Influence of Urban-Rural Gradient on Wetlands of Bangalore:

A case study using amphibians

Gururaja KVCiSTUP, IISc, BangaloreEmail: gururaj@cistup.iisc.ernet.in

Water bodies in Bangalore

• Vrishabhavathi, Challaghatta and Hebbal

• # > 300, hundred year back, almost all man made; as of today 81 with water (except a few, all polluted)

• 28 lakes officially converted to bus stand, sports complex, residential/commercial complex

• 7 lakes cannot be traced! 18 an-authorized urban poor dwelling, 14 dried up

• 12 lakes given to BDA for restoration!

• Encroachment, sewage, industrial discharge, sand mining!

Group Species

Butterflies 154

Fishes 41

Frogs 18

Reptiles 37

Birds 395

Mammals 41

Plants >500

Source: Karthikeyan (1999)+BNG BirdsPersonal obsevations

Why Amphibians?• Greek, Amphi – dual; bios

– life, two life stages• Tadpole stage, generally in

water• Adult stage, either water

or land

• Ectotherms, Skin breathers, Anamniotes

• Best bio-pest controllers– Algaecide, larvicide

• Human welfare: AMPs• Cultural Issues

– Rig veda; – Association with rain

Variables usedWater bodies Distance

(km)

Pollution Road

(km)

Green

(%)

Connectivity

Area

(ha)

Pop.Density

(ind/sq.km)

Bannerghatta 23.16 No 0 100 Yes 2 1025.9

Doddannekundi 10.32 Yes 0.72 25 No 47.08 1816.5

Hebbala 7.27 Yes 2.05 37 Yes 64.5 5678.48

IISc 5.23 No 0 100 No <1 4069.21

Kommaghatta 14.28 No 1.47 87 Yes 15 2279.37

Konsandra 14.85 No 0.26 100 Yes 11.41 2279.37

Lalbagh 3.54 Yes 0.18 75 No 12.9 14590.69

Madivala 8.04 Yes 2.51 0 No 114.16 5308.96

Malathalli 10.23 No 0 87 Yes 3 2554.29

Mattikere 7.2 Yes 0.85 0 No 39.34 19109.27

Puttenahalli 14.63 Yes 0.31 50 Yes 8.87 3097.17

Rachenahalli 10.04 No 0.76 50 Yes 60 2046.34

Ramasandra 14.61 No 0.62 100 Yes 30 2279.37

Sankey 3.52 Yes 1.15 50 No 10 4069.21

Sompura 15 No 0.23 100 Yes 3.07 850.33

Thalaghattapura 13.8 No 0.04 75 Yes 3 850.33

Tindlu 10.02 No 0.53 38 Yes 46.44 5152.38

Ullalu 11.85 No 0 100 Yes 4 2279.37

Ulsoor 2.62 Yes 3 0 No 35.81 21363.69

Varthur 17.24 Yes 1.41 50 Yes 180.4 929.1

Vengaiah Kere 12.3 Yes 1.01 13 No 21.78 4977.54

Venkateshpura 11.39 No 0 87 Yes 2.8 874.96

1

Amphibian density and diversity

Eup_cya Mic_ orn Fej_cap Pol_ mac Dut_mel Fej sp. Hop_tig Ram_var Kal_tap

Bannerghatta 8 6 3 2 3 1 1 1

Doddannekundi

Hebbala 3 2 1

IISc 2 2 2 1

Kommaghatta 2

Konsandra 2 1 1

Lalbagh

Madivala 1 1

Malathalli 2

Mattikere 1

Puttenahalli 4 3 2

Rachenahalli 2 2 2

Ramasandra 1 1 1 1 1

Sankey

Sompura 2 1

Thalaghattapura 1 1 1

Tindlu 4 3 2 1

Ullalu 2 2 2 1

Ulsoor

Varthur 3 1 2 1

Vengaiah Kere 1

Venkateshpura 4 1 1 1

Distance from water body 1

Species Min (m) Max (m) n

Euphlyctis cyanophlyctis 0.5 5.0 10

Microhyla ornata 0.5 5.0 10

Fejervarya caperata 0.5 5.0 10

Polypedates maculatus 1.0 100.0 5

Duttaphrynus melanostictus 0.5 150.0 4

Fejervarya sp 0.5 10.0 10

Hoplobatrachus tigerinus 2.0 75.0 4

Ramanella variegata 3.0 15.0 2

Kalaoula pulchra 1.5 60.0 6

Non-metric multidimensional Scaling

Tindlu

Sankey

Doddannekundi

Kommaghatta

Ullalu

Malathalli

Rachenahalli

Venkateshpura_

Talaghatta

Konasandra

Sompura

Varthur

Bannerghatta

IISc

RamasandraUlsoor

Lalbagh

Madivala

Hebbala

Mattikere

Vengaiah_Kere

Puttenahalli

-0.4 -0.32 -0.24 -0.16 -0.08 0.08 0.16 0.24 0.32

Coordinate 1

-0.2

-0.16

-0.12

-0.08

-0.04

0.04

0.08

0.12

0.16

Co

ord

ina

te 2

Distance from city centre, species richness, Green cover

Asp

hal

ted

ro

ad, P

ollu

tio

n, P

op

.de

nsi

ty WetlandTerrestrial buffer

Aquatic buffer

50m

Findings

• Water bodies are not ‘tea cups’ – Drain, dredge, develop will not work – With pavements all around, percolation gets reduced– Reduced green cover, reduces receiving capacity and

increases run off– Toxic run off directly gets into water

• Water bodies are not sewers: Three important things they do - Receive, Store and Release

• Beneficial to individuals to entire city!

Future directions

• Managerial question: How to do it? – Ecological underpinnings in development and design

– One reporting agency, many collaborating agencies

– On priority – work on peripheral water bodies

– Treat individual water body based on its environmental history

– Local community involvement

– Legislation

– Understanding Synurbanization

– Urban dynamics (temporal changes)

Thank you