stored in the soil and used by crops is which water footprint component?
A. Green
Green = rainwater evapotranspired; blue = surface or groundwater consumed; grey = dilution volume for pollution.
A country imports 2,000,000 t of wheat with a virtual water content of 1,300 m3/t. How much virtual water does it import?
D. 2.6 km3
2,000,000 x 1,300 = 2,600,000,000 m3 = 2.6 km3 (1 km3 = 10^9 m3).
A 1,000 km2 unconfined aquifer's water table falls 1.0 m in a year; specific yield is 0.12. How much groundwater storage is lost?
D. 0.12 km3
1,000,000,000 m2 x 1.0 m x 0.12 = 120,000,000 m3 = 0.12 km3. Ignoring specific yield gives the whole rock volume; using (1 - Sy) is wrong.
Which programme (from 2020) supports community-led groundwater management in water-stressed blocks of India?
A. Atal Bhujal Yojana
Atal Bhujal Yojana targets participatory groundwater management.
A roof of 100 m2 receives 800 mm of rain a year, with a runoff coefficient of 0.8. How much water can be harvested?
C. 64 m3
100 x 0.8 m x 0.8 = 64 m3. Ignoring the coefficient gives 80; using mm as m gives the third.
India's campaign promoting rainwater harvesting under the slogan 'Catch the Rain' is:
C. Jal Shakti Abhiyan
Jal Shakti Abhiyan promotes water conservation and harvesting; Namami Gange focuses on cleaning the Ganga.
Irrigation water contains Na = 20.0 meq/L, Ca = 4.0 meq/L and Mg = 4.0 meq/L. What is its sodium adsorption ratio?
B. 10.0
SAR = 20.0 / sqrt((4.0 + 4.0)/2) = 20.0/2 = 10.0. Omitting the square root or the /2 gives the other values.
The doctrine 'first in time, first in right' describes:
D. Prior appropriation
Prior appropriation, from the western US, gives priority to earliest beneficial users.
Which body brokered the Indus Waters Treaty between India and Pakistan?
C. The World Bank
The World Bank brokered the 1960 treaty and has roles in its dispute mechanisms.
Ten here, 17 in the app. The Laisha app has every practice question we have written to GATE in this subject, marked as you go, with timed papers, a jump-to-unanswered list and a certificate when you pass at 70 per cent.
Free for ten days, then one subscription of US$10 a month. We would rather say so here than have you find it later.
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