03-18-2021, 12:13 PM
Rainfall Analysis
CPHEEO MANUAL ON STORM WATER DRAINAGE (PART-A) 2019
Rainfall analysis is carried out to identify and sort out various magnitudes (intensities) of rainfall events and their corresponding durations occurring at a station from a continuous series of historical rainfall records taken for a fairly long period viz. last 25 - 30 years or more. IDF curves are not static as they are influenced by change in pattern of rainfall and therefore IDF curve should be prepared at an interval of 5 – 10 years for accurate results. The rainfall analysis helps to establish intensity-duration-frequency relationship for various frequencies which are used in estimation of runoff for design of storm water drains. The frequency or return period of a storm event may be defined as the average recurrence interval between events equal to or exceeding a specified magnitude. Thus, if it is stated that the return period of rainfall of 20 cm in 24 hours is 10 years at a certain station A, it implies that on an average rainfall magnitudes equal to or greater than 20 cm in 24 hours occur once in 10 years.
for more detail download ..
CPHEEO MANUAL ON STORM WATER DRAINAGE (PART-A) 2019
Rainfall analysis is carried out to identify and sort out various magnitudes (intensities) of rainfall events and their corresponding durations occurring at a station from a continuous series of historical rainfall records taken for a fairly long period viz. last 25 - 30 years or more. IDF curves are not static as they are influenced by change in pattern of rainfall and therefore IDF curve should be prepared at an interval of 5 – 10 years for accurate results. The rainfall analysis helps to establish intensity-duration-frequency relationship for various frequencies which are used in estimation of runoff for design of storm water drains. The frequency or return period of a storm event may be defined as the average recurrence interval between events equal to or exceeding a specified magnitude. Thus, if it is stated that the return period of rainfall of 20 cm in 24 hours is 10 years at a certain station A, it implies that on an average rainfall magnitudes equal to or greater than 20 cm in 24 hours occur once in 10 years.
for more detail download ..
