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International Journal of Scientific Research in _______________________________ Research Paper .
Multidisciplinary Studies E-ISSN: 2454-9312
Vol.5, Issue.8, pp.114-132, August (2019) P-ISSN: 2454-6143
Rainfall Analysis for Modelling of IDF Curves for Bangalore Rural,
Karnataka
Mohammed Badiuddin Parvez
1
*, M Inayathulla
2
1,2
Dept. of Civil Engineering, UVCE, Bangalore University, Bangalore ,Karnataka, India
Corresponding Author: parvezuvce@gmail.com Tel.: +919060506390
Available online at: www.isroset.org
Received: 15/Aug/2019, Accepted: 28/Aug/2019, Online: 31/Aug/2019
Abstract- Changes in the hydrologic cycle due to increase in greenhouse gases cause variations in intensity, duration, and
frequency of precipitation events. Quantifying the potential effects of climate change and adapting to them is one way to
reduce urban vulnerability. Since rainfall characteristics are often used to design water structures, reviewing and updating
rainfall characteristics (i.e., Intensity –Duration–Frequency (IDF) curves) for future climate scenarios is necessary. The present
study regards the evaluation of the IDF curves for Four raingauge stations of Bangalore rural : Anugondanahalli, Devanahally,
Doddabalapura and Hoskote. Starting from daily rainfall observed data, to define the IDF curves and the extreme values in a
smaller time window (2, 5, 10, 15, 30, 60, 120, 720, 1440 minutes), disaggregation techniques of the collected data have been
used, in order to generate a synthetic sequence of rainfall, with statistical properties similar to the recorded data. Then, the
rainfall pattern of the Four raingauge stations was analyzed and IDF curves were evaluated.
Key words: Gumbel Distribution, Intensity Duration Frequency (IDF), Log Normal Distribution, Normal Distribution, Pearson
Type III Distribution, Log Pearson Type III Distribution Rainfall Duration, Return Period, Rainfall Intensity.
I. INTRODUCTION
Degradation of water quality, property damage and potential
loss of life due to flooding is caused by extreme rainfall
events. Historic rainfall event statistics (in terms of intensity,
duration, and return period) are used to design flood
protection structures, and many other civil engineering
structures involving hydrologic flows. Since rainfall
characteristics are often used to design water structures,
reviewing and updating rainfall characteristics (i.e.,
Intensity–Duration–Frequency (IDF) curves) for future
climate scenarios is necessary. A lot of studies, especially
recently, have been developed to analyze the factors for
assessment, adaptation and mitigation of climate change, and
to enhance and sharpen the disaster management for the
many and various stakeholders.
IDF stands for Intensity-Duration-Frequency. Rainfall
intensity is defined as the ratio of the total amount of rain
(rainfall depth) falling during a given period to the duration
of the period It is expressed in depth units per unit time,
usually as mm per hour . The period of time over which
rainfall is measured is called duration. The number of times,
during a specified period of years, that precipitation of a
certain magnitude or greater occurs or will occur at a station
is called frequency. (FAO, 2012).
The relation between rainfall and runoff is influenced by
various storm and basin characteristics. Because of these
complexities and the frequent paucity of adequate runoff
data, many approximate formulae have been developed to
relate rainfall and runoff. The earliest of these formulae were
usually empirical statements.
Section I contains the IDF information, Section II contain
the Study Area and methodology adopted, Section III
contain the result and discussions, Section IV concludes
research work with future directions.
II. MATERIALS AND METHODS
A. Study Area
The Study Area is located be tween Latitude 12º57′40.47′′ N
to 13º29′30.3′′ N and 77º10′30.3′′ E to 77º57′22.9′′ E
Longitude. The average mean daily temperature varies from
14 to 35
0
C respectively. Four Raingauges Stations were
considered as shown in Figure 1.