project

1. “Management of floods in urban environment - A study from Bengaluru”
Presentation by
Anusha C.M (1GA18CV009)
Ashik G.K (1GA18CV012)
Bhumika H.S (1GA18CV015)
C Harsha (1GA18CV017)
Under the guidance of
Dr. Radhika K.N. Msc PhD
Associate Professor
Department of Civil Engineering
Global Academy of Technology
Department of Civil Engineering
Global Academy of Technology, Bengaluru – 98
2021-2022
Visvesvaraya Technological University

2. CONTENTS
• ABSTRACT
• INTRODUCTION
• JUSTIFICATION OF PROBLEM
• OBJECTIVE
• STUDY AREA
• LITERATURE SURVEY
• METHODOLOGY
• HYDRO-METEOROLOGICAL STUDIES
• STRUCTURAL AND NON-STRUCTURAL MEASURES
• CONCLUSION
• REFERENCES
2
B.E. Dept of Civil Engg.
GAT, Bengaluru – 98

3. ABSTRACT:
 Urban flooding has been a problem in recent years as a result of
urbanization taxing urban drainage systems.
 If no improvements are made to the management of urban surface water,
these are expected to rise exponentially.
 In the current study, a systematic method to analyzing the cause of urban
floods has been made.
 Due to the invasion of IT, Bengaluru is currently experiencing the pinnacle
of its urbanization process.
B.E. Dept of Civil Engg. GAT, B engaluru
– 98 3

4.  Future urban expansion is predicted to result in an increase in population,
which will increase the risk of flooding in our metropolis.
 In the present study the hydrological parameters such as precipitation,
infiltration capacity, and evapotranspiration are comprehended. After
subtracting losses, the surplus runoff of 983.84mm was then calculated.
 By considering all the relevant data such as geological, geotechnical, and
hydrological data the subsurface drainage system was planned from
Nayandalli to collect excess runoff.
B.E. Dept of Civil Engg. GAT, Bengaluru
– 98 4

5. INTRODUCTION:
 Heavy rainfall that exceeds the capacity of the drainage system results in urban
floods. It already has significant social and economic effects.
 Due to the nature of the flood, even while the economic losses are substantial, the
number of casualties is typically quite low.
 While some floods develop over time and dissipate gradually, others, like flash
floods, can emerge suddenly and recede just as fast.
 In India, floods occur relatively frequently, although urban flooding has recently
evolved and is being investigated.
 Land use changes resulting from increased population and urbanization factor have
been directly connected to flood events in Bangalore city during the last decade.
B.E. Dept of Civil Engg. GAT, Bengaluru
– 98 5

6. JUSTIFICATON OF PROBLEM:
 Flooding in cities causes a slew of issues that affect people's daily lives.
Indeed, in our country, urban flooding has become a major disaster
management issue.
 We have a difficult problem as we approach the height of urbanisation,
when about 300 million people are estimated to be added to our cities over
the following two decades.
 Finally, population pressures, particularly in urban areas, have resulted in
haphazard and unplanned settlements in floodplains, exposing more people
to flood dangers.
B.E. Dept of Civil Engg. GAT, Bengaluru
– 98 6

7.  The following are the most common and anticipated problems associated with
urban flooding:
 Commuters have a tough time passing through under pass and fly overs which
are water clogged due to heavy rainfall.
 Several vehicles parked in the basement were covered with slush, had to be
towed away for expensive repairs.
 Work on storm water drains were in progress in several parts. These sites are
now flooded and water has over flowed on the roads.
 If there are heavy rains traffic in the city gets affected.
 Every time there is rain, there is flooding with 3 feet of water in houses.Lack
of outlet to rainwater to flow causes water clogging and flooding.
B.E. Dept of Civil Engg. GAT, Bengaluru
– 98 7

8.  The following photographs Show the effect of urban flooding face by Bangaloreans in
the recent times .
Fig 1. Flood related disaster in Bangalore
B.E. Dept of Civil Engg. GAT, Bengaluru
– 98 8

9. OBJECTIVES:
1. To identify the drainage pattern and analysis of land use/land cover of
flood prone areas.
2. To determine how the city's rainfall pattern influences the available water's
run-off characteristics.
3. Designing proper structural and non-structural preventive measures that
are less expensive than restoration after storm water damage.
4. Utilization of open spaces make the city self-sustainable.
5. To understand the topographical and lithological features.
B.E. Dept of Civil Engg. GAT, Bengaluru
– 98 9

10. B.E. Dept of Civil Engg. GAT, Bengaluru
– 98 10
DRAINAGE MAP OF BANGALORE URBAN MAP OF LAND USE LAND COVER

11. B.E. Dept of Civil Engg. GAT, Bengaluru
– 98 11
SLOPE PATTERN OF BANGALORE URBAN

12. STUDY AREA:
Population: 1.31 crores as of 2022 ( “Increased by 3.35% from 2021” )
Longitude and Latitude: 12º 40’-13º 20’ N; 77º 20’-77º 50’ E
Elevation: 920 m
Total area: 709 km²
Soil: The soils of districts can be grouped into red loamy soil and lateritic soil.
B.E. Dept of Civil Engg. GAT, Bengaluru
– 98 12
LOCATION MAP OF BENGALURU URBAN

13. LITERATURE SURVEY:
SL NO DETAILS OF
RESEARCH ARTICLE
POINTS TO BE
POUNDED
INFERENCE
01 Romali and Zulkifli
Yusop.
[2020]
Flood damage and risk
assessment for urban
area in Malaysia.
The assessment
considers flood hazard,
exposure, and flood
vulnerability. Assess
ment of effect of
flooding due to
residential and
commercial land usage,
and the estimation of
flood damage and
percentage of damage.
Overall, this research
has succeeded in
developing a
framework for
assessing flood damage
and risk in a city. The
hazard, exposure, and
vulnerability factors are
combined in the flood
damage estimation
framework. A site-
specific damage curve,
flood inundation maps,
flood damage
estimates, flood
damage–probability
curve, expected annual
damage (EAD), and
flood damage risk map
of Segamat town are
among the study's key
outputs.
B.E. Dept of Civil Engg. GAT, Bengaluru
– 98 13

14. SL NO DETAILS OF
RESEARCH ARTICLE
POINTS TO BE
POUNDED
INFERENCE
02 R. K. Price & Z.
Vojinovic
[2008]
Urban flood disaster
management
Collection of historical
rainfall data. Modelling
and flood hazard
mapping, flood damage
analysis, risk
assessment, structural
and non-structural
measures and disaster
management strategies.
This paper presents and
describes the digital
city concept as a means
of managing in an
affordable way the
urban storm water. The
particular focus of the
paper is on urban flood
disaster management.
Such floods are
generated either by
flows originating from
outside the urban area.
B.E. Dept of Civil Engg. GAT, Bengaluru
– 98 14

15. SL NO DETAILS OF
RESEARCH ARTICLE
POINTS TO BE
POUNDED
INFERENCE
03 Vasantha Kumar S. &
Shishodiya
Ghanshyam Singh.
[2022]
A systematic approach
for effective storm
water management at
building level during
extreme rainfall events
– a case study.
Preparation of maps for
extracting topographic
and hydrologic
parameters.
Identification of low-
lying areas using the
maps of topographic
and hydrologic
parameters. Study of
effectiveness of
stormwater
management plan
through hydrological
analysis of extreme
rainfall events.
Proper management of
storm water runoff
would help to recharge
the groundwater and
reduce the load on the
central storm water
drains. Further,
flooding in streets and
water stagnation around
the buildings can be
avoided. The study
reported in this paper
would be useful in
places where the water
stagnation is a potential
problem after a heavy
rainfall.
B.E. Dept of Civil Engg. GAT, Bengaluru
– 98 15

16. SL NO DETAILS OF
RESEARCH ARTICLE
POINTS TO BE
POUNDED
INFERENCE
04 Shubha Avinash.
[2014]
Flood Related Disaster:
Concerned to urban
flooding in Bangalore,
India.
Analysis of average
annual and monthly
rainfall in Bangalore.
Zonal distribution of
low lying areas in
BBMP, watershed
catchments and storm
water drain networks in
Bangalore.
The analysis reveals
that the excess runoff is
due to less carrying
capacity of storm water
drains in area. Due to
urban development on
wetlands and open
spaces, the paved area
is increased. It has
caused less infiltration
and more runoff.
B.E. Dept of Civil Engg. GAT, Bengaluru
– 98 16

17. SL NO DETAILS OF
RESEARCH ARTICLE
POINTS TO BE
POUNDED
INFERENCE
05 Shubha Avinash , K.
Lakshmi Prasad , G.S.
Srinivasa Reddy , D.
Mukund
[2019]
Influence of Land Use
Changes on Urban
Flooding: Case Study
of Bangalore City, India
Google earth, the
geospatial software
program maps the earth
by superimposing
satellite images, aerial
photography, and GIS
data onto a 3D globe.
Which in turn acts as a
guide in calculation of
impervious area
coefficient of runoff
and runoff volume.
Since the expanding
urban drainage system
requires a massive
investment with host of
commercial and
residential building in
the city, alternative
rainwater strategies
should be considered.
rainwater harvesting,
paved areas could be
minimized or replaced
with porous paving, and
also a variety of
landscape measures and
practices could be
applied to reduce the
volume of rainwater
runoff to decrease the
effects of flood.
B.E. Dept of Civil Engg. GAT, Bengaluru
– 98 17

18. SL NO DETAILS OF
RESEARCH ARTICLE
POINTS TO BE
POUNDED
INFERENCE
06 V. S. K. Vanama, Y. S.
Rao & C. M. Bhatt
[2021]
Change detection
based flood mapping
using multi-temporal
Earth Observation
satellite images:
2018 flood event of
Kerala, India
The overall
methodology adopted is
broadly divided into
five modules, i.e. data
preprocessing, PWB
mask creation, training
dataset creation and
flood mapping
techniques and CD
indices.
In this study, the
potential of freely
available multi-
temporal EO images
in flood mapping was
demonstrated for 2018
Kerala flood event.
This study explores this
scenario for assessing
the combined use of
ascending and
descending pass
satellite images over
the same location on
the same date to
monitor
the flood progression
and recession in the
duration of
a flood event.
B.E. Dept of Civil Engg. GAT, Bengaluru
– 98 18

19. METHODOLOGY:
Collection of Rainfall Data
Sorting and Compilation of data to
study area
Calculation of Hydrological
parameters
Structural stratergy design
Area selection—Nayandalli
B.E. Dept of Civil Engg. GAT, Bengaluru
– 98 19
slope, geological, geotechnical characteristics
a)Stepped apron
b)Subsurface drainage system

20. HYDRO METEOROLOGICAL STUDIES:
ANALYTICAL DATA:
Monthly Rainfall variation in Bangalore:
Month
January
,
Temperature
28° / 16
Rainfall(
mm)
22
February 31° / 18° 24.5
March 33° / 20 26.5
April 34° / 22 28
May 33° / 22 27.5
June 29° / 20 24.5
July 28° / 20 24
August 28° / 20 24
September 28° / 20 24
October 28° / 20 24
November 27° / 18° 22.5
December 27° / 16 21.5
B.E. Dept of Civil Engg. GAT, Bengaluru
– 98 20

21. B.E. Dept of Civil Engg. GAT, Bengaluru
– 98 21
The change in rainfall pattern over the year is
one of the reasons for urban flooding and this
has occurred in the year 2009, 2013, 2017 and
as well as in 2020.
953.307
811.736
936.397
552.058
849.352
764.411
1170.412
697.411
1201.26
1050
950.72
1210
0
200
400
600
800
1000
1200
1400
2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020
ANNUAL
RAINFALL
YEAR
ANNUAL RAINFALL
YEAR
ANNUAL
RAINFAL
L
2009 953.307
2010 811.736
2011 936.397
2012 552.058
2013 849.352
2014 764.411
2015 1170.412
2016 697.411
2017 1201.26
2018 1050
2019 950.72
2020 1210
TOTAL ANNUAL
RAINFALL FROM 2009-
2020 RAINFALL

22. Annual average monthly rainfall:
Sl.no. YEAR JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC
Total
annual(mm)
1 2009 0.738 1.231 185.401 665.364 1688.353 1020.680 470.580 1272.450 2999.312 337.161 782.864 108.931 953
2 2010 48.000 41.900 76.900 667.733 828.492 653.307 1182.294 996.982 1233.424 827.194 1473.171 88.235 812
3 2011.000 8.235 136.765 60.000 1119.706 1519.265 523.235 957.353 2143.824 811.765 1616.412 399.529 67.882 936
4 2012 9.706 2.941 25.882 244.412 860.882 133.824 670.882 1141.176 362.647 847.941 1039.118 181.176 552
5 2013 2.353 51.176 27.941 390.588 1164.412 980.588 862.941 852.059 2517.353 1134.412 495.294 14.412 849
6 2014 0.000 0.294 160.588 113.529 940.588 844.706 643.235 780.000 1377.941 2412.353 323.824 47.059 764
7 2015 130.000 0.882 321.765 1464.118 1439.412 1033.235 530.588 1291.471 2245.000 967.353 2184.412 95.882 1170
8 2016 68.529 0.000 47.647 67.353 1279.706 1560.000 2046.176 440.294 407.647 345.588 36.471 674.706 697
9 2017 8.824 0.294 194.500 272.353 2101.700 456.400 314.120 2506.500 3405.000 2458.580 105.800 188.700 1201
Monthly temperature
JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC
22 24.5 26.5 28 27.5 24.5 24 24 24 24 22.5 21.5
Lm 10.56 11.76 12.72 13.44 13.2 11.76 11.52 11.52 11.52 11.52 10.8 10.32
Runoff using Khosla's formula[Rm=Pm-Lm] (Lm=0.48Tm)
Sl.no. YEAR JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC
1 2009 0.0 0.0 172.7 651.9 1675.2 1008.9 459.1 1260.9 2987.8 325.6 772.1 98.6
2 2010 37.4 30.1 64.2 654.3 815.3 641.5 1170.8 985.5 1221.9 815.7 1462.4 77.9
3 2011 0.0 125.0 47.3 1106.3 1506.1 511.5 945.8 2132.3 800.2 1604.9 388.7 57.6
4 2012 0.0 0.0 13.2 231.0 847.7 122.1 659.4 1129.7 351.1 836.4 1028.3 181.2
5 2013 0.0 39.4 15.2 377.1 1151.2 968.8 851.4 840.5 2505.8 1122.9 484.5 4.1
6 2014 0.0 0.0 147.9 100.1 927.4 832.9 631.7 768.5 1366.4 2400.8 313.0 36.7
7 2015 119.4 0.0 309.0 1450.7 1426.2 1021.5 519.1 1280.0 2233.5 955.8 2173.6 85.6
8 2016 58.0 0.0 34.9 53.9 1266.5 1548.2 2034.7 428.8 396.1 334.1 25.7 664.4
9 2017 0.0 0.0 181.8 258.9 2088.5 444.6 302.6 2495.0 3393.5 2447.1 95.0 178.4
B.E. Dept of Civil Engg. GAT, Bengaluru
– 98 22

23. Calculation:
Runoff method using Khosla’s formulae
Rm=Pm-Lm
Lm=0.48Tm
Where Rm=Monthly runoff (mm)
Pm=Monthly precipitation(mm)
Lm=Monthly losses(mm)
Example 1:At Tm=22℃
Lm=0.48Tm
=0.48(28)
= 13.44 mm
If Pm=0.738
Rm=Pm-Lm
= 665.364-13.44
=651.9 mm
B.E. Dept of Civil Engg. GAT, Bengaluru
– 98 23

24. Evapotranspiration Data:
Evapotranspiration by Thornthwaite formula [Et= 1.6La(10*T/It)^a]
JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC
12.22 12.04 14.22 14.85 15.67 14.29 14.67 14.15 13.36 13.23 12.08 12.11
Monthy Temperature
JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC
22 24.5 26.5 28 27.5 24.5 24 24 24 24 22.5 21.5
Adjustment factor for La
JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC
0.97 0.91 1.03 1.04 1.11 1.08 1.12 1.08 1.02 1.01 0.95 0.97
It [(T/5)^1.514]
JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC
9.42 11.09 12.49 13.58 13.21 11.09 10.75 10.75 10.75 10.75 9.75 9.10
Emperical constant (a)
JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC
0.65 0.68 0.71 0.72 0.72 0.68 0.68 0.68 0.68 0.68 0.66 0.65
B.E. Dept of Civil Engg. GAT, Bengaluru
– 98 24

25. CALCULATION:
Evapotranspiration by Thornthwaite formulae
Ep=1.6La(10T/It)^a
Where It=(T/5)^1.514
It=Annual heat index.
Ep=Monthly potential(mm).
La=Total monthly daylight hours/360.
a=cubic function.
T=temperature.
Example 1:
T=22℃
It=(T/5)^1.514
=(22/5)^1.514
=9.42 mm
B.E. Dept of Civil Engg. GAT, Bengaluru
– 98 25

26. Ep=1.6La(10T/It)^a
=1.6*0.97(10*22/9.42)^0.65
= 12.03 mm
Where La =0.97 & a=0.65 are taken from the above data.
B.E. Dept of Civil Engg. GAT, Bengaluru
– 98 26

27. NON STRUCTURAL MEASURE:
B.E. Dept. of Civil Engg. GAT,
Bengaluru – 98 27
Sponge City, China
Green roof home , Singapore
Source : https://www.bgs.ac.uk/home.html
Sustainable drainage systems (SuDS)
Source : http://www.storm-water.co.uk/
Tongcan Xianen Fujain, China
Infiltration System

28. RESULT
STRUCTURAL MEASURES
B.E. Dept of Civil Engg. GAT, Bengaluru
– 98 28
C/S OF STEPPED APRON L/S OF OVER BREAK

29. B.E. Dept of Civil Engg. GAT, Bengaluru
– 98 29
PLAN OF SUBSURFACE DRAINAGE SYSTEM

30. B.E. Dept of Civil Engg. GAT, Bengaluru
– 98 30
GOOGLE EARTH IMAGE
Distance between Nayanda Halli and Rajarajeshwari Nagar

31. CONCLUSION
 The current work was done to suggest suitable storm water
management techniques for Bangalore City.
 Additionally, a wide range of information is provided regarding the
factors that regulate how storm water flows through cities as well as
the effects of rising urbanisation.
 The drainage features, slope, topography change, and land use and
land cover during the past decades were thoroughly mapped out.
 This assisted us to realise the city's current situation and the new
rise of urban floods.
 This also helped us to understand the problematic regions, such as
Nayandahalli.
B.E. Dept of Civil Engg. GAT, Bengaluru
– 98 31

32. ADVANTAGES
 By considering all geological, geotechnical, hydrological
parameters substructure drainage system was designed to overcome
the problem of urban floods.
 Since the design is of subsurface drainage system it doesn’t affect
the existing surface components.
DISADVANTAGES
 Presence of steeped apron in the design may reduce the velocity of
runoff .
 Excess water runoff along with the sludge leads to clogging results
in difficulty for cleaning.
B.E. Dept of Civil Engg. GAT, Bengaluru
– 98 32

33. REFERENCES:
[1] Radhika et.al, (2022) An approach for management of urban floods in Bengluru :
lessons from neighbouring countries.
[2] Flood damage and risk assessment for urban area in Malaysia. Noor Suraya Romali and Zulkifli
Yusop.
[3] Urban flood disaster management. R. K. Price & Z. Vojinovic
[4] A systematic approach for effective storm water management at building level during extreme
rainfall events – a case study. Vasantha Kumar S. & Shishodiya Ghanshyam Singh.
[5] Change detection based flood mapping using multi-temporal Earth Observation satellite images:
2018 flood event of Kerala, India. V. S. K. Vanama, Y. S. Rao & C. M. Bhatt
[6] Flood Related Disaster: Concerned to urban flooding in Bangalore, India. Shubha Avinash.
[7] Influence of Land Use Changes on Urban Flooding: Case Study of Bangalore City, India. Shubha
Avinash , K. Lakshmi Prasad , G.S. Srinivasa Reddy , D. Mukund
B.E. Dept of Civil Engg. GAT, Bengaluru
– 98 33

34. THANK YOU
B.E. Dept of Civil Engg. GAT, Bengaluru
– 98 34