Precipitation and Frequency of Rainfall Data · Hydrology · GATE CE

A 1-hour rainfall of 10 cm has a return period of 50 years. The probability that 1 hour of rainfall 10 cm or more will occur in each of two successive years is

An isohyet is a line joining points of

The return period for the annual maximum flood of a given magnitude is 8 years. The probability that this flood magnitude will be executed once during the next 5 years is

Hyetograph is a graph representing

A tropical cyclone in a northern hemisphere is a wind stream with

A storm with a recorded precipitation of 11.0 cm, as shown in the table, produced a direct run-off of 6.0 cm.

Time from start (hours)	1	2	3	4	5	6	7	8
Recorded cumulative precipitation (cm)	0.5	1.5	3.1	5.5	7.3	8.9	10.2	11.0

The Ø-index of this storm is ______________ cm/hr (rounded off to 2 decimal places).

The ordinates of a 1-hour unit hydrograph (UH) are given below.

Time (hours)	0	1	2	3	4	5
Ordinates of 1-hour UH (m3/s)	0	13	50	80	95	85

Time (hours)	6	7	8	9	10	11
Ordinates of 1-hour UH (m3/s)	55	35	15	10	3	0

These ordinates are used to derive a 3-hour UH. The peak discharge (in m³/s) for the derived 3-hour UH is ___________ (rounded off to the nearest integer).

A catchment may be idealized as a circle of radius 30 km. There are five rain gauges, one at the center of the catchment and four on the boundary (equi-spaced), as shown in the figure (not to scale).

The annual rainfall recorded at these gauges in a particular year are given below.

$$ \begin{array}{|l|l|l|l|l|l|} \hline \text { Gauge } & \mathrm{G}_1 & \mathrm{G}_2 & \mathrm{G}_3 & \mathrm{G}_4 & \mathrm{G}_5 \\ \hline \text { Rainfall }(\mathrm{mm}) & 910 & 930 & 925 & 895 & 905 \\ \hline \end{array} $$

Using the Thiessen polygon method, what is the average rainfall (in mm, rounded off to two decimal places) over the catchment in that year? ________

A catchment is idealized as a 25 km × 25 km square. It has five rain gauges, one at each corner and one at the center, as shown in the figure. During a month, the precipitation at these gauges is measured as G₁ = 300 mm, G₂ = 285 mm, G₃ = 272 mm, G₄ = 290 mm and G₅ = 288 mm. The average precipitation (in mm, up to one decimal place) over the catchment during this month by using the Thiessen polygon method is_______ .

In a catchment, there are four rain-gauge stations, P, Q, R, and S. Normal annual precipitation values at these stations are 780 mm, 850 mm, 920 mm, and 980 mm, respectively. In the year 2013, stations Q, R, and S, were operative but P was not. Using the normal ratio method, the precipitation at station P for the year 2013 has been estimated as 860 mm. If the observed precipitation at stations Q and R for the year 2013 were 930 mm and 1010 mm, respectively; what was the observed precipitation (in mm) at station S for that year?