The document contains 5 experiments related to hydrology. Experiment 1 asks to determine the additional number of raingauges needed for a catchment area that currently has 5 raingauges, to reduce the error in estimating the mean rainfall to 6%. Experiment 2 provides rainfall data for a station and surrounding areas over 16 years and asks to check for consistency, identify any change in regime, and compute adjusted rainfall for the affected period. Experiment 3 asks to estimate infiltration rate using a double ring infiltrometer. Experiment 4 asks to derive the ordinates of a 6-hour unit hydrograph using the ordinates of a 3-hour unit hydrograph and the method of superposition. Experiment 5 asks to derive the ordinates of an

1. Exp:1
A catchment has five raingauge stations. In a year, the annual rainfall recorded by the
gauges are 78.8cm, 90.2cm, 98.6cm, 102.4cm and 70.4cm. For a 6% error in the
estimation of mean rainfall, determine the additional number of raingauge needed.
Exp:2
The annual rainfall at station X and the average of annual rainfalls at 10 surrounding
base stations in cm are given below for a period of 16 years, starting from 1970.
1) Check whether the data at station X is consistent.
2) In which year a change in regime is indicate?
3) Compute the adjusted annual rainfalls at X for the affected period.
Exp:3
Estimate the infiltration rate at the catchment by using the double ring infiltrometer
Exp:4
The following are the ordinates of a 3-hour unit hydrograph. Derive the ordinates
of a 6-hour unit hydrograph and plot the same. (by using methods of superposition)

2. Exp:5
The ordinates of a 4-hour unit hydrograph for a particular basin are given below. Derive
the ordinates of (i) the S-curve hydrograph, and (ii) the 2-hour unit hydrograph, and plot
them, area of the basin is 630 km2.