How to Prepare Hydrology for GATE Civil Engineering
This article on Hydrology has been written by Rohit Sachdeva. He graduated from Delhi College of Engineering (now DTU) in 2012 (a gold medalist in his batch) in Civil Engineering branch. Then he appeared in Civil Engineering (CE) paper in GATE 2017 and secured an All India Rank (AIR) of 93.
In this blog, I will be discussing how to prepare for one of the easiest subject in Civil Engineering: Hydrology. If you take a little effort to prepare, marks can be scored easily this subject.
A rough breakup of questions of various chapters in last 30 years in GATE is as follows:
|Sl No||Topic||No. of Questions|
|1 mark||2 marks||5 marks|
|1||Precipitation & Frequency of Rainfall Data||7||1|
|2||Evaporation and Transpiration||2||3|
|5||Maximum Flood Estimation||1|
If we check the last 5 years GATE papers, we can see that Hydrology and Irrigation Engineering together carry 6-9 marks.
Time Required for Preparation (for Hydrology)
12-14 days (if you have 8-10 months of preparation) with 3 hours daily
6-7 days (if you have 4-5 months of preparation) with 6-7 hours daily
In this blog, I will be dealing with hydrology only. Irrigation and hydraulic structures will be discussed in following blogs. It is advisable to prepare separate notes for formulae and for working out numerical questions. The topic wise preparation strategy is given below, with the most important concepts in bold & italics. Approximate time required for each chapter is mentioned along with it. This can be varied according to individual interests. The textbook(s) to be referred are mentioned in a separate comprehensive blog which you should refer.
- PRECIPTATION & FREQUENCY OF RAINFALL DATA (2 DAYS)
Basics of precipitation, measurement of precipitation, rain gauge networks, optimum number of rain gauges, calculation of missing rainfall data, representation of rainfall data, methods to calculate mean precipitation, calculation of probability, return period and risk are the important topics. In this chapter, give equal importance to both concepts and numerical questions related to all these topics.
2. EVAPORATION & TRANSPIRATION (2 DAYS)
Basics of evaporation, transpiration and evapotranspiration, their measurements and methods to calculate are the important topics. Give importance to numerical questions which deal with inflow-outflow-storage-losses relations.
3. INFILTRATION (2 DAYS)
Horton’s infiltration curve and infiltration indices are most important. Numerical questions from these topics are commonly asked in GATE.
4. HYDROGRAPHS (3 DAYS)
Components of hydrographs, factors affecting flood hydrograph, effective runoff hydrograph, direct hydrographs and unit hydrographs are included in this chapter. This is the most important topic in this subject. Get the concepts cleared and work out maximum numerical questions to get a thorough idea.
5. MAXIMUM FLOOD ESTIMATION (1 DAY)
Go through the different methods to estimate maximum flood (rational method is the most common one). In-depth study is not necessary for this chapter.
6. FLOOD ROUTING (1 DAY)
Hydrologic routing and hydraulic routing are included in this chapter. Linear reservoir and Muskingum method are important. Give importance to theory. Match the following questions are common. Since the numerical questions are lengthy, just work out one or two to get an idea.
7. WELL HYDRAULICS (2 DAYS)
Aquifers, Dupuit’s theory, specific yield and retention and recuperation test on open wells. Give importance to numerical questions related to the calculation of discharge from aquifers as well as water storage in aquifers.