Engineering Hydrology (CE-802 (A)) - Important Questions

Explain the practical applications of hydrology in civil engineering projects such as irrigation, flood control, reservoir planning, drainage, and bridge design.

A watershed of $695 \text{ Km}^2$ with six rainfall gauges can be divided into Thiessen polygon with the data listed in the accompanying table. Using the total storm rainfall depth listed, find the average rainfall over the watershed.

Define rainfall mass curve. Explain the procedure for its construction and interpretation with suitable sketch and applications.

Describe the hydrologic cycle with neat sketch and also write the detail note on water budget equation.

Explain the procedure for supplementing the missing rainfall data. The maximum one day rainfall indicated that a depth of $280\,mm$ had return period of $50$ years. Determine the probability of a one-day rainfall depth equal to or greater than $280\,mm$ at this city occurring (i) Once in $20$ successive years (ii) two times in $15$ successive years and (iii) at least once in $20$ successive years.

Types of rain gauges used in India with merits and demerits, forms of precipitation, and convective and orographic precipitation.

What are the different types of precipitation, and how do they vary in terms of form and intensity?

How precipitation is measured and description of commonly used types of rain gauges.

In a catchment area, the annual rainfall recorded by rain gauges A, B, C, D, E and F are 52, 63, 35, 56, 40 and 59 cm respectively. For a 10% error in estimation of mean rainfall, calculate the optimum number of rain gauges in the area.

What is stream flow? Explain the various methods of stream flow measurement, their principles, and applications.

Define evapotranspiration, explain factors affecting evapotranspiration, and describe methods for estimating evapotranspiration from water bodies.

Describe the construction and working of a double ring infiltrometer with a neat sketch. Mention its advantages and limitations.

Given $\phi$-index and storm data, estimate net runoff, total rainfall and W-index.

Explain steady radial flow to a well in a confined aquifer and apply Dupuit's equation to determine well discharge from drawdowns at two observation wells.

Determine the $\Phi$-index from successive rainfall intensities and observed runoff volume.

Derive infiltration rate and average infiltration rate from cumulative infiltration equation $F(t)$.

Distinguish between (i) Infiltration capacity and Infiltration Rate (ii) Actual and potential evaporation (iii) Field capacity and permanent wilting point (iv) Depression storage and interception.

A well of $0.5\,m$ diameter penetrates fully into a confined aquifer of thickness $20\,m$ and hydraulic conductivity $8.2 \times 10^{-4}\,m/s$. What is the maximum yield expected from this well if the draw down in the well is not to exceed $3$. The radius of influence may be taken as $260\,m$.

Derive the steady-state discharge equation for a well in an unconfined aquifer relating discharge to water-table depths at two known radial distances, stating all assumptions.

Discuss infiltration equations and determination of Horton's constants $f_c$, $f_o$ and $k$ from experimental data.

Calculate infiltration rate from power-law rate equation $f(t)=k t^2$.

Write Horton-type infiltration equation and compute time for infiltration rate to reach a given value.

A researcher is studying the impact of soil texture on infiltration rates. In a sandy soil, the infiltration rate is found to be 0.5 mm/hour, while in a clayey soil, it's 0.2 mm/hour. Calculate the difference in infiltration rates between these two soil types.

Given the ordinates of a unit hydrograph of one duration, construct the S-curve hydrograph and use it to derive the ordinates of a unit hydrograph of a different duration.

Explain characteristics of a flood hydrograph with sketch and solve triangular hydrograph for peak direct runoff and runoff volume.

Define runoff. Explain the various factors affecting runoff from a catchment with suitable examples.

Calculate DRH ordinates from given unit hydrograph ordinates for a given rainfall excess

Explain the procedure for derivation of Snyder's synthetic unit hydrograph for an ungaged catchment.

Write detailed short note on method of superposition, instantaneous unit hydrograph, and synthetic unit hydrograph

Calculate the synthetic unit hydrograph for a watershed given time to peak, time of concentration, and basin lag parameters.

Define a hydrograph, explain its components, and describe watershed response to rainfall.

Route a flood hydrograph through a river reach using the Muskingum method with $K=8$ hours and $x=0.25$ given initial outflow discharge.

Define Instantaneous Unit Hydrograph (IUH), explain its characteristics and describe the procedure for its derivation with sketch.

Using Gumbel's method with flood peaks known for two return periods, estimate the flood magnitude for a return period of $1000$ years.

Using Gumbel's method with given mean, standard deviation and large sample size, estimate the design flood for $90\%$ assurance of no failure in the next $50$ years.

A flood of $4000\,m^3/s$ in a certain river has a return period of $40$ years. (i) What is its probability of exceedence? (ii) What is the probability that a flood of $4000\,m^3/s$ or greater magnitude may occur in next $20$ years? (iii) What is the probability of occurrence of a flood of magnitude less than $4000\,m^3/s$?

Describe the numerical method of hydrologic reservoir routing.

Distinguish between hydraulic versus hydrologic flood routing methods, and between hydrologic storage routing versus hydrologic channel routing.

Define Instantaneous Unit Hydrograph (IUH) and explain how it differs from a conventional unit hydrograph.

Compare and contrast reservoir (storage) routing versus channel routing in flood routing, including characteristics and applications.

Discuss the causes of reservoir sedimentation and the factors influencing the rate of sediment deposition.

Explain the various methods used for controlling reservoir sedimentation, including sediment flushing, dredging and watershed management practices.

Write a short note on any two :